BACKGROUND: A standardized and cost-effective molecular identification system is now an urgent need for Fungi owing to their wide involvement in human life quality. In particular the potential use of mitochondrial DNA species markers has been taken in account. Unfortunately, a serious difficulty in the PCR and bioinformatic surveys is due to the presence of mobile introns in almost all the fungal mitochondrial genes. The aim of this work is to verify the incidence of this phenomenon in Ascomycota, testing, at the same time, a new bioinformatic tool for extracting and managing sequence databases annotations, in order to identify the mitochondrial gene regions where introns are missing so as to propose them as species markers.
METHODS: The general trend towards a large occurrence of introns in the mitochondrial genome of Fungi has been confirmed in Ascomycota by an extensive bioinformatic analysis, performed on all the entries concerning 11 mitochondrial protein coding genes and 2 mitochondrial rRNA (ribosomal RNA) specifying genes, belonging to this phylum, available in public nucleotide sequence databases. A new query approach has been developed to retrieve effectively introns information included in these entries.
RESULTS: After comparing the new query-based approach with a blast-based procedure, with the aim of designing a faithful Ascomycota mitochondrial intron map, the first method appeared clearly the most accurate. Within this map, despite the large pervasiveness of introns, it is possible to distinguish specific regions comprised in several genes, including the full NADH dehydrogenase subunit 6 (ND6) gene, which could be considered as barcode candidates for Ascomycota due to their paucity of introns and to their length, above 400 bp, comparable to the lower end size of the length range of barcodes successfully used in animals.
CONCLUSION: The development of the new query system described here would answer the pressing requirement to improve drastically the bioinformatics support to the DNA Barcode Initiative. The large scale investigation of Ascomycota mitochondrial introns performed through this tool, allowing to exclude the introns-rich sequences from the barcode candidates exploration, could be the first step towards a mitochondrial barcoding strategy for these organisms, similar to the standard approach employed in metazoans.
BACKGROUND: DNA sequences have become a primary source of information in biodiversity analysis. For example, short standardized species-specific genomic regions, DNA barcodes, are being used as a global standard for species identification and biodiversity studies. Most DNA barcodes are being generated by laboratories that have an expertise in DNA sequencing but not in bioinformatics data analysis. Therefore, we have developed a web-based suite of tools to help the DNA barcode researchers analyze their vast datasets.
RESULTS: Our web-based tools, available at http://www.ibarcode.org, allow the user to manage their barcode datasets, cull out non-unique sequences, identify haplotypes within a species, and examine the within- to between-species divergences. In addition, we provide a number of phylogenetics tools that will allow the user to manipulate phylogenetic trees generated by other popular programs.
CONCLUSION: The use of a web-based portal for barcode analysis is convenient, especially since the WWW is inherently platform-neutral. Indeed, we have even taken care to ensure that our website is usable from handheld devices such as PDAs and smartphones. Although the current set of tools available at iBarcode.org were developed to meet our own analytic needs, we hope that feedback from users will spark the development of future tools. We also welcome user-built modules that can be incorporated into the iBarcode framework.
BACKGROUND: DNA sequences have become a primary source of information in biodiversity analysis. For example, short standardized species-specific genomic regions, DNA barcodes, are being used as a global standard for species identification and biodiversity studies. Most DNA barcodes are being generated by laboratories that have an expertise in DNA sequencing but not in bioinformatics data analysis. Therefore, we have developed a web-based suite of tools to help the DNA barcode researchers analyze their vast datasets.
RESULTS: Our web-based tools, available at http://www.ibarcode.org, allow the user to manage their barcode datasets, cull out non-unique sequences, identify haplotypes within a species, and examine the within- to between-species divergences. In addition, we provide a number of phylogenetics tools that will allow the user to manipulate phylogenetic trees generated by other popular programs.
CONCLUSION: The use of a web-based portal for barcode analysis is convenient, especially since the WWW is inherently platform-neutral. Indeed, we have even taken care to ensure that our website is usable from handheld devices such as PDAs and smartphones. Although the current set of tools available at iBarcode.org were developed to meet our own analytic needs, we hope that feedback from users will spark the development of future tools. We also welcome user-built modules that can be incorporated into the iBarcode framework.
BACKGROUND: DNA sequences have become a primary source of information in biodiversity analysis. For example, short standardized species-specific genomic regions, DNA barcodes, are being used as a global standard for species identification and biodiversity studies. Most DNA barcodes are being generated by laboratories that have an expertise in DNA sequencing but not in bioinformatics data analysis. Therefore, we have developed a web-based suite of tools to help the DNA barcode researchers analyze their vast datasets.
RESULTS: Our web-based tools, available at http://www.ibarcode.org, allow the user to manage their barcode datasets, cull out non-unique sequences, identify haplotypes within a species, and examine the within- to between-species divergences. In addition, we provide a number of phylogenetics tools that will allow the user to manipulate phylogenetic trees generated by other popular programs.
CONCLUSION: The use of a web-based portal for barcode analysis is convenient, especially since the WWW is inherently platform-neutral. Indeed, we have even taken care to ensure that our website is usable from handheld devices such as PDAs and smartphones. Although the current set of tools available at iBarcode.org were developed to meet our own analytic needs, we hope that feedback from users will spark the development of future tools. We also welcome user-built modules that can be incorporated into the iBarcode framework.
In the United States alone, over 7400 bird–aircraft collisions (birdstrikes) were reported in 2007. Most of these strikes occurred during takeoff or landing of the flight, and it is during these flight phases that aircraft experience their highest risk of substantial damage after colliding with birds. Birdstrikes carry enormous potential costs in terms of lives and money. Using feather remains and other tissue samples collected from the engines of US Airways Flight 1549, which crash landed in the Hudson River in New York City on 15 January 2009 after a birdstrike, we apply molecular tools and stable hydrogen isotopes to demonstrate that migratory Canada geese were responsible for the crash. Determining whether the geese involved in this birdstrike event were resident or migratory is essential to the development of management techniques that could reduce the risk of future collisions. Currently, the US civil aviation industry is not required to report birdstrikes, yet information on frequency, timing, and species involved, as well as the geographic origin of the birds, is critical to reducing the number of birdstrikes. Integrating this information with bird migration patterns, bird-detecting radar, and bird dispersal programs at airports can minimize the risk of such collisions in the future.
One of the most difficult interactions to observe in nature is the relationship between a predator and its prey. When direct observations are impossible, we rely on morphological classification of prey remains, although this is particularly challenging among generalist predators whose faeces contain mixed and degraded prey fragments. In this investigation, we used a polymerase chain reaction and sequence-based technique to identify prey fragments in the guano of the generalist insectivore, the eastern red bat (Lasiurus borealis), and evaluate several hypotheses about prey selection and prey defences. The interaction between bats and insects is of significant evolutionary interest because of the adaptive nature of insect hearing against echolocation. However, measuring the successes of predator tactics or particular prey defences is limited because we cannot normally identify these digested prey fragments beyond order or family. Using a molecular approach, we recovered sequences from 89% of the fragments tested, and through comparison to a reference database of sequences, we were able to identify 127 different species of prey. Our results indicate that despite the robust jaws of L. borealis, most prey taxa were softer-bodied Lepidoptera. Surprisingly, more than 60% of the prey species were tympanate, with ears thought to afford protection against these echolocating bats. Moths of the family Arctiidae, which employ multiple defensive strategies, were not detected as a significant dietary component. Our results provide an unprecedented level of detail for the study of predator2013prey relationships in bats and demonstrate the advantages which molecular tools can provide in investigations of complex ecological systems and food-web relationships.
One of the most difficult interactions to observe in nature is the relationship between a predator and its prey. When direct observations are impossible, we rely on morphological classification of prey remains, although this is particularly challenging among generalist predators whose faeces contain mixed and degraded prey fragments. In this investigation, we used a polymerase chain reaction and sequence-based technique to identify prey fragments in the guano of the generalist insectivore, the eastern red bat (Lasiurus borealis), and evaluate several hypotheses about prey selection and prey defences. The interaction between bats and insects is of significant evolutionary interest because of the adaptive nature of insect hearing against echolocation. However, measuring the successes of predator tactics or particular prey defences is limited because we cannot normally identify these digested prey fragments beyond order or family. Using a molecular approach, we recovered sequences from 89% of the fragments tested, and through comparison to a reference database of sequences, we were able to identify 127 different species of prey. Our results indicate that despite the robust jaws of L. borealis, most prey taxa were softer-bodied Lepidoptera. Surprisingly, more than 60% of the prey species were tympanate, with ears thought to afford protection against these echolocating bats. Moths of the family Arctiidae, which employ multiple defensive strategies, were not detected as a significant dietary component. Our results provide an unprecedented level of detail for the study of predator2013prey relationships in bats and demonstrate the advantages which molecular tools can provide in investigations of complex ecological systems and food-web relationships.
One of the most difficult interactions to observe in nature is the relationship between a predator and its prey. When direct observations are impossible, we rely on morphological classification of prey remains, although this is particularly challenging among generalist predators whose faeces contain mixed and degraded prey fragments. In this investigation, we used a polymerase chain reaction and sequence-based technique to identify prey fragments in the guano of the generalist insectivore, the eastern red bat (Lasiurus borealis), and evaluate several hypotheses about prey selection and prey defences. The interaction between bats and insects is of significant evolutionary interest because of the adaptive nature of insect hearing against echolocation. However, measuring the successes of predator tactics or particular prey defences is limited because we cannot normally identify these digested prey fragments beyond order or family. Using a molecular approach, we recovered sequences from 89% of the fragments tested, and through comparison to a reference database of sequences, we were able to identify 127 different species of prey. Our results indicate that despite the robust jaws of L. borealis, most prey taxa were softer-bodied Lepidoptera. Surprisingly, more than 60% of the prey species were tympanate, with ears thought to afford protection against these echolocating bats. Moths of the family Arctiidae, which employ multiple defensive strategies, were not detected as a significant dietary component. Our results provide an unprecedented level of detail for the study of predator2013prey relationships in bats and demonstrate the advantages which molecular tools can provide in investigations of complex ecological systems and food-web relationships.
One of the most difficult interactions to observe in nature is the relationship between a predator and its prey. When direct observations are impossible, we rely on morphological classification of prey remains, although this is particularly challenging among generalist predators whose faeces contain mixed and degraded prey fragments. In this investigation, we used a polymerase chain reaction and sequence-based technique to identify prey fragments in the guano of the generalist insectivore, the eastern red bat (Lasiurus borealis), and evaluate several hypotheses about prey selection and prey defences. The interaction between bats and insects is of significant evolutionary interest because of the adaptive nature of insect hearing against echolocation. However, measuring the successes of predator tactics or particular prey defences is limited because we cannot normally identify these digested prey fragments beyond order or family. Using a molecular approach, we recovered sequences from 89% of the fragments tested, and through comparison to a reference database of sequences, we were able to identify 127 different species of prey. Our results indicate that despite the robust jaws of L. borealis, most prey taxa were softer-bodied Lepidoptera. Surprisingly, more than 60% of the prey species were tympanate, with ears thought to afford protection against these echolocating bats. Moths of the family Arctiidae, which employ multiple defensive strategies, were not detected as a significant dietary component. Our results provide an unprecedented level of detail for the study of predator2013prey relationships in bats and demonstrate the advantages which molecular tools can provide in investigations of complex ecological systems and food-web relationships.
The exact phylogenetic position of Gnetales, a small, highly modified group of gymnosperms with an accelerated rate of molecular evolution, is one of the most challenging issues for seed plant systematics. Recent results from entire plastid genome (ptDNA) sequencing revealed the absence of the entire suite of plastid ndh genes in several species of Gnetales and the pine family (Pinaceae) potentially highlighting a major structural feature linking these two groups—concerted loss of all plastid genes for the NADH dehydrogenase complex. However, the precise extent of ndh gene loss in gymnosperms has not been surveyed. Using a slot-blot hybridization method, we probed all 11 ndh genes in 162 species from 70 of 85 gymnosperm genera. We find that all ndh genes are absent across Gnetales and Pinaceae, but not in any other group of gymnosperms. This feature represents either a major synapomorphy for a clade consisting of these two lineages or, less likely, a convergent loss. Our survey substantially extends previous inferences based on more limited sampling and, if the former evolutionary interpretation is correct, it provides additional support for the contentious “gnepine” hypothesis, which places Gnetales as sister to Pinaceae.
The exact phylogenetic position of Gnetales, a small, highly modified group of gymnosperms with an accelerated rate of molecular evolution, is one of the most challenging issues for seed plant systematics. Recent results from entire plastid genome (ptDNA) sequencing revealed the absence of the entire suite of plastid ndh genes in several species of Gnetales and the pine family (Pinaceae) potentially highlighting a major structural feature linking these two groups—concerted loss of all plastid genes for the NADH dehydrogenase complex. However, the precise extent of ndh gene loss in gymnosperms has not been surveyed. Using a slot-blot hybridization method, we probed all 11 ndh genes in 162 species from 70 of 85 gymnosperm genera. We find that all ndh genes are absent across Gnetales and Pinaceae, but not in any other group of gymnosperms. This feature represents either a major synapomorphy for a clade consisting of these two lineages or, less likely, a convergent loss. Our survey substantially extends previous inferences based on more limited sampling and, if the former evolutionary interpretation is correct, it provides additional support for the contentious “gnepine” hypothesis, which places Gnetales as sister to Pinaceae.
Renal infections by parasitic ciliates were studied in adult snails of Helix aspersa aspersa and Helix aspersa maxima collected from 2 mixed rearing system-based heliciculture farms located in Galicia (NW Spain). The occurrence of ciliates was also examined in slugs (Deroceras reticulatum) invading the greenhouses where first growing and fattening of snails is carried out. Histological examinations revealed a severe destruction of the renal epithelium in heavily infected hosts. Three ciliate isolates, one from each host species, were obtained and grown in axenic cultures. Cultured and parasitic ciliates were characterized morphologically and morphometrically. In addition, the encystment behaviour, the occurrence of autogamy, and the sequences of the mitochondrial cytochrome-c oxidase subunit 1 (cox1) and the small subunit ribosomal RNA (SSU rRNA) genes were also studied in the 3 isolates. A polymorphic life cycle involving resting and reproductive cysts, together with the morphological and morphometrical characteristics and the confirmation that autogamy occurs within cysts, demonstrate that our ciliates belong to the species Tetrahymena rostrata (Kahl, 1926) Corliss, 1952. The 3 isolates formed a well-supported clade using both genetic markers, and were clearly separate from the strain ATCC(R) 30770, which has been identified as Tetrahymena rostrata. We argue that our Spanish isolates should be regarded as Tetrahymena rostrata, and that the ATCC isolate should be regarded as a misidentification as neither cytological nor cytogenetical support for its identity has been presented.
A new mouse-eared bat (Mammalia: Chiroptera: Vespertilionidae) from the Myotis “siligorensis” species group is being described from the Hon Ba Mountain, ca. 30 km WSW of Nha Trang, Khanh Hoa Province, Vietnam (12.1113° N, 108.953° E, 1250 m ASL), based on a set of morphological and genetic characters. The new species is essentially similar to M. siligorensis alticraniatus, differing in slightly larger size, morphometrics, fine cranial and bacular traits. 12S rDNA demonstrates ca. 2% sequence divergence between the new species and its nearest neighbour, suggesting a history of genetic isolation. Provisional bat survey data from the Bi Doup-Hon Ba massif suggest that, although the new species co-occurs with M. siligorensis in the southern part of the Vietnam Central Highlands area, they are separated by an altitudinal gradient and habitat preferences, the former occupying mature forest at higher elevations and the latter confined to disturbed foothill areas.
The exact phylogenetic position of Gnetales, a small, highly modified group of gymnosperms with an accelerated rate of molecular evolution, is one of the most challenging issues for seed plant systematics. Recent results from entire plastid genome (ptDNA) sequencing revealed the absence of the entire suite of plastid ndh genes in several species of Gnetales and the pine family (Pinaceae) potentially highlighting a major structural feature linking these two groups—concerted loss of all plastid genes for the NADH dehydrogenase complex. However, the precise extent of ndh gene loss in gymnosperms has not been surveyed. Using a slot-blot hybridization method, we probed all 11 ndh genes in 162 species from 70 of 85 gymnosperm genera. We find that all ndh genes are absent across Gnetales and Pinaceae, but not in any other group of gymnosperms. This feature represents either a major synapomorphy for a clade consisting of these two lineages or, less likely, a convergent loss. Our survey substantially extends previous inferences based on more limited sampling and, if the former evolutionary interpretation is correct, it provides additional support for the contentious “gnepine” hypothesis, which places Gnetales as sister to Pinaceae.
Renal infections by parasitic ciliates were studied in adult snails of Helix aspersa aspersa and Helix aspersa maxima collected from 2 mixed rearing system-based heliciculture farms located in Galicia (NW Spain). The occurrence of ciliates was also examined in slugs (Deroceras reticulatum) invading the greenhouses where first growing and fattening of snails is carried out. Histological examinations revealed a severe destruction of the renal epithelium in heavily infected hosts. Three ciliate isolates, one from each host species, were obtained and grown in axenic cultures. Cultured and parasitic ciliates were characterized morphologically and morphometrically. In addition, the encystment behaviour, the occurrence of autogamy, and the sequences of the mitochondrial cytochrome-c oxidase subunit 1 (cox1) and the small subunit ribosomal RNA (SSU rRNA) genes were also studied in the 3 isolates. A polymorphic life cycle involving resting and reproductive cysts, together with the morphological and morphometrical characteristics and the confirmation that autogamy occurs within cysts, demonstrate that our ciliates belong to the species Tetrahymena rostrata (Kahl, 1926) Corliss, 1952. The 3 isolates formed a well-supported clade using both genetic markers, and were clearly separate from the strain ATCC(R) 30770, which has been identified as Tetrahymena rostrata. We argue that our Spanish isolates should be regarded as Tetrahymena rostrata, and that the ATCC isolate should be regarded as a misidentification as neither cytological nor cytogenetical support for its identity has been presented.
A new mouse-eared bat (Mammalia: Chiroptera: Vespertilionidae) from the Myotis “siligorensis” species group is being described from the Hon Ba Mountain, ca. 30 km WSW of Nha Trang, Khanh Hoa Province, Vietnam (12.1113° N, 108.953° E, 1250 m ASL), based on a set of morphological and genetic characters. The new species is essentially similar to M. siligorensis alticraniatus, differing in slightly larger size, morphometrics, fine cranial and bacular traits. 12S rDNA demonstrates ca. 2% sequence divergence between the new species and its nearest neighbour, suggesting a history of genetic isolation. Provisional bat survey data from the Bi Doup-Hon Ba massif suggest that, although the new species co-occurs with M. siligorensis in the southern part of the Vietnam Central Highlands area, they are separated by an altitudinal gradient and habitat preferences, the former occupying mature forest at higher elevations and the latter confined to disturbed foothill areas.
A new mouse-eared bat (Mammalia: Chiroptera: Vespertilionidae) from the Myotis “siligorensis” species group is being described from the Hon Ba Mountain, ca. 30 km WSW of Nha Trang, Khanh Hoa Province, Vietnam (12.1113° N, 108.953° E, 1250 m ASL), based on a set of morphological and genetic characters. The new species is essentially similar to M. siligorensis alticraniatus, differing in slightly larger size, morphometrics, fine cranial and bacular traits. 12S rDNA demonstrates ca. 2% sequence divergence between the new species and its nearest neighbour, suggesting a history of genetic isolation. Provisional bat survey data from the Bi Doup-Hon Ba massif suggest that, although the new species co-occurs with M. siligorensis in the southern part of the Vietnam Central Highlands area, they are separated by an altitudinal gradient and habitat preferences, the former occupying mature forest at higher elevations and the latter confined to disturbed foothill areas.
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
Using data from published mitochondrial or complete genomes, we developed and tested primers for amplification and sequencing of the barcode region of cytochrome oxidase 1 (COX1) of the fungal genus Fusarium, related genera of the order Hypocreales, and degenerate primers for fungi in the subdivision Pezizomycotina. The primers were successful for amplifying and sequencing COX1 barcodes from 13 genera of Hypocreales (Acremonium, Beauveria, Clonostachys, Emericellopsis, Fusarium, Gliocladium, Hypocrea, Lanatonectria, Lecanicillium, Metarhizium, Monocillium, Neonectria and Stilbella), 22 taxa of Fusarium, and two genera in other orders (Arthrosporium, Monilochaetes). Parologous copies of COX1 occurred in several strains of Fusarium. In some, copies of the same length were detected either by heterozygous bases in otherwise clean sequences or in different replicates of amplification and sequencing events; this may indicate multiple transcribed copies. Other strains included one or two introns. Two intron insertion sites had at least two nonhomologous intron sequences among Fusarium species. Irrespective of whether the multiple copy issue could be resolved by sequencing RNA transcripts, developing a precise COX1-based barcoding system for Fusarium may not be feasible. The overall divergence among homologous COX1 sequences obtained so far is rather low, with many species sharing identical sequences.
The use of DNA sequences for identifying fungi and fungus-like organisms predates the DNA barcoding movement by at least 10 years. A brief overview of the mycological shift from phenotypic to molecular taxonomy is provided. Exploration of the animal barcode marker, cytochrome oxidase 1, by Canadian mycologists has been fruitful for some fungi, but intron issues and lack of resolution in other taxa prevent its universal application. The momentum established by 15 years of research on the fungal nuclear ribosomal internal transcribed spacer (ITS) sequences will lead to a proposal to the Consortium for the Barcode of Life on the adoption of this marker as the fungal barcode. Existing mycological research networks should facilitate the rapid development of DNA barcoding of fungi once the marker issue is settled. Some available online fungal identification databases are briefly described.
Using data from published mitochondrial or complete genomes, we developed and tested primers for amplification and sequencing of the barcode region of cytochrome oxidase 1 (COX1) of the fungal genus Fusarium, related genera of the order Hypocreales, and degenerate primers for fungi in the subdivision Pezizomycotina. The primers were successful for amplifying and sequencing COX1 barcodes from 13 genera of Hypocreales (Acremonium, Beauveria, Clonostachys, Emericellopsis, Fusarium, Gliocladium, Hypocrea, Lanatonectria, Lecanicillium, Metarhizium, Monocillium, Neonectria and Stilbella), 22 taxa of Fusarium, and two genera in other orders (Arthrosporium, Monilochaetes). Parologous copies of COX1 occurred in several strains of Fusarium. In some, copies of the same length were detected either by heterozygous bases in otherwise clean sequences or in different replicates of amplification and sequencing events; this may indicate multiple transcribed copies. Other strains included one or two introns. Two intron insertion sites had at least two nonhomologous intron sequences among Fusarium species. Irrespective of whether the multiple copy issue could be resolved by sequencing RNA transcripts, developing a precise COX1-based barcoding system for Fusarium may not be feasible. The overall divergence among homologous COX1 sequences obtained so far is rather low, with many species sharing identical sequences.
The use of DNA sequences for identifying fungi and fungus-like organisms predates the DNA barcoding movement by at least 10 years. A brief overview of the mycological shift from phenotypic to molecular taxonomy is provided. Exploration of the animal barcode marker, cytochrome oxidase 1, by Canadian mycologists has been fruitful for some fungi, but intron issues and lack of resolution in other taxa prevent its universal application. The momentum established by 15 years of research on the fungal nuclear ribosomal internal transcribed spacer (ITS) sequences will lead to a proposal to the Consortium for the Barcode of Life on the adoption of this marker as the fungal barcode. Existing mycological research networks should facilitate the rapid development of DNA barcoding of fungi once the marker issue is settled. Some available online fungal identification databases are briefly described.
We developed a COX1 barcode oligonucleotide array based on 358 sequences, including 58 known and two new species of Penicillium subgenus Penicillium, and 12 allied species. The array was robotically spotted at near microarray density on membranes. Species and clade-specific oligonucleotides were selected using the computer programs SigOli and Array Designer. Robotic spotting allowed 768 spots with duplicate sets of perfect match and the corresponding mismatch and positive control oligonucleotides, to be printed on 2 × 6 cm2 nylon membranes. The array was validated with hybridizations between the array and digoxigenin (DIG)-labelled COX1 polymerase chain reaction amplicons from 70 pure DNA samples, and directly from environmental samples (cheese and plants) without culturing. DNA hybridization conditions were optimized, but undesired cross-reactions were detected frequently, reflecting the relatively high sequence similarity of the COX1 gene among Penicillium species. Approximately 60% of the perfect match oligonucleotides were rejected because of low specificity and 76 delivered useful group-specific or species-specific reactions and could be used for detecting certain species of Penicillium in environmental samples. In practice, the presence of weak signals on arrays exposed to amplicons from environmental samples, which could have represented weak detections or weak cross reactions, made interpretation difficult for over half of the oligonucleotides. DNA regions with very few single nucleotide polymorphisms or lacking insertions/deletions among closely related species are not ideal for oligonucleotide-based diagnostics, and supplementing the COX1-based array with oligonucleotides derived from additional genes would result in a more robust hierarchical identification system.
The use of DNA sequences for identifying fungi and fungus-like organisms predates the DNA barcoding movement by at least 10 years. A brief overview of the mycological shift from phenotypic to molecular taxonomy is provided. Exploration of the animal barcode marker, cytochrome oxidase 1, by Canadian mycologists has been fruitful for some fungi, but intron issues and lack of resolution in other taxa prevent its universal application. The momentum established by 15 years of research on the fungal nuclear ribosomal internal transcribed spacer (ITS) sequences will lead to a proposal to the Consortium for the Barcode of Life on the adoption of this marker as the fungal barcode. Existing mycological research networks should facilitate the rapid development of DNA barcoding of fungi once the marker issue is settled. Some available online fungal identification databases are briefly described.
Our study evaluated in silico the potential of 14 mitochondrial genes encoding the subunits of the respiratory chain complexes, including cytochrome c oxidase I (CO1), as Basidiomycota DNA barcode. Fifteen complete and partial mitochondrial genomes were recovered and characterized in this study. Mitochondrial genes showed high values of molecular divergence, indicating a potential for the resolution of lower-level relationships. However, numerous introns occurred in CO1 as well as in six other genes, potentially interfering with polymerase chain reaction amplification. Considering these results and given the minimal length of 600-bp that is optimal for a fungal barcode, the genes encoding for the ATPase subunit 6, the cytochrome oxidase subunit 3 and the NADH dehydrogenase subunit 6 have the most promising characteristics for DNA barcoding among the mitochondrial genes studied. However, biological validation on two fungal data sets indicated that no single mitochondrial gene gave a better taxonomic resolution than the ITS, the region already widely used in fungal taxonomy.
Our study evaluated in silico the potential of 14 mitochondrial genes encoding the subunits of the respiratory chain complexes, including cytochrome c oxidase I (CO1), as Basidiomycota DNA barcode. Fifteen complete and partial mitochondrial genomes were recovered and characterized in this study. Mitochondrial genes showed high values of molecular divergence, indicating a potential for the resolution of lower-level relationships. However, numerous introns occurred in CO1 as well as in six other genes, potentially interfering with polymerase chain reaction amplification. Considering these results and given the minimal length of 600-bp that is optimal for a fungal barcode, the genes encoding for the ATPase subunit 6, the cytochrome oxidase subunit 3 and the NADH dehydrogenase subunit 6 have the most promising characteristics for DNA barcoding among the mitochondrial genes studied. However, biological validation on two fungal data sets indicated that no single mitochondrial gene gave a better taxonomic resolution than the ITS, the region already widely used in fungal taxonomy.
Efficient design of barcode oligonucleotides can lead to significant cost reductions in the manufacturing of DNA arrays. Previous methods are based on either a preliminary alignment, which reduces their efficiency for intron-rich regions, or on a brute force approach, not feasible for large-scale problems or on data structures with very poor performance in the worst case. One of the algorithms we propose uses 'oligonucleotide sorting' for the discovery of oligonucleotide barcodes of given sizes, with good asymptotic performance. Specific barcode oligonucleotides with at least one base difference from other sequences in a database are found for each individual sequence. With another algorithm, specific oligonucleotides can also be found for groups or clades in the database, which have 100% homology for all oligonucleotide sequences within the group or clade while having differences with the rest of the data. By re-organizing the sequences/groups in the database, oligonucleotides for different hierarchical levels can be found. The oligonucleotides or polymorphism locations identified as species or clade specific by the new algorithm are refined and screened further for hybridization thermodynamic properties with third party software.
The challenge for first responders, physicians in the emergency room, public health personnel, as well as for food manufacturers, distributors and retailers is accurate and reliable identification of pathogenic agents and their corresponding diseases. This is the weakest point in biological agent detection capability today. There is intense research for new molecular detection technologies that could be used for very accurate detection of pathogens that would be a concern to first responders. These include the need for sensors for multiple applications as varied as understanding the ecology of pathogenic micro-organisms, forensics, environmental sampling for detect-to-treat applications, biological sensors for 'detect to warn' in infrastructure protection, responses to reports of 'suspicious powders', and customs and borders enforcement, to cite a few examples. The benefits of accurate detection include saving millions of dollars annually by reducing disruption of the workforce and the national economy and improving delivery of correct countermeasures to those who are most in need of the information to provide protective and/or response measures.
The challenge for first responders, physicians in the emergency room, public health personnel, as well as for food manufacturers, distributors and retailers is accurate and reliable identification of pathogenic agents and their corresponding diseases. This is the weakest point in biological agent detection capability today. There is intense research for new molecular detection technologies that could be used for very accurate detection of pathogens that would be a concern to first responders. These include the need for sensors for multiple applications as varied as understanding the ecology of pathogenic micro-organisms, forensics, environmental sampling for detect-to-treat applications, biological sensors for 'detect to warn' in infrastructure protection, responses to reports of 'suspicious powders', and customs and borders enforcement, to cite a few examples. The benefits of accurate detection include saving millions of dollars annually by reducing disruption of the workforce and the national economy and improving delivery of correct countermeasures to those who are most in need of the information to provide protective and/or response measures.
We developed a COX1 barcode oligonucleotide array based on 358 sequences, including 58 known and two new species of Penicillium subgenus Penicillium, and 12 allied species. The array was robotically spotted at near microarray density on membranes. Species and clade-specific oligonucleotides were selected using the computer programs SigOli and Array Designer. Robotic spotting allowed 768 spots with duplicate sets of perfect match and the corresponding mismatch and positive control oligonucleotides, to be printed on 2 × 6 cm2 nylon membranes. The array was validated with hybridizations between the array and digoxigenin (DIG)-labelled COX1 polymerase chain reaction amplicons from 70 pure DNA samples, and directly from environmental samples (cheese and plants) without culturing. DNA hybridization conditions were optimized, but undesired cross-reactions were detected frequently, reflecting the relatively high sequence similarity of the COX1 gene among Penicillium species. Approximately 60% of the perfect match oligonucleotides were rejected because of low specificity and 76 delivered useful group-specific or species-specific reactions and could be used for detecting certain species of Penicillium in environmental samples. In practice, the presence of weak signals on arrays exposed to amplicons from environmental samples, which could have represented weak detections or weak cross reactions, made interpretation difficult for over half of the oligonucleotides. DNA regions with very few single nucleotide polymorphisms or lacking insertions/deletions among closely related species are not ideal for oligonucleotide-based diagnostics, and supplementing the COX1-based array with oligonucleotides derived from additional genes would result in a more robust hierarchical identification system.
A small but vocal community of critics has questioned the epistemological value of DNA barcoding by suggesting that either it 'cannot work' for the identification or discovery of species or that it ignores the 'richness' inherent in traditional approaches. We re-examine these arguments through a comparison of DNA barcoding and morphological taxonomy in terms of their accuracy and diversity of characters employed. We conclude that morphology often does not work and that it is often nowhere near as 'rich' as has been argued. Morphology is particularly poor in numerous important situations, such as the association of larvae with adults and discrimination among cryptic species. The vehemence of some of the criticisms is surprising given that morphology alone is known to be inadequate to the task of species-level identification in many instances.
Efficient design of barcode oligonucleotides can lead to significant cost reductions in the manufacturing of DNA arrays. Previous methods are based on either a preliminary alignment, which reduces their efficiency for intron-rich regions, or on a brute force approach, not feasible for large-scale problems or on data structures with very poor performance in the worst case. One of the algorithms we propose uses 'oligonucleotide sorting' for the discovery of oligonucleotide barcodes of given sizes, with good asymptotic performance. Specific barcode oligonucleotides with at least one base difference from other sequences in a database are found for each individual sequence. With another algorithm, specific oligonucleotides can also be found for groups or clades in the database, which have 100% homology for all oligonucleotide sequences within the group or clade while having differences with the rest of the data. By re-organizing the sequences/groups in the database, oligonucleotides for different hierarchical levels can be found. The oligonucleotides or polymorphism locations identified as species or clade specific by the new algorithm are refined and screened further for hybridization thermodynamic properties with third party software.
Frequently, the diversity of umbrella taxa is invoked to predict patterns of other, less well-known, life. However, the utility of this strategy has been questioned. We tested whether a phylogenetic diversity (PD) analysis of CO1 DNA barcodes could act as a proxy for standard methods of determining sampling efficiency within and between sites, namely that an accumulation curve of barcode diversity would be similar to curves generated using morphology or nuclear genetic markers. Using taxa at the forefront of the taxonomic impediment 2014 parasitoid wasps (Ichneumonidae, Braconidae, Cynipidae and Diapriidae), contrasted with a taxon expected to be of low diversity (Formicidae) from an area where total diversity is expected to be low (Churchill, Manitoba), we found that barcode accumulation curves based on PD were significantly different in both slope and scale from curves generated using names based on morphological data, while curves generated using nuclear genetic data were only different in scale. We conclude that these differences clearly identify the taxonomic impediment within the strictly morphological alpha-taxonomy of these hyperdiverse insects. The absence of an asymptote within the barcode PD trend of parasitoid wasps reflects the as yet incomplete sampling of the site (and more accurately its total diversity), while the morphological analysis asymptote represents a collision with the taxonomic impediment rather than complete sampling. We conclude that a PD analysis of standardized DNA barcodes can be a transparent and reproducible triage tool for the management and conservation of species and spaces.
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The phylum Platyhelminthes is a diverse group of flatworms that includes parasites with serious impacts on human health, animal husbandry, aquaculture and wildlife management. Here we present degenerate primers for the barcode region of the mitochondrial cytochrome c oxidase I (COI) gene in flatworms. Although amplicons were obtained from a wide taxonomic range in the Cestoda and Trematoda, COI fragments from many taxa in these classes did not amplify. Primers specific to trematodes in the family Diplostomidae were also developed. Amplification success was much higher with diplostomid-specific primers and sequences were obtained from 504 of 585 specimens of Diplostomum and Tylodelphys. Sequences from the barcode region resolved all specimens to the species level, with mean divergence between congeners of 19% (3.9201325%). Because many of our specimens were small, we initially amplified part of the nuclear small subunit ribosomal (r) RNA gene to evaluate the quality and quantity of DNA in our specimens. Short sequences (~380 nt) of this gene were recovered from most specimens and can be used to distinguish specimens at the family level and often the generic level. We suggest that rRNA genes could be used to screen samples of completely unknown taxonomy, after which specific COI primers could be used to obtain species-level identifications.
The promise of DNA barcoding is based on a small DNA fragment divergence coinciding with biological species separation. Here we evaluated the performance of three markers as diatom barcodes, the small ribosomal subunit (1600 bp), a 5' end fragment of cytochrome c oxidase subunit 1 (430 bp), and the second internal transcribed spacer region combined with the 5.8S gene (5.8S + ITS-2, 3002013400 bp). Forty-four sequences per marker representing 28 species from all diatom classes were analysed. Sequence alignment of the three genetic markers and uncorrected genetic distances (P) were calculated at the intra- and heterospecific level. All three markers correctly separated the species examined and had advantages which contribute to their feasibility as a DNA barcode. Small ribosomal subunit had the largest GenBank data set, its success rate in amplification and sequencing was assumed to be the highest of all three and was readily aligned. However, it required a long fragment to recover divergence sufficient for species separation and small genetic distances increased the potential for misidentifications. Cytochrome c oxidase subunit 1 demonstrated a substantial heterospecific divergence level and was also readily alignable, but it showed very low amplification and sequencing success rates with currently existing primers. 5.8S + ITS-2 was amplified and sequenced with high success rate and was the most variable of the three markers, but its secondary structure was needed to aid in alignment. However, since it has been recently suggested that ITS-2 may provide insight into sexual compatibility, this marker offers an additional advantage. We therefore propose that the 5.8S + ITS-2 fragment is the best candidate as a diatom DNA barcode.
The promise of DNA barcoding is based on a small DNA fragment divergence coinciding with biological species separation. Here we evaluated the performance of three markers as diatom barcodes, the small ribosomal subunit (1600 bp), a 5' end fragment of cytochrome c oxidase subunit 1 (430 bp), and the second internal transcribed spacer region combined with the 5.8S gene (5.8S + ITS-2, 3002013400 bp). Forty-four sequences per marker representing 28 species from all diatom classes were analysed. Sequence alignment of the three genetic markers and uncorrected genetic distances (P) were calculated at the intra- and heterospecific level. All three markers correctly separated the species examined and had advantages which contribute to their feasibility as a DNA barcode. Small ribosomal subunit had the largest GenBank data set, its success rate in amplification and sequencing was assumed to be the highest of all three and was readily aligned. However, it required a long fragment to recover divergence sufficient for species separation and small genetic distances increased the potential for misidentifications. Cytochrome c oxidase subunit 1 demonstrated a substantial heterospecific divergence level and was also readily alignable, but it showed very low amplification and sequencing success rates with currently existing primers. 5.8S + ITS-2 was amplified and sequenced with high success rate and was the most variable of the three markers, but its secondary structure was needed to aid in alignment. However, since it has been recently suggested that ITS-2 may provide insight into sexual compatibility, this marker offers an additional advantage. We therefore propose that the 5.8S + ITS-2 fragment is the best candidate as a diatom DNA barcode.
The phylum Platyhelminthes is a diverse group of flatworms that includes parasites with serious impacts on human health, animal husbandry, aquaculture and wildlife management. Here we present degenerate primers for the barcode region of the mitochondrial cytochrome c oxidase I (COI) gene in flatworms. Although amplicons were obtained from a wide taxonomic range in the Cestoda and Trematoda, COI fragments from many taxa in these classes did not amplify. Primers specific to trematodes in the family Diplostomidae were also developed. Amplification success was much higher with diplostomid-specific primers and sequences were obtained from 504 of 585 specimens of Diplostomum and Tylodelphys. Sequences from the barcode region resolved all specimens to the species level, with mean divergence between congeners of 19% (3.9201325%). Because many of our specimens were small, we initially amplified part of the nuclear small subunit ribosomal (r) RNA gene to evaluate the quality and quantity of DNA in our specimens. Short sequences (~380 nt) of this gene were recovered from most specimens and can be used to distinguish specimens at the family level and often the generic level. We suggest that rRNA genes could be used to screen samples of completely unknown taxonomy, after which specific COI primers could be used to obtain species-level identifications.
The Adelgidae are relatively small, cryptic insects, exhibiting complex life cycles with parthenogenetic reproduction. Due to these characteristics, the taxonomy of the group is problematic. Here, we test the effectiveness of the standard 658-bp barcode fragment from the 5'-end of the mitochondrial cytochrome c oxidase 1 gene (COI) in differentiating among 17 species of Adelgidae, in associating life-cycle stages, and in assessing patterns of geographical variation in selected species. Species of Adelgidae are well-differentiated by DNA barcodes, enabling the identification of different morphological forms, immature stages and individuals on different hosts and at different periods of the life cycle. DNA barcodes have uncovered cryptic diversity within taxa and, in other cases, a lack of sequence divergence in species pairs previously separated by life-cycle characteristics, indicating a need for further taxonomic analysis.
Acacia species are quite difficult to differentiate using morphological characters. Routine identification of Acacia samples is important in order to distinguish invasive species from rare species or those of economic importance, particularly in the forest industry. The genus Acacia is quite abundant and diverse comprising approximately 1355 species, which is currently divided into three subgenera: subg. Acacia (c. 161 species), subg. Aculiferum (c. 235 species), and subg. Phyllodineae (c. 960 species). It would be prudent to utilize DNA barcoding in the accurate and efficient identification of acacias. The objective of this research is to test barcoding in discriminating multiple populations among a sister-species complex in pantropical Acacia subg. Acacia, across three continents. Based on previous research, we chose three cpDNA regions (rbcL, trnH-psbA and matK). Our results show that all three regions (rbcL, matK and trnH-psbA) can distinguish and support the newly proposed genera of Vachellia Wight & Arn. from Acacia Mill., discriminate sister species within either genera and differentiate biogeographical patterns among populations from India, Africa and Australia. A morphometric analysis confirmed the cryptic nature of these sister species and the limitations of a classification based on phenetic data. These results support the claim that DNA barcoding is a powerful tool for taxonomy and biogeography with utility for identifying cryptic species, biogeograhic patterns and resolving classifications at the rank of genera and species.
Acacia species are quite difficult to differentiate using morphological characters. Routine identification of Acacia samples is important in order to distinguish invasive species from rare species or those of economic importance, particularly in the forest industry. The genus Acacia is quite abundant and diverse comprising approximately 1355 species, which is currently divided into three subgenera: subg. Acacia (c. 161 species), subg. Aculiferum (c. 235 species), and subg. Phyllodineae (c. 960 species). It would be prudent to utilize DNA barcoding in the accurate and efficient identification of acacias. The objective of this research is to test barcoding in discriminating multiple populations among a sister-species complex in pantropical Acacia subg. Acacia, across three continents. Based on previous research, we chose three cpDNA regions (rbcL, trnH-psbA and matK). Our results show that all three regions (rbcL, matK and trnH-psbA) can distinguish and support the newly proposed genera of Vachellia Wight & Arn. from Acacia Mill., discriminate sister species within either genera and differentiate biogeographical patterns among populations from India, Africa and Australia. A morphometric analysis confirmed the cryptic nature of these sister species and the limitations of a classification based on phenetic data. These results support the claim that DNA barcoding is a powerful tool for taxonomy and biogeography with utility for identifying cryptic species, biogeograhic patterns and resolving classifications at the rank of genera and species.
Marine crustaceans are known as a group with a high level of morphological and ecological diversity but are difficult to identify by traditional approaches and usually require the help of highly trained taxonomists. A faster identification method, DNA barcoding, was found to be an effective tool for species identification in many metazoan groups including some crustaceans. Here we expand the DNA barcode database with a case study involving 80 malacostracan species from the Estuary and Gulf of St Lawrence. DNA sequences for 460 specimens grouped into clusters corresponding to known morphological species in 95% of cases. Genetic distances between species were on average 25 times higher than within species. Intraspecific divergence was high (3.78201313.6%) in specimens belonging to four morphological species, suggesting the occurrence of cryptic species. Moreover, we detected the presence of an invasive amphipod species in the St Lawrence Estuary. This study reconfirms the usefulness of DNA barcoding for the identification of marine crustaceans.
Our research brought together traditional aboriginal knowledge (TK) and scientific knowledge (SK) to explore the relationship between scientific and aboriginal systems of botanical classification and the corresponding valorization(s) of biological diversity in the Western Ghats of southern India. We worked with two aboriginal cultures namely 'Irulas' and 'Malasars' of the Nilgiri Biosphere Reserve with an objective of evaluating the ability of different knowledge systems (SK and TK) to distinguish grass species belonging to the genus Tripogon, and assess the ability of DNA barcoding to discriminate a new cryptic species 'Tripogon cope' as deciphered by the hill tribes. We discovered that the aboriginal informants identified a common ethnotaxa 'Sunai pul', which is a cryptic species of grass not recognized by the SK classification.'sunai pul' is very important to both aboriginal cultures with ritualistic and economic utility. Morphometric analysis confirms the cryptic nature of this new species, which was validated using DNA barcoding. DNA barcode regions matK and trnH-psbA showed distinct sequence variations among the closely related ethnotaxa. Given the cryptic nature of ethnotaxa, we propose that a DNA barcode may be a reliable tool to identify ethnotaxa. We have initiated further studies in other cultures to develop theoretically sophisticated insights concerning the encounter between 'local' and 'scientific' approaches to the use of biodiversity knowledge. Furthermore, the research will add to a unifying global effort to speed up the documentation and understanding of the planet's natural diversity, while simultaneously respecting the cultural heterogeneity as a vital component of biological diversity.
Our research brought together traditional aboriginal knowledge (TK) and scientific knowledge (SK) to explore the relationship between scientific and aboriginal systems of botanical classification and the corresponding valorization(s) of biological diversity in the Western Ghats of southern India. We worked with two aboriginal cultures namely 'Irulas' and 'Malasars' of the Nilgiri Biosphere Reserve with an objective of evaluating the ability of different knowledge systems (SK and TK) to distinguish grass species belonging to the genus Tripogon, and assess the ability of DNA barcoding to discriminate a new cryptic species 'Tripogon cope' as deciphered by the hill tribes. We discovered that the aboriginal informants identified a common ethnotaxa 'Sunai pul', which is a cryptic species of grass not recognized by the SK classification.'sunai pul' is very important to both aboriginal cultures with ritualistic and economic utility. Morphometric analysis confirms the cryptic nature of this new species, which was validated using DNA barcoding. DNA barcode regions matK and trnH-psbA showed distinct sequence variations among the closely related ethnotaxa. Given the cryptic nature of ethnotaxa, we propose that a DNA barcode may be a reliable tool to identify ethnotaxa. We have initiated further studies in other cultures to develop theoretically sophisticated insights concerning the encounter between 'local' and 'scientific' approaches to the use of biodiversity knowledge. Furthermore, the research will add to a unifying global effort to speed up the documentation and understanding of the planet's natural diversity, while simultaneously respecting the cultural heterogeneity as a vital component of biological diversity.
As part of an extensive DNA-based floristic survey of marine macroalgae in Canadian waters, an unexpected sequence for a Gracilaria sp. was generated from British Columbia. Before further molecular analyses and corresponding morphological/anatomical observations this mystery sequence was temporarily entered into our database as Gracilaria BCsp. Continued sampling uncovered this species from four additional locations. A timely collaboration with international colleagues introduced sequences from the invasive Gracilaria vermiculophylla into our cytochrome c oxidase I alignments 2014 these a perfect match to BCsp indicating that this species occurs in British Columbia. A discussion of the origin of this taxon in Canadian waters, whether natural or introduced, is provided.
We investigate the species discriminatory power of a subset of the proposed plant barcoding loci (matK, rbcL, rpoC1, rpoB, trnH-psbA) in Carex, a cosmopolitan genus that represents one of the three largest plant genera on earth (c. 2000 species). To assess the ability of barcoding loci to resolve Carex species, we focused our sampling on three of the taxonomically best-known groups in the genus, sections Deweyanae (6/8 species sampled), Griseae (18/21 species sampled), and Phyllostachyae (10/10 species sampled). Each group represents one of three major phylogenetic lineages previously identified in Carex and its tribe Cariceae, thus permitting us to evaluate the potential of DNA barcodes to broadly identify species across the tribe and to differentiate closely related sister species. Unlike some previous studies that have suggested that plant barcoding could achieve species identification rates around 90%, our results suggest that no single locus or multilocus barcode examined will resolve much greater than 60% of Carex species. In fact, no multilocus combination can significantly increase the resolution and statistical support (i.e., 2265 70% bootstrap) for species than matK alone, even combinations involving the second most variable region, trnH-psbA. Results suggest that a matK barcode could help with species discovery as 47% of Carex taxa recently named or resolved within cryptic complexes in the past 25 years also formed unique species clusters in upgma trees. Comparisons between the nrDNA internal transcribed spacer region (ITS) and matK in sect. Phyllostachyae suggest that matK not only discriminates more species (50201360% vs. 25%), but it provides more resolved phylogenies than ITS. Given the low levels of species resolution in rpoC1 and rpoB (0201313%), and difficulties with polymerase chain reaction amplification and DNA sequencing in rbcL and trnH-psbA (alignment included), we strongly advocate that matK should be part of a universal plant barcoding system. Although identification rates in this study are low, they can be significantly improved by a regional approach to barcoding.
We investigate the species discriminatory power of a subset of the proposed plant barcoding loci (matK, rbcL, rpoC1, rpoB, trnH-psbA) in Carex, a cosmopolitan genus that represents one of the three largest plant genera on earth (c. 2000 species). To assess the ability of barcoding loci to resolve Carex species, we focused our sampling on three of the taxonomically best-known groups in the genus, sections Deweyanae (6/8 species sampled), Griseae (18/21 species sampled), and Phyllostachyae (10/10 species sampled). Each group represents one of three major phylogenetic lineages previously identified in Carex and its tribe Cariceae, thus permitting us to evaluate the potential of DNA barcodes to broadly identify species across the tribe and to differentiate closely related sister species. Unlike some previous studies that have suggested that plant barcoding could achieve species identification rates around 90%, our results suggest that no single locus or multilocus barcode examined will resolve much greater than 60% of Carex species. In fact, no multilocus combination can significantly increase the resolution and statistical support (i.e., 2265 70% bootstrap) for species than matK alone, even combinations involving the second most variable region, trnH-psbA. Results suggest that a matK barcode could help with species discovery as 47% of Carex taxa recently named or resolved within cryptic complexes in the past 25 years also formed unique species clusters in upgma trees. Comparisons between the nrDNA internal transcribed spacer region (ITS) and matK in sect. Phyllostachyae suggest that matK not only discriminates more species (50201360% vs. 25%), but it provides more resolved phylogenies than ITS. Given the low levels of species resolution in rpoC1 and rpoB (0201313%), and difficulties with polymerase chain reaction amplification and DNA sequencing in rbcL and trnH-psbA (alignment included), we strongly advocate that matK should be part of a universal plant barcoding system. Although identification rates in this study are low, they can be significantly improved by a regional approach to barcoding.
Marine crustaceans are known as a group with a high level of morphological and ecological diversity but are difficult to identify by traditional approaches and usually require the help of highly trained taxonomists. A faster identification method, DNA barcoding, was found to be an effective tool for species identification in many metazoan groups including some crustaceans. Here we expand the DNA barcode database with a case study involving 80 malacostracan species from the Estuary and Gulf of St Lawrence. DNA sequences for 460 specimens grouped into clusters corresponding to known morphological species in 95% of cases. Genetic distances between species were on average 25 times higher than within species. Intraspecific divergence was high (3.78201313.6%) in specimens belonging to four morphological species, suggesting the occurrence of cryptic species. Moreover, we detected the presence of an invasive amphipod species in the St Lawrence Estuary. This study reconfirms the usefulness of DNA barcoding for the identification of marine crustaceans.
A small but vocal community of critics has questioned the epistemological value of DNA barcoding by suggesting that either it 'cannot work' for the identification or discovery of species or that it ignores the 'richness' inherent in traditional approaches. We re-examine these arguments through a comparison of DNA barcoding and morphological taxonomy in terms of their accuracy and diversity of characters employed. We conclude that morphology often does not work and that it is often nowhere near as 'rich' as has been argued. Morphology is particularly poor in numerous important situations, such as the association of larvae with adults and discrimination among cryptic species. The vehemence of some of the criticisms is surprising given that morphology alone is known to be inadequate to the task of species-level identification in many instances.
Frequently, the diversity of umbrella taxa is invoked to predict patterns of other, less well-known, life. However, the utility of this strategy has been questioned. We tested whether a phylogenetic diversity (PD) analysis of CO1 DNA barcodes could act as a proxy for standard methods of determining sampling efficiency within and between sites, namely that an accumulation curve of barcode diversity would be similar to curves generated using morphology or nuclear genetic markers. Using taxa at the forefront of the taxonomic impediment 2014 parasitoid wasps (Ichneumonidae, Braconidae, Cynipidae and Diapriidae), contrasted with a taxon expected to be of low diversity (Formicidae) from an area where total diversity is expected to be low (Churchill, Manitoba), we found that barcode accumulation curves based on PD were significantly different in both slope and scale from curves generated using names based on morphological data, while curves generated using nuclear genetic data were only different in scale. We conclude that these differences clearly identify the taxonomic impediment within the strictly morphological alpha-taxonomy of these hyperdiverse insects. The absence of an asymptote within the barcode PD trend of parasitoid wasps reflects the as yet incomplete sampling of the site (and more accurately its total diversity), while the morphological analysis asymptote represents a collision with the taxonomic impediment rather than complete sampling. We conclude that a PD analysis of standardized DNA barcodes can be a transparent and reproducible triage tool for the management and conservation of species and spaces.
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The ability to discriminate between species using barcoding loci has proved more difficult in plants than animals, raising the possibility that plant species boundaries are less well defined. Here, we review a selection of published barcoding data sets to compare species discrimination in plants vs. animals. Although the use of different genetic markers, analytical methods and depths of taxon sampling may complicate comparisons, our results using common metrics demonstrate that the number of species supported as monophyletic using barcoding markers is higher in animals (> 90%) than plants (~70%), even after controlling for the amount of parsimony-informative information per species. This suggests that more than a simple lack of variability limits species discrimination in plants. Both animal and plant species pairs have variable size gaps between intra- and interspecific genetic distances, but animal species tend to have larger gaps than plants, even in relatively densely sampled genera. An analysis of 12 plant genera suggests that hybridization contributes significantly to variation in genetic discontinuity in plants. Barcoding success may be improved in some plant groups by careful choice of markers and appropriate sampling; however, overall fine-scale species discrimination in plants relative to animals may be inherently more difficult because of greater levels of gene-tree paraphyly.
The ability to discriminate between species using barcoding loci has proved more difficult in plants than animals, raising the possibility that plant species boundaries are less well defined. Here, we review a selection of published barcoding data sets to compare species discrimination in plants vs. animals. Although the use of different genetic markers, analytical methods and depths of taxon sampling may complicate comparisons, our results using common metrics demonstrate that the number of species supported as monophyletic using barcoding markers is higher in animals (> 90%) than plants (~70%), even after controlling for the amount of parsimony-informative information per species. This suggests that more than a simple lack of variability limits species discrimination in plants. Both animal and plant species pairs have variable size gaps between intra- and interspecific genetic distances, but animal species tend to have larger gaps than plants, even in relatively densely sampled genera. An analysis of 12 plant genera suggests that hybridization contributes significantly to variation in genetic discontinuity in plants. Barcoding success may be improved in some plant groups by careful choice of markers and appropriate sampling; however, overall fine-scale species discrimination in plants relative to animals may be inherently more difficult because of greater levels of gene-tree paraphyly.
Frequently, the diversity of umbrella taxa is invoked to predict patterns of other, less well-known, life. However, the utility of this strategy has been questioned. We tested whether a phylogenetic diversity (PD) analysis of CO1 DNA barcodes could act as a proxy for standard methods of determining sampling efficiency within and between sites, namely that an accumulation curve of barcode diversity would be similar to curves generated using morphology or nuclear genetic markers. Using taxa at the forefront of the taxonomic impediment 2014 parasitoid wasps (Ichneumonidae, Braconidae, Cynipidae and Diapriidae), contrasted with a taxon expected to be of low diversity (Formicidae) from an area where total diversity is expected to be low (Churchill, Manitoba), we found that barcode accumulation curves based on PD were significantly different in both slope and scale from curves generated using names based on morphological data, while curves generated using nuclear genetic data were only different in scale. We conclude that these differences clearly identify the taxonomic impediment within the strictly morphological alpha-taxonomy of these hyperdiverse insects. The absence of an asymptote within the barcode PD trend of parasitoid wasps reflects the as yet incomplete sampling of the site (and more accurately its total diversity), while the morphological analysis asymptote represents a collision with the taxonomic impediment rather than complete sampling. We conclude that a PD analysis of standardized DNA barcodes can be a transparent and reproducible triage tool for the management and conservation of species and spaces.
http://www3.interscience.wiley.com/cgi-bin/fulltext/122342777/HTMLSTART
DNA barcoding has been evaluated for many animal taxa and is now advocated as a reliable and rapid means for species-level identification. The coming-to-light of this identification tool is timely as we are now facing perhaps the greatest rate of species loss in recent millennia. This study contributes to an ever-increasing number of published accounts of DNA barcoding successfully and accurately distinguishing animal taxa, in this instance, the bee fauna of Nova Scotia, Canada. Most members of this well-known fauna were resolved with particular clarity; the average intraspecific divergence was less than 0.5%, and COI sequences from over 75% of the province's species are now in the Barcodes of Life Data System. DNA barcoding also revealed some surprises within this fauna, including the possible recognition of two undescribed genetically unique species, one in the genus Ceratina (subgenus Zadontomerus), the second in the genus Andrena (subgenus Larandrena); both are presently receiving further taxonomic study. In addition, DNA barcoding has allowed sex-associations among two pairs of cleptoparasitic species. The resulting utility of DNA barcoding for ecological studies of bee communities is discussed.
The Adelgidae are relatively small, cryptic insects, exhibiting complex life cycles with parthenogenetic reproduction. Due to these characteristics, the taxonomy of the group is problematic. Here, we test the effectiveness of the standard 658-bp barcode fragment from the 5'-end of the mitochondrial cytochrome c oxidase 1 gene (COI) in differentiating among 17 species of Adelgidae, in associating life-cycle stages, and in assessing patterns of geographical variation in selected species. Species of Adelgidae are well-differentiated by DNA barcodes, enabling the identification of different morphological forms, immature stages and individuals on different hosts and at different periods of the life cycle. DNA barcodes have uncovered cryptic diversity within taxa and, in other cases, a lack of sequence divergence in species pairs previously separated by life-cycle characteristics, indicating a need for further taxonomic analysis.
DNA barcoding has been evaluated for many animal taxa and is now advocated as a reliable and rapid means for species-level identification. The coming-to-light of this identification tool is timely as we are now facing perhaps the greatest rate of species loss in recent millennia. This study contributes to an ever-increasing number of published accounts of DNA barcoding successfully and accurately distinguishing animal taxa, in this instance, the bee fauna of Nova Scotia, Canada. Most members of this well-known fauna were resolved with particular clarity; the average intraspecific divergence was less than 0.5%, and COI sequences from over 75% of the province's species are now in the Barcodes of Life Data System. DNA barcoding also revealed some surprises within this fauna, including the possible recognition of two undescribed genetically unique species, one in the genus Ceratina (subgenus Zadontomerus), the second in the genus Andrena (subgenus Larandrena); both are presently receiving further taxonomic study. In addition, DNA barcoding has allowed sex-associations among two pairs of cleptoparasitic species. The resulting utility of DNA barcoding for ecological studies of bee communities is discussed.
DNA barcoding has been evaluated for many animal taxa and is now advocated as a reliable and rapid means for species-level identification. The coming-to-light of this identification tool is timely as we are now facing perhaps the greatest rate of species loss in recent millennia. This study contributes to an ever-increasing number of published accounts of DNA barcoding successfully and accurately distinguishing animal taxa, in this instance, the bee fauna of Nova Scotia, Canada. Most members of this well-known fauna were resolved with particular clarity; the average intraspecific divergence was less than 0.5%, and COI sequences from over 75% of the province's species are now in the Barcodes of Life Data System. DNA barcoding also revealed some surprises within this fauna, including the possible recognition of two undescribed genetically unique species, one in the genus Ceratina (subgenus Zadontomerus), the second in the genus Andrena (subgenus Larandrena); both are presently receiving further taxonomic study. In addition, DNA barcoding has allowed sex-associations among two pairs of cleptoparasitic species. The resulting utility of DNA barcoding for ecological studies of bee communities is discussed.
The ability to discriminate between species using barcoding loci has proved more difficult in plants than animals, raising the possibility that plant species boundaries are less well defined. Here, we review a selection of published barcoding data sets to compare species discrimination in plants vs. animals. Although the use of different genetic markers, analytical methods and depths of taxon sampling may complicate comparisons, our results using common metrics demonstrate that the number of species supported as monophyletic using barcoding markers is higher in animals (> 90%) than plants (~70%), even after controlling for the amount of parsimony-informative information per species. This suggests that more than a simple lack of variability limits species discrimination in plants. Both animal and plant species pairs have variable size gaps between intra- and interspecific genetic distances, but animal species tend to have larger gaps than plants, even in relatively densely sampled genera. An analysis of 12 plant genera suggests that hybridization contributes significantly to variation in genetic discontinuity in plants. Barcoding success may be improved in some plant groups by careful choice of markers and appropriate sampling; however, overall fine-scale species discrimination in plants relative to animals may be inherently more difficult because of greater levels of gene-tree paraphyly.
Close interactions between insects and plants have played a major role in the evolution of both these diverse groups of organisms. Studying these interactions, however, can be difficult because many insects, especially parasites, impinge most strongly on plants during larval stages when they are morphologically difficult to identify, and many belong to diverse groups for which most species remain undescribed. We used DNA barcoding to identify nondescript lepidopteran larvae that regularly parasitize flower buds of the coastal dune endemic Camissoniopsis cheiranthifolia (Onagraceae). We obtained cytochrome oxidase 1 mitochondrial DNA sequences from 201 parasite specimens from across the host geographical range. The Barcode of Life Database Identification System combined with Bayesian analysis grouped all 15 parasite haplotypes in a distinct, monophyletic clade within the genus Mompha (Lepidoptera: Coleophoridae: Momphinae), a group known to be host specialists on plants of the Onagraceae. Species identity and phylogenetic affinities within Mompha could not be confirmed because few barcode sequences exist from this diverse and poorly known group of moths. However, morphological analysis, including detailed dissection of genitalia for a subsample of 23 reared adults and comparison with known species of Mompha, also indicated that the larvae parasitizing C. cheiranthifolia constitute a distinct and undescribed species within this genus. Knowing that floral parasitism of C. cheiranthifolia involves a single, putatively host-specific microlepidopteran greatly facilitates formulating and testing hypotheses concerning how floral parasitism has promoted the evolution of striking floral diversity within this species. More generally, DNA barcoding combined with morphological analysis can greatly hasten identification of problematic specimens and enhance our understanding of the diversity, ecology and evolution of plant2013insect interactions.
Shark fisheries worldwide are mostly unmanaged, but the burgeoning shark fin industry in the last few decades has made monitoring catch and trade of these animals critical. As a tool for molecular species identification, DNA barcoding offers significant potential. However, the genetic distance-based approach towards species identification employed by the Barcode of Life Data Systems may oftentimes lack the specificity needed for regulatory or legal applications that require unambiguous identification results. This is because such specificity is not typically realized by anything less than a 100% match of the query sequence to an entry in the reference database using genetic distance. Although various divergence thresholds have been proposed to define acceptable levels of intraspecific variation, enough exceptions exist to cast reasonable doubt on many less than exact matches using a distance-based approach for the identification of unknowns. An alternative approach relies on the identification of discrete molecular characters that can be used to unambiguously diagnose species. The objective of this study was to assess the performance differences between these competing approaches by examining more than 1000 DNA barcodes representing nearly 20% of all known elasmobranch species. Our results demonstrate that a character-based, nucleotide diagnostic (ND) approach to barcode identification is feasible and also provides novel insights into the structure of haplotype diversity among closely related species of sharks. Considerations for the use of NDs in applied fields are also explored.
Shark fisheries worldwide are mostly unmanaged, but the burgeoning shark fin industry in the last few decades has made monitoring catch and trade of these animals critical. As a tool for molecular species identification, DNA barcoding offers significant potential. However, the genetic distance-based approach towards species identification employed by the Barcode of Life Data Systems may oftentimes lack the specificity needed for regulatory or legal applications that require unambiguous identification results. This is because such specificity is not typically realized by anything less than a 100% match of the query sequence to an entry in the reference database using genetic distance. Although various divergence thresholds have been proposed to define acceptable levels of intraspecific variation, enough exceptions exist to cast reasonable doubt on many less than exact matches using a distance-based approach for the identification of unknowns. An alternative approach relies on the identification of discrete molecular characters that can be used to unambiguously diagnose species. The objective of this study was to assess the performance differences between these competing approaches by examining more than 1000 DNA barcodes representing nearly 20% of all known elasmobranch species. Our results demonstrate that a character-based, nucleotide diagnostic (ND) approach to barcode identification is feasible and also provides novel insights into the structure of haplotype diversity among closely related species of sharks. Considerations for the use of NDs in applied fields are also explored.
Shark fisheries worldwide are mostly unmanaged, but the burgeoning shark fin industry in the last few decades has made monitoring catch and trade of these animals critical. As a tool for molecular species identification, DNA barcoding offers significant potential. However, the genetic distance-based approach towards species identification employed by the Barcode of Life Data Systems may oftentimes lack the specificity needed for regulatory or legal applications that require unambiguous identification results. This is because such specificity is not typically realized by anything less than a 100% match of the query sequence to an entry in the reference database using genetic distance. Although various divergence thresholds have been proposed to define acceptable levels of intraspecific variation, enough exceptions exist to cast reasonable doubt on many less than exact matches using a distance-based approach for the identification of unknowns. An alternative approach relies on the identification of discrete molecular characters that can be used to unambiguously diagnose species. The objective of this study was to assess the performance differences between these competing approaches by examining more than 1000 DNA barcodes representing nearly 20% of all known elasmobranch species. Our results demonstrate that a character-based, nucleotide diagnostic (ND) approach to barcode identification is feasible and also provides novel insights into the structure of haplotype diversity among closely related species of sharks. Considerations for the use of NDs in applied fields are also explored.
Shark fisheries worldwide are mostly unmanaged, but the burgeoning shark fin industry in the last few decades has made monitoring catch and trade of these animals critical. As a tool for molecular species identification, DNA barcoding offers significant potential. However, the genetic distance-based approach towards species identification employed by the Barcode of Life Data Systems may oftentimes lack the specificity needed for regulatory or legal applications that require unambiguous identification results. This is because such specificity is not typically realized by anything less than a 100% match of the query sequence to an entry in the reference database using genetic distance. Although various divergence thresholds have been proposed to define acceptable levels of intraspecific variation, enough exceptions exist to cast reasonable doubt on many less than exact matches using a distance-based approach for the identification of unknowns. An alternative approach relies on the identification of discrete molecular characters that can be used to unambiguously diagnose species. The objective of this study was to assess the performance differences between these competing approaches by examining more than 1000 DNA barcodes representing nearly 20% of all known elasmobranch species. Our results demonstrate that a character-based, nucleotide diagnostic (ND) approach to barcode identification is feasible and also provides novel insights into the structure of haplotype diversity among closely related species of sharks. Considerations for the use of NDs in applied fields are also explored.
With more than 15 000 described marine species, fishes are a conspicuous, diverse and increasingly threatened component of marine life. It is generally accepted that most large-bodied fishes have been described, but this conclusion presumes that current taxonomic systems are robust. DNA barcoding, the analysis of a standardized region of the cytochrome c oxidase 1 gene (COI), was used to examine patterns of sequence divergence between populations of 35 fish species from opposite sides of the Indian Ocean, chosen to represent differing lifestyles from inshore to offshore. A substantial proportion of inshore species showed deep divergences between populations from South African and Australian waters (mean = 5.10%), a pattern which also emerged in a few inshore/offshore species (mean = 0.84%), but not within strictly offshore species (mean = 0.26%). Such deep divergences, detected within certain inshore and inshore/offshore taxa, are typical of divergences between congeneric species rather than between populations of a single species, suggesting that current taxonomic systems substantially underestimate species diversity. We estimate that about one third of the 1000 fish species thought to bridge South African and Australian waters actually represent two taxa.
Studies that assess intraspecific genetic variation in ciliates are few and quite recent. Consequently, knowledge of the subject and understanding of the processes that underlie it are limited. We sought to assess the degree of intraspecific genetic variation in Carchesium polypinum (Ciliophora: Peritrichia), a cosmopolitan, freshwater ciliate. We isolated colonies of C. polypinum from locations in the Grand River basin in Southwestern Ontario, Canada. We then used the nuclear markers--ITS1, ITS2, and the hypervariable regions of the large subunit rRNA--and an 819-bp fragment of the mitochondrial cytochrome c oxidase I gene (cox-1) to investigate the intraspecific genetic variation of C. polypinum and the degree of resolution of the above-mentioned markers at the population level. We also sought to determine whether the organism demonstrated any population structure that mapped onto the geography of the region. Our study shows that there is a high degree of genetic diversity at the isolate level, revealed by the mitochondrial markers but not the nuclear markers. Furthermore, our results indicate that C. polypinum is likely not a single morphospecies as previously thought.
Studies that assess intraspecific genetic variation in ciliates are few and quite recent. Consequently, knowledge of the subject and understanding of the processes that underlie it are limited. We sought to assess the degree of intraspecific genetic variation in Carchesium polypinum (Ciliophora: Peritrichia), a cosmopolitan, freshwater ciliate. We isolated colonies of C. polypinum from locations in the Grand River basin in Southwestern Ontario, Canada. We then used the nuclear markers--ITS1, ITS2, and the hypervariable regions of the large subunit rRNA--and an 819-bp fragment of the mitochondrial cytochrome c oxidase I gene (cox-1) to investigate the intraspecific genetic variation of C. polypinum and the degree of resolution of the above-mentioned markers at the population level. We also sought to determine whether the organism demonstrated any population structure that mapped onto the geography of the region. Our study shows that there is a high degree of genetic diversity at the isolate level, revealed by the mitochondrial markers but not the nuclear markers. Furthermore, our results indicate that C. polypinum is likely not a single morphospecies as previously thought.
General criticisms of a single mtDNA gene barcodes include failure to identify newly evolved species, use of species-delimitation thresholds, effects of selective sweeps and chance occurrence of reciprocal monophyly within species, inability to deal with hybridization and incomplete lineage sorting, and superiority of multiple genes in species identification. We address these criticisms in birds because most species are known and thus provide an ideal test data set, and we argue with selected examples that with the exception of thresholds these criticisms are not problematic for avian taxonomy. Even closely related sister species of birds have distinctive COI barcodes, but it is not possible to universally apply distance thresholds based on ratios of within-species and among-species variation. Instead, more rigorous methods of species delimitation should be favoured using coalescent-based techniques that include tests of chance reciprocal monophyly, and times of lineage separation and sequence divergence. Incomplete lineage sorting is also easily detected with DNA barcodes, and usually at a younger time frame than a more slowly evolving nuclear gene. Where DNA barcodes detect divergent reciprocally monophyletic lineages, the COI sequences can be combined with multiple nuclear genes to distinguish between speciation or population subdivision arising from high female philopatry or regional selective sweeps. Although selective sweeps are increasingly invoked to explain patterns of shallow within-species coalescences in COI gene trees, caution is warranted in this conjecture because of limited sampling of individuals and the reduced power to detect additional mtDNA haplotypes with one gene.
Although devices combining microfluidic and advanced sequencing technologies promise a future where one can generate a DNA barcode in minutes, current analytical regimes typically involve workflows that extend over 2 days. Here we describe simple protocols enabling the advance from a specimen to barcode-based identification in less than 2 h. The protocols use frozen or lyophilized reagents that can be prepackaged into 'kits' and support barcode analysis across the animal kingdom. The analytical procedure allows 5 min for DNA extraction, 25 min for polymerase chain reaction amplification of the barcode region, 25 min for cycle-sequencing, 10 min for cleanup, 45 min for capillary sequencing and 5 min for trace file analysis to complete DNA-based identification. This study involved the comparison of varied DNA preservation and extraction methods, and evaluated Taq polymerases with high processivity and resistance to inhibitors.
With more than 15 000 described marine species, fishes are a conspicuous, diverse and increasingly threatened component of marine life. It is generally accepted that most large-bodied fishes have been described, but this conclusion presumes that current taxonomic systems are robust. DNA barcoding, the analysis of a standardized region of the cytochrome c oxidase 1 gene (COI), was used to examine patterns of sequence divergence between populations of 35 fish species from opposite sides of the Indian Ocean, chosen to represent differing lifestyles from inshore to offshore. A substantial proportion of inshore species showed deep divergences between populations from South African and Australian waters (mean = 5.10%), a pattern which also emerged in a few inshore/offshore species (mean = 0.84%), but not within strictly offshore species (mean = 0.26%). Such deep divergences, detected within certain inshore and inshore/offshore taxa, are typical of divergences between congeneric species rather than between populations of a single species, suggesting that current taxonomic systems substantially underestimate species diversity. We estimate that about one third of the 1000 fish species thought to bridge South African and Australian waters actually represent two taxa.
Shark fisheries worldwide are mostly unmanaged, but the burgeoning shark fin industry in the last few decades has made monitoring catch and trade of these animals critical. As a tool for molecular species identification, DNA barcoding offers significant potential. However, the genetic distance-based approach towards species identification employed by the Barcode of Life Data Systems may oftentimes lack the specificity needed for regulatory or legal applications that require unambiguous identification results. This is because such specificity is not typically realized by anything less than a 100% match of the query sequence to an entry in the reference database using genetic distance. Although various divergence thresholds have been proposed to define acceptable levels of intraspecific variation, enough exceptions exist to cast reasonable doubt on many less than exact matches using a distance-based approach for the identification of unknowns. An alternative approach relies on the identification of discrete molecular characters that can be used to unambiguously diagnose species. The objective of this study was to assess the performance differences between these competing approaches by examining more than 1000 DNA barcodes representing nearly 20% of all known elasmobranch species. Our results demonstrate that a character-based, nucleotide diagnostic (ND) approach to barcode identification is feasible and also provides novel insights into the structure of haplotype diversity among closely related species of sharks. Considerations for the use of NDs in applied fields are also explored.
Inventory of the caterpillars, their food plants and parasitoids began in 1978 for today's Area de Conservacion Guanacaste (ACG), in northwestern Costa Rica. This complex mosaic of 120 000 ha of conserved and regenerating dry, cloud and rain forest over 020132000 m elevation contains at least 10 000 species of non-leaf-mining caterpillars used by more than 5000 species of parasitoids. Several hundred thousand specimens of ACG-reared adult Lepidoptera and parasitoids have been intensively and extensively studied morphologically by many taxonomists, including most of the co-authors. DNA barcoding 2014 the use of a standardized short mitochondrial DNA sequence to identify specimens and flush out undisclosed species 2014 was added to the taxonomic identification process in 2003. Barcoding has been found to be extremely accurate during the identification of about 100 000 specimens of about 3500 morphologically defined species of adult moths, butterflies, tachinid flies, and parasitoid wasps. Less than 1% of the species have such similar barcodes that a molecularly based taxonomic identification is impossible. No specimen with a full barcode was misidentified when its barcode was compared with the barcode library. Also as expected from early trials, barcoding a series from all morphologically defined species, and correlating the morphological, ecological and barcode traits, has revealed many hundreds of overlooked presumptive species. Many but not all of these cryptic species can now be distinguished by subtle morphological and/or ecological traits previously ascribed to 'variation' or thought to be insignificant for species-level recognition. Adding DNA barcoding to the inventory has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution.
Inventory of the caterpillars, their food plants and parasitoids began in 1978 for today's Area de Conservacion Guanacaste (ACG), in northwestern Costa Rica. This complex mosaic of 120 000 ha of conserved and regenerating dry, cloud and rain forest over 020132000 m elevation contains at least 10 000 species of non-leaf-mining caterpillars used by more than 5000 species of parasitoids. Several hundred thousand specimens of ACG-reared adult Lepidoptera and parasitoids have been intensively and extensively studied morphologically by many taxonomists, including most of the co-authors. DNA barcoding 2014 the use of a standardized short mitochondrial DNA sequence to identify specimens and flush out undisclosed species 2014 was added to the taxonomic identification process in 2003. Barcoding has been found to be extremely accurate during the identification of about 100 000 specimens of about 3500 morphologically defined species of adult moths, butterflies, tachinid flies, and parasitoid wasps. Less than 1% of the species have such similar barcodes that a molecularly based taxonomic identification is impossible. No specimen with a full barcode was misidentified when its barcode was compared with the barcode library. Also as expected from early trials, barcoding a series from all morphologically defined species, and correlating the morphological, ecological and barcode traits, has revealed many hundreds of overlooked presumptive species. Many but not all of these cryptic species can now be distinguished by subtle morphological and/or ecological traits previously ascribed to 'variation' or thought to be insignificant for species-level recognition. Adding DNA barcoding to the inventory has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution.
With more than 15 000 described marine species, fishes are a conspicuous, diverse and increasingly threatened component of marine life. It is generally accepted that most large-bodied fishes have been described, but this conclusion presumes that current taxonomic systems are robust. DNA barcoding, the analysis of a standardized region of the cytochrome c oxidase 1 gene (COI), was used to examine patterns of sequence divergence between populations of 35 fish species from opposite sides of the Indian Ocean, chosen to represent differing lifestyles from inshore to offshore. A substantial proportion of inshore species showed deep divergences between populations from South African and Australian waters (mean = 5.10%), a pattern which also emerged in a few inshore/offshore species (mean = 0.84%), but not within strictly offshore species (mean = 0.26%). Such deep divergences, detected within certain inshore and inshore/offshore taxa, are typical of divergences between congeneric species rather than between populations of a single species, suggesting that current taxonomic systems substantially underestimate species diversity. We estimate that about one third of the 1000 fish species thought to bridge South African and Australian waters actually represent two taxa.
Building a global library of DNA barcodes will require efficient logistics of pre-laboratory specimen processing and seamless interfacing with molecular protocols. If not addressed properly, the task of aggregating specimens may become the biggest bottleneck in the analytical chain. Three years of experience in developing a collection management system to facilitate high-throughput DNA barcoding have allowed the Canadian Centre for DNA Barcoding to recognize and resolve the most common logistical obstacles. Dealing with these challenges on a larger scale will be an important step towards building a solid collection-based foundation for the international DNA barcoding effort.
Although devices combining microfluidic and advanced sequencing technologies promise a future where one can generate a DNA barcode in minutes, current analytical regimes typically involve workflows that extend over 2 days. Here we describe simple protocols enabling the advance from a specimen to barcode-based identification in less than 2 h. The protocols use frozen or lyophilized reagents that can be prepackaged into 'kits' and support barcode analysis across the animal kingdom. The analytical procedure allows 5 min for DNA extraction, 25 min for polymerase chain reaction amplification of the barcode region, 25 min for cycle-sequencing, 10 min for cleanup, 45 min for capillary sequencing and 5 min for trace file analysis to complete DNA-based identification. This study involved the comparison of varied DNA preservation and extraction methods, and evaluated Taq polymerases with high processivity and resistance to inhibitors.
General criticisms of a single mtDNA gene barcodes include failure to identify newly evolved species, use of species-delimitation thresholds, effects of selective sweeps and chance occurrence of reciprocal monophyly within species, inability to deal with hybridization and incomplete lineage sorting, and superiority of multiple genes in species identification. We address these criticisms in birds because most species are known and thus provide an ideal test data set, and we argue with selected examples that with the exception of thresholds these criticisms are not problematic for avian taxonomy. Even closely related sister species of birds have distinctive COI barcodes, but it is not possible to universally apply distance thresholds based on ratios of within-species and among-species variation. Instead, more rigorous methods of species delimitation should be favoured using coalescent-based techniques that include tests of chance reciprocal monophyly, and times of lineage separation and sequence divergence. Incomplete lineage sorting is also easily detected with DNA barcodes, and usually at a younger time frame than a more slowly evolving nuclear gene. Where DNA barcodes detect divergent reciprocally monophyletic lineages, the COI sequences can be combined with multiple nuclear genes to distinguish between speciation or population subdivision arising from high female philopatry or regional selective sweeps. Although selective sweeps are increasingly invoked to explain patterns of shallow within-species coalescences in COI gene trees, caution is warranted in this conjecture because of limited sampling of individuals and the reduced power to detect additional mtDNA haplotypes with one gene.
Building a global library of DNA barcodes will require efficient logistics of pre-laboratory specimen processing and seamless interfacing with molecular protocols. If not addressed properly, the task of aggregating specimens may become the biggest bottleneck in the analytical chain. Three years of experience in developing a collection management system to facilitate high-throughput DNA barcoding have allowed the Canadian Centre for DNA Barcoding to recognize and resolve the most common logistical obstacles. Dealing with these challenges on a larger scale will be an important step towards building a solid collection-based foundation for the international DNA barcoding effort.
DNA barcoding has gained increased recognition as a molecular tool for species identification in various groups of organisms. In this preliminary study, we tested the efficacy of a 615-bp fragment of the cytochrome c oxidase I (COI) as a DNA barcode in the medically important family Simuliidae, or black flies. A total of 65 (25%) morphologically distinct species and sibling species in species complexes of the 255 recognized Nearctic black fly species were used to create a preliminary barcode profile for the family. Genetic divergence among congeners averaged 14.93% (range 2.83201315.33%), whereas intraspecific genetic divergence between morphologically distinct species averaged 0.72% (range 020133.84%). DNA barcodes correctly identified nearly 100% of the morphologically distinct species (87% of the total sampled taxa), whereas in species complexes (13% of the sampled taxa) maximum values of divergence were comparatively higher (max. 4.5820136.5%), indicating cryptic diversity. The existence of sibling species in Prosimulium travisi and P. neomacropyga was also demonstrated, thus confirming previous cytological evidence about the existence of such cryptic diversity in these two taxa. We conclude that DNA barcoding is an effective method for species identification and discovery of cryptic diversity in black flies.
As part of an extensive DNA-based floristic survey of marine macroalgae in Canadian waters, an unexpected sequence for a Gracilaria sp. was generated from British Columbia. Before further molecular analyses and corresponding morphological/anatomical observations this mystery sequence was temporarily entered into our database as Gracilaria BCsp. Continued sampling uncovered this species from four additional locations. A timely collaboration with international colleagues introduced sequences from the invasive Gracilaria vermiculophylla into our cytochrome c oxidase I alignments 2014 these a perfect match to BCsp indicating that this species occurs in British Columbia. A discussion of the origin of this taxon in Canadian waters, whether natural or introduced, is provided.
DNA barcoding has gained increased recognition as a molecular tool for species identification in various groups of organisms. In this preliminary study, we tested the efficacy of a 615-bp fragment of the cytochrome c oxidase I (COI) as a DNA barcode in the medically important family Simuliidae, or black flies. A total of 65 (25%) morphologically distinct species and sibling species in species complexes of the 255 recognized Nearctic black fly species were used to create a preliminary barcode profile for the family. Genetic divergence among congeners averaged 14.93% (range 2.83201315.33%), whereas intraspecific genetic divergence between morphologically distinct species averaged 0.72% (range 020133.84%). DNA barcodes correctly identified nearly 100% of the morphologically distinct species (87% of the total sampled taxa), whereas in species complexes (13% of the sampled taxa) maximum values of divergence were comparatively higher (max. 4.5820136.5%), indicating cryptic diversity. The existence of sibling species in Prosimulium travisi and P. neomacropyga was also demonstrated, thus confirming previous cytological evidence about the existence of such cryptic diversity in these two taxa. We conclude that DNA barcoding is an effective method for species identification and discovery of cryptic diversity in black flies.
Close interactions between insects and plants have played a major role in the evolution of both these diverse groups of organisms. Studying these interactions, however, can be difficult because many insects, especially parasites, impinge most strongly on plants during larval stages when they are morphologically difficult to identify, and many belong to diverse groups for which most species remain undescribed. We used DNA barcoding to identify nondescript lepidopteran larvae that regularly parasitize flower buds of the coastal dune endemic Camissoniopsis cheiranthifolia (Onagraceae). We obtained cytochrome oxidase 1 mitochondrial DNA sequences from 201 parasite specimens from across the host geographical range. The Barcode of Life Database Identification System combined with Bayesian analysis grouped all 15 parasite haplotypes in a distinct, monophyletic clade within the genus Mompha (Lepidoptera: Coleophoridae: Momphinae), a group known to be host specialists on plants of the Onagraceae. Species identity and phylogenetic affinities within Mompha could not be confirmed because few barcode sequences exist from this diverse and poorly known group of moths. However, morphological analysis, including detailed dissection of genitalia for a subsample of 23 reared adults and comparison with known species of Mompha, also indicated that the larvae parasitizing C. cheiranthifolia constitute a distinct and undescribed species within this genus. Knowing that floral parasitism of C. cheiranthifolia involves a single, putatively host-specific microlepidopteran greatly facilitates formulating and testing hypotheses concerning how floral parasitism has promoted the evolution of striking floral diversity within this species. More generally, DNA barcoding combined with morphological analysis can greatly hasten identification of problematic specimens and enhance our understanding of the diversity, ecology and evolution of plant2013insect interactions.
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
The Canadian Barcode of Life Network has made a substantial contribution to the literature on DNA barcoding with the new release of a special issue of Molecular Ecology Resources that is entirely dedicated to barcoding. This volume stems from our Network's Scientific Symposium held at the ROM last spring and represents a major milestone for our national network.
This collection of 27 papers is accessible online: http://www3.interscience.wiley.com/journal/122342767/issue
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009. Download the Flyer (PDF, 150Kb)
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009. Download the Flyer (PDF, 150Kb)
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
As part of the MarBOL (DNA Barcoding of Marine Biodiversity, see http://www.marinebarcoding.org/) effort, three workshops will be held during Spring 2009 to identify bottlenecks and facilitate coordination among active marine barcoding centers – especially those associated with Census of Marine Life (CoML) and Consortium for the Barcode of Life (CBOL) projects. The goal of the workshops is to accelerate progress, explore various applications of barcodes, including species identification, trophic analysis, use of microarrays, environmental sequencing, and metagenetics.
The MarBOL workshops will be held at three locations on the following dates:
EUROPE: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany. Dates: April 16 – 17, 2009. Download the Flyer (PDF, 150Kb)
USA: Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Dates: April 30 – May 1, 2009
ASIA: Ocean Research Institute, University of Tokyo, Tokyo, Japan. Dates: May 21 – 22, 2009
At each location, there will be a one day DNA Barcoding Symposium featuring invited keynote speakers, who will provide overviews on topics of general scientific interest and practical importance for the MarBOL effort. The Symposium will also include contributed talks by researchers from the region, and a student poster session. The language of all three workshops is English.
How to apply: Participation at the MarBOL workshop is by invitation. All interested researchers, staff, and students are invited to apply using the form available on the MarBOL (http://www.marinebarcoding.org/) project websites Limited funding is available to defray partial costs of workshop attendance for some participants; requests for consideration for travel support should be indicated on the application form.
Due date for applications: Applications will be reviewed as they are received; applications received by March 6, 2009 will receive full consideration.
Questions? Please contact:
Ann Bucklin
Professor and Head, Department of Marine Sciences Director,
Marine Sciences and Technology Center University of Connecticut
Avery Point 1080 Shennecossett Road Groton, CT 06340
USA Tel. 860-405-9208; Fax 860-405-9153
Email: ann.bucklin@uconn.edu
Traditional taxonomic practices are insufficient on their own to cope with the growing need for accurate identifications. The recent development of DNA barcoding has been applied to plants. The next step is the development of a high-throughput Automated Identification Technology (AIT) system. Our research indicates that the efficacy of an AIT system equates with savings in time and funding. Given the potential interconnectivity of web-based applications, we suggest an AIT system for plants that uses several existing systems and suggest several applications where AIT could serve as a tool for biologists and for society at large.
Tetrodotoxin is a neurotoxin that occurs in select species of the family Tetraodontidae (puffer fish). It causes paralysis and potentially death if ingested in sufficient quantities. In 2007, two individuals developed symptoms consistent with tetrodotoxin poisoning after ingesting home-cooked puffer fish purchased in Chicago. Both the Chicago retailer and the California supplier denied having sold or imported puffer fish but claimed the product was monkfish. However, genetic analysis and visual inspection determined that the ingested fish and others from the implicated lot retrieved from the supplier belonged to the family Tetraodontidae. Tetrodotoxin was detected at high levels in both remnants of the ingested meal and fish retrieved from the implicated lot. The investigation led to a voluntary recall of monkfish distributed by the supplier in three states and placement of the supplier on the U.S. Food and Drug Administration’s Import Alert for species misbranding. This case of tetrodotoxin poisoning highlights the need for continued stringent regulation of puffer fish importation by the U.S. Food and Drug Administration, education of the public regarding the dangers of puffer fish consumption, and raising awareness among medical providers of the diagnosis and management of foodborne toxin ingestions and the need for reporting to public health agencies.
Traditional taxonomic practices are insufficient on their own to cope with the growing need for accurate identifications. The recent development of DNA barcoding has been applied to plants. The next step is the development of a high-throughput Automated Identification Technology (AIT) system. Our research indicates that the efficacy of an AIT system equates with savings in time and funding. Given the potential interconnectivity of web-based applications, we suggest an AIT system for plants that uses several existing systems and suggest several applications where AIT could serve as a tool for biologists and for society at large.
Tetrodotoxin is a neurotoxin that occurs in select species of the family Tetraodontidae (puffer fish). It causes paralysis and potentially death if ingested in sufficient quantities. In 2007, two individuals developed symptoms consistent with tetrodotoxin poisoning after ingesting home-cooked puffer fish purchased in Chicago. Both the Chicago retailer and the California supplier denied having sold or imported puffer fish but claimed the product was monkfish. However, genetic analysis and visual inspection determined that the ingested fish and others from the implicated lot retrieved from the supplier belonged to the family Tetraodontidae. Tetrodotoxin was detected at high levels in both remnants of the ingested meal and fish retrieved from the implicated lot. The investigation led to a voluntary recall of monkfish distributed by the supplier in three states and placement of the supplier on the U.S. Food and Drug Administration’s Import Alert for species misbranding. This case of tetrodotoxin poisoning highlights the need for continued stringent regulation of puffer fish importation by the U.S. Food and Drug Administration, education of the public regarding the dangers of puffer fish consumption, and raising awareness among medical providers of the diagnosis and management of foodborne toxin ingestions and the need for reporting to public health agencies.
Traditional taxonomic practices are insufficient on their own to cope with the growing need for accurate identifications. The recent development of DNA barcoding has been applied to plants. The next step is the development of a high-throughput Automated Identification Technology (AIT) system. Our research indicates that the efficacy of an AIT system equates with savings in time and funding. Given the potential interconnectivity of web-based applications, we suggest an AIT system for plants that uses several existing systems and suggest several applications where AIT could serve as a tool for biologists and for society at large.
Tetrodotoxin is a neurotoxin that occurs in select species of the family Tetraodontidae (puffer fish). It causes paralysis and potentially death if ingested in sufficient quantities. In 2007, two individuals developed symptoms consistent with tetrodotoxin poisoning after ingesting home-cooked puffer fish purchased in Chicago. Both the Chicago retailer and the California supplier denied having sold or imported puffer fish but claimed the product was monkfish. However, genetic analysis and visual inspection determined that the ingested fish and others from the implicated lot retrieved from the supplier belonged to the family Tetraodontidae. Tetrodotoxin was detected at high levels in both remnants of the ingested meal and fish retrieved from the implicated lot. The investigation led to a voluntary recall of monkfish distributed by the supplier in three states and placement of the supplier on the U.S. Food and Drug Administration’s Import Alert for species misbranding. This case of tetrodotoxin poisoning highlights the need for continued stringent regulation of puffer fish importation by the U.S. Food and Drug Administration, education of the public regarding the dangers of puffer fish consumption, and raising awareness among medical providers of the diagnosis and management of foodborne toxin ingestions and the need for reporting to public health agencies.
The theme of the 2009 Inter-congress (PSI 2009) is : “Pacific countries and their ocean facing local and global changes”. Five sessions will be organized around the following sub-themes :
For further information, proceed to the meeting website.
The theme of the 2009 Inter-congress (PSI 2009) is : “Pacific countries and their ocean facing local and global changes”. Five sessions will be organized around the following sub-themes :
For further information, proceed to the meeting website.
An integrative taxonomic approach that utilizes the DNA barcode region of cytochrome c oxidase subunit 1 in conjunction with traditional morphological approaches identifies five distinct species previously recognized as Lasioglossum (Dialictus) tegulare (Robertson). Differences in DNA sequences and congruent, albeit minor, morphological variation support separation of L. tegulare into five species. Unique nucleotide substitution patterns for each species allows for character-based diagnostics using DNA barcodes. The names L. ellisiae (Sandhouse) and L. lepidii (Graenicher) are removed from synonymy. Two new species, L. puteulanum Gibbs sp. n. and L. carlinvillense Gibbs sp. n., are described. A key is provided, which permits the identification of both males and females. The utility of the DNA barcode region as part of an integrative taxonomic framework is discussed.
An integrative taxonomic approach that utilizes the DNA barcode region of cytochrome c oxidase subunit 1 in conjunction with traditional morphological approaches identifies five distinct species previously recognized as Lasioglossum (Dialictus) tegulare (Robertson). Differences in DNA sequences and congruent, albeit minor, morphological variation support separation of L. tegulare into five species. Unique nucleotide substitution patterns for each species allows for character-based diagnostics using DNA barcodes. The names L. ellisiae (Sandhouse) and L. lepidii (Graenicher) are removed from synonymy. Two new species, L. puteulanum Gibbs sp. n. and L. carlinvillense Gibbs sp. n., are described. A key is provided, which permits the identification of both males and females. The utility of the DNA barcode region as part of an integrative taxonomic framework is discussed.
Wide variation and overlap in morphological characters have led to confusion in species identification within the fungal rust genus Melampsora. The Melampsora species with uredinial–telial stages on white poplar and aspens are especially prone to misidentification. This group includes the Melampsora populnea species complex and the highly destructive pine twisting rust, Melampsora pinitorqua, which alternates between hosts in Populus section Populus and Pinus. Our objective was to compare morphologically based identification to genetic material extracted from Melampsora species pathogenic to aspen and white poplar. We compared morphometric traits and DNA barcodes obtained from internal transcribed spacer (ITS), large ribosomal RNA subunit (28S), and mitochondrial cytochrome oxidase 1 (CO1) sequences to delimit within this taxonomically difficult group. Eight different Melampsora species were initially defined based on host specificity and morphometric data. DNA barcodes were then overlaid on these initial species definitions. The DNA barcodes, specifically those defined on ITS and 28S sequences, provided a highly accurate means of identifying and resolving Melampsora taxa. We highlighted species misidentification in specimens from Canadian herbaria related to either Melampsora medusae f. sp. tremuloidae or Melampsora aecidioides. Finally, we evidenced that the north-American species found on Populus alba, M. aecidioides is closely related but distinct from the four species of the M. populnea complex (Melampsora larici-tremulae, Melampsora magnusiana, Melampsora pinitorqua, and Melampsora rostrupii) found in Eurasia.
Wide variation and overlap in morphological characters have led to confusion in species identification within the fungal rust genus Melampsora. The Melampsora species with uredinial–telial stages on white poplar and aspens are especially prone to misidentification. This group includes the Melampsora populnea species complex and the highly destructive pine twisting rust, Melampsora pinitorqua, which alternates between hosts in Populus section Populus and Pinus. Our objective was to compare morphologically based identification to genetic material extracted from Melampsora species pathogenic to aspen and white poplar. We compared morphometric traits and DNA barcodes obtained from internal transcribed spacer (ITS), large ribosomal RNA subunit (28S), and mitochondrial cytochrome oxidase 1 (CO1) sequences to delimit within this taxonomically difficult group. Eight different Melampsora species were initially defined based on host specificity and morphometric data. DNA barcodes were then overlaid on these initial species definitions. The DNA barcodes, specifically those defined on ITS and 28S sequences, provided a highly accurate means of identifying and resolving Melampsora taxa. We highlighted species misidentification in specimens from Canadian herbaria related to either Melampsora medusae f. sp. tremuloidae or Melampsora aecidioides. Finally, we evidenced that the north-American species found on Populus alba, M. aecidioides is closely related but distinct from the four species of the M. populnea complex (Melampsora larici-tremulae, Melampsora magnusiana, Melampsora pinitorqua, and Melampsora rostrupii) found in Eurasia.
Background
DNA barcoding promises to revolutionize the way taxonomists work, facilitating species identification by using small, standardized portions of the genome as substitutes for morphology. The concept has gained considerable momentum in many animal groups, but the higher plant world has been largely recalcitrant to the effort. In plants, efforts are concentrated on various regions of the plastid genome, but no agreement exists as to what kinds of regions are ideal, though most researchers agree that more than one region is necessary. One reason for this discrepancy is differences in the tests that are used to evaluate the performance of the proposed regions. Most tests have been made in a floristic setting, where the genetic distance and therefore the level of variation of the regions between taxa is large, or in a limited set of congeneric species.
Methodology and Principal Findings
Here we present the first in-depth coverage of a large taxonomic group, all 86 known species (except two doubtful ones) of crocus. Even six average-sized barcode regions do not identify all crocus species. This is currently an unrealistic burden in a barcode context. Whereas most proposed regions work well in a floristic context, the majority will – as is the case in crocus – undoubtedly be less efficient in a taxonomic setting. However, a reasonable but less than perfect level of identification may be reached – even in a taxonomic context.
Conclusions/Significance
The time is ripe for selecting barcode regions in plants, and for prudent examination of their utility. Thus, there is no reason for the plant community to hold back the barcoding effort by continued search for the Holy Grail. We must acknowledge that an emerging system will be far from perfect, fraught with problems and work best in a floristic setting.
Background
The Neotropical avifauna is more diverse than that of any other biogeographic region, but our understanding of patterns of regional divergence is limited. Critical examination of this issue is currently constrained by the limited genetic information available. This study begins to address this gap by assembling a library of mitochondrial COI sequences, or DNA barcodes, for Argentinian birds and comparing their patterns of genetic diversity to those of North American birds.
Methodology and Principal Findings
Five hundred Argentinian species were examined, making this the first major examination of DNA barcodes for South American birds. Our results indicate that most southern Neotropical bird species show deep sequence divergence from their nearest-neighbour, corroborating that the high diversity of this fauna is not based on an elevated incidence of young species radiations. Although species ages appear similar in temperate North and South American avifaunas, patterns of regional divergence are more complex in the Neotropics, suggesting that the high diversity of the Neotropical avifauna has been fueled by greater opportunities for regional divergence. Deep genetic splits were observed in at least 21 species, though distribution patterns of these lineages were variable. The lack of shared polymorphisms in species, even in species with less than 0.5M years of reproductive isolation, further suggests that selective sweeps could regularly excise ancestral mitochondrial polymorphisms.
Conclusions
These findings confirm the efficacy of species delimitation in birds via DNA barcodes, even when tested on a global scale. Further, they demonstrate how large libraries of a standardized gene region provide insight into evolutionary processes.
Background
The Neotropical avifauna is more diverse than that of any other biogeographic region, but our understanding of patterns of regional divergence is limited. Critical examination of this issue is currently constrained by the limited genetic information available. This study begins to address this gap by assembling a library of mitochondrial COI sequences, or DNA barcodes, for Argentinian birds and comparing their patterns of genetic diversity to those of North American birds.
Methodology and Principal Findings
Five hundred Argentinian species were examined, making this the first major examination of DNA barcodes for South American birds. Our results indicate that most southern Neotropical bird species show deep sequence divergence from their nearest-neighbour, corroborating that the high diversity of this fauna is not based on an elevated incidence of young species radiations. Although species ages appear similar in temperate North and South American avifaunas, patterns of regional divergence are more complex in the Neotropics, suggesting that the high diversity of the Neotropical avifauna has been fueled by greater opportunities for regional divergence. Deep genetic splits were observed in at least 21 species, though distribution patterns of these lineages were variable. The lack of shared polymorphisms in species, even in species with less than 0.5M years of reproductive isolation, further suggests that selective sweeps could regularly excise ancestral mitochondrial polymorphisms.
Conclusions
These findings confirm the efficacy of species delimitation in birds via DNA barcodes, even when tested on a global scale. Further, they demonstrate how large libraries of a standardized gene region provide insight into evolutionary processes.
Background
The Neotropical avifauna is more diverse than that of any other biogeographic region, but our understanding of patterns of regional divergence is limited. Critical examination of this issue is currently constrained by the limited genetic information available. This study begins to address this gap by assembling a library of mitochondrial COI sequences, or DNA barcodes, for Argentinian birds and comparing their patterns of genetic diversity to those of North American birds.
Methodology and Principal Findings
Five hundred Argentinian species were examined, making this the first major examination of DNA barcodes for South American birds. Our results indicate that most southern Neotropical bird species show deep sequence divergence from their nearest-neighbour, corroborating that the high diversity of this fauna is not based on an elevated incidence of young species radiations. Although species ages appear similar in temperate North and South American avifaunas, patterns of regional divergence are more complex in the Neotropics, suggesting that the high diversity of the Neotropical avifauna has been fueled by greater opportunities for regional divergence. Deep genetic splits were observed in at least 21 species, though distribution patterns of these lineages were variable. The lack of shared polymorphisms in species, even in species with less than 0.5M years of reproductive isolation, further suggests that selective sweeps could regularly excise ancestral mitochondrial polymorphisms.
Conclusions
These findings confirm the efficacy of species delimitation in birds via DNA barcodes, even when tested on a global scale. Further, they demonstrate how large libraries of a standardized gene region provide insight into evolutionary processes.
Background
The Neotropical avifauna is more diverse than that of any other biogeographic region, but our understanding of patterns of regional divergence is limited. Critical examination of this issue is currently constrained by the limited genetic information available. This study begins to address this gap by assembling a library of mitochondrial COI sequences, or DNA barcodes, for Argentinian birds and comparing their patterns of genetic diversity to those of North American birds.
Methodology and Principal Findings
Five hundred Argentinian species were examined, making this the first major examination of DNA barcodes for South American birds. Our results indicate that most southern Neotropical bird species show deep sequence divergence from their nearest-neighbour, corroborating that the high diversity of this fauna is not based on an elevated incidence of young species radiations. Although species ages appear similar in temperate North and South American avifaunas, patterns of regional divergence are more complex in the Neotropics, suggesting that the high diversity of the Neotropical avifauna has been fueled by greater opportunities for regional divergence. Deep genetic splits were observed in at least 21 species, though distribution patterns of these lineages were variable. The lack of shared polymorphisms in species, even in species with less than 0.5M years of reproductive isolation, further suggests that selective sweeps could regularly excise ancestral mitochondrial polymorphisms.
Conclusions
These findings confirm the efficacy of species delimitation in birds via DNA barcodes, even when tested on a global scale. Further, they demonstrate how large libraries of a standardized gene region provide insight into evolutionary processes.
DNA barcoding taxon identification using a standardized DNA region has received much attention recently, and is being further developed through an international initiative. We anticipate that DNA barcoding techniques will be increasingly used by ecologists. They will be able to not only identify a single species from a specimen or an organism's remains but also determine the species composition of environmental samples. Short DNA fragments persist in the environment and might allow an assessment of local biodiversity from soil or water. Even DNA-based diet composition can be estimated using fecal samples. Here we review the new avenues offered to ecologists by DNA barcoding, particularly in the context of new sequencing technologies.
FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.
FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.
FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.
FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.
FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.
Dracunculus insignis is a nematode parasite that infects the subcutaneous tissues of mammals such as raccoon (Procyon lotor), mink (Neovison vison) and fisher (Martes pennanti). D. lutrae, a morphologically similar species, has only been recovered from the otter (Lontra canadensis). Species identification of these two North American guinea worms has only been achieved by morphology of males and host identity. As a result, where only female specimens are present, accurate identifications are not possible. To date, specimens recovered from otter have been assumed to be D. lutrae, while those from all other hosts are assumed to be D. insignis. This study uses DNA barcoding to differentiate between these two North American dracunculoids. Our results show that D. insignis is a 'true' generalist, showing little sequence divergence regardless of host association, although our studies did validate its occurrence in a new host 2014 the otter. Interestingly, specimens of the host specialist, D. lutrae, showed some sequence divergence, although it was low. The finding of D. insignis in otter substantiates the need to supplement morphology-based methods in providing species identifications for certain dracunculoids.
Dracunculus insignis is a nematode parasite that infects the subcutaneous tissues of mammals such as raccoon (Procyon lotor), mink (Neovison vison) and fisher (Martes pennanti). D. lutrae, a morphologically similar species, has only been recovered from the otter (Lontra canadensis). Species identification of these two North American guinea worms has only been achieved by morphology of males and host identity. As a result, where only female specimens are present, accurate identifications are not possible. To date, specimens recovered from otter have been assumed to be D. lutrae, while those from all other hosts are assumed to be D. insignis. This study uses DNA barcoding to differentiate between these two North American dracunculoids. Our results show that D. insignis is a 'true' generalist, showing little sequence divergence regardless of host association, although our studies did validate its occurrence in a new host 2014 the otter. Interestingly, specimens of the host specialist, D. lutrae, showed some sequence divergence, although it was low. The finding of D. insignis in otter substantiates the need to supplement morphology-based methods in providing species identifications for certain dracunculoids.
Dracunculus insignis is a nematode parasite that infects the subcutaneous tissues of mammals such as raccoon (Procyon lotor), mink (Neovison vison) and fisher (Martes pennanti). D. lutrae, a morphologically similar species, has only been recovered from the otter (Lontra canadensis). Species identification of these two North American guinea worms has only been achieved by morphology of males and host identity. As a result, where only female specimens are present, accurate identifications are not possible. To date, specimens recovered from otter have been assumed to be D. lutrae, while those from all other hosts are assumed to be D. insignis. This study uses DNA barcoding to differentiate between these two North American dracunculoids. Our results show that D. insignis is a 'true' generalist, showing little sequence divergence regardless of host association, although our studies did validate its occurrence in a new host 2014 the otter. Interestingly, specimens of the host specialist, D. lutrae, showed some sequence divergence, although it was low. The finding of D. insignis in otter substantiates the need to supplement morphology-based methods in providing species identifications for certain dracunculoids.
Dracunculus insignis is a nematode parasite that infects the subcutaneous tissues of mammals such as raccoon (Procyon lotor), mink (Neovison vison) and fisher (Martes pennanti). D. lutrae, a morphologically similar species, has only been recovered from the otter (Lontra canadensis). Species identification of these two North American guinea worms has only been achieved by morphology of males and host identity. As a result, where only female specimens are present, accurate identifications are not possible. To date, specimens recovered from otter have been assumed to be D. lutrae, while those from all other hosts are assumed to be D. insignis. This study uses DNA barcoding to differentiate between these two North American dracunculoids. Our results show that D. insignis is a 'true' generalist, showing little sequence divergence regardless of host association, although our studies did validate its occurrence in a new host 2014 the otter. Interestingly, specimens of the host specialist, D. lutrae, showed some sequence divergence, although it was low. The finding of D. insignis in otter substantiates the need to supplement morphology-based methods in providing species identifications for certain dracunculoids.
Geneticists are using the building blocks of life to combat a horrific illegal trade. For more information on this article, please click here.
Geneticists are using the building blocks of life to combat a horrific illegal trade. For more information on this article, please click here.
Fisheries managers and scientists worldwide are struggling with a lack of basic information for many shark and ray species. One factor hampering the data collection is inaccurate identification of many chondrichthyan species and their body parts. Morphologically similar species, and specimens which are poorly preserved or have had key diagnostic features removed, can be difficult to identify. This study examined DNA barcoding as a method to identify shark species from dried fins, confiscated from a vessel fishing illegally in Australian waters. 211 left pectoral fins were examined. 18 either did not provide a sequenceable product or yielded a microbial sequence, while 193 fins (91.5%) provided a chondrichthyan sequence. All of these could be matched to reference specimens in a DNA barcode database, and so were able to be identified. 27 species were detected, 20 species of sharks and seven species of rays The most abundant species (22% of fins) was Carcharhinus dussumieri. Many of these species are listed on the World Conservation Union (IUCN) Red List and include one, Anoyxpristis cuspidata (3%), rated as critically endangered. Fishing authorities can use DNA barcoding to gather data on which chondrichthyan species are targeted by illegal fishers, information that will greatly assist in management and conservation.
Fisheries managers and scientists worldwide are struggling with a lack of basic information for many shark and ray species. One factor hampering the data collection is inaccurate identification of many chondrichthyan species and their body parts. Morphologically similar species, and specimens which are poorly preserved or have had key diagnostic features removed, can be difficult to identify. This study examined DNA barcoding as a method to identify shark species from dried fins, confiscated from a vessel fishing illegally in Australian waters. 211 left pectoral fins were examined. 18 either did not provide a sequenceable product or yielded a microbial sequence, while 193 fins (91.5%) provided a chondrichthyan sequence. All of these could be matched to reference specimens in a DNA barcode database, and so were able to be identified. 27 species were detected, 20 species of sharks and seven species of rays The most abundant species (22% of fins) was Carcharhinus dussumieri. Many of these species are listed on the World Conservation Union (IUCN) Red List and include one, Anoyxpristis cuspidata (3%), rated as critically endangered. Fishing authorities can use DNA barcoding to gather data on which chondrichthyan species are targeted by illegal fishers, information that will greatly assist in management and conservation.
Fisheries managers and scientists worldwide are struggling with a lack of basic information for many shark and ray species. One factor hampering the data collection is inaccurate identification of many chondrichthyan species and their body parts. Morphologically similar species, and specimens which are poorly preserved or have had key diagnostic features removed, can be difficult to identify. This study examined DNA barcoding as a method to identify shark species from dried fins, confiscated from a vessel fishing illegally in Australian waters. 211 left pectoral fins were examined. 18 either did not provide a sequenceable product or yielded a microbial sequence, while 193 fins (91.5%) provided a chondrichthyan sequence. All of these could be matched to reference specimens in a DNA barcode database, and so were able to be identified. 27 species were detected, 20 species of sharks and seven species of rays The most abundant species (22% of fins) was Carcharhinus dussumieri. Many of these species are listed on the World Conservation Union (IUCN) Red List and include one, Anoyxpristis cuspidata (3%), rated as critically endangered. Fishing authorities can use DNA barcoding to gather data on which chondrichthyan species are targeted by illegal fishers, information that will greatly assist in management and conservation.
Fisheries managers and scientists worldwide are struggling with a lack of basic information for many shark and ray species. One factor hampering the data collection is inaccurate identification of many chondrichthyan species and their body parts. Morphologically similar species, and specimens which are poorly preserved or have had key diagnostic features removed, can be difficult to identify. This study examined DNA barcoding as a method to identify shark species from dried fins, confiscated from a vessel fishing illegally in Australian waters. 211 left pectoral fins were examined. 18 either did not provide a sequenceable product or yielded a microbial sequence, while 193 fins (91.5%) provided a chondrichthyan sequence. All of these could be matched to reference specimens in a DNA barcode database, and so were able to be identified. 27 species were detected, 20 species of sharks and seven species of rays The most abundant species (22% of fins) was Carcharhinus dussumieri. Many of these species are listed on the World Conservation Union (IUCN) Red List and include one, Anoyxpristis cuspidata (3%), rated as critically endangered. Fishing authorities can use DNA barcoding to gather data on which chondrichthyan species are targeted by illegal fishers, information that will greatly assist in management and conservation.
ABSTRACT: BACKGROUND: We compared here the suitability and efficacy of traditional morphological approach and DNA barcoding to distinguish filarioid nematodes species (Nematoda, Spirurida). A reliable and rapid taxonomic identification of these parasites is the basis for a correct diagnosis of important and widespread parasitic diseases. The performance of DNA barcoding with different parameters was compared measuring the strength of correlation between morphological and molecular identification approaches. Molecular distance estimation was performed with two different mitochondrial markers (coxI and 12S rDNA) and different combinations of data handling were compared in order to provide a stronger tool for easy identification of filarioid worms. RESULTS: DNA barcoding and morphology based identification of filarioid nematodes revealed high coherence. Despite both coxI and 12S rDNA allow to reach high-quality performances, only coxI revealed to be manageable. Both alignment algorithm, gaps treatment, and the criteria used to define the threshold value were found to affect the performance of DNA barcoding with 12S rDNA marker. Using coxI and a defined level of nucleotide divergence to delimit species boundaries, DNA barcoding can also be used to infer potential new species. CONCLUSIONS: An integrated approach allows to reach a higher discrimination power. The results clearly show where DNA-based and morphological identifications are consistent, and where they are not. The coherence between DNA-based and morphological identification for almost all the species examined in our work is very strong. We propose DNA barcoding as a reliable, consistent, and democratic tool for species discrimination in routine identification of parasitic nematodes.
The freshwater fish fauna of Mexico and Guatemala is exceptionally diverse with >600 species, many endemic. In this study, patterns of sequence divergence were analysed in representatives of this fauna using cytochrome c oxidase subunit 1 (COI) DNA barcodes for 61 species in 36 genera. The average divergence among conspecific individuals was 0·45%, while congeneric taxa showed 5·1% divergence. Three species of Poblana, each occupying a different crater lake in the arid regions of Central Mexico, have had a controversial taxonomic history but are usually regarded as endemics to a single lake. They possess identical COI barcodes, suggesting a very recent history of isolation. Representatives of the Cichlidae, a complex and poorly understood family, were well discriminated by barcodes. Many species of Characidae seem to be young, with low divergence values (<2%), but nevertheless, clear barcode clusters were apparent in the Bramocharax2013Astyanax complex. The symbranchid, Opisthernon aenigmaticum, has been regarded as a single species ranging from Guatemala to Mexico, but it includes two deeply divergent barcode lineages, one a possible new endemic species. Aside from these special cases, the results confirm that DNA barcodes will be highly effective in discriminating freshwater fishes from Central America and that a comprehensive analysis will provide new important insights for understanding diversity of this fauna.
The freshwater fish fauna of Mexico and Guatemala is exceptionally diverse with >600 species, many endemic. In this study, patterns of sequence divergence were analysed in representatives of this fauna using cytochrome c oxidase subunit 1 (COI) DNA barcodes for 61 species in 36 genera. The average divergence among conspecific individuals was 0·45%, while congeneric taxa showed 5·1% divergence. Three species of Poblana, each occupying a different crater lake in the arid regions of Central Mexico, have had a controversial taxonomic history but are usually regarded as endemics to a single lake. They possess identical COI barcodes, suggesting a very recent history of isolation. Representatives of the Cichlidae, a complex and poorly understood family, were well discriminated by barcodes. Many species of Characidae seem to be young, with low divergence values (<2%), but nevertheless, clear barcode clusters were apparent in the Bramocharax2013Astyanax complex. The symbranchid, Opisthernon aenigmaticum, has been regarded as a single species ranging from Guatemala to Mexico, but it includes two deeply divergent barcode lineages, one a possible new endemic species. Aside from these special cases, the results confirm that DNA barcodes will be highly effective in discriminating freshwater fishes from Central America and that a comprehensive analysis will provide new important insights for understanding diversity of this fauna.
Anthidium manicatum (L.) is an adventive species of European origin first recorded in North America in the late 1960’s; from that point until 2001 its range on the continent was restricted to the northeast central USA and central Canada (Ontario, more recently Que´bec). In 2005, this species was reported from Nova Scotia, a rapid and wide increase in its distribution. In this paper, we document a similar rapid spread of A. manicatum into western North America, including British Columbia and Idaho, and discuss the potential risks of this species in eastern Canada. In addition, the potential of DNA barcoding as a rapid and reliable means of recognizing adventive bee species is advocated.
The freshwater fish fauna of Mexico and Guatemala is exceptionally diverse with >600 species, many endemic. In this study, patterns of sequence divergence were analysed in representatives of this fauna using cytochrome c oxidase subunit 1 (COI) DNA barcodes for 61 species in 36 genera. The average divergence among conspecific individuals was 0·45%, while congeneric taxa showed 5·1% divergence. Three species of Poblana, each occupying a different crater lake in the arid regions of Central Mexico, have had a controversial taxonomic history but are usually regarded as endemics to a single lake. They possess identical COI barcodes, suggesting a very recent history of isolation. Representatives of the Cichlidae, a complex and poorly understood family, were well discriminated by barcodes. Many species of Characidae seem to be young, with low divergence values (<2%), but nevertheless, clear barcode clusters were apparent in the Bramocharax2013Astyanax complex. The symbranchid, Opisthernon aenigmaticum, has been regarded as a single species ranging from Guatemala to Mexico, but it includes two deeply divergent barcode lineages, one a possible new endemic species. Aside from these special cases, the results confirm that DNA barcodes will be highly effective in discriminating freshwater fishes from Central America and that a comprehensive analysis will provide new important insights for understanding diversity of this fauna.
The freshwater fish fauna of Mexico and Guatemala is exceptionally diverse with >600 species, many endemic. In this study, patterns of sequence divergence were analysed in representatives of this fauna using cytochrome c oxidase subunit 1 (COI) DNA barcodes for 61 species in 36 genera. The average divergence among conspecific individuals was 0·45%, while congeneric taxa showed 5·1% divergence. Three species of Poblana, each occupying a different crater lake in the arid regions of Central Mexico, have had a controversial taxonomic history but are usually regarded as endemics to a single lake. They possess identical COI barcodes, suggesting a very recent history of isolation. Representatives of the Cichlidae, a complex and poorly understood family, were well discriminated by barcodes. Many species of Characidae seem to be young, with low divergence values (<2%), but nevertheless, clear barcode clusters were apparent in the Bramocharax2013Astyanax complex. The symbranchid, Opisthernon aenigmaticum, has been regarded as a single species ranging from Guatemala to Mexico, but it includes two deeply divergent barcode lineages, one a possible new endemic species. Aside from these special cases, the results confirm that DNA barcodes will be highly effective in discriminating freshwater fishes from Central America and that a comprehensive analysis will provide new important insights for understanding diversity of this fauna.
Anthidium manicatum (L.) is an adventive species of European origin first recorded in North America in the late 1960’s; from that point until 2001 its range on the continent was restricted to the northeast central USA and central Canada (Ontario, more recently Que´bec). In 2005, this species was reported from Nova Scotia, a rapid and wide increase in its distribution. In this paper, we document a similar rapid spread of A. manicatum into western North America, including British Columbia and Idaho, and discuss the potential risks of this species in eastern Canada. In addition, the potential of DNA barcoding as a rapid and reliable means of recognizing adventive bee species is advocated.
Details of the phylogenetic relationships among tetrahymenine ciliates remain unresolved despite a rich history of investigation with nuclear gene sequences and other characters. We examined all available species of Tetrahymena and three other tetrahymenine ciliates, and inferred their phylogenetic relationships using nearly complete mitochondrial cytochrome c oxidase subunit 1 (cox1) and small subunit (SSU) rRNA gene sequences. The inferred phylogenies showed the genus Tetrahymena to be monophyletic. The three "classical" morphology-and-ecology-based groupings are paraphyletic. The SSUrRNA phylogeny confirmed the previously established australis and borealis groupings, and nine ribosets. However, these nine ribosets were not well supported. Using cox1 gene, the deduced phylogenies based on this gene revealed 12 well supported groupings, called coxisets, which mostly corresponded to the nine ribosets. This study demonstrated the utility of cox1 for resolving the recent phylogeny of Tetrahymena, whereas the SSU rRNA gene provided resolution of deeper phylogenetic relationships within the genus.
The relative rates of nucleotide substitution at synonymous and nonsynonymous sites within protein-coding regions have been widely used to infer the action of natural selection from comparative sequence data. It is known, however, that mutational and repair biases can affect rates of evolution at both synonymous and nonsynonymous sites. More importantly, it is also known that synonymous sites are particularly prone to the effects of nucleotide bias. This means that nucleotide biases may affect the calculated ratio of substitution rates at synonymous and nonsynonymous sites. Using a large data set of animal mitochondrial sequences, we demonstrate that this is, in fact, the case. Highly biased nucleotide sequences are characterized by significantly elevated dN/dS ratios, but only when the nucleotide frequencies are not taken into account. When the analysis is repeated taking the nucleotide frequencies at each codon position into account, such elevated ratios disappear. These results suggest that the recently reported differences in dN/dS ratios between vertebrate and invertebrate mitochondrial sequences could be explained by variations in mitochondrial nucleotide frequencies rather than the effects of positive Darwinian selection.
Details of the phylogenetic relationships among tetrahymenine ciliates remain unresolved despite a rich history of investigation with nuclear gene sequences and other characters. We examined all available species of Tetrahymena and three other tetrahymenine ciliates, and inferred their phylogenetic relationships using nearly complete mitochondrial cytochrome c oxidase subunit 1 (cox1) and small subunit (SSU) rRNA gene sequences. The inferred phylogenies showed the genus Tetrahymena to be monophyletic. The three "classical" morphology-and-ecology-based groupings are paraphyletic. The SSUrRNA phylogeny confirmed the previously established australis and borealis groupings, and nine ribosets. However, these nine ribosets were not well supported. Using cox1 gene, the deduced phylogenies based on this gene revealed 12 well supported groupings, called coxisets, which mostly corresponded to the nine ribosets. This study demonstrated the utility of cox1 for resolving the recent phylogeny of Tetrahymena, whereas the SSU rRNA gene provided resolution of deeper phylogenetic relationships within the genus.
The relative rates of nucleotide substitution at synonymous and nonsynonymous sites within protein-coding regions have been widely used to infer the action of natural selection from comparative sequence data. It is known, however, that mutational and repair biases can affect rates of evolution at both synonymous and nonsynonymous sites. More importantly, it is also known that synonymous sites are particularly prone to the effects of nucleotide bias. This means that nucleotide biases may affect the calculated ratio of substitution rates at synonymous and nonsynonymous sites. Using a large data set of animal mitochondrial sequences, we demonstrate that this is, in fact, the case. Highly biased nucleotide sequences are characterized by significantly elevated dN/dS ratios, but only when the nucleotide frequencies are not taken into account. When the analysis is repeated taking the nucleotide frequencies at each codon position into account, such elevated ratios disappear. These results suggest that the recently reported differences in dN/dS ratios between vertebrate and invertebrate mitochondrial sequences could be explained by variations in mitochondrial nucleotide frequencies rather than the effects of positive Darwinian selection.
Lepetodrilid limpets are common inhabitants of deep-sea hydrothermal vents worldwide, but the frequent occurrence of morphologically cryptic species makes their identification very difficult. To facilitate these identifications, we provide DNA barcodes based on 1,000 bp of cytochrome-c-oxidase subunit I (COI), for 20 taxa within the genus Lepetodrilus. The method was also used to identify lepetodrilids that were found living on vent decapods. A preliminary phylogenetic analysis resolved relationships among members of several cryptic species complexes; however, COI sequences alone were unable to resolve higher-level systematic relationships caused by saturation of synonymous nucleotide substitutions.
Morphologic and phylogenetic analysis of freshwater sponges endemic to lakes in Central Sulawesi, Siberia and South-East Europe is presented. We also analyzed several cosmopolitan sponge species from Eurasia and North America and included sponge sequences from public databases. In agreement with previous reports [Addis, J.S., Peterson, K.J., 2005. Phylogenetic relationships of freshwater sponges (Porifera, Spongillina) inferred from analyses of 18S rDNA, COI mtDNA, and ITS2 rDNA sequences. Zool. Scr. 34, 549-557], the metaniid sponge Corvomeyenia sp. was the most deeply branching species within a monophyletic lineage of the suborder Spongillina. Pachydictyum globosum (Malawispongiidae) and Nudospongilla vasta (Spongillidae), two morphologically quite distinct species from Sulawesi were found in a joint clade with Trochospongilla (Spongillidae) rendering Trochospongilla paraphyletic. Furthermore, Ochridaspongia sp., another Malawispongiidae, clustered far away from that clade, together with Ephydatia fluviatilis, making the latter family polyphyletic. The Lubomirskiidae endemic to Lake Baikal, Lubomirskia abietina, Baikalospongia bacillifera, B. intermedia, and Swartschewskia papyracea formed a well-supported clade that was most closely linked to the genus Ephydatia (99.9% identity over a total length of 2169 concatenated nucleotide positions). Our study indicates the frequent and independent origin of sponge species endemic to different freshwater ecosystems from a few cosmopolitan founder species. The highly specific primer sets newly developed here facilitate work on the molecular phylogeny and DNA barcoding of sponges.
The Consortium for the Barcode of Life organized a workshop on the topic of "Access and Benefit Sharing in Non-commercial Biodiversity Research" that was held at the Museum Koenig in Bonn, Germany, on 6-9 November 2008. The workshop was co-sponsored by nine other national agencies and international scientific organizations that are involved in biodiversity research and the Convention on Biological Diversity.
BACKGROUND: Pythium species are an agriculturally important genus of plant pathogens, yet are not understood well at the molecular, genetic, or genomic level. They are closely related to other oomycete plant pathogens such as Phytophthora species and are ubiquitous in their geographic distribution and host rage. To gain a better understanding of its gene complement, we generated Expressed Sequence Tags (ESTs) from the transcriptome of Pythium ultimum DAOM BR144 (= ATCC 200006 = CBS 805.95) using two high throughput sequencing methods, Sanger-based chain termination sequencing and pyrosequencing-based sequencing-by-synthesis. RESULTS: A single half-plate pyrosequencing (454 FLX) run on adapter-ligated cDNA from a normalized cDNA population generated 90,664 reads with an average read length of 190 nucleotides following cleaning and removal of sequences shorter than 100 base pairs. After clustering and assembly, a total of 35,507 unique sequences were generated. In parallel, 9,578 reads were generated from a library constructed from the same normalized cDNA population using dideoxy chain termination Sanger sequencing, which upon clustering and assembly generated 4,689 unique sequences. A hybrid assembly of both Sanger- and pyrosequencing-derived ESTs resulted in 34,495 unique sequences with 1,110 sequences (3.2%) that were solely derived from Sanger sequencing alone. A high degree of similarity was seen between P. ultimum sequences and other sequenced plant pathogenic oomycetes with 91% of the hybrid assembly derived sequences > 500 bp having similarity to sequences from plant pathogenic Phytophthora species. An analysis of Gene Ontology assignments revealed a similar representation of molecular function ontologies in the hybrid assembly in comparison to the predicted proteomes of three Phytophthora species, suggesting a broad representation of the P. ultimum transcriptome was present in the normalized cDNA population. P. ultimum sequences with similarity to oomycete RXLR and Crinkler effectors, Kazal-like and cystatin-like protease inhibitors, and elicitins were identified. Sequences with similarity to thiamine biosynthesis enzymes that are lacking in the genome sequences of three Phytophthora species and one downy mildew were identified and could serve as useful phylogenetic markers. Furthermore, we identified 179 candidate simple sequence repeats that can be used for genotyping strains of P. ultimum. CONCLUSION: Through these two technologies, we were able to generate a robust set (approximately 10 Mb) of transcribed sequences for P. ultimum. We were able to identify known sequences present in oomycetes as well as identify novel sequences. An ample number of candidate polymorphic markers were identified in the dataset providing resources for phylogenetic and diagnostic marker development for this species. On a technical level, in spite of the depth possible with 454 FLX platform, the Sanger and pyro-based sequencing methodologies were complementary as each method generated sequences unique to each platform.
BACKGROUND: Pythium species are an agriculturally important genus of plant pathogens, yet are not understood well at the molecular, genetic, or genomic level. They are closely related to other oomycete plant pathogens such as Phytophthora species and are ubiquitous in their geographic distribution and host rage. To gain a better understanding of its gene complement, we generated Expressed Sequence Tags (ESTs) from the transcriptome of Pythium ultimum DAOM BR144 (= ATCC 200006 = CBS 805.95) using two high throughput sequencing methods, Sanger-based chain termination sequencing and pyrosequencing-based sequencing-by-synthesis. RESULTS: A single half-plate pyrosequencing (454 FLX) run on adapter-ligated cDNA from a normalized cDNA population generated 90,664 reads with an average read length of 190 nucleotides following cleaning and removal of sequences shorter than 100 base pairs. After clustering and assembly, a total of 35,507 unique sequences were generated. In parallel, 9,578 reads were generated from a library constructed from the same normalized cDNA population using dideoxy chain termination Sanger sequencing, which upon clustering and assembly generated 4,689 unique sequences. A hybrid assembly of both Sanger- and pyrosequencing-derived ESTs resulted in 34,495 unique sequences with 1,110 sequences (3.2%) that were solely derived from Sanger sequencing alone. A high degree of similarity was seen between P. ultimum sequences and other sequenced plant pathogenic oomycetes with 91% of the hybrid assembly derived sequences > 500 bp having similarity to sequences from plant pathogenic Phytophthora species. An analysis of Gene Ontology assignments revealed a similar representation of molecular function ontologies in the hybrid assembly in comparison to the predicted proteomes of three Phytophthora species, suggesting a broad representation of the P. ultimum transcriptome was present in the normalized cDNA population. P. ultimum sequences with similarity to oomycete RXLR and Crinkler effectors, Kazal-like and cystatin-like protease inhibitors, and elicitins were identified. Sequences with similarity to thiamine biosynthesis enzymes that are lacking in the genome sequences of three Phytophthora species and one downy mildew were identified and could serve as useful phylogenetic markers. Furthermore, we identified 179 candidate simple sequence repeats that can be used for genotyping strains of P. ultimum. CONCLUSION: Through these two technologies, we were able to generate a robust set (approximately 10 Mb) of transcribed sequences for P. ultimum. We were able to identify known sequences present in oomycetes as well as identify novel sequences. An ample number of candidate polymorphic markers were identified in the dataset providing resources for phylogenetic and diagnostic marker development for this species. On a technical level, in spite of the depth possible with 454 FLX platform, the Sanger and pyro-based sequencing methodologies were complementary as each method generated sequences unique to each platform.
A 658-bp fragment of mitochondrial DNA from the 5' region of the mitochondrial cytochrome c oxidase 1 (COI) gene has been adopted as the standard DNA barcode region for animal life. In this study, we test its effectiveness in the discrimination of over 300 species of aphids from more than 130 genera. Most (96%) species were well differentiated, and sequence variation within species was low, averaging just 0.2%. Despite the complex life cycles and parthenogenetic reproduction of aphids, DNA barcodes are an effective tool for identification.
Two species complexes within the genus Xylophanes are addressed using a combination of morphological study and analysis of DNA barcode sequences. The existence of two and three cryptic species respectively within the X. loelia and X. neoptolemus complexes is revealed following consideration of both adult habitus and genital morphology, and the results of a phylogenetic analysis of partial COI sequences—DNA barcodes—for 38 specimens. The taxonomic status of the available names is discussed and to clarify and stabilize the confused nomenclature of this group, a neotype for Sphinx neoptolemus Cramer, 1780, and lectotypes for Choerocampa loelia Druce, 1878 and Chaerocampa trilineata Walker, [1865], are designated. We describe three new species: X. lolita n. sp. Vaglia and Haxaire; X. balcazari n. sp. Haxaire and Vaglia; and X. cthulhu n. sp. Haxaire and Vaglia. The first is endemic to southeastern Brazil and closely allied to X. loelia; the second two are relatives of X. neoptolemus, of which the first is known only from Guerrero and Michoacán states in Mexico while the second is widely distributed in lowland forests of Central America.
A new species of Dipturus is described from ten specimens collected off Patagonia, Argentina. Morphological and molecular approaches were used to compare among specimens of recognized Dipturus species. By comparing morphometric, meristic and mitochondrial cytochrome c oxidase I (COI) sequence data, specimens referred to as longnose skate and originally regarded as D. chilensis were shown to be a discrete species as distinguished from both the Yellownose skate, D. chilensis and the Roughskin skate, D. trachyderma. Dipturus argentinensis n. sp. can be distinguished from all other southwestern Atlantic longnose skate species by its color pattern, lack of squamation on both upper and lower surfaces of the disc, and a long, thin tail that is approximately half the total length. The new species has one median row of 10 to 24 small caudal thorns, one or two interdorsal thorns and 35 to 40, and 34 to 43 tooth rows on upper and lower jaws, respectively. The 648 base pair COI mitochondrial DNA “barcodes” derived from specimens of D. argentinensis are identical to each other and exhibit greater than 3% sequence divergence from all other Dipturus species similarly characterized to date. Taken together, these independent morphological and molecular observations serve to corroborate one another and thus provide strong evidence for the recognition of D. argentinensis as a new species
A new species of Dipturus is described from ten specimens collected off Patagonia, Argentina. Morphological and molecular approaches were used to compare among specimens of recognized Dipturus species. By comparing morphometric, meristic and mitochondrial cytochrome c oxidase I (COI) sequence data, specimens referred to as longnose skate and originally regarded as D. chilensis were shown to be a discrete species as distinguished from both the Yellownose skate, D. chilensis and the Roughskin skate, D. trachyderma. Dipturus argentinensis n. sp. can be distinguished from all other southwestern Atlantic longnose skate species by its color pattern, lack of squamation on both upper and lower surfaces of the disc, and a long, thin tail that is approximately half the total length. The new species has one median row of 10 to 24 small caudal thorns, one or two interdorsal thorns and 35 to 40, and 34 to 43 tooth rows on upper and lower jaws, respectively. The 648 base pair COI mitochondrial DNA “barcodes” derived from specimens of D. argentinensis are identical to each other and exhibit greater than 3% sequence divergence from all other Dipturus species similarly characterized to date. Taken together, these independent morphological and molecular observations serve to corroborate one another and thus provide strong evidence for the recognition of D. argentinensis as a new species
Two new species of Hemileucinae are described from the region of Muzo (Boyaca department) in the Eastern Cordillera of Colombia. Leucanella bonillensis, new species, is a small greyish species whose closest relatives are L. newmani (Lemaire) and L. acutissima (Walker). It can be distinguished from those two species by several subtle differences in wing pattern and coloration as well as a few characters of the male genitalia, which are overall very conserved within the genus. Cerodirphia zulemae, new species, belongs to the very uniform species-group of C. speciosa (Cramer), characterised by a pink ground colour and the presence of a “Y”-shaped discal mark on the forewing. Based on its male genitalia, the new species is related to C. brunnea (Draudt) and C. apunctata Dias & Lemaire. It may be distinguished from the former by its more vivid ground colour, but detailed examination of the male genitalia are necessary to differentiate it from C. apunctata. Colour pictures of the habitus of the new species and their relatives are provided, and their genital structures are figured as well, including both sexes for C. zulemae. We also provide additional support to these descriptions based on genetic data obtained in the context of a global DNA barcoding campaign recently initiated for saturniid moths. Both L. bonillensis and C. zulemae are unambiguously distinguished from closest relatives based on genetic distances (no intraspecific distances in either case; interspecific distance ranges 5.6–6.6% and 6.7–12.5%, respectively) and inference of phylogenetic hypotheses based on partial sequences of the COI mitochondrial gene. These results emphasize the potential of DNA barcoding to support taxonomic work in species-groups considered difficult to address through morphology.
A 658-bp fragment of mitochondrial DNA from the 5' region of the mitochondrial cytochrome c oxidase 1 (COI) gene has been adopted as the standard DNA barcode region for animal life. In this study, we test its effectiveness in the discrimination of over 300 species of aphids from more than 130 genera. Most (96%) species were well differentiated, and sequence variation within species was low, averaging just 0.2%. Despite the complex life cycles and parthenogenetic reproduction of aphids, DNA barcodes are an effective tool for identification.
A 658-bp fragment of mitochondrial DNA from the 5' region of the mitochondrial cytochrome c oxidase 1 (COI) gene has been adopted as the standard DNA barcode region for animal life. In this study, we test its effectiveness in the discrimination of over 300 species of aphids from more than 130 genera. Most (96%) species were well differentiated, and sequence variation within species was low, averaging just 0.2%. Despite the complex life cycles and parthenogenetic reproduction of aphids, DNA barcodes are an effective tool for identification.
A 658-bp fragment of mitochondrial DNA from the 5' region of the mitochondrial cytochrome c oxidase 1 (COI) gene has been adopted as the standard DNA barcode region for animal life. In this study, we test its effectiveness in the discrimination of over 300 species of aphids from more than 130 genera. Most (96%) species were well differentiated, and sequence variation within species was low, averaging just 0.2%. Despite the complex life cycles and parthenogenetic reproduction of aphids, DNA barcodes are an effective tool for identification.
A new species of Dipturus is described from ten specimens collected off Patagonia, Argentina. Morphological and molecular approaches were used to compare among specimens of recognized Dipturus species. By comparing morphometric, meristic and mitochondrial cytochrome c oxidase I (COI) sequence data, specimens referred to as longnose skate and originally regarded as D. chilensis were shown to be a discrete species as distinguished from both the Yellownose skate, D. chilensis and the Roughskin skate, D. trachyderma. Dipturus argentinensis n. sp. can be distinguished from all other southwestern Atlantic longnose skate species by its color pattern, lack of squamation on both upper and lower surfaces of the disc, and a long, thin tail that is approximately half the total length. The new species has one median row of 10 to 24 small caudal thorns, one or two interdorsal thorns and 35 to 40, and 34 to 43 tooth rows on upper and lower jaws, respectively. The 648 base pair COI mitochondrial DNA “barcodes” derived from specimens of D. argentinensis are identical to each other and exhibit greater than 3% sequence divergence from all other Dipturus species similarly characterized to date. Taken together, these independent morphological and molecular observations serve to corroborate one another and thus provide strong evidence for the recognition of D. argentinensis as a new species
MEEGID IX, University of California at Irvine, 30 October - 1 November 2008
Communications on genetics, genomics, proteomics, phylogenetics, population biology, mathematical modeling, and bioinformatics are welcome. They can report on the host, the pathogen, or the vector for vector-borne diseases. Papers considering host + pathogen or pathogen + vector (co-evolution) are particularly encouraged. All pathogens are within the scope of MEEGID: viruses, parasitic protozoa, helminths, fungal organisms, and prions. All infectious models can be explored, including those of veterinary or agronomical relevance.
SYMPOSIUM ON DNA BARCODING
Speakers interested in presenting on applications of DNA barcoding (hosts, pathogens, vectors) in molecular epidemiology and infectious disease research at the 9th International Meeting "Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases" (MEEGID IX), held at UC Irvine, California, should contact the convenor, Sergios-Orestis Kolokotronis (koloko@amnh.org) with a CC to the principal organizer, Michel Tibayrenc (Michel.Tibayrenc@ird.fr) by 15 September.
MEEGID IX, University of California at Irvine, 30 October - 1 November 2008
Communications on genetics, genomics, proteomics, phylogenetics, population biology, mathematical modeling, and bioinformatics are welcome. They can report on the host, the pathogen, or the vector for vector-borne diseases. Papers considering host + pathogen or pathogen + vector (co-evolution) are particularly encouraged. All pathogens are within the scope of MEEGID: viruses, parasitic protozoa, helminths, fungal organisms, and prions. All infectious models can be explored, including those of veterinary or agronomical relevance.
SYMPOSIUM ON DNA BARCODING
Speakers interested in presenting on applications of DNA barcoding (hosts, pathogens, vectors) in molecular epidemiology and infectious disease research at the 9th International Meeting "Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases" (MEEGID IX), held at UC Irvine, California, should contact the convenor, Sergios-Orestis Kolokotronis (koloko@amnh.org) with a CC to the principal organizer, Michel Tibayrenc (Michel.Tibayrenc@ird.fr) by 15 September.
A small group of insect researchers have invented a device to identify every creature on Earth. So why do other biologists hate the idea?
With the aim of developing widely applicable gene markers for phylogenetic reconstructions at low taxonomic level, we tested the low copy nuclear Conserved Ortholog Set (COS) genes. Most of the 15 genes tested provided good amplification efficiency (as compared with rbcL) from a set of 67 representative angiosperm families. Nine selected COS markers were further characterized at both intra- and interfamilial level on a test set, including 25 species representative of 15 different families. While four of the COS led to incongruent results, the remaining five improved the phylogenetic reconstructions of closely related species as illustrated in the case of Orobanchaceae species. They were found to be highly informative in phylogenetic reconstruction of congeneric species, where introns provide a higher proportion of parsimony informative sites in comparison with traditional phylogenetic markers such as ITS and matK. At higher phylogenetic distance, where only coding regions could be aligned, the polymorphism levels of the COS ranged between those of ndhF and matK. On the basis of these results, the success rate in developing universally amplifiable low copy nuclear markers based on COS genes is about 30%. We report the successful development of five pCOS that, together with a few other well characterized genes, such as Rpb2 and GbssI, can be considered the closest approximation to low-copy "universally" amplifiable markers for phylogeny in plants at present. The possible pitfalls of universally amplifiable COS marker development and their range of applicability at different taxonomic levels in comparison with traditional phylogenetic molecular markers are discussed. © The Willi Hennig Society 2008.
Inspired by commercial barcodes, DNA tags could provide a quick inexpensive way to identify species.
Two regions of mtDNA, cytochrome b and cytochrome c oxidase subunit 1, were sequenced in nine species of Bathyraja from the Southern Ocean and New Zealand. Based on sequence divergence, the species that has been referred to as Bathyraja eatonii from the Antarctic continental shelf and slope is a species distinct from B. eatonii from the Kerguelen Plateau (the type locality) and is a new and undescribed species Bathyraja sp. (cf. eatonii). There was no sequence divergence among samples of Bathyraja sp. (dwarf) from the Ross Sea and the South Atlantic. However, for both Bathyraja sp. (cf. eatonii) and Bathyraja maccaini in the Ross Sea and the South Atlantic Ocean, the DNA sequence divergences indicate differentiation among ocean basins and within Bathyraja sp. (cf. eatonii) divergences are similar to those among recognized species of Bathyraja in the North Pacific Ocean.
Seafood authentication and food safety concerns are a growing issue in today’s global marketplace, although traditional morphology-based identification keys and existing molecular approaches have limitations for species identification. Recently, DNA barcoding has gained support as a rapid, cost-effective and broadly applicable molecular diagnostic technique for this purpose. However, the maturity of the barcode database as a tool for seafood authentication has yet to be tested using real market samples. The present case study was undertaken for this reason. Though the database is undergoing continual development, it was able to provide species matches of >97% sequence similarity for 90 of 91 samples tested. Twenty-five percent of the samples were potentially mislabeled, demonstrating that DNA barcodes are already a powerful tool for the identification of seafood to the species level. We conclude that barcodes have broad applicability for authenticity testing and the phylogeographic patterning of genetic diversity can also inform aspects of traceability.
Seafood authentication and food safety concerns are a growing issue in today’s global marketplace, although traditional morphology-based identification keys and existing molecular approaches have limitations for species identification. Recently, DNA barcoding has gained support as a rapid, cost-effective and broadly applicable molecular diagnostic technique for this purpose. However, the maturity of the barcode database as a tool for seafood authentication has yet to be tested using real market samples. The present case study was undertaken for this reason. Though the database is undergoing continual development, it was able to provide species matches of >97% sequence similarity for 90 of 91 samples tested. Twenty-five percent of the samples were potentially mislabeled, demonstrating that DNA barcodes are already a powerful tool for the identification of seafood to the species level. We conclude that barcodes have broad applicability for authenticity testing and the phylogeographic patterning of genetic diversity can also inform aspects of traceability.
Seafood authentication and food safety concerns are a growing issue in today’s global marketplace, although traditional morphology-based identification keys and existing molecular approaches have limitations for species identification. Recently, DNA barcoding has gained support as a rapid, cost-effective and broadly applicable molecular diagnostic technique for this purpose. However, the maturity of the barcode database as a tool for seafood authentication has yet to be tested using real market samples. The present case study was undertaken for this reason. Though the database is undergoing continual development, it was able to provide species matches of >97% sequence similarity for 90 of 91 samples tested. Twenty-five percent of the samples were potentially mislabeled, demonstrating that DNA barcodes are already a powerful tool for the identification of seafood to the species level. We conclude that barcodes have broad applicability for authenticity testing and the phylogeographic patterning of genetic diversity can also inform aspects of traceability.
Inspired by commercial barcodes, DNA tags could provide a quick inexpensive way to identify species.
Seafood authentication and food safety concerns are a growing issue in today’s global marketplace, although traditional morphology-based identification keys and existing molecular approaches have limitations for species identification. Recently, DNA barcoding has gained support as a rapid, cost-effective and broadly applicable molecular diagnostic technique for this purpose. However, the maturity of the barcode database as a tool for seafood authentication has yet to be tested using real market samples. The present case study was undertaken for this reason. Though the database is undergoing continual development, it was able to provide species matches of >97% sequence similarity for 90 of 91 samples tested. Twenty-five percent of the samples were potentially mislabeled, demonstrating that DNA barcodes are already a powerful tool for the identification of seafood to the species level. We conclude that barcodes have broad applicability for authenticity testing and the phylogeographic patterning of genetic diversity can also inform aspects of traceability.
Seafood authentication and food safety concerns are a growing issue in today’s global marketplace, although traditional morphology-based identification keys and existing molecular approaches have limitations for species identification. Recently, DNA barcoding has gained support as a rapid, cost-effective and broadly applicable molecular diagnostic technique for this purpose. However, the maturity of the barcode database as a tool for seafood authentication has yet to be tested using real market samples. The present case study was undertaken for this reason. Though the database is undergoing continual development, it was able to provide species matches of >97% sequence similarity for 90 of 91 samples tested. Twenty-five percent of the samples were potentially mislabeled, demonstrating that DNA barcodes are already a powerful tool for the identification of seafood to the species level. We conclude that barcodes have broad applicability for authenticity testing and the phylogeographic patterning of genetic diversity can also inform aspects of traceability.
Large-scale sequencing of short mtDNA fragments for biodiversity inventories ('DNA barcoding') indicates that sequence variation in animal mtDNA is highly structured and partitioned into discrete genetic clusters that correspond broadly to species-level entities. Here we explore how the migration rate, an important demographic parameter that is directly related to population isolation, might affect variation in the strength of mtDNA clustering among taxa. Patterns of mtDNA variation were investigated in two groups of beetles that both contain lineages occupying habitats predicted to select for different dispersal abilities: predacious diving beetles (Dytiscidae) in the genus Bidessus from lotic and lentic habitats across Europe and darkling beetles (Tenebrionidae) in the genus Eutagenia from sand and other soil types in the Aegean Islands. The degree of genetic clustering was determined using the recently developed 'mixed Yule coalescent' (MYC) model that detects the transition from between-species to within-population branching patterns. Lineages from presumed stable habitats, and therefore displaying lower dispersal ability and migration rates, showed greater levels of mtDNA clustering and geographical subdivision than their close relatives inhabiting ephemeral habitats. Simulations of expected patterns of mtDNA variation under island models showed that MYC clusters are only detected when the migration rates are much lower than the value of Nm=1 typically used to define the threshold for neutral genetic divergence. Therefore, discrete mtDNA clusters provide strong evidence for independently evolving populations or species, but their formation is suppressed even under very low levels of dispersal.
The first African Fish Barcode of Life initiative (FISH-BOL) Regional Working Group workshop was hosted in association with the fourth Pan-African Fish and Fisheries Association (PAFFA) conference in Addis Ababa on the 21st of August 2008. The workshop was sponsored by the Consortium for the Barcode of Life (CBOL) in partnership with the South African Institute for Aquatic Biodiversity (SAIAB). The FISH-BOL African Regional Working Group, SAIAB and the PAFFA organizing committee organized the workshop. Most of the 25 participants were already active in FISH-BOL, but some new African regional working group partners from various research institutions were sponsored to represent the different African regions (see, Appendix 1, List of delegates).
The major objective of the meeting was to develop funding proposals for the collection of DNA barcodes for all African freshwater and marine fish species.
The first African Fish Barcode of Life initiative (FISH-BOL) Regional Working Group workshop was hosted in association with the fourth Pan-African Fish and Fisheries Association (PAFFA) conference in Addis Ababa on the 21st of August 2008. The workshop was sponsored by the Consortium for the Barcode of Life (CBOL) in partnership with the South African Institute for Aquatic Biodiversity (SAIAB). The FISH-BOL African Regional Working Group, SAIAB and the PAFFA organizing committee organized the workshop. Most of the 25 participants were already active in FISH-BOL, but some new African regional working group partners from various research institutions were sponsored to represent the different African regions (see, Appendix 1, List of delegates).
The major objective of the meeting was to develop funding proposals for the collection of DNA barcodes for all African freshwater and marine fish species.
The first African Fish Barcode of Life initiative (FISH-BOL) Regional Working Group workshop was hosted in association with the fourth Pan-African Fish and Fisheries Association (PAFFA) conference in Addis Ababa on the 21st of August 2008. The workshop was sponsored by the Consortium for the Barcode of Life (CBOL) in partnership with the South African Institute for Aquatic Biodiversity (SAIAB). The FISH-BOL African Regional Working Group, SAIAB and the PAFFA organizing committee organized the workshop. Most of the 25 participants were already active in FISH-BOL, but some new African regional working group partners from various research institutions were sponsored to represent the different African regions (see, Appendix 1, List of delegates).
The major objective of the meeting was to develop funding proposals for the collection of DNA barcodes for all African freshwater and marine fish species.
Background: The goal of DNA barcoding is to develop a species-specific sequence library for all eukaryotes. A 650 bp fragment of the cytochrome c oxidase 1 (CO1) gene has been used successfully for species-level identification in several animal groups. It may be difficult in practice, however, to retrieve a 650 bp fragment from archival specimens, (because of DNA degradation) or from environmental samples (where universal primers are needed).
Results: We used a bioinformatics analysis using all CO1 barcode sequences from GenBank and calculated the probability of having species-specific barcodes for varied size fragments. This analysis established the potential of much smaller fragments, mini-barcodes, for identifying unknown specimens. We then developed a universal primer set for the amplification of mini-barcodes. We further successfully tested the utility of this primer set on a comprehensive set of taxa from all major eukaryotic groups as well as archival specimens.
Conclusion: In this study we address the important issue of minimum amount of sequence information required for identifying species in DNA barcoding. We establish a novel approach based on a much shorter barcode sequence and demonstrate its effectiveness in archival specimens. This approach will significantly broaden the application of DNA barcoding in biodiversity studies.
Background: The goal of DNA barcoding is to develop a species-specific sequence library for all eukaryotes. A 650 bp fragment of the cytochrome c oxidase 1 (CO1) gene has been used successfully for species-level identification in several animal groups. It may be difficult in practice, however, to retrieve a 650 bp fragment from archival specimens, (because of DNA degradation) or from environmental samples (where universal primers are needed).
Results: We used a bioinformatics analysis using all CO1 barcode sequences from GenBank and calculated the probability of having species-specific barcodes for varied size fragments. This analysis established the potential of much smaller fragments, mini-barcodes, for identifying unknown specimens. We then developed a universal primer set for the amplification of mini-barcodes. We further successfully tested the utility of this primer set on a comprehensive set of taxa from all major eukaryotic groups as well as archival specimens.
Conclusion: In this study we address the important issue of minimum amount of sequence information required for identifying species in DNA barcoding. We establish a novel approach based on a much shorter barcode sequence and demonstrate its effectiveness in archival specimens. This approach will significantly broaden the application of DNA barcoding in biodiversity studies.
Background: The goal of DNA barcoding is to develop a species-specific sequence library for all eukaryotes. A 650 bp fragment of the cytochrome c oxidase 1 (CO1) gene has been used successfully for species-level identification in several animal groups. It may be difficult in practice, however, to retrieve a 650 bp fragment from archival specimens, (because of DNA degradation) or from environmental samples (where universal primers are needed).
Results: We used a bioinformatics analysis using all CO1 barcode sequences from GenBank and calculated the probability of having species-specific barcodes for varied size fragments. This analysis established the potential of much smaller fragments, mini-barcodes, for identifying unknown specimens. We then developed a universal primer set for the amplification of mini-barcodes. We further successfully tested the utility of this primer set on a comprehensive set of taxa from all major eukaryotic groups as well as archival specimens.
Conclusion: In this study we address the important issue of minimum amount of sequence information required for identifying species in DNA barcoding. We establish a novel approach based on a much shorter barcode sequence and demonstrate its effectiveness in archival specimens. This approach will significantly broaden the application of DNA barcoding in biodiversity studies.
Background: The goal of DNA barcoding is to develop a species-specific sequence library for all eukaryotes. A 650 bp fragment of the cytochrome c oxidase 1 (CO1) gene has been used successfully for species-level identification in several animal groups. It may be difficult in practice, however, to retrieve a 650 bp fragment from archival specimens, (because of DNA degradation) or from environmental samples (where universal primers are needed).
Results: We used a bioinformatics analysis using all CO1 barcode sequences from GenBank and calculated the probability of having species-specific barcodes for varied size fragments. This analysis established the potential of much smaller fragments, mini-barcodes, for identifying unknown specimens. We then developed a universal primer set for the amplification of mini-barcodes. We further successfully tested the utility of this primer set on a comprehensive set of taxa from all major eukaryotic groups as well as archival specimens.
Conclusion: In this study we address the important issue of minimum amount of sequence information required for identifying species in DNA barcoding. We establish a novel approach based on a much shorter barcode sequence and demonstrate its effectiveness in archival specimens. This approach will significantly broaden the application of DNA barcoding in biodiversity studies.
Background: The goal of DNA barcoding is to develop a species-specific sequence library for all eukaryotes. A 650 bp fragment of the cytochrome c oxidase 1 (CO1) gene has been used successfully for species-level identification in several animal groups. It may be difficult in practice, however, to retrieve a 650 bp fragment from archival specimens, (because of DNA degradation) or from environmental samples (where universal primers are needed).
Results: We used a bioinformatics analysis using all CO1 barcode sequences from GenBank and calculated the probability of having species-specific barcodes for varied size fragments. This analysis established the potential of much smaller fragments, mini-barcodes, for identifying unknown specimens. We then developed a universal primer set for the amplification of mini-barcodes. We further successfully tested the utility of this primer set on a comprehensive set of taxa from all major eukaryotic groups as well as archival specimens.
Conclusion: In this study we address the important issue of minimum amount of sequence information required for identifying species in DNA barcoding. We establish a novel approach based on a much shorter barcode sequence and demonstrate its effectiveness in archival specimens. This approach will significantly broaden the application of DNA barcoding in biodiversity studies.
Nuclear mitochondrial pseudogenes (numts) are nonfunctional copies of mtDNA in the nucleus that have been found in major clades of eukaryotic organisms. They can be easily coamplified with orthologous mtDNA by using conserved universal primers; however, this is especially problematic for DNA barcoding, which attempts to characterize all living organisms by using a short fragment of the mitochondrial cytochrome c oxidase I (COI) gene. Here, we study the effect of numts on DNA barcoding based on phylogenetic and barcoding analyses of numt and mtDNA sequences in two divergent lineages of arthropods: grasshoppers and crayfish. Single individuals from both organisms have numts of the COI gene, many of which are highly divergent from orthologous mtDNA sequences, and DNA barcoding analysis incorrectly overestimates the number of unique species based on the standard metric of 3% sequence divergence. Removal of numts based on a careful examination of sequence characteristics, including indels, in-frame stop codons, and nucleotide composition, drastically reduces the incorrect inferences of the number of unique species, but even such rigorous quality control measures fail to identify certain numts. We also show that the distribution of numts is lineage-specific and the presence of numts cannot be known a priori. Whereas DNA barcoding strives for rapid and inexpensive generation of molecular species tags, we demonstrate that the presence of COI numts makes this goal difficult to achieve when numts are prevalent and can introduce serious ambiguity into DNA barcoding.
We investigate the diversity of the North American tiger moth genus Grammia Rambur (Lepidoptera: Noctuidae) by comparing mitochondrial DNA (mtDNA) 'barcode' fragments of cytochrome oxidase I with non-molecular characters such as morphology, ecology, behaviour and distribution. Mitochondrial DNA genealogy is strikingly at odds with morpho-species taxonomy for most of the 28 sampled species, as haplotypic polyphyly not only is taxonomically widespread, but involves multiple shared haplotypes among two to four species. Morpho-ecological traits show that those species sharing haplotypes are often not closely related. Furthermore, high mtDNA divergences occur within species. Haplotypic variation is highly discordant with species taxonomy, but variation at a continental scale reveals significant geographic structuring of haplogroups, transcending morpho-species boundaries. A nested clade analysis and comparison of non-molecular with mtDNA data indicate that most discordance between mtDNA and taxonomy in Grammia is explained best by taxonomically and geographically widespread ongoing hybridization events resulting in mtDNA introgression. We hypothesize that broad areas of sympatry, interspecifically compatible genitalic structure, and species overlap in pheromone components facilitate hybridization, with disparate interspecies abundances promoting mitochondrial introgression. The molecular evolution of Grammia challenges the view that interspecific gene exchange occurs rarely and is restricted to recently diverged species. These results show the value of mtDNA in detecting cryptic hybridization, while highlighting the inherent dangers of drawing taxonomic conclusions based solely on mtDNA.
This study assessed the potential effects of transgenic aspen overexpressing a polyphenol oxidase gene on diversity in rhizosphere communities. Cultivation-independent methods were used to better delineate bacterial and fungal populations associated with transgenic and nontransgenic trees. Gene libraries for the bacterial component of the rhizosphere were established using 16S rRNA and chaperonin-60 (CPN-60) gene sequences, while the fungal community was characterized using 18S rRNA gene sequences. The 16S rRNA gene libraries were dominated by alphaproteobacterial sequences, while the CPN-60 gene libraries were dominated by members of the Bacteroidetes/Chlorobi group. In both the CPN-60 and 16S rRNA libraries, there were differences in only minor components of the bacterial community between transgenic and unmodified trees, and no significant differences in species diversity were observed. Compared to the bacterial gene libraries, greater coverage of the underlying population was achieved with the fungal 18S rRNA libraries. Members of the Zygomycota, Chytridiomycota, Ascomycota, and Basidiomycota were recovered from both libraries. The dominant groups of fungi associated with each tree type were very similar, although there were some qualitative differences in the recovery of less-abundant fungi, likely as a result of the underlying heterogeneity of the fungal population. The methods employed revealed only minor differences between the bacterial and fungal communities associated with transgenic and unmodified trees.
A new disease causing wilt and death of adult plants of Phaseolus vulgaris was discovered in plastic-house crops of southeast Spain in 2004. The causal agent was shown to be a Pythium species with a unique type of oogonium ornamentation different from any of the described species. Zoospores were not observed, but globose or subglobose hyphal swellings, intercalary or terminal, were frequently found. Moreover, the ribosomal ITS region showed a unique sequence, significantly different (>14%) from any other known species of Pythium. This paper describes and illustrates the morphology of the new Pythium species and its pathogenicity to green beans. Its taxonomic position and phylogenetic relationships with other Pythium species are discussed.
A new disease causing wilt and death of adult plants of Phaseolus vulgaris was discovered in plastic-house crops of southeast Spain in 2004. The causal agent was shown to be a Pythium species with a unique type of oogonium ornamentation different from any of the described species. Zoospores were not observed, but globose or subglobose hyphal swellings, intercalary or terminal, were frequently found. Moreover, the ribosomal ITS region showed a unique sequence, significantly different (>14%) from any other known species of Pythium. This paper describes and illustrates the morphology of the new Pythium species and its pathogenicity to green beans. Its taxonomic position and phylogenetic relationships with other Pythium species are discussed.
The molecular evolution of the V6 and V9 domains of the mitochondrial SSU-rDNA was investigated to evaluate the use of these sequences for DNA barcodes in the Basidiomycota division. The PCR products from 27 isolates belonging to 11 Tricholoma species were sequenced. Both domains in the isolates belonging to the same species had identical sequences. All the species possess distinctive V9 sequences due to point mutations and insertion/deletion events. Secondary structures revealed that the insertion-deletion events occurred in regions not directly involved in the maintenance of the standard SSU-rRNA structure. The inserted sequences possess conserved motifs that enable their alignment among phylogenetically distant species. Hence, the V9 domain by displaying identical sequences within species, an adequate divergence level, easy amplification, and alignment represents an alternative molecular marker for the Basidiomycota division and opens the way for this sequence to be used as specific molecular markers of the fungal kingdom.
This study assessed the potential effects of transgenic aspen overexpressing a polyphenol oxidase gene on diversity in rhizosphere communities. Cultivation-independent methods were used to better delineate bacterial and fungal populations associated with transgenic and nontransgenic trees. Gene libraries for the bacterial component of the rhizosphere were established using 16S rRNA and chaperonin-60 (CPN-60) gene sequences, while the fungal community was characterized using 18S rRNA gene sequences. The 16S rRNA gene libraries were dominated by alphaproteobacterial sequences, while the CPN-60 gene libraries were dominated by members of the Bacteroidetes/Chlorobi group. In both the CPN-60 and 16S rRNA libraries, there were differences in only minor components of the bacterial community between transgenic and unmodified trees, and no significant differences in species diversity were observed. Compared to the bacterial gene libraries, greater coverage of the underlying population was achieved with the fungal 18S rRNA libraries. Members of the Zygomycota, Chytridiomycota, Ascomycota, and Basidiomycota were recovered from both libraries. The dominant groups of fungi associated with each tree type were very similar, although there were some qualitative differences in the recovery of less-abundant fungi, likely as a result of the underlying heterogeneity of the fungal population. The methods employed revealed only minor differences between the bacterial and fungal communities associated with transgenic and unmodified trees.
The intertidal brown algal genus Fucus (Phaeophyceae) consists of individuals with a generally dichotomously branched habit. Morphological variability within species, combined with morphological similarity between species, renders field identification difficult. In light of recent taxonomic revisions, which reduced 10 taxa traditionally recognized in Canada to four species, we tested the utility of the DNA barcode (mitochondrial cytochrome oxidase 1, 5′) for assigning individuals to these species. We sequenced the DNA barcode for 125 specimens representing all morphologies recognized. We confirmed our results by sequencing the internal transcribed spacer region for 66 specimens. This is the first study to establish that the DNA barcode successfully assigns different morphologies of brown algae to known species as well as other single-gene molecular markers currently used. Furthermore, the results uncovered substantial phenotypic plasticity in Pacific Fucus distichus, from moss-like fragments embedded in estuarine mud, strap-like morphs on exposed rocky coasts, to “spiralis”-like morphs in the upper intertidal whereas phenotypic expression for this species was more restricted in the Atlantic.
Research using cytochrome c oxidase barcoding techniques on zoological specimens was initiated by Hebert et al. [Hebert, P.D.N., Ratnasingham, S., deWaard, J.R., 2003. Barcoding animal life: cytochrome c oxidase subunit 1 divergences among closely related species. Proc. R. Soc. Lond. B 270, S96-S99]. By March 2004, the Consortium for the Barcode of Life started to promote the use of a standardized DNA barcoding approach, consisting of identifying a specimen as belonging to a certain animal species based on a single universal marker: the DNA barcode sequence. Over the last 4 years, this approach has become increasingly popular and advances as well as limitations have clearly emerged as increasing amounts of organisms have been studied. Our purpose is to briefly expose DNA Barcode of Life principles, pros and cons, relevance and universality. The initially proposed Barcode of life framework has greatly evolved, giving rise to a flexible description of DNA barcoding and a larger range of applications.
Three new species of Leohumicola (anamorphic Leotiomycetes) are described using morphological characters and phylogenetic analyses of DNA barcodes. Leohumicola levissima and L. atra were isolated from soils collected after forest fires in Crater Lake National Park, United States. Leohumicola incrustata was isolated from burned fynbos from the Cape of Good Hope Nature Reserve, South Africa. The three species exhibit characteristic Leohumicola morphology but are morphologically distinct based on conidial characters. Two DNA barcode regions, the Internal Transcribed Spacer (ITS) nuclear rDNA region and the cytochrome oxidase subunit I (Cox1) mitochondrial gene, were sequenced. Single gene parsimony, dual-gene parsimony and dual-gene Bayesian inference phylogenetic analyses support L. levissima, L. atra, L. incrustata as distinct phylogenetic species. Both ITS and Cox1 barcodes are effective for the molecular identification of Leohumicola species.
Three new species of Leohumicola (anamorphic Leotiomycetes) are described using morphological characters and phylogenetic analyses of DNA barcodes. Leohumicola levissima and L. atra were isolated from soils collected after forest fires in Crater Lake National Park, United States. Leohumicola incrustata was isolated from burned fynbos from the Cape of Good Hope Nature Reserve, South Africa. The three species exhibit characteristic Leohumicola morphology but are morphologically distinct based on conidial characters. Two DNA barcode regions, the Internal Transcribed Spacer (ITS) nuclear rDNA region and the cytochrome oxidase subunit I (Cox1) mitochondrial gene, were sequenced. Single gene parsimony, dual-gene parsimony and dual-gene Bayesian inference phylogenetic analyses support L. levissima, L. atra, L. incrustata as distinct phylogenetic species. Both ITS and Cox1 barcodes are effective for the molecular identification of Leohumicola species.
We DNA barcoded 2,597 parasitoid wasps belonging to 6 microgastrine braconid genera reared from parapatric tropical dry forest, cloud forest, and rain forest in Area de Conservacio´n Guanacaste (ACG) in northwestern Costa Rica and combined these data with records of caterpillar hosts and morphological analyses. We asked whether barcoding and morphology discover the same provisional species and whether the biological entities revealed by our analysis are congruent with wasp host specificity. Morphological analysis revealed 171 provisional species, but barcoding exposed an additional 142 provisional species; 95% of the total is likely to be undescribed. These 313 provisional species are extraordinarily host specific; more than 90% attack only 1 or 2 species of caterpillars out of more than 3,500 species sampled. The most extreme case of overlooked diversity is the morphospecies Apanteles leucostigmus. This minute black wasp with a distinctive white wing stigma was thought to parasitize 32 species of ACG hesperiid caterpillars, but barcoding revealed 36 provisional species, each attacking one or a very few closely related species of caterpillars. When host records and/or within-ACG distributions suggested that DNA barcoding had missed a species-pair, or when provisional species were separated only by slight differences in their barcodes, we examined nuclear sequences to test hypotheses of presumptive species boundaries and to further probe host specificity. Our iterative process of combining morphological analysis, ecology, and DNA barcoding and reiteratively using specimens maintained in permanent collections has resulted in a much more fine-scaled understanding of parasitoid diversity and host specificity than any one of these elements could have produced on its own.
We DNA barcoded 2,597 parasitoid wasps belonging to 6 microgastrine braconid genera reared from parapatric tropical dry forest, cloud forest, and rain forest in Area de Conservacio´n Guanacaste (ACG) in northwestern Costa Rica and combined these data with records of caterpillar hosts and morphological analyses. We asked whether barcoding and morphology discover the same provisional species and whether the biological entities revealed by our analysis are congruent with wasp host specificity. Morphological analysis revealed 171 provisional species, but barcoding exposed an additional 142 provisional species; 95% of the total is likely to be undescribed. These 313 provisional species are extraordinarily host specific; more than 90% attack only 1 or 2 species of caterpillars out of more than 3,500 species sampled. The most extreme case of overlooked diversity is the morphospecies Apanteles leucostigmus. This minute black wasp with a distinctive white wing stigma was thought to parasitize 32 species of ACG hesperiid caterpillars, but barcoding revealed 36 provisional species, each attacking one or a very few closely related species of caterpillars. When host records and/or within-ACG distributions suggested that DNA barcoding had missed a species-pair, or when provisional species were separated only by slight differences in their barcodes, we examined nuclear sequences to test hypotheses of presumptive species boundaries and to further probe host specificity. Our iterative process of combining morphological analysis, ecology, and DNA barcoding and reiteratively using specimens maintained in permanent collections has resulted in a much more fine-scaled understanding of parasitoid diversity and host specificity than any one of these elements could have produced on its own.
We DNA barcoded 2,597 parasitoid wasps belonging to 6 microgastrine braconid genera reared from parapatric tropical dry forest, cloud forest, and rain forest in Area de Conservacio´n Guanacaste (ACG) in northwestern Costa Rica and combined these data with records of caterpillar hosts and morphological analyses. We asked whether barcoding and morphology discover the same provisional species and whether the biological entities revealed by our analysis are congruent with wasp host specificity. Morphological analysis revealed 171 provisional species, but barcoding exposed an additional 142 provisional species; 95% of the total is likely to be undescribed. These 313 provisional species are extraordinarily host specific; more than 90% attack only 1 or 2 species of caterpillars out of more than 3,500 species sampled. The most extreme case of overlooked diversity is the morphospecies Apanteles leucostigmus. This minute black wasp with a distinctive white wing stigma was thought to parasitize 32 species of ACG hesperiid caterpillars, but barcoding revealed 36 provisional species, each attacking one or a very few closely related species of caterpillars. When host records and/or within-ACG distributions suggested that DNA barcoding had missed a species-pair, or when provisional species were separated only by slight differences in their barcodes, we examined nuclear sequences to test hypotheses of presumptive species boundaries and to further probe host specificity. Our iterative process of combining morphological analysis, ecology, and DNA barcoding and reiteratively using specimens maintained in permanent collections has resulted in a much more fine-scaled understanding of parasitoid diversity and host specificity than any one of these elements could have produced on its own.
We DNA barcoded 2,597 parasitoid wasps belonging to 6 microgastrine braconid genera reared from parapatric tropical dry forest, cloud forest, and rain forest in Area de Conservacio´n Guanacaste (ACG) in northwestern Costa Rica and combined these data with records of caterpillar hosts and morphological analyses. We asked whether barcoding and morphology discover the same provisional species and whether the biological entities revealed by our analysis are congruent with wasp host specificity. Morphological analysis revealed 171 provisional species, but barcoding exposed an additional 142 provisional species; 95% of the total is likely to be undescribed. These 313 provisional species are extraordinarily host specific; more than 90% attack only 1 or 2 species of caterpillars out of more than 3,500 species sampled. The most extreme case of overlooked diversity is the morphospecies Apanteles leucostigmus. This minute black wasp with a distinctive white wing stigma was thought to parasitize 32 species of ACG hesperiid caterpillars, but barcoding revealed 36 provisional species, each attacking one or a very few closely related species of caterpillars. When host records and/or within-ACG distributions suggested that DNA barcoding had missed a species-pair, or when provisional species were separated only by slight differences in their barcodes, we examined nuclear sequences to test hypotheses of presumptive species boundaries and to further probe host specificity. Our iterative process of combining morphological analysis, ecology, and DNA barcoding and reiteratively using specimens maintained in permanent collections has resulted in a much more fine-scaled understanding of parasitoid diversity and host specificity than any one of these elements could have produced on its own.
We reviewed the use and relevance of barcodes for insect studies and investigated the barcode sequence of Diatraea saccharalis. This sequence has a high level of homology (99%) with the barcode sequence of the Crambidae (Lepidoptera). The sequence data can be used to construct relationships between species, allowing a multidisciplinary approach for taxonomy, which includes morphological, molecular and distribution data, all of which are essential for the understanding of biodiversity. The D. saccharalis barcode is a previously undescribed sequence that could be used to analyze Lepidoptera biology.
Africa has a rich diversity of marine and freshwater fishes, but very little taxonomic expertise or funding to describe it. New approaches to using modern technology, such as DNA barcoding, can facilitate collaboration between field biologists, reference collections and sequencing facilities to speed up the process of species identification and diversity assessments, provided specimen vouchers, tissues, photographs of the specimen and DNA sequences (barcodes) are clearly linked. The FISH-BOL project in Africa aims to establish a collaborative Pan-African regional working group to facilitate barcoding of fish across the continent and the surrounding FAO marine regions. This is being established through existing African biodiversity networks and global biodiversity programmes that are already in place. Barcoding is expected to inform African fisheries management and conservation through more accurate identification of species and their different life-history stages, by speeding up biodiversity assessments. Barcoding is an important development, contributing towards an evolutionary history perspective on which to base Africa's conservation strategies.
Fifteen fish species, totalling 149 specimens, were cytochrome c oxidase I sequenced—barcoded—from Northern (Atlantic and Mediterranean) and Southern (Australasian) Hemisphere waters. Thirteen species showed no significant evidence of spatial genetic differentiation for this gene, although small sample sizes reduced statistical power. For marine fish, barcodes collected in one part of a species range are likely to be useful as identifiers in all other parts of its range. Two species did show striking north–south differentiation, with FST values of 0.84 and 0.96 (both p << 0.001). One of these, the silver scabbardfish Lepidopus caudatus, showed 2.75% genetic distance between northern and southern clades. The other, John dory Zeus faber, showed 7.44% differentiation between northern and southern clades. All specimens of these 2 species fell correctly into the northern or southern clade. We suggest that both taxa conceal a currently unrecognised, cryptic species, and recommend further taxonomic and genetic investigation.
Africa has a rich diversity of marine and freshwater fishes, but very little taxonomic expertise or funding to describe it. New approaches to using modern technology, such as DNA barcoding, can facilitate collaboration between field biologists, reference collections and sequencing facilities to speed up the process of species identification and diversity assessments, provided specimen vouchers, tissues, photographs of the specimen and DNA sequences (barcodes) are clearly linked. The FISH-BOL project in Africa aims to establish a collaborative Pan-African regional working group to facilitate barcoding of fish across the continent and the surrounding FAO marine regions. This is being established through existing African biodiversity networks and global biodiversity programmes that are already in place. Barcoding is expected to inform African fisheries management and conservation through more accurate identification of species and their different life-history stages, by speeding up biodiversity assessments. Barcoding is an important development, contributing towards an evolutionary history perspective on which to base Africa's conservation strategies.
Fifteen fish species, totalling 149 specimens, were cytochrome c oxidase I sequenced—barcoded—from Northern (Atlantic and Mediterranean) and Southern (Australasian) Hemisphere waters. Thirteen species showed no significant evidence of spatial genetic differentiation for this gene, although small sample sizes reduced statistical power. For marine fish, barcodes collected in one part of a species range are likely to be useful as identifiers in all other parts of its range. Two species did show striking north–south differentiation, with FST values of 0.84 and 0.96 (both p << 0.001). One of these, the silver scabbardfish Lepidopus caudatus, showed 2.75% genetic distance between northern and southern clades. The other, John dory Zeus faber, showed 7.44% differentiation between northern and southern clades. All specimens of these 2 species fell correctly into the northern or southern clade. We suggest that both taxa conceal a currently unrecognised, cryptic species, and recommend further taxonomic and genetic investigation.
DNA barcoding, based on sequence diversity in the mitochondrial COI gene, has proven an excellent tool for identifying species in many animal groups. Here, we report the first barcode studies for freshwater zooplankton from Mexico and Guatemala and discuss the taxonomic and biological implications of this work. Our studies examined 61 species of Cladocera and 21 of Copepoda, about 40% of the known fauna in this region. Sequence divergences among conspecific individuals of cladocerans and copepods averaged 0.82%and 0.79%, respectively, while sequence divergences among congeneric taxa were on average 15-20 times as high. Barcodes were successful in discriminating all species in our study, but sequences for Mexican Daphnia exilis overlapped with those of D. spinulata from Argentina. Our barcode data revealed evidence of many species overlooked by current classification systems —for example, based on COI genotypes the Diapahanosoma birgei group appears to include 5 species, while Ceriodaphnia cf. rigaudi, Moina cf. micrura, Mastigodiaptomus albuquerquensis and Mastigodiaptomus reidae all include 2–3 taxa. The barcode results support recent taxonomic revisions, such as recognition of the genus Leberis, and the presence of several species in the D. birgei and Chydorus sphaericus complexes. The present results indicate that DNA barcoding will provide powerful new insights into both the incidence of cryptic species and a better understanding of zooplankton distributions, aiding evaluation of the factors influencing competitive outcomes, and the colonization of aquatic environments.
Here we present an objective, repeatable approach to delineating species when populations are divergent and highly structured geographically using the Californian trapdoor spider species complex Aptostichus atomarius Simon as a model system. This system is particularly difficult because under strict criteria of geographical concordance coupled with estimates of genetic divergence, an unrealistic number of population lineages would qualify as species (20 to 60). Our novel phylogeographic approach, which is generally applicable but particularly relevant to highly structured systems, uses genealogical exclusivity to establish a topological framework to examine lineages for genetic and ecological exchangeability in an effort to delimit cohesion species. Both qualitative assessments of habitat and niche-based distribution modeling are employed to evaluate selective regime and ecological interchangeability among genetic lineages; adaptive divergence among populations is weighted more heavily than simple geographical concordance. Based on these analyses we conclude that five cohesion species should be recognized, three of which are new to science.
Fifteen fish species, totalling 149 specimens, were cytochrome c oxidase I sequenced—barcoded—from Northern (Atlantic and Mediterranean) and Southern (Australasian) Hemisphere waters. Thirteen species showed no significant evidence of spatial genetic differentiation for this gene, although small sample sizes reduced statistical power. For marine fish, barcodes collected in one part of a species range are likely to be useful as identifiers in all other parts of its range. Two species did show striking north–south differentiation, with FST values of 0.84 and 0.96 (both p << 0.001). One of these, the silver scabbardfish Lepidopus caudatus, showed 2.75% genetic distance between northern and southern clades. The other, John dory Zeus faber, showed 7.44% differentiation between northern and southern clades. All specimens of these 2 species fell correctly into the northern or southern clade. We suggest that both taxa conceal a currently unrecognised, cryptic species, and recommend further taxonomic and genetic investigation.
Fifteen fish species, totalling 149 specimens, were cytochrome c oxidase I sequenced—barcoded—from Northern (Atlantic and Mediterranean) and Southern (Australasian) Hemisphere waters. Thirteen species showed no significant evidence of spatial genetic differentiation for this gene, although small sample sizes reduced statistical power. For marine fish, barcodes collected in one part of a species range are likely to be useful as identifiers in all other parts of its range. Two species did show striking north–south differentiation, with FST values of 0.84 and 0.96 (both p << 0.001). One of these, the silver scabbardfish Lepidopus caudatus, showed 2.75% genetic distance between northern and southern clades. The other, John dory Zeus faber, showed 7.44% differentiation between northern and southern clades. All specimens of these 2 species fell correctly into the northern or southern clade. We suggest that both taxa conceal a currently unrecognised, cryptic species, and recommend further taxonomic and genetic investigation.
A multi-gene genealogy based on maximum parsimony and distance analyses of the exonic genes for actin (act) and translation elongation factor 1 alpha (tef), the nuclear genes for the small (18S) and large (28S) subunit ribosomal RNA (comprising 807, 1092, 1863, 389 characters, respectively) of all 50 genera of the Mucorales (Zygomycetes) suggests that the Choanephoraceae is a monophyletic group. The monotypic Gilbertellaceae appears in close phylogenetic relatedness to the Choanephoraceae. The monophyly of the Choanephoraceae has moderate to strong support (bootstrap proportions 67 % and 96 % in distance and maximum parsimony analyses, respectively), whereas the monophyly of the Choanephoraceae-Gilbertellaceae clade is supported by high bootstrap values (100 % and 98 %). This suggests that the two families can be joined into one family, which leads to the elimination of the Gilbertellaceae as a separate family. In order to test this hypothesis single-locus neighbor-joining analyses were performed on nuclear genes of the 18S, 5.8S, 28S and internal transcribed spacer (ITS) 1 ribosomal RNA and the translation elongation factor 1 alpha (tef) and beta tubulin (tub) nucleotide sequences. The common monophyletic origin of the Choanephoraceae-Gilbertellaceae clade could be confirmed in all gene trees and by investigation of their ultrastructure. Sporangia with persistent, sutured walls splitting in half at maturity and ellipsoidal sporangiospores with striated ornamentations and polar ciliate appendages arising from spores in persistent sporangia and dehiscent sporangiola represent synapomorphic characters of this group. We discuss our data in the context of the historical development of their taxonomy and physiology and propose a reduction of the two families to one family, the Choanephoraceae sensu lato comprising species which are facultative plant pathogens and parasites, especially in subtropical to tropical regions.
* Ectomycorrhizal (ECM) symbiosis is a widespread plant nutrition strategy in Australia, especially in semiarid regions. This study aims to determine the diversity, community structure and host preference of ECM fungi in a Tasmanian wet sclero-phyll forest. * Ectomycorrhizal fungi were identified based on anatomotyping and rDNA internal transcribed spacer (ITS)-large subunit (LSU) sequence analysis using taxon-specific primers. Host tree roots were identified based on root morphology and length differences of the chloroplast trnL region. * A total of 123 species of ECM fungi were recovered from root tips of Eucalyptus regnans (Myrtaceae), Pomaderris apetala (Rhamnaceae) and Nothofagus cunninghamii (Nothofagaceae). The frequency of two thirds of the most common ECM fungi from several lineages was significantly influenced by host species. The lineages of Cortinarius, Tomentella-Thelephora, Russula-Lactarius, Clavulina, Descolea and Laccaria prevailed in the total community and their species richness and relative abundance did not differ by host species. * This study demonstrates that strongly host-preferring, though not directly specific, ECM fungi may dominate the below-ground community. Apart from the richness of Descolea, Tulasnella and Helotiales and the lack of Suillus-Rhizopogon and Amphinema-Tylospora, the ECM fungal diversity and phylogenetic community structure is similar to that in the Holarctic realm.
Seacoast to inland soil transects of 1 and 2 km were researched over 2 years to understand the previous termmicrobial diversitynext term in previous termanext term post ice age, isostatically, rebounding, soil environment. Community level substrate utilization analysis and 16S rDNA eubacterial previous termdiversitynext term were employed. The community level substrate analysis demonstrated that regardless of the location along the transect from seacoast to forest, sandy or peat soil, the previous termmicrobial diversitynext term (Shannon previous termdiversitynext term index about 3) was virtually the same. Shannon previous termdiversitynext term indexes based on PCR-DGGE analysis yielded values between about 0.6 and about 2 depending on the sand or peat soil type and the year the samples were collected and analyzed (2002 and 2003). Regardless of the genetic previous termdiversity,next term the soils exhibited similar metabolic capabilities. This is previous termanext term good example of redundant, functional, physiology regardless of the species present at each location along the transects.
Forty-six monoclonal cultures of the diatom Pseudo-nitzschia delicatissima (Cleve) Heiden were isolated from coastal waters of Eastern Canada. Of these, 12 clones were successfully sexualized. The range of their morphological and genetic divergence was used as a reference for clones whose sexual identity remains unknown. All characters that were examined, including valve morphology, the nuclear internal transcribed spacer (ITS) region, and mitochondrial cytochrome c oxidase (cox1) sequences, showed a high degree of similarity within and between mating and nonsexualized clones. Within the 638 bp long aligned fragment in the ITS region, only five variable sites were found and just two were found within the 576 bp fragment of cox1 near the 5′ terminus of the gene. Our own data and those retrieved from GenBank suggest that the northern North Atlantic is populated by a single metapopulation of genetically very similar P. delicatissima, as determined using the ITS sequence of the epitype of the species. The ITS region of our clones was distinct from ITS-types present in isolates that we will refer to as P. delicatissima-like diatoms from the Mediterranean Sea and other low latitude Atlantic sites, thereby providing a means to discriminate between otherwise morphologically indistinguishable (cryptic) species. Such a distribution pattern suggests different physiological and environmental requirements for mating optima. This work furthers our understanding of the relationship between biological, molecular, and morphological species boundaries in diatoms and their ecology, and contributes to evaluation of the utility of ITS and cox1 sequences in DNA barcoding of diatoms.
Amylostereum areolatum (Fr.) Boidin (Russulales: Stereaceae) is a white rot fungus that has a symbiotic relationship with several woodwasps including Sirex noctilio Fabricius (Hymenoptera: Siricidae). The vectored fungus together with a phytotoxic mucus, both injected during oviposition by the female S. noctilio, rapidly weaken the host tree, rendering it susceptible to larval development (3). Host trees of A. areolatum include species of Pinus (mainly), Abies, Larix, and Picea and Cryptomeria japonica and Pseudotsuga menziesii (Fungal Databases [online]; USDA). The siricid woodwasp is native to Eurasia and North Africa and has been introduced into New Zealand, Australia, South America, and South Africa (1). In July of 2005, the first established North American population of S. noctilio was reported in Oswego, NY. Prompted by this initial discovery, a trap survey of Ontario counties located along the Canada-U.S. border, close to Upstate New York, was conducted in September and October of 2005. S. noctilio females were captured in four locations in southern Ontario. Two additional locations for S. noctilio were also reported in a survey conducted independently (2). In September and October of 2006, logs of Scots pines showing current Sirex oviposition sites were harvested from the Ontario area bordered by Lakes Huron, Erie, and Ontario to determine the presence of the species-specific fungal symbiont of S. noctilio, A. areolatum. Fungal isolates were obtained by surface sterilizing wood chips showing decay columns followed by incubation at 20°C on 2% malt extract agar. Cultures with morphological characteristics typical of A. areolatum–presence of clamp connections and arthrospores–were used for DNA analysis to confirm species identification. DNA sequences of the internal transcribed spacer (ITS) of the ribosomal RNA gene were queried against the NCBI GenBank database. There was a 99 to 100% match between the ITS sequences from the Ontario isolates and sequences from European and Asian A. areolatum isolates (GenBank Accession Nos. EU249343 and EU249344 versus AF454428, AF506405, AY781245, and AF218389). Matches with A. chailletii (Pers.) Boidin, a native related species, were around 97%. These results confirmed the presence of A. areolatum in the infested material. Cultures were deposited in the National Mycological Herbarium of Canada (DAOM 239280–DAOM 239295). To our knowledge, this represents the first report of A. areolatum in Canada. In its natural range, the insect-fungal complex exists in equilibrium with its host trees and parasites, thus, few negative impacts are observed. However, in the Southern Hemisphere where it has been introduced, it has become a major pest, attacking many important commercial North American species planted as exotics (1). Conifer forests in Canada are threatened by the spread of the S. noctilio/A. areolatum complex, particularly plantations and stands of Pinus banksiana, P. contorta, P. ponderosa, P. resinosa, P. strobus, and P. sylvestris. A survey of Eastern Canada to detect the presence of S. noctilio is on going, and genetics work is being conducted to determine the origin of the introduction of A. areolatum.
Forty-six monoclonal cultures of the diatom Pseudo-nitzschia delicatissima (Cleve) Heiden were isolated from coastal waters of Eastern Canada. Of these, 12 clones were successfully sexualized. The range of their morphological and genetic divergence was used as a reference for clones whose sexual identity remains unknown. All characters that were examined, including valve morphology, the nuclear internal transcribed spacer (ITS) region, and mitochondrial cytochrome c oxidase (cox1) sequences, showed a high degree of similarity within and between mating and nonsexualized clones. Within the 638 bp long aligned fragment in the ITS region, only five variable sites were found and just two were found within the 576 bp fragment of cox1 near the 5′ terminus of the gene. Our own data and those retrieved from GenBank suggest that the northern North Atlantic is populated by a single metapopulation of genetically very similar P. delicatissima, as determined using the ITS sequence of the epitype of the species. The ITS region of our clones was distinct from ITS-types present in isolates that we will refer to as P. delicatissima-like diatoms from the Mediterranean Sea and other low latitude Atlantic sites, thereby providing a means to discriminate between otherwise morphologically indistinguishable (cryptic) species. Such a distribution pattern suggests different physiological and environmental requirements for mating optima. This work furthers our understanding of the relationship between biological, molecular, and morphological species boundaries in diatoms and their ecology, and contributes to evaluation of the utility of ITS and cox1 sequences in DNA barcoding of diatoms.
The field of DNA barcoding is working towards generating a genetic system for the quick and accurate identification of eukaryotic species. For the more systematic minded, however, DNA barcoding offers a new approach towards screening and uniting large numbers of biological specimens in genetic groups as a first step towards assigning them to species and genera in an approach best termed “molecular-assisted alpha taxonomy”. This approach is particularly amenable in organisms with simple morphologies, a propensity for convergence, extensive phenotypic plasticity, and life histories with an alternation of heteromorphic generations. It is hard to imagine a group of organisms better defined by all of these traits than the marine macroalgae. In an effort to assess the utility of the DNA barcode (COI-5′) for testing the current concepts of biodiversity of marine macroalgae in Canada, a study to assess species diversity in the red algal family, Dumontiaceae, was initiated. Through this work I confirm the presence in Canadian waters of Dilsea californica (J. Agardh) Kuntze, Dilsea integra (Kjellman) Rosenvinge, and Neodilsea borealis (I.A. Abbott) Lindstrom of the Dilsea–Neodilsea complex, and Weeksia coccinea (Harvey) Lindstrom for the genus Weeksia. However, our work has uncovered two additional species of the former complex, Dilsea lindstromiae Saunders sp. nov. and Dilsea pygmaea (Setchell) Setchell, and an additional species of the latter, Weeksia reticulata Setchell, effectively doubling representation of these foliose dumontiacean genera in Canadian waters.
The field of DNA barcoding is working towards generating a genetic system for the quick and accurate identification of eukaryotic species. For the more systematic minded, however, DNA barcoding offers a new approach towards screening and uniting large numbers of biological specimens in genetic groups as a first step towards assigning them to species and genera in an approach best termed “molecular-assisted alpha taxonomy”. This approach is particularly amenable in organisms with simple morphologies, a propensity for convergence, extensive phenotypic plasticity, and life histories with an alternation of heteromorphic generations. It is hard to imagine a group of organisms better defined by all of these traits than the marine macroalgae. In an effort to assess the utility of the DNA barcode (COI-5′) for testing the current concepts of biodiversity of marine macroalgae in Canada, a study to assess species diversity in the red algal family, Dumontiaceae, was initiated. Through this work I confirm the presence in Canadian waters of Dilsea californica (J. Agardh) Kuntze, Dilsea integra (Kjellman) Rosenvinge, and Neodilsea borealis (I.A. Abbott) Lindstrom of the Dilsea–Neodilsea complex, and Weeksia coccinea (Harvey) Lindstrom for the genus Weeksia. However, our work has uncovered two additional species of the former complex, Dilsea lindstromiae Saunders sp. nov. and Dilsea pygmaea (Setchell) Setchell, and an additional species of the latter, Weeksia reticulata Setchell, effectively doubling representation of these foliose dumontiacean genera in Canadian waters.
A universal barcode system for land plants would be a valuable resource, with potential utility in fields as diverse as ecology, floristics, law enforcement and industry. However, the application of plant barcoding has been constrained by a lack of consensus regarding the most variable and technically practical DNA region(s). We compared eight candidate plant barcoding regions from the plastome and one from the mitochondrial genome for how well they discriminated the monophyly of 92 species in 32 diverse genera of land plants (N = 251 samples). The plastid markers comprise portions of five coding (rpoB, rpoC1, rbcL, matK and 23S rDNA) and three non-coding (trnH-psbA, atpF-atpH, and psbK-psbI) loci. Our survey included several taxonomically complex groups, and in all cases we examined multiple populations and species. The regions differed in their ability to discriminate species, and in ease of retrieval, in terms of amplification and sequencing success. Single locus resolution ranged from 7% (23S rDNA) to 59% (trnH-psbA) of species with well-supported monophyly. Sequence recovery rates were related primarily to amplification success (85-100% for plastid loci), with matK requiring the greatest effort to achieve reasonable recovery (88% using 10 primer pairs). Several loci (matK, psbK-psbI, trnH-psbA) were problematic for generating fully bidirectional sequences. Setting aside technical issues related to amplification and sequencing, combining the more variable plastid markers provided clear benefits for resolving species, although with diminishing returns, as all combinations assessed using four to seven regions had only marginally different success rates (69-71%; values that were approached by several two- and three-region combinations). This performance plateau may indicate fundamental upper limits on the precision of species discrimination that is possible with DNA barcoding systems that include moderate numbers of plastid markers. Resolution to the contentious debate on plant barcoding should therefore involve increased attention to practical issues related to the ease of sequence recovery, global alignability, and marker redundancy in multilocus plant DNA barcoding systems.
We are pleased to announce that grants received from several funding agencies, have enabled us to plan for hosting a three-day Global Pollinator Summit on behalf of the National Science Foundation, The Global Biodiversity Information Facility (GBIF), Consortium for the Barcoding of Life (CBOL) and the Integrated Taxonomic Information Systems (ITIS).
Global Pollinator Summit Circular
Global Pollinator Summit Agenda
Directions to Tala Game Reserve venue
List of Participants
Chironomids (Diptera) typically comprise the most abundant group of macroinvertebrates collected in water quality surveys. Species in the genus Cricotopus display a wide range of tolerance for manmade pollutants, making them excellent bioindicators. Unfortunately, the usefulness of Cricotopus is overshadowed by the difficulty of accurately identifying larvae using current morphological keys. Molecular approaches are now being used for identification and taxonomic resolution in many animal taxa. In this study, a sequence-based approach for the mitochondrial gene, cytochrome oxidase I (COI), was developed to facilitate identification of Cricotopus species collected from Baltimore area streams. Using unique COI sequence variations, we developed profiles for seven described Cricotopus sp., four described Orthocladius sp., one described Paratrichocladius sp. and one putative species of Cricotopus. In addition to providing an accurate method for identification of Cricotopus, this method will make a useful contribution to the development of keys for Nearctic Cricotopus.
Amylostereum areolatum (Fr.) Boidin (Russulales: Stereaceae) is a white rot fungus that has a symbiotic relationship with several woodwasps including Sirex noctilio Fabricius (Hymenoptera: Siricidae). The vectored fungus together with a phytotoxic mucus, both injected during oviposition by the female S. noctilio, rapidly weaken the host tree, rendering it susceptible to larval development (3). Host trees of A. areolatum include species of Pinus (mainly), Abies, Larix, and Picea and Cryptomeria japonica and Pseudotsuga menziesii (Fungal Databases [online]; USDA). The siricid woodwasp is native to Eurasia and North Africa and has been introduced into New Zealand, Australia, South America, and South Africa (1). In July of 2005, the first established North American population of S. noctilio was reported in Oswego, NY. Prompted by this initial discovery, a trap survey of Ontario counties located along the Canada-U.S. border, close to Upstate New York, was conducted in September and October of 2005. S. noctilio females were captured in four locations in southern Ontario. Two additional locations for S. noctilio were also reported in a survey conducted independently (2). In September and October of 2006, logs of Scots pines showing current Sirex oviposition sites were harvested from the Ontario area bordered by Lakes Huron, Erie, and Ontario to determine the presence of the species-specific fungal symbiont of S. noctilio, A. areolatum. Fungal isolates were obtained by surface sterilizing wood chips showing decay columns followed by incubation at 20°C on 2% malt extract agar. Cultures with morphological characteristics typical of A. areolatum–presence of clamp connections and arthrospores–were used for DNA analysis to confirm species identification. DNA sequences of the internal transcribed spacer (ITS) of the ribosomal RNA gene were queried against the NCBI GenBank database. There was a 99 to 100% match between the ITS sequences from the Ontario isolates and sequences from European and Asian A. areolatum isolates (GenBank Accession Nos. EU249343 and EU249344 versus AF454428, AF506405, AY781245, and AF218389). Matches with A. chailletii (Pers.) Boidin, a native related species, were around 97%. These results confirmed the presence of A. areolatum in the infested material. Cultures were deposited in the National Mycological Herbarium of Canada (DAOM 239280–DAOM 239295). To our knowledge, this represents the first report of A. areolatum in Canada. In its natural range, the insect-fungal complex exists in equilibrium with its host trees and parasites, thus, few negative impacts are observed. However, in the Southern Hemisphere where it has been introduced, it has become a major pest, attacking many important commercial North American species planted as exotics (1). Conifer forests in Canada are threatened by the spread of the S. noctilio/A. areolatum complex, particularly plantations and stands of Pinus banksiana, P. contorta, P. ponderosa, P. resinosa, P. strobus, and P. sylvestris. A survey of Eastern Canada to detect the presence of S. noctilio is on going, and genetics work is being conducted to determine the origin of the introduction of A. areolatum.
A universal barcode system for land plants would be a valuable resource, with potential utility in fields as diverse as ecology, floristics, law enforcement and industry. However, the application of plant barcoding has been constrained by a lack of consensus regarding the most variable and technically practical DNA region(s). We compared eight candidate plant barcoding regions from the plastome and one from the mitochondrial genome for how well they discriminated the monophyly of 92 species in 32 diverse genera of land plants (N = 251 samples). The plastid markers comprise portions of five coding (rpoB, rpoC1, rbcL, matK and 23S rDNA) and three non-coding (trnH-psbA, atpF-atpH, and psbK-psbI) loci. Our survey included several taxonomically complex groups, and in all cases we examined multiple populations and species. The regions differed in their ability to discriminate species, and in ease of retrieval, in terms of amplification and sequencing success. Single locus resolution ranged from 7% (23S rDNA) to 59% (trnH-psbA) of species with well-supported monophyly. Sequence recovery rates were related primarily to amplification success (85-100% for plastid loci), with matK requiring the greatest effort to achieve reasonable recovery (88% using 10 primer pairs). Several loci (matK, psbK-psbI, trnH-psbA) were problematic for generating fully bidirectional sequences. Setting aside technical issues related to amplification and sequencing, combining the more variable plastid markers provided clear benefits for resolving species, although with diminishing returns, as all combinations assessed using four to seven regions had only marginally different success rates (69-71%; values that were approached by several two- and three-region combinations). This performance plateau may indicate fundamental upper limits on the precision of species discrimination that is possible with DNA barcoding systems that include moderate numbers of plastid markers. Resolution to the contentious debate on plant barcoding should therefore involve increased attention to practical issues related to the ease of sequence recovery, global alignability, and marker redundancy in multilocus plant DNA barcoding systems.
This is the first study to assess the diversity and community structure of the Agaricomycotina in an ectotrophic forest using above-ground fruiting body surveys as well as soil rDNA sampling. We recovered 132 molecular operational taxonomic units, or 'species', from fruiting bodies and 66 from soil, with little overlap. Fruiting body sampling primarily recovered fungi from the Agaricales, Russulales, Boletales and Cantharellales. Many of these species are ectomycorrhizal and form large fruiting bodies. Soil rDNA sampling recovered fungi from these groups in addition to taxa overlooked during the fruiting body survey from the Atheliales, Trechisporales and Sebacinales. Species from these groups form inconspicuous, resupinate and corticioid fruiting bodies. Soil sampling also detected fungi from the Hysterangiales that form fruiting bodies underground. Generally, fruiting body and soil rDNA samples recover a largely different assemblage of fungi at the species level; however, both methods identify the same dominant fungi at the genus-order level and ectomycorrhizal fungi as the prevailing type. Richness, abundance, and phylogenetic diversity (PD) identify the Agaricales as the dominant fungal group above- and below-ground; however, we find that molecularly highly divergent lineages may account for a greater proportion of total diversity using the PD measure compared with richness and abundance. Unless an exhaustive inventory is required, the rapidity and versatility of DNA-based sampling may be sufficient for a first assessment of the dominant taxonomic and ecological groups of fungi in forest soil.
Molecular identification of animal or plant species in fresh and degraded products (e.g. food, faeces, hair and other organic remains) has become a very important issue in both conservation biology and food science. In this proof-of-concept study, we developed a microarray-based method using cytochrome b-derived probes to identify the main commercial and/or endangered vertebrate species in both food and forensic samples. This method allowed the unambiguous identification of 71 out of 77 species tested. In the remaining six cases, identification was hampered due to false sequences deposited in GenBank and high intraspecific variability. Our evaluation of this DNA chip for routine control demonstrated its effectiveness for the simultaneous identification of at least five species, and that its sensitivity varied according to the type of sample analysed. Synthesis and applications. Taken together, our results suggest that cytb-based microarray is a reliable and powerful identification tool for vertebrates, and more generally highlights the significant role of both molecular and traditional taxonomy in the development of molecular identification methods.
The concept and practice of DNA barcoding have been designed as a system to facilitate species identification and recognition. The primary challenge for barcoding plants has been to identify a suitable region on which to focus the effort. The slow relative nucleotide substitution rates of plant mitochondria and the technical issues with the use of nuclear regions have focused attention on several proposed regions in the plastid genome. One of the challenges for barcoding is to discriminate closely related or recently evolved species. The Myristicaceae, or nutmeg family, is an older group within the angiosperms that contains some recently evolved species providing a challenging test for barcoding plants. The goal of this study is to determine the relative utility of six coding (Universal Plastid Amplicon — UPA, rpoB, rpoc1, accD, rbcL, matK) and one noncoding (trnH-psbA) chloroplast loci for barcoding in the genus Compsoneura using both single region and multiregion approaches. Five of the regions we tested were predominantly invariant across species (UPA, rpoB, rpoC1, accD, rbcL). Two of the regions (matK and trnH-psbA) had significant variation and show promise for barcoding in nutmegs. We demonstrate that a two-gene approach utilizing a moderately variable region (matK) and a more variable region (trnH-psbA) provides resolution among all the Compsonuera species we sampled including the recently evolved C. sprucei and C. mexicana. Our classification analyses based on nonmetric multidimensional scaling ordination, suggest that the use of two regions results in a decreased range of intraspecific variation relative to the distribution of interspecific divergence with 95% of the samples correctly identified in a sequence identification analysis.
The concept and practice of DNA barcoding have been designed as a system to facilitate species identification and recognition. The primary challenge for barcoding plants has been to identify a suitable region on which to focus the effort. The slow relative nucleotide substitution rates of plant mitochondria and the technical issues with the use of nuclear regions have focused attention on several proposed regions in the plastid genome. One of the challenges for barcoding is to discriminate closely related or recently evolved species. The Myristicaceae, or nutmeg family, is an older group within the angiosperms that contains some recently evolved species providing a challenging test for barcoding plants. The goal of this study is to determine the relative utility of six coding (Universal Plastid Amplicon — UPA, rpoB, rpoc1, accD, rbcL, matK) and one noncoding (trnH-psbA) chloroplast loci for barcoding in the genus Compsoneura using both single region and multiregion approaches. Five of the regions we tested were predominantly invariant across species (UPA, rpoB, rpoC1, accD, rbcL). Two of the regions (matK and trnH-psbA) had significant variation and show promise for barcoding in nutmegs. We demonstrate that a two-gene approach utilizing a moderately variable region (matK) and a more variable region (trnH-psbA) provides resolution among all the Compsonuera species we sampled including the recently evolved C. sprucei and C. mexicana. Our classification analyses based on nonmetric multidimensional scaling ordination, suggest that the use of two regions results in a decreased range of intraspecific variation relative to the distribution of interspecific divergence with 95% of the samples correctly identified in a sequence identification analysis.
Background
DNA barcoding aims to provide an efficient method for species-level identifications using an array of species specific molecular tags derived from the 5′ region of the mitochondrial cytochrome c oxidase I (COI) gene. The efficiency of the method hinges on the degree of sequence divergence among species and species-level identifications are relatively straightforward when the average genetic distance among individuals within a species does not exceed the average genetic distance between sister species. Fishes constitute a highly diverse group of vertebrates that exhibit deep phenotypic changes during development. In this context, the identification of fish species is challenging and DNA barcoding provide new perspectives in ecology and systematics of fishes. Here we examined the degree to which DNA barcoding discriminate freshwater fish species from the well-known Canadian fauna, which currently encompasses nearly 200 species, some which are of high economic value like salmons and sturgeons.
Methodology/Principal Findings
We bi-directionally sequenced the standard 652 bp "barcode" region of COI for 1360 individuals belonging to 190 of the 203 Canadian freshwater fish species (95%). Most species were represented by multiple individuals (7.6 on average), the majority of which were retained as voucher specimens. The average genetic distance was 27 fold higher between species than within species, as K2P distance estimates averaged 8.3% among congeners and only 0.3% among concpecifics. However, shared polymorphism between sister-species was detected in 15 species (8% of the cases). The distribution of K2P distance between individuals and species overlapped and identifications were only possible to species group using DNA barcodes in these cases. Conversely, deep hidden genetic divergence was revealed within two species, suggesting the presence of cryptic species.
Conclusions/Significance
The present study evidenced that freshwater fish species can be efficiently identified through the use of DNA barcoding, especially the species complex of small-sized species, and that the present COI library can be used for subsequent applications in ecology and systematics.
We study the phylogenetic relationships among some North American Colias ("sulfur") butterflies, using mitochondrial gene sequences (ribosomal RNA, cytochrome oxidase I+II) totaling about 20% of the mitochondrial genome. We find that (1) the lowland species complex shows a branching order different from earlier views; (2) several montane and northern taxa may be more distinct than in earlier views; (3) one morphologically conservative Holarctic assemblage, C. hecla, is differentiated at the molecular-genetic level into at least three taxa which occupy distinct positions in the phylogeny and are sisters to diverse other taxa. These conclusions, constituting phylogenetic hypotheses, are supported by parsimony, maximum-likelihood, and Bayesian reconstruction algorithms. They are tested formally, by interior branch tests and paired-site tests, against alternative hypotheses derived from conventional species and subspecies naming combinations. In all cases our hypotheses are supported by these tests and the conventional alternatives are rejected. The "barcoding" subset of cytochrome oxidase I sequence identifies only some of the taxa supported by our full data set. Comparison of genetic divergence values among Colias taxa with those among related Pierid butterflies suggests that species radiations within Colias are comparatively younger. This emerging Colias phylogeny facilitates comparisons of genetic polymorphism and other adaptive mechanisms among taxa, thereby connecting micro- and macro-evolutionary processes.
Although larvae feeding and food source are vital to the development, survival and population regulation of African malaria vectors, the prey organisms of Anopheles gambiae larvae in the natural environment have not been well studied. This study used a molecular barcoding approach to investigate the natural diets of Anopheles gambiae s.l. larvae in western Kenya. Gut contents from third- and fourth-instar larvae from natural habitats were dissected and DNA was extracted. The 18S ribosomal DNA gene was amplified, the resulting clones were screened using a restriction fragment length polymorphism method and nonmosquito clones were sequenced. Homology search and phylogenetic analyses were then conducted using the sequences of non-mosquito clones to identify the putative microorganisms ingested. The phylogenetic analyses clustered ingested microorganisms in four clades, including two clades of green algae (Chlorophyta, Chlorophyceae Class, Chlamydomonadales and Chlorococcales families), one fungal clade, and one unknown eukaryote clade. In parallel, using the same approach, an analysis of the biodiversity present in the larval habitats was carried out. This present study demonstrated the feasibility of the barcoding approach to infer the natural diets of Anopheles gambiae larvae. Our analysis suggests that despite the wide range of microorganisms available in natural habitats, mosquito larvae fed on specific groups of algae. The novel tools developed from this study can be used to improve our understanding of the larval ecology of African malaria vectors and to facilitate the development of new mosquito control tools.
The performance of DNA barcoding as a tool for fast taxonomic verification in ecological assessment projects of small mammals was evaluated during a collecting trip to a lowland tropical rainforest site in Suriname. We also compared the performance of tissue sampling onto FTA CloneSaver cards vs. liquid nitrogen preservation. DNA barcodes from CloneSaver cards were recovered from 85% of specimens, but DNA degradation was apparent, because only 36% of sequence reads were long (over 600 bp). In contrast, cryopreserved tissue delivered 99% barcode recovery (97% > 600 bp). High humidity, oversampling or tissue type may explain the poor performance of CloneSaver cards. Comparison of taxonomic assignments made in the field and from barcode results revealed inconsistencies in just 3.4% of cases and most of the discrepancies were due to field misidentifications (3%) rather than sampling/analytical error (0.5%). This result reinforces the utility of DNA barcoding as a tool for verification of taxonomic identifications in ecological surveys, which is especially important when the collection of voucher specimens is not possible.
We analysed cytochrome oxidase I (COI) barcodes for 35 putative fish species collected in the Scotia Sea, and compared the resultant molecular data with field-based morphological identifications, and additional sequence data obtained from GenBank and the Barcode of Life Data System (BOLD). There was high congruence between morphological and molecular classification, and COI provided effective species-level discrimination for nearly all putative species. No effect of geographic sampling was observed for COI sequence variation. For two families, including the Liparidae and Zoarcidae, for which morphological field identification was unable to resolve taxonomy, DNA barcoding revealed significant species-level divergence. However, the dataset lacked sufficient sensitivity for resolving species within the Bathydraco and Artedidraco genera. Analysis of cytochrome b for these two genera also failed to resolve taxonomic identity. The data are discussed in relation to emergent priorities for additional taxonomic studies. We emphasize the utility of DNA barcoding in providing a valuable taxonomic framework for fundamental population studies through assigning life history stages or other morphologically ambiguous samples to parental species.
Background
DNA barcoding aims to provide an efficient method for species-level identifications using an array of species specific molecular tags derived from the 5′ region of the mitochondrial cytochrome c oxidase I (COI) gene. The efficiency of the method hinges on the degree of sequence divergence among species and species-level identifications are relatively straightforward when the average genetic distance among individuals within a species does not exceed the average genetic distance between sister species. Fishes constitute a highly diverse group of vertebrates that exhibit deep phenotypic changes during development. In this context, the identification of fish species is challenging and DNA barcoding provide new perspectives in ecology and systematics of fishes. Here we examined the degree to which DNA barcoding discriminate freshwater fish species from the well-known Canadian fauna, which currently encompasses nearly 200 species, some which are of high economic value like salmons and sturgeons.
Methodology/Principal Findings
We bi-directionally sequenced the standard 652 bp "barcode" region of COI for 1360 individuals belonging to 190 of the 203 Canadian freshwater fish species (95%). Most species were represented by multiple individuals (7.6 on average), the majority of which were retained as voucher specimens. The average genetic distance was 27 fold higher between species than within species, as K2P distance estimates averaged 8.3% among congeners and only 0.3% among concpecifics. However, shared polymorphism between sister-species was detected in 15 species (8% of the cases). The distribution of K2P distance between individuals and species overlapped and identifications were only possible to species group using DNA barcodes in these cases. Conversely, deep hidden genetic divergence was revealed within two species, suggesting the presence of cryptic species.
Conclusions/Significance
The present study evidenced that freshwater fish species can be efficiently identified through the use of DNA barcoding, especially the species complex of small-sized species, and that the present COI library can be used for subsequent applications in ecology and systematics.
Comparing introduced to ancestral populations within a phylogeographical context is crucial in any study aiming to understand the ecological genetics of an invasive species. Zaprionus indianus is a cosmopolitan drosophilid that has recently succeeded to expand its geographical range upon three continents (Africa, Asia and the Americas). We studied the distribution of mitochondrial DNA (mtDNA) haplotypes for two genes (CO-I and CO-II) among 23 geographical populations. mtDNA revealed the presence of two well-supported phylogenetic lineages (phylads), with bootstrap value of 100%. Phylad I included three African populations, reinforcing the African-origin hypothesis of the species. Within phylad II, a distinct phylogeographical pattern was discovered: Atlantic populations (from the Americas and Madeira) were closer to the ancestral African populations than to Eastern ones (from Madagascar, Middle East and India). This means that during its passage from endemism to cosmopolitanism, Z. indianus exhibited two independent radiations, the older (the Eastern) to the East, and the younger (the Atlantic) to the West. Discriminant function analysis using 13 morphometrical characters was also able to discriminate between the two molecular phylads (93.34 ± 1.67%), although detailed morphological analysis of male genitalia using scanning electron microscopy showed no significant differences. Finally, crossing experiments revealed the presence of reproductive barrier between populations from the two phylads, and further between populations within phylad I. Hence, a bona species status was assigned to two new, cryptic species: Zaprionus africanus and Zaprionus gabonicus, and both were encompassed along with Z. indianus and Zaprionus megalorchis into the indianus complex. The ecology of these two species reveals that they are forest dwellers, which explains their restricted endemic distribution, in contrast to their relative cosmopolitan Z. indianus, known to be a human-commensal. Our results reconfirm the great utility of mtDNA at both inter- and intraspecific analyses within the frame of an integrated taxonomical project.
The performance of DNA barcoding as a tool for fast taxonomic verification in ecological assessment projects of small mammals was evaluated during a collecting trip to a lowland tropical rainforest site in Suriname. We also compared the performance of tissue sampling onto FTA CloneSaver cards vs. liquid nitrogen preservation. DNA barcodes from CloneSaver cards were recovered from 85% of specimens, but DNA degradation was apparent, because only 36% of sequence reads were long (over 600 bp). In contrast, cryopreserved tissue delivered 99% barcode recovery (97% > 600 bp). High humidity, oversampling or tissue type may explain the poor performance of CloneSaver cards. Comparison of taxonomic assignments made in the field and from barcode results revealed inconsistencies in just 3.4% of cases and most of the discrepancies were due to field misidentifications (3%) rather than sampling/analytical error (0.5%). This result reinforces the utility of DNA barcoding as a tool for verification of taxonomic identifications in ecological surveys, which is especially important when the collection of voucher specimens is not possible.
The performance of DNA barcoding as a tool for fast taxonomic verification in ecological assessment projects of small mammals was evaluated during a collecting trip to a lowland tropical rainforest site in Suriname. We also compared the performance of tissue sampling onto FTA CloneSaver cards vs. liquid nitrogen preservation. DNA barcodes from CloneSaver cards were recovered from 85% of specimens, but DNA degradation was apparent, because only 36% of sequence reads were long (over 600 bp). In contrast, cryopreserved tissue delivered 99% barcode recovery (97% > 600 bp). High humidity, oversampling or tissue type may explain the poor performance of CloneSaver cards. Comparison of taxonomic assignments made in the field and from barcode results revealed inconsistencies in just 3.4% of cases and most of the discrepancies were due to field misidentifications (3%) rather than sampling/analytical error (0.5%). This result reinforces the utility of DNA barcoding as a tool for verification of taxonomic identifications in ecological surveys, which is especially important when the collection of voucher specimens is not possible.
The performance of DNA barcoding as a tool for fast taxonomic verification in ecological assessment projects of small mammals was evaluated during a collecting trip to a lowland tropical rainforest site in Suriname. We also compared the performance of tissue sampling onto FTA CloneSaver cards vs. liquid nitrogen preservation. DNA barcodes from CloneSaver cards were recovered from 85% of specimens, but DNA degradation was apparent, because only 36% of sequence reads were long (over 600 bp). In contrast, cryopreserved tissue delivered 99% barcode recovery (97% > 600 bp). High humidity, oversampling or tissue type may explain the poor performance of CloneSaver cards. Comparison of taxonomic assignments made in the field and from barcode results revealed inconsistencies in just 3.4% of cases and most of the discrepancies were due to field misidentifications (3%) rather than sampling/analytical error (0.5%). This result reinforces the utility of DNA barcoding as a tool for verification of taxonomic identifications in ecological surveys, which is especially important when the collection of voucher specimens is not possible.
We analysed cytochrome oxidase I (COI) barcodes for 35 putative fish species collected in the Scotia Sea, and compared the resultant molecular data with field-based morphological identifications, and additional sequence data obtained from GenBank and the Barcode of Life Data System (BOLD). There was high congruence between morphological and molecular classification, and COI provided effective species-level discrimination for nearly all putative species. No effect of geographic sampling was observed for COI sequence variation. For two families, including the Liparidae and Zoarcidae, for which morphological field identification was unable to resolve taxonomy, DNA barcoding revealed significant species-level divergence. However, the dataset lacked sufficient sensitivity for resolving species within the Bathydraco and Artedidraco genera. Analysis of cytochrome b for these two genera also failed to resolve taxonomic identity. The data are discussed in relation to emergent priorities for additional taxonomic studies. We emphasize the utility of DNA barcoding in providing a valuable taxonomic framework for fundamental population studies through assigning life history stages or other morphologically ambiguous samples to parental species.
The history of science often has difficulty connecting with science at the lab-bench level, raising questions about the value of history of science for science. This essay offers a case study from taxonomy in which lessons learned about particular failings of numerical taxonomy (phenetics) in the second half of the twentieth century bear on the new movement toward DNA barcoding. In particular, it argues that an unwillingness to deal with messy theoretical questions in both cases leads to important problems in the theory and practice of identifying taxa. This argument makes use of scientific and historical considerations in a way that the authors hope leads to convincing conclusions about the history of taxonomy as well as about its present practice.
Background
DNA barcoding aims to provide an efficient method for species-level identifications using an array of species specific molecular tags derived from the 5′ region of the mitochondrial cytochrome c oxidase I (COI) gene. The efficiency of the method hinges on the degree of sequence divergence among species and species-level identifications are relatively straightforward when the average genetic distance among individuals within a species does not exceed the average genetic distance between sister species. Fishes constitute a highly diverse group of vertebrates that exhibit deep phenotypic changes during development. In this context, the identification of fish species is challenging and DNA barcoding provide new perspectives in ecology and systematics of fishes. Here we examined the degree to which DNA barcoding discriminate freshwater fish species from the well-known Canadian fauna, which currently encompasses nearly 200 species, some which are of high economic value like salmons and sturgeons.
Methodology/Principal Findings
We bi-directionally sequenced the standard 652 bp "barcode" region of COI for 1360 individuals belonging to 190 of the 203 Canadian freshwater fish species (95%). Most species were represented by multiple individuals (7.6 on average), the majority of which were retained as voucher specimens. The average genetic distance was 27 fold higher between species than within species, as K2P distance estimates averaged 8.3% among congeners and only 0.3% among concpecifics. However, shared polymorphism between sister-species was detected in 15 species (8% of the cases). The distribution of K2P distance between individuals and species overlapped and identifications were only possible to species group using DNA barcodes in these cases. Conversely, deep hidden genetic divergence was revealed within two species, suggesting the presence of cryptic species.
Conclusions/Significance
The present study evidenced that freshwater fish species can be efficiently identified through the use of DNA barcoding, especially the species complex of small-sized species, and that the present COI library can be used for subsequent applications in ecology and systematics.
ABSTRACT: BACKGROUND: Reliable and consistent methods are required for the identification and classification of freshwater snails belonging to the genus Bulinus (Gastropoda, Planorbidae) which act as intermediate hosts for schistosomes of both medical and veterinary importance. The current project worked towards two main objectives, the development of a cost effective, simple screening method for the routine identification of Bulinus isolates and the use of resultant sequencing data to produce a model of relationships within the group. RESULTS: Phylogenetic analysis of the DNA sequence for a large section (1009 bp) of the mitochondrial gene cytochrome oxidase subunit 1 (cox1) for isolates of Bulinus demonstrated superior resolution over that employing the second internal transcribed spacer (its2) of the ribosomal gene complex. Removal of transitional substitutions within cox1 because of saturation effects still allowed identification of snails at species group level. Within groups, some species could be identified with ease but there were regions where the high degree of molecular diversity meant that clear identification of species was problematic, this was particularly so within the B. africanus group. CONCLUSION: The sequence diversity within cox1 is such that a barcoding approach may offer the best method for characterization of populations and species within the genus from different geographical locations. The study has confirmed the definition of some accepted species within the species groups but additionally has revealed some unrecognized isolates which underlines the need to use molecular markers in addition to more traditional methods of identification. A barcoding approach based on part of the cox1 gene as defined by the Folmer primers is proposed.
Species inventories are essential for documenting global diversity and generating necessary material for taxonomic study and conservation planning. However, for inventories to be immediately relevant, the taxonomic process must reduce the time to describe and identify specimens. To address these concerns for the inventory of arthropods across the Malagasy region, we present here a collaborative approach to taxonomy where collectors, morphologists and DNA barcoders using cytochrome c oxidase 1 (CO1) participate collectively in a team-driven taxonomic process. We evaluate the role of DNA barcoding as a tool to accelerate species identification and description. This revision is primarily based on arthropod surveys throughout the Malagasy region from 1992 to 2006. The revision is based on morphological and CO1 DNA barcode analysis of 500 individuals. In the region, five species of Anochetus (A. boltonisp. nov., A. goodmanisp. nov., A. grandidieri, and A. madagascarensis from Madagascar, and A. pattersonisp. nov. from Seychelles) and three species of Odontomachus (O. coquereli, O. troglodytes and O. simillimus) are recognized. DNA barcoding (using cytochrome c oxidase 1 (CO1)) facilitated caste association and type designation, and highlighted population structure associated with reproductive strategy, biogeographic and evolutionary patterns for future exploration. This study provides an example of collaborative taxonomy, where morphology is combined with DNA barcoding. We demonstrate that CO1 DNA barcoding is a practical tool that allows formalized alpha-taxonomy at a speed, detail, precision, and scale unattainable by employing morphology alone.
Many plant species are considered difficult for DNA isolation due to their high concentrations of secondary metabolites such as polysaccharides and polyphenols. Several protocols have been developed to overcome this problem, but they are typically time-consuming, not scalable for high throughput and not compatible with automation. Although a variety of commercial kits are available for plant DNA isolation, their cost is high and these kits usually have limited taxonomic applicability. In a previous study we developed an inexpensive automation-friendly protocol for DNA extraction from animal tissues. Here we demonstrate that a similar protocol allows DNA isolation from plants.
An isolate of the filamentous red alga Acrochaetium efflorescens from the NE Atlantic was followed in culture through a triphasic sexual life history. Morphology of each phase matched previous descriptions for this alga. However, inclusion of A. efflorescens in the genus Acrochaetium is problematic. In current taxonomic treatments this genus includes acrochaetioid algae with a stellate plastid and a large central pyrenoid. Acrochaetium efflorescens, on the other hand, has consistently been reported to possess spiral to ribbon-shaped plastids. To determine the phylogenetic affinities of A. efflorescens, we sequenced large subunit ribosomal DNA and resolved full support (Bayesian posterior probabilities; maximum likelihood, neighbour joining, and parsimony bootstrap percentages) for inclusion of A. efflorescens within the order Acrochaetiales. However, it does not associate closely with any of the existing genera in this order, showing only a weak affinity to the genus Rhodochorton. The genus Grania, originally established by Kylin, is currently available for this species. Given its distinct anatomy (ribbon-shaped plastids in combination with seriate carposporangia), unique molecular signature, and lack of congruence with other current generic concepts within the Acrochaetiales, we advocate resurrecting the genus Graniafor G. efflorescens.
Species inventories are essential for documenting global diversity and generating necessary material for taxonomic study and conservation planning. However, for inventories to be immediately relevant, the taxonomic process must reduce the time to describe and identify specimens. To address these concerns for the inventory of arthropods across the Malagasy region, we present here a collaborative approach to taxonomy where collectors, morphologists and DNA barcoders using cytochrome c oxidase 1 (CO1) participate collectively in a team-driven taxonomic process. We evaluate the role of DNA barcoding as a tool to accelerate species identification and description. This revision is primarily based on arthropod surveys throughout the Malagasy region from 1992 to 2006. The revision is based on morphological and CO1 DNA barcode analysis of 500 individuals. In the region, five species of Anochetus (A. boltonisp. nov., A. goodmanisp. nov., A. grandidieri, and A. madagascarensis from Madagascar, and A. pattersonisp. nov. from Seychelles) and three species of Odontomachus (O. coquereli, O. troglodytes and O. simillimus) are recognized. DNA barcoding (using cytochrome c oxidase 1 (CO1)) facilitated caste association and type designation, and highlighted population structure associated with reproductive strategy, biogeographic and evolutionary patterns for future exploration. This study provides an example of collaborative taxonomy, where morphology is combined with DNA barcoding. We demonstrate that CO1 DNA barcoding is a practical tool that allows formalized alpha-taxonomy at a speed, detail, precision, and scale unattainable by employing morphology alone.
An isolate of the filamentous red alga Acrochaetium efflorescens from the NE Atlantic was followed in culture through a triphasic sexual life history. Morphology of each phase matched previous descriptions for this alga. However, inclusion of A. efflorescens in the genus Acrochaetium is problematic. In current taxonomic treatments this genus includes acrochaetioid algae with a stellate plastid and a large central pyrenoid. Acrochaetium efflorescens, on the other hand, has consistently been reported to possess spiral to ribbon-shaped plastids. To determine the phylogenetic affinities of A. efflorescens, we sequenced large subunit ribosomal DNA and resolved full support (Bayesian posterior probabilities; maximum likelihood, neighbour joining, and parsimony bootstrap percentages) for inclusion of A. efflorescens within the order Acrochaetiales. However, it does not associate closely with any of the existing genera in this order, showing only a weak affinity to the genus Rhodochorton. The genus Grania, originally established by Kylin, is currently available for this species. Given its distinct anatomy (ribbon-shaped plastids in combination with seriate carposporangia), unique molecular signature, and lack of congruence with other current generic concepts within the Acrochaetiales, we advocate resurrecting the genus Graniafor G. efflorescens.
Here we describe a new octoploid species of clawed frog from the Itombwe Massif of South Kivu Province, Democratic Republic of the Congo. This new species is the sister taxon of Xenopus wittei, but is substantially diverged in morphology, male vocalization, and mitochondrial and autosomal DNA. Analysis of mitochondrial “DNA barcodes” in polyploid clawed frogs demonstrates that they are variable between most species, but also reveals limitations of this type of information for distinguishing closely related species of differing ploidy level. The discovery of this new species highlights the importance of the Itombwe Massif for conservation of African biodiversity south of the Sahara.
Here we describe a new octoploid species of clawed frog from the Itombwe Massif of South Kivu Province, Democratic Republic of the Congo. This new species is the sister taxon of Xenopus wittei, but is substantially diverged in morphology, male vocalization, and mitochondrial and autosomal DNA. Analysis of mitochondrial “DNA barcodes” in polyploid clawed frogs demonstrates that they are variable between most species, but also reveals limitations of this type of information for distinguishing closely related species of differing ploidy level. The discovery of this new species highlights the importance of the Itombwe Massif for conservation of African biodiversity south of the Sahara.
Many plant species are considered difficult for DNA isolation due to their high concentrations of secondary metabolites such as polysaccharides and polyphenols. Several protocols have been developed to overcome this problem, but they are typically time-consuming, not scalable for high throughput and not compatible with automation. Although a variety of commercial kits are available for plant DNA isolation, their cost is high and these kits usually have limited taxonomic applicability. In a previous study we developed an inexpensive automation-friendly protocol for DNA extraction from animal tissues. Here we demonstrate that a similar protocol allows DNA isolation from plants.
Many plant species are considered difficult for DNA isolation due to their high concentrations of secondary metabolites such as polysaccharides and polyphenols. Several protocols have been developed to overcome this problem, but they are typically time-consuming, not scalable for high throughput and not compatible with automation. Although a variety of commercial kits are available for plant DNA isolation, their cost is high and these kits usually have limited taxonomic applicability. In a previous study we developed an inexpensive automation-friendly protocol for DNA extraction from animal tissues. Here we demonstrate that a similar protocol allows DNA isolation from plants.
DNA sequences consisting of about 600 base pairs of the 5' region of the cytochrome c oxidase subunit 1 (COI) gene has been proposed as DNA Barcodes for taxonomical identification of species in different animals. We evaluated the application of two-dimensional barcodes for 'DNA Barcoding'. 'PDF417' symbology was applied to convert DNA Barcode sequences already proposed [N. Pradeep Kumar, A.R. Rajavel, R. Natarajan, P. Jambulingam, DNA Barcodes can distinguish species of Indian mosquitoes (Diptera: Culicidae). J. Med. Entomol. 77 (2007) 1-7.] for 10 different species of mosquitoes prevalent in India. Decoding of these digital images using 2-D scanner and a suitable software reproduced the input DNA sequences unchanged. This analysis indicated the utility of PDF417 for 'DNA Barcoding', which could be of definite use for taxonomic documentation of animals.
Diagnostic features of morphology, physiology, serology and genetics of species belonging to the Exophiala spinifera clade (including 11 species: Exophiala oligosperma, E. spinifera, E. xenobiotica, E. jeanselmei, E. exophialae, E. nishimurae, E. bergeri, E. nigra, Rhinocladiella similis, Ramichloridium basitonum and Phaeoannellomyces elegans), comprising a large number of human-associated Exophiala species, are summarized. Several species have closely similar morphological characters and physiological profiles. Taxonomy is therefore primarily based on sequence diversity of the Internal Transcribed Spacer (ITS) region of ribosomal DNA (rDNA). Multilocus sequencing has shown that ITS is reliable for identification of the species in this clade, and is a therefore a good candidate for barcoding species of Exophiala. Species-specific fragments were searched in the ITS region of species in the Exophiala spinifera clade and can be used to design probes for diagnosis by hybridization
Species inventories are essential for documenting global diversity and generating necessary material for taxonomic study and conservation planning. However, for inventories to be immediately relevant, the taxonomic process must reduce the time to describe and identify specimens. To address these concerns for the inventory of arthropods across the Malagasy region, we present here a collaborative approach to taxonomy where collectors, morphologists and DNA barcoders using cytochrome c oxidase 1 (CO1) participate collectively in a team-driven taxonomic process. We evaluate the role of DNA barcoding as a tool to accelerate species identification and description. This revision is primarily based on arthropod surveys throughout the Malagasy region from 1992 to 2006. The revision is based on morphological and CO1 DNA barcode analysis of 500 individuals. In the region, five species of Anochetus (A. boltonisp. nov., A. goodmanisp. nov., A. grandidieri, and A. madagascarensis from Madagascar, and A. pattersonisp. nov. from Seychelles) and three species of Odontomachus (O. coquereli, O. troglodytes and O. simillimus) are recognized. DNA barcoding (using cytochrome c oxidase 1 (CO1)) facilitated caste association and type designation, and highlighted population structure associated with reproductive strategy, biogeographic and evolutionary patterns for future exploration. This study provides an example of collaborative taxonomy, where morphology is combined with DNA barcoding. We demonstrate that CO1 DNA barcoding is a practical tool that allows formalized alpha-taxonomy at a speed, detail, precision, and scale unattainable by employing morphology alone.
DNA barcodes can be used to identify cryptic species of skipper butterflies previously detected by classic taxonomic methods and to provide first clues to the existence of yet other cryptic species. A striking case is the common geographically and ecologically widespread neotropical skipper butterfly Perichares philetes (Lepidoptera, Hesperiidae), described in 1775, which barcoding splits into a complex of four species in Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica. Three of the species are new, and all four are described. Caterpillars, pupae, and foodplants offer better distinguishing characters than do adults, whose differences are mostly average, subtle, and blurred by intraspecific variation. The caterpillars of two species are generalist grass-eaters; of the other two, specialist palm-eaters, each of which feeds on different genera. But all of these cryptic species are more specialized in their diet than was the morphospecies that held them. The four ACG taxa discovered to date belong to a panneotropical complex of at least eight species. This complex likely includes still more species, whose exposure may require barcoding. Barcoding ACG hesperiid morphospecies has increased their number by nearly 10%, an unexpectedly high figure for such relatively well known insects.
Royal Ontario Museum in Toronto: The conference will highlight key advances in a DNA barcode-based approach to biodiversity recognition, including recent bioinformatic developments. Taking place over two days, the conference will address what is known of barcodes for both Canadian and global biodiversity. The impacts of this knowledge will be examined in terms of both technology development and the implications for scientific and public policy.
Keynote speakers:
Daniel H. Janzen, DiMaura Professor, University of Pennsylvania
Scott E. Miller, Office of the Under Secretary for Science at the Smithsonian Institution: With special Network research theme presentations by:
Spencer Barrett (University of Toronto) - Plants
Brian Golding (McMaster University) - Informatics
Paul Hebert (University of Guelph) - Animals
Donal Hickey (Concordia University) - Fungi
Gary Saunders (University of New Brunswick) - Protists
Registration will include access to all sessions on April 28th and 29th, after-hours admission to Darwin: the Evolution Revolution, reception and dinner April 28th at the ROM, and refreshments at all breaks and lunches on both days. Abstract submission deadline has been extended until March 28th. For more information, read the Call for Abstracts (http://www.bolnet.ca/Announcement%20-%20Call%20for%20abstracts.pdf). Please register for the conference using this form. (http://www.bolnet.ca/registration.pdf) Thank you to everyone who has already registered. If you wish to assist in spreading the word about the conference, please print this poster (http://www.bolnet.ca/bolnet-poster.pdf) for distribution.
Please contact Sue-Ann Connolly (sujohnst@uoguelph.ca) with questions.
The 2nd Scientific Symposium of the Canadian Barcode of Life Network will take place April 28-29, 2008 at the Royal Ontario Museum in Toronto, Canada. Save the dates, and note a reception and dinner are planned for the evening of the 28th. Registration details will be posted on www.bolnet.ca in January of 2008.
A PCR-based DNA macroarray hybridization technique (also called reverse dot blot hybridization) was developed for cranberry fruit rot (CFR) fungal pathogens, and its detection capability was compared with that of the traditional isolation plating method for CFR isolation and identification from over 2000 field samples. DNA array hybridization results correlated well with detection by isolation when cranberry fruit samples had calyces removed. It also provided detection of CFR fungi not recovered by isolation. When calyces were not removed, the number of cranberry samples where a species was isolated but not detected on the array increased. Isolation without array detection was also correlated with using greater amounts of berry mass for DNA extraction. This was due to the complexity of DNA template mixtures and the presence of some fungal species at very low concentrations. Multiple PCR reactions may be necessary to accurately detect the diversity of fungal pathogens in such situations. Overall, the use of DNA array hybridization for CFR fungi detection is a rapid, sensitive, and cost-effective technique that shows great potential for future CFR research
We examined phylogeographic relationships in the cosmopolitan polypore fungus Ganoderma applanatum and allies, and conservatively infer a possible age of origin for these fungi. Results indicate that it is very unlikely that members of this species complex diversified before the break-up of Gondwana from Laurasia ca 120M years ago, and also before the final separation of the Gondwanan landmasses from each other that was achieved about 66M years ago. An earliest possible age of origin of 30M years was estimated from nucleotide substitution rates in the 18S rDNA gene. Phylogenetic reconstruction of a worldwide sampling of ITS rDNA sequences reveals at least eight distinct clades that are strongly correlated with the geographic origin of the strains, and also correspond to mating groups. These include one Southern Hemisphere clade, one Southern Hemisphere-Eastern Asia clade, two temperate Northern Hemisphere clades, three Asian clades, and one neotropical clade. Geographically distant collections from the Southern Hemisphere shared identical ITS haplotypes, and an ITS recombinant was noted. Nested clade analysis of a parsimony network among isolates of the Southern Hemisphere clade indicated restricted gene flow with isolation-by-distance among the New Zealand, Australia-Tasmania, Chile-Argentine, and South Africa populations, suggesting episodic events of long-distance dispersal within the Southern Hemisphere. This study indicates that dispersal bias plays a more important role than generally admitted to explain the Southern Hemisphere distribution of many taxa, at least for saprobic fungi.
Early detection of economically important insects is critical to preventing their establishment as serious pests. To accomplish this, tools for rapid and accurate species identification are needed. DNA barcoding, using short DNA sequences as species "genetic identification tags," has already shown large potential as a tool for rapid and accurate detection of economically important insects. DNA extraction is the critical first step in generating DNA barcodes and can be a rate-limiting step in very large barcoding studies. Consequently, a DNA extraction method that is rapid, easy to use, cost-effective, robust enough to cope with range of qualities and quantities of tissue, and can be adapted to robotic systems will provide the best method for high-throughput production of DNA barcodes. We tested the performance of a new commercial kit (prepGEM), which uses a novel, streamlined approach to DNA extraction, and we compared it with two other commercial kits (ChargeSwitch and Aquapure), which differ in their method of DNA extraction. We compared performance of these kits by measuring percentage of polymerase chain reaction (PCR) success and mean PCR product yield across a variety of arthropod taxa, whichincluded freshly collected, ethanol-preserved, and dried specimens of different ages. ChargeSwitch and prepGEM performed equally well, but they outperformed Aquapure. prepGEM was much faster, easier to use, and cheaper than ChargeSwitch, but ChargeSwitch performed slightly better for older (> 5-yr-old) dried insect specimens. Overall, prepGEM may provide a highly streamlined method of DNA extraction for fresh, ethanol-preserved, and young, dried specimens, especially when adapted for high-throughput, robotic systems.
Mitochondrial genomes show wide variation in their GC content. This study examines the correlations between mitochondrial genome-wide shifts in this feature and a fragment of the cytochrome c oxidase subunit I (COI) gene in animals, plants, and fungi. Because this approach utilizes COI as a sentinel, analyzing sequences from repositories such as GenBank and the Barcode of Life Data System (BOLD) can provide rapid insights into nucleotide usage. With this approach we probe nucleotide composition in a variety of taxonomic groups and establish the degree to which mitochondrial GC content varies among them. We then focus on two groups in particular, the classes Insecta and Aves, which possess the highest and lowest GC content, respectively. We establish that the sentinel approach provides strong indicators of mitochondrial GC content within divergent phyla (R values = 0.86-0.95, p < 0.001, in test cases) and provide evidence that selective pressures acting on GC content extend to noncoding regions of the plant and fungal mitochondrial genomes. We demonstrate that there is considerable variation in GC content of the mitochondrial genome within phyla and at each taxonomic level, leading to a substantial overlap zone in GC content between chordates and invertebrates. Our results provide a novel insight into the mitochondrial genome composition of animals, plants, and fungi and advocate this sentinel technique for the detection of rapid alterations in nucleotide usage as a measure of mitochondrial genome biodiversity.
Mitochondrial genomes show wide variation in their GC content. This study examines the correlations between mitochondrial genome-wide shifts in this feature and a fragment of the cytochrome c oxidase subunit I (COI) gene in animals, plants, and fungi. Because this approach utilizes COI as a sentinel, analyzing sequences from repositories such as GenBank and the Barcode of Life Data System (BOLD) can provide rapid insights into nucleotide usage. With this approach we probe nucleotide composition in a variety of taxonomic groups and establish the degree to which mitochondrial GC content varies among them. We then focus on two groups in particular, the classes Insecta and Aves, which possess the highest and lowest GC content, respectively. We establish that the sentinel approach provides strong indicators of mitochondrial GC content within divergent phyla (R values = 0.86-0.95, p < 0.001, in test cases) and provide evidence that selective pressures acting on GC content extend to noncoding regions of the plant and fungal mitochondrial genomes. We demonstrate that there is considerable variation in GC content of the mitochondrial genome within phyla and at each taxonomic level, leading to a substantial overlap zone in GC content between chordates and invertebrates. Our results provide a novel insight into the mitochondrial genome composition of animals, plants, and fungi and advocate this sentinel technique for the detection of rapid alterations in nucleotide usage as a measure of mitochondrial genome biodiversity.
Although genetic methods of species identification, especially DNA barcoding, are strongly debated, tests of these methods have been restricted to a few empirical cases for pragmatic reasons. Here we use simulation to test the performance of methods based on sequence comparison (BLAST and genetic distance) and tree topology over a wide range of evolutionary scenarios. Sequences were simulated on a range of gene trees spanning almost three orders of magnitude in tree depth and in coalescent depth; that is, deep or shallow trees with deep or shallow coalescences. When the query's conspecific sequences were included in the reference alignment, the rate of positive identification was related to the degree to which different species were genetically differentiated. The BLAST, distance, and liberal tree-based methods returned higher rates of correct identification than did the strict tree-based requirement that the query was within, but not sister to, a single-species clade. Under this more conservative approach, ambiguous outcomes occurred in inverse proportion to the number of reference sequences per species. When the query's conspecific sequences were not in the reference alignment, only the strict tree-based approach was relatively immune to making false-positive identifications. Thresholds affected the rates at which false-positive identifications were made when the query's species was unrepresented in the reference alignment but did not otherwise influence outcomes. A conservative approach using the strict tree-based method should be used initially in large-scale identification systems, with effort made to maximize sequence sampling within species. Once the genetic variation within a taxonomic group is well characterized and the taxonomy resolved, then the choice of method used should be dictated by considerations of computational efficiency. The requirement for extensive genetic sampling may render these techniques inappropriate in some circumstances.
DNA barcoding as a method for species identification is rapidly increasing in popularity. However, there are still relatively few rigorous methodological tests of DNA barcoding. Current distance-based methods are frequently criticized for treating the nearest neighbor as the closest relative via a raw similarity score, lacking an objective set of criteria to delineate taxa, or for being incongruent with classical character-based taxonomy. Here, we propose an artificial intelligence-based approach - inferring species membership via DNA barcoding with back-propagation neural networks (named BP-based species identification) - as a new advance to the spectrum of available methods. We demonstrate the value of this approach with simulated data sets representing different levels of sequence variation under coalescent simulations with various evolutionary models, as well as with two empirical data sets of COI sequences from East Asian ground beetles (Carabidae) and Costa Rican skipper butterflies. With a 630-to 690-bp fragment of the COI gene, we identified 97.50% of 80 unknown sequences of ground beetles, 95.63%, 96.10%, and 100% of 275, 205, and 9 unknown sequences of the neotropical skipper butterfly to their correct species, respectively. Our simulation studies indicate that the success rates of species identification depend on the divergence of sequences, the length of sequences, and the number of reference sequences. Particularly in cases involving incomplete lineage sorting, this new BP-based method appears to be superior to commonly used methods for DNA-based species identification.
Mitochondrial genomes show wide variation in their GC content. This study examines the correlations between mitochondrial genome-wide shifts in this feature and a fragment of the cytochrome c oxidase subunit I (COI) gene in animals, plants, and fungi. Because this approach utilizes COI as a sentinel, analyzing sequences from repositories such as GenBank and the Barcode of Life Data System (BOLD) can provide rapid insights into nucleotide usage. With this approach we probe nucleotide composition in a variety of taxonomic groups and establish the degree to which mitochondrial GC content varies among them. We then focus on two groups in particular, the classes Insecta and Aves, which possess the highest and lowest GC content, respectively. We establish that the sentinel approach provides strong indicators of mitochondrial GC content within divergent phyla (R values = 0.86-0.95, p < 0.001, in test cases) and provide evidence that selective pressures acting on GC content extend to noncoding regions of the plant and fungal mitochondrial genomes. We demonstrate that there is considerable variation in GC content of the mitochondrial genome within phyla and at each taxonomic level, leading to a substantial overlap zone in GC content between chordates and invertebrates. Our results provide a novel insight into the mitochondrial genome composition of animals, plants, and fungi and advocate this sentinel technique for the detection of rapid alterations in nucleotide usage as a measure of mitochondrial genome biodiversity.
Mitochondrial genomes show wide variation in their GC content. This study examines the correlations between mitochondrial genome-wide shifts in this feature and a fragment of the cytochrome c oxidase subunit I (COI) gene in animals, plants, and fungi. Because this approach utilizes COI as a sentinel, analyzing sequences from repositories such as GenBank and the Barcode of Life Data System (BOLD) can provide rapid insights into nucleotide usage. With this approach we probe nucleotide composition in a variety of taxonomic groups and establish the degree to which mitochondrial GC content varies among them. We then focus on two groups in particular, the classes Insecta and Aves, which possess the highest and lowest GC content, respectively. We establish that the sentinel approach provides strong indicators of mitochondrial GC content within divergent phyla (R values = 0.86-0.95, p < 0.001, in test cases) and provide evidence that selective pressures acting on GC content extend to noncoding regions of the plant and fungal mitochondrial genomes. We demonstrate that there is considerable variation in GC content of the mitochondrial genome within phyla and at each taxonomic level, leading to a substantial overlap zone in GC content between chordates and invertebrates. Our results provide a novel insight into the mitochondrial genome composition of animals, plants, and fungi and advocate this sentinel technique for the detection of rapid alterations in nucleotide usage as a measure of mitochondrial genome biodiversity.
We examined phylogeographic relationships in the cosmopolitan polypore fungus Ganoderma applanatum and allies, and conservatively infer a possible age of origin for these fungi. Results indicate that it is very unlikely that members of this species complex diversified before the break-up of Gondwana from Laurasia ca 120M years ago, and also before the final separation of the Gondwanan landmasses from each other that was achieved about 66M years ago. An earliest possible age of origin of 30M years was estimated from nucleotide substitution rates in the 18S rDNA gene. Phylogenetic reconstruction of a worldwide sampling of ITS rDNA sequences reveals at least eight distinct clades that are strongly correlated with the geographic origin of the strains, and also correspond to mating groups. These include one Southern Hemisphere clade, one Southern Hemisphere-Eastern Asia clade, two temperate Northern Hemisphere clades, three Asian clades, and one neotropical clade. Geographically distant collections from the Southern Hemisphere shared identical ITS haplotypes, and an ITS recombinant was noted. Nested clade analysis of a parsimony network among isolates of the Southern Hemisphere clade indicated restricted gene flow with isolation-by-distance among the New Zealand, Australia-Tasmania, Chile-Argentine, and South Africa populations, suggesting episodic events of long-distance dispersal within the Southern Hemisphere. This study indicates that dispersal bias plays a more important role than generally admitted to explain the Southern Hemisphere distribution of many taxa, at least for saprobic fungi.
The full promise of human genomics will be realized only when the genomes of thousands of individuals can be sequenced for comparative analysis. A reference sequence enables the use of short read length. We report an amplification-free method for determining the nucleotide sequence of more than 280,000 individual DNA molecules simultaneously. A DNA polymerase adds labeled nucleotides to surface-immobilized primer-template duplexes in stepwise fashion, and the asynchronous growth of individual DNA molecules was monitored by fluorescence imaging. Read lengths of >25 bases and equivalent phred software program quality scores approaching 30 were achieved. We used this method to sequence the M13 virus to an average depth of >150x and with 100% coverage; thus, we resequenced the M13 genome with high-sensitivity mutation detection. This demonstrates a strategy for high-throughput low-cost resequencing.
Platymantis is a group of neobatrachian frogs that occurs from the Philippines to New Guinea – an area situated at the interface between the Australian and Asian biogeographical region that is highly fragmented by stretches of open sea. Partial sequences of the mitochondrial 12S rRNA gene are herein used to infer the relationships of species from the Indonesian part of New Guinea (Papua and West Papua Province). The phylogenetic trees reveal a deep bifurcation between the Asian and Western New Guinean clades being consistent with phylogeographic patterns observed in various other faunal groups. While most species are well differentiated in the examined locus, low interspecific genetic distances between one and three percent were observed in the New Guinean species Platymantis papuensis and P. cryptotis as well as P. pelewensis from Palau. Platymantis papuensis and P. pelewensis are geographically separated from each other by a 1100 km stretch of open sea. The minor degree of genetic differentiation between both species points to a recent event of transmarine dispersal as causation for the occurrence of P. pelewensis on Palau. The low genetic differentiation between P. cryptotis and the sympatric P. papuensis, two species that are bioacoustically and morphologically distinct, may indicate its possibly recent evolutionary origin or, alternatively, yet undetected hybridization between the two species. The same may also hold true for frogs from Yapen that exhibit calls different from the sympatric P. papuensis. Tentatively referred to as Platymantis spec., these frogs are also genetically not well differentiated. It is furthermore concluded that the partly low genetic differentiation of the New Guinean Platymantis species render this group one of the cases in which DNA barcoding would likely fail to produce reliable results.
This paper re-evaluated the use of DNA barcodes in earthworm species identification by re-analyzing sequence data for the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. This analysis unveiled and confirmed taxonomic inconsistencies which significantly affect data interpretation. When considering synonymy and misidentification in published records, our results revealed no shared COI haplotypes between morphologically distinct species and higher interspecific than intraspecific divergence in most cases, with interspecific and intraspecific distances averaging 18.7% and 1.3% respectively. However, a few earthworm species endemic to Taiwan have deep intraspecific divergences which may represent potential cases of cryptic diversity, although incomplete lineage sorting cannot be ruled out without further study. We recognize the potential of DNA barcoding for earthworm taxonomy, but have identified several issues regarding the evolution of the COI gene in these organisms which remain to be further elucidated.
This paper re-evaluated the use of DNA barcodes in earthworm species identification by re-analyzing sequence data for the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. This analysis unveiled and confirmed taxonomic inconsistencies which significantly affect data interpretation. When considering synonymy and misidentification in published records, our results revealed no shared COI haplotypes between morphologically distinct species and higher interspecific than intraspecific divergence in most cases, with interspecific and intraspecific distances averaging 18.7% and 1.3% respectively. However, a few earthworm species endemic to Taiwan have deep intraspecific divergences which may represent potential cases of cryptic diversity, although incomplete lineage sorting cannot be ruled out without further study. We recognize the potential of DNA barcoding for earthworm taxonomy, but have identified several issues regarding the evolution of the COI gene in these organisms which remain to be further elucidated.
This paper re-evaluated the use of DNA barcodes in earthworm species identification by re-analyzing sequence data for the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. This analysis unveiled and confirmed taxonomic inconsistencies which significantly affect data interpretation. When considering synonymy and misidentification in published records, our results revealed no shared COI haplotypes between morphologically distinct species and higher interspecific than intraspecific divergence in most cases, with interspecific and intraspecific distances averaging 18.7% and 1.3% respectively. However, a few earthworm species endemic to Taiwan have deep intraspecific divergences which may represent potential cases of cryptic diversity, although incomplete lineage sorting cannot be ruled out without further study. We recognize the potential of DNA barcoding for earthworm taxonomy, but have identified several issues regarding the evolution of the COI gene in these organisms which remain to be further elucidated.
This paper re-evaluated the use of DNA barcodes in earthworm species identification by re-analyzing sequence data for the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. This analysis unveiled and confirmed taxonomic inconsistencies which significantly affect data interpretation. When considering synonymy and misidentification in published records, our results revealed no shared COI haplotypes between morphologically distinct species and higher interspecific than intraspecific divergence in most cases, with interspecific and intraspecific distances averaging 18.7% and 1.3% respectively. However, a few earthworm species endemic to Taiwan have deep intraspecific divergences which may represent potential cases of cryptic diversity, although incomplete lineage sorting cannot be ruled out without further study. We recognize the potential of DNA barcoding for earthworm taxonomy, but have identified several issues regarding the evolution of the COI gene in these organisms which remain to be further elucidated.
BACKGROUND: DNA barcoding of life using a standardized COI sequence was proposed as a species identification system, and as a method for detecting putative new species. Previous tests in birds showed that individuals can be correctly assigned to species in ~94% of the cases and suggested a threshold of 10x mean intraspecific difference to detect potential new species. However, these tests were criticized because they were based on a single maternally inherited gene rather than multiple nuclear genes, did not compare phylogenetically identified sister species, and thus likely overestimated the efficacy of DNA barcodes in identifying species. RESULTS: To test the efficacy of DNA barcodes we compared ~650 bp of COI in 60 sister-species pairs identified in multigene phylogenies from 10 orders of birds. In all pairs, individuals of each species were monophyletic in a neighbor-joining (NJ) tree, and each species possessed fixed mutational differences distinguishing them from their sister species. Consequently, individuals were correctly assigned to species using a statistical coalescent framework. A coalescent test of taxonomic distinctiveness based on chance occurrence of reciprocal monophyly in two lineages was verified in known sister species, and used to identify recently separated lineages that represent putative species. This approach avoids the use of a universal distance cutoff which is invalidated by variation in times to common ancestry of sister species and in rates of evolution. CONCLUSION: Closely related sister species of birds can be identified reliably by barcodes of fixed diagnostic substitutions in COI sequences, verifying coalescent-based statistical tests of reciprocal monophyly for taxonomic distinctiveness. Contrary to recent criticisms, a single DNA barcode is a rapid way to discover monophyletic lineages within a metapopulation that might represent undiscovered cryptic species, as envisaged in the unified species concept. This identifies a smaller set of lineages that can also be tested independently for species status with multiple nuclear gene approaches and other phenotypic characters.
BACKGROUND: DNA barcoding of life using a standardized COI sequence was proposed as a species identification system, and as a method for detecting putative new species. Previous tests in birds showed that individuals can be correctly assigned to species in ~94% of the cases and suggested a threshold of 10x mean intraspecific difference to detect potential new species. However, these tests were criticized because they were based on a single maternally inherited gene rather than multiple nuclear genes, did not compare phylogenetically identified sister species, and thus likely overestimated the efficacy of DNA barcodes in identifying species. RESULTS: To test the efficacy of DNA barcodes we compared ~650 bp of COI in 60 sister-species pairs identified in multigene phylogenies from 10 orders of birds. In all pairs, individuals of each species were monophyletic in a neighbor-joining (NJ) tree, and each species possessed fixed mutational differences distinguishing them from their sister species. Consequently, individuals were correctly assigned to species using a statistical coalescent framework. A coalescent test of taxonomic distinctiveness based on chance occurrence of reciprocal monophyly in two lineages was verified in known sister species, and used to identify recently separated lineages that represent putative species. This approach avoids the use of a universal distance cutoff which is invalidated by variation in times to common ancestry of sister species and in rates of evolution. CONCLUSION: Closely related sister species of birds can be identified reliably by barcodes of fixed diagnostic substitutions in COI sequences, verifying coalescent-based statistical tests of reciprocal monophyly for taxonomic distinctiveness. Contrary to recent criticisms, a single DNA barcode is a rapid way to discover monophyletic lineages within a metapopulation that might represent undiscovered cryptic species, as envisaged in the unified species concept. This identifies a smaller set of lineages that can also be tested independently for species status with multiple nuclear gene approaches and other phenotypic characters.
Although a mitochondrial DNA barcode has been shown to be of great utility for species identification and discovery in an increasing number of diverse taxa, caution has been urged with its application to one of the most taxonomically diverse vertebrate groups - the amphibians. Here, we test three of the perceived shortcomings of a CO1 DNA barcode's utility with a group of Holarctic amphibians: primer fit, sequence variability and overlapping intra- and interspecific variability. We found that although the CO1 DNA barcode priming regions were variable, we were able to reliably amplify a CO1 fragment from degenerate primers and primers with G-C residues at the 3' end. Any overlap between intra- and interspecific variation in our taxonomic sampling was due to introgressive hybridization (Bufo/Anaxyrus), complex genetics (Ambystoma) or incomplete taxonomy (Triturus). Rates of hybridization and species discovery are not expected to be greater for amphibians than for other vertebrate groups, and thus problems with the utility of using a single mitochondrial gene for species identification will not be specific to amphibians. Therefore, we conclude that there is greater potential for a CO1 barcode's use with amphibians than has been reported to date. A large-scale effort to barcode the amphibians of the world, using the same primary barcode region of CO1, will yield important findings for science and conservation.
Although a mitochondrial DNA barcode has been shown to be of great utility for species identification and discovery in an increasing number of diverse taxa, caution has been urged with its application to one of the most taxonomically diverse vertebrate groups - the amphibians. Here, we test three of the perceived shortcomings of a CO1 DNA barcode's utility with a group of Holarctic amphibians: primer fit, sequence variability and overlapping intra- and interspecific variability. We found that although the CO1 DNA barcode priming regions were variable, we were able to reliably amplify a CO1 fragment from degenerate primers and primers with G-C residues at the 3' end. Any overlap between intra- and interspecific variation in our taxonomic sampling was due to introgressive hybridization (Bufo/Anaxyrus), complex genetics (Ambystoma) or incomplete taxonomy (Triturus). Rates of hybridization and species discovery are not expected to be greater for amphibians than for other vertebrate groups, and thus problems with the utility of using a single mitochondrial gene for species identification will not be specific to amphibians. Therefore, we conclude that there is greater potential for a CO1 barcode's use with amphibians than has been reported to date. A large-scale effort to barcode the amphibians of the world, using the same primary barcode region of CO1, will yield important findings for science and conservation.
Although a mitochondrial DNA barcode has been shown to be of great utility for species identification and discovery in an increasing number of diverse taxa, caution has been urged with its application to one of the most taxonomically diverse vertebrate groups - the amphibians. Here, we test three of the perceived shortcomings of a CO1 DNA barcode's utility with a group of Holarctic amphibians: primer fit, sequence variability and overlapping intra- and interspecific variability. We found that although the CO1 DNA barcode priming regions were variable, we were able to reliably amplify a CO1 fragment from degenerate primers and primers with G-C residues at the 3' end. Any overlap between intra- and interspecific variation in our taxonomic sampling was due to introgressive hybridization (Bufo/Anaxyrus), complex genetics (Ambystoma) or incomplete taxonomy (Triturus). Rates of hybridization and species discovery are not expected to be greater for amphibians than for other vertebrate groups, and thus problems with the utility of using a single mitochondrial gene for species identification will not be specific to amphibians. Therefore, we conclude that there is greater potential for a CO1 barcode's use with amphibians than has been reported to date. A large-scale effort to barcode the amphibians of the world, using the same primary barcode region of CO1, will yield important findings for science and conservation.
DNA barcoding is a technique in which species identification is performed by using DNA sequences from a small fragment of the genome, with the aim of contributing to a wide range of ecological and conservation studies in which traditional taxonomic identification is not practical. DNA barcoding is well established in animals, but there is not yet any universally accepted barcode for plants. Here, we undertook intensive field collections in two biodiversity hotspots (Mesoamerica and southern Africa). Using >1,600 samples, we compared eight potential barcodes. Going beyond previous plant studies, we assessed to what extent a "DNA barcoding gap" is present between intra- and interspecific variations, using multiple accessions per species. Given its adequate rate of variation, easy amplification, and alignment, we identified a portion of the plastid matK gene as a universal DNA barcode for flowering plants. Critically, we further demonstrate the applicability of DNA barcoding for biodiversity inventories. In addition, analyzing >1,000 species of Mesoamerican orchids, DNA barcoding with matK alone reveals cryptic species and proves useful in identifying species listed in Convention on International Trade of Endangered Species (CITES) appendixes.
The gene encoding for the protein Cytochrome oxidase is a remarkable tool in species identification and classification, writes R S P Rao. Please click here for more information on this article.
DNA barcoding has become a promising means for identifying organisms of all life stages. Currently, phenetic approaches and tree-building methods have been used to define species boundaries and discover 'cryptic species'. However, a universal threshold of genetic distance values to distinguish taxonomic groups cannot be determined. As an alternative, DNA barcoding approaches can be 'character based', whereby species are identified through the presence or absence of discrete nucleotide substitutions (character states) within a DNA sequence. We demonstrate the potential of character-based DNA barcodes by analysing 833 odonate specimens from 103 localities belonging to 64 species. A total of 54 species and 22 genera could be discriminated reliably through unique combinations of character states within only one mitochondrial gene region (NADH dehydrogenase 1). Character-based DNA barcodes were further successfully established at a population level discriminating seven population-specific entities out of a total of 19 populations belonging to three species. Thus, for the first time, DNA barcodes have been found to identify entities below the species level that may constitute separate conservation units or even species units. Our findings suggest that character-based DNA barcoding can be a rapid and reliable means for (i) the assignment of unknown specimens to a taxonomic group, (ii) the exploration of diagnosability of conservation units, and (iii) complementing taxonomic identification systems.
A "barcode gene that can be used to distinguish between the majority of plant species has been identified, say scientists. For more information on this article please click here.
A "barcode gene that can be used to distinguish between the majority of plant species has been identified, say scientists. For more information on this article please click here.
For more information on this article, please click here.
The Gulf of St. Lawrence aster, Symphyotrichum laurentianum (Fernald) G.L. Nesom (Asteraceae), a small annual halophyte endemic to disturbed and highly transient habitats in the Gulf of St. Lawrence, is classified as “threatened” by the Committee on the Status of Endangered Wildlife in Canada. Lepidopteran larvae that are predispersal seed predators of the Gulf of St. Lawrence aster are reported for the first time from populations in Prince Edward Island National Park. DNA barcoding was used to identify the seed predators tentatively as larvae of the casebearing moth Coleophora triplicis McDunnough (Lepidoptera: Coleophoridae), which is typically associated with a related halophyte, Solidago sempervirens L. (Asteraceae). These larvae were found to consume a large proportion of seeds from one of two aster populations in Prince Edward Island National Park and may be yet another risk to the survival of this threatened species.
Fungi are one of the most diverse groups of Eukarya and play essential roles in terrestrial ecosystems as decomposers, pathogens and mutualists. This study unifies disparate reports of unclassified fungal sequences from soils of diverse origins and anchors many of them in a well-supported clade of the Ascomycota equivalent to a subphylum. We refer to this clade as Soil Clone Group I (SCGI). We expand the breadth of environments surveyed and develop a taxon-specific primer to amplify 2.4 kbp rDNA fragments directly from soil. Our results also expand the known range of this group from North America to Europe and Australia. The ancient origin of SCGI implies that it may represent an important transitional form among the basal Ascomycota groups. SCGI is unusual because it currently represents the only major fungal lineage known only from sequence data. This is an important contribution towards building a more complete fungal phylogeny and highlights the need for further work to determine the function and biology of SCGI taxa.
DNA barcoding was applied to the identification of smoked products from fish in 10 families in four orders and allowed identification to the species level, even among closely related species in the same genus. Barcoding is likely to become a standard tool for identification of fish specimens and products.
Fungi are one of the most diverse groups of Eukarya and play essential roles in terrestrial ecosystems as decomposers, pathogens and mutualists. This study unifies disparate reports of unclassified fungal sequences from soils of diverse origins and anchors many of them in a well-supported clade of the Ascomycota equivalent to a subphylum. We refer to this clade as Soil Clone Group I (SCGI). We expand the breadth of environments surveyed and develop a taxon-specific primer to amplify 2.4 kbp rDNA fragments directly from soil. Our results also expand the known range of this group from North America to Europe and Australia. The ancient origin of SCGI implies that it may represent an important transitional form among the basal Ascomycota groups. SCGI is unusual because it currently represents the only major fungal lineage known only from sequence data. This is an important contribution towards building a more complete fungal phylogeny and highlights the need for further work to determine the function and biology of SCGI taxa.
Only a tiny fraction of bees produce honey. Researcher Laurence Packer’s mission is to learn everything he can about the vast majority that don’t. For more information on this article, please click here.
DNA barcoding was applied to the identification of smoked products from fish in 10 families in four orders and allowed identification to the species level, even among closely related species in the same genus. Barcoding is likely to become a standard tool for identification of fish specimens and products.
Only a tiny fraction of bees produce honey. Researcher Laurence Packer’s mission is to learn everything he can about the vast majority that don’t. For more information on this article, please click here.
DNA barcoding - the sequencing of a c. 650 base pair region of the mitochondrial cytochrome c oxidase I gene - strongly suggests that barramundi (Lates calcarifer) from Australia and from Myanmar are different species (Kimura 2 parameter distance of c. 9·5%). Cytochrome b sequence data support this conclusion (distance c. 11.3%). Further examination, both genetic and morphological, of L. calcarifer throughout its range is recommended.
The evolution rates of mtDNA in early metazoans hold important implications for DNA barcoding. Here, we present a comprehensive analysis of intra- and interspecific COI variabilities in Porifera and Cnidaria (separately as Anthozoa, Hydrozoa, and Scyphozoa) using a data set of 619 sequences from 224 species. We found variation within and between species to be much lower in Porifera and Anthozoa compared to Medusozoa (Hydrozoa and Scyphozoa), which has divergences similar to typical metazoans. Given that recent evidence has shown that fungi also exhibit limited COI divergence, slow-evolving mtDNA is likely to be plesiomorphic for the Metazoa. Higher rates of evolution could have originated independently in Medusozoa and Bilateria or been acquired in the Cnidaria + Bilateria clade and lost in the Anthozoa. Low identification success and substantial overlap between intra- and interspecific COI distances render the Anthozoa unsuitable for DNA barcoding. Caution is also advised for Porifera and Hydrozoa because of relatively low identification success rates as even threshold divergence that maximizes the "barcoding gap" does not improve identification success.
DNA barcoding - the sequencing of a c. 650 base pair region of the mitochondrial cytochrome c oxidase I gene - strongly suggests that barramundi (Lates calcarifer) from Australia and from Myanmar are different species (Kimura 2 parameter distance of c. 9·5%). Cytochrome b sequence data support this conclusion (distance c. 11.3%). Further examination, both genetic and morphological, of L. calcarifer throughout its range is recommended.
For more information on this article please click here.
DNA barcoding was applied to the identification of smoked products from fish in 10 families in four orders and allowed identification to the species level, even among closely related species in the same genus. Barcoding is likely to become a standard tool for identification of fish specimens and products.
DNA barcoding was applied to the identification of smoked products from fish in 10 families in four orders and allowed identification to the species level, even among closely related species in the same genus. Barcoding is likely to become a standard tool for identification of fish specimens and products.
DNA barcoding was applied to the identification of smoked products from fish in 10 families in four orders and allowed identification to the species level, even among closely related species in the same genus. Barcoding is likely to become a standard tool for identification of fish specimens and products.
The Gulf of St. Lawrence aster, Symphyotrichum laurentianum (Fernald) G.L. Nesom (Asteraceae), a small annual halophyte endemic to disturbed and highly transient habitats in the Gulf of St. Lawrence, is classified as “threatened” by the Committee on the Status of Endangered Wildlife in Canada. Lepidopteran larvae that are predispersal seed predators of the Gulf of St. Lawrence aster are reported for the first time from populations in Prince Edward Island National Park. DNA barcoding was used to identify the seed predators tentatively as larvae of the casebearing moth Coleophora triplicis McDunnough (Lepidoptera: Coleophoridae), which is typically associated with a related halophyte, Solidago sempervirens L. (Asteraceae). These larvae were found to consume a large proportion of seeds from one of two aster populations in Prince Edward Island National Park and may be yet another risk to the survival of this threatened species.
Parallel tagged sequencing (PTS) is a molecular barcoding method designed to adapt the recently developed high-throughput 454 parallel sequencing technology for use with multiple samples. Unlike other barcoding methods, PTS can be applied to any type of double-stranded DNA (dsDNA) sample, including shotgun DNA libraries and pools of PCR products, and requires no amplification or gel purification steps. The method relies on attaching sample-specific barcoding adapters, which include sequence tags and a restriction site, to blunt-end repaired DNA samples by ligation and strand-displacement. After pooling multiple barcoded samples, molecules without sequence tags are effectively excluded from sequencing by dephosphorylation and restriction digestion, and using the tag sequences, the source of each DNA sequence can be traced. This protocol allows for sequencing 300 or more complete mitochondrial genomes on a single 454 GS FLX run, or twenty-five 6-kb plasmid sequences on only one 16th plate region. Most of the reactions can be performed in a multichannel setup on 96-well reaction plates, allowing for processing up to several hundreds of samples in a few days
Please click here for more information on this article.
Please click here for more information on this article.
DNA barcoding – sequencing a region of the mitochondrial cytochrome c oxidase 1 gene (cox1) – promises a rapid and accurate means of species identification, and of any life history stage. For sharks and rays, it may offer a ready means of identifying legal or illegal shark catches, including shark fins taken for the profitable shark fin market. Here it is shown that an analysis of sequence variability in a 655 bp region of cox1 from 945 specimens of 210 chondrichthyan species from 36 families permits the discrimination of 99.0% of these species. Only the two stingarees Urolophus sufflavus and U. cruciatus could not be separated, although these could be readily distinguished from eight other congeners. The average Kimura 2 parameter distance separating individuals within species was 0.37%, and the average distance separating species within genera was 7.48%. Two specimens that clustered with congeners rather than with their identified species-cluster were noted: these could represent instances of hybridisation (although this has not be documented for chondrichthyans), misidentification or mislabelling. It is concluded that cox1 barcoding can be used to identify shark and ray species with a very high degree of accuracy. The sequence variability characteristics of individuals of five species (Aetomylaeus nichofii, Dasyatis kuhlii, Dasyatis leylandi, Himantura gerrardi and Orectolobus maculatus) were consistent with cryptic speciation, and it is suggested that these five taxa be subjected to detailed taxonomic examination to confirm or refute this suggestion. The present barcoding study holds out great hope for the ready identification of sharks, shark products and shark fins, and also highlights some taxonomic issues that need to be investigated further.
Invasive alien species constitute a substantial conservation challenge in the terrestrial sub-Antarctic. Management plans, for many of the islands in the region, call for the prevention, early detection, and management of such alien species. However, such management may be confounded by difficulties of identification of immatures, especially of holometabolous insects. Here we show how a DNA barcoding approach has helped to overcome such a problem associated with the likely establishment of an alien moth species on Marion Island. The discovery of unidentifiable immatures of a noctuid moth species, 5 km from the research station, suggested that a new moth species had colonized the island. Efforts to identify the larvae by conventional means or by rearing to the adult stage failed. However, sequencing of 617 bp of the mitochondrial cytochrome oxidase subunit I gene, and comparison of the sequence data with sequences on GENBANK and the barcoding of life database enabled us to identify the species as Agrotis ipsilon (Hufnagel), a species of which adults had previously been found regularly at the research station. Discovery of immatures of this species, some distance from the research station, suggests that a population may have established. It is recommended that steps to be taken to eradicate the species from Marion Island.
Fifty-six sequences of the mitochondrial 16S RNA gene were generated for hydroids, belonging to six nominal families — Eudendriidae, Lafoeidae, Haleciidae, Sertulariidae, Plumulariidae and Aglaopheniidae — collected from bathyal environments of the Gulf of Cadiz (22 haplotypes), Greenland (1 haplotype), Azores (1 haplotype), the shallow waters of the UK (17 haplotypes) and Portugal (2 haplotypes). When combined and analysed with 68 additional sequences published in GenBank, corresponding to 63 nominal species of these families (nine species in common between the GenBank sequences and those presented by the authors), cryptic species were detected (e.g. two species of Nemertesia and other of Lafoea), as well as apparent cases of conspecificity (e.g. Nemertesia antennina and N. perrieri and Aglaophenia octodonta, A. pluma and A. tubiformis). Other taxonomic inconsistencies were found in the data including cases where species from different genera clustered together (e.g. Sertularia cupressina, Thuiaria thuja, Abietinaria abietina and Ab. filicula). The mitochondrial 16S rRNA proved to be a useful DNA ‘barcode’ gene for hydroids, not only allowing discrimination of species, but also in some cases of populations, genera and families, and their intra- or interphylogenetic associations. Although still under-represented in public data bases, the 16S rRNA gene is starting to be used frequently in the study of hydroids. These data provide powerful complementary evidence for advancing our understanding of hydrozoan systematics.
The benthic marine worm Xenoturbella is frequently contaminated with molluscan DNA, which had earlier caused confusion resulting in a suggested bivalve relationship. In order to find the source of the contaminant, we have used molluscan sequences derived from Xenoturbella and compared them to barcodes obtained from several individuals of the nonmicroscopic molluscs sharing the same environment as Xenoturbella. Using cytochrome oxidase 1, we found the contaminating sequences to be 98% similar to the bivalve Ennucula tenuis. Using the highly variable D1–D2 region of the large ribosomal subunit in Xenoturbella, we found three distinct species of contaminating molluscs, one of which is 99% similar to the bivalve Abra nitida, one of the most abundant bivalves in the Gullmarsfjord where Xenoturbella was found, and another 99% similar to the bivalve Nucula sulcata. These data clearly show that Xenoturbella only contains molluscan DNA originating from bivalves living in the same environment, refuting former hypotheses of a bivalve relationship. In addition, these data suggest that Xenoturbella feeds specifically on bivalve prey from multiple species, possibly in the form of eggs and larvae.
A nondestructive, chemical-free method is presented for the extraction of DNA from small insects. Blackflies were submerged in sterile, distilled water and sonicated for varying lengths of time to provide DNA which was assessed in terms of quantity, purity and amplification efficiency. A verified DNA barcode was produced from DNA extracted from blackfly larvae, pupae and adult specimens. A 60-second sonication period was found to release the highest quality and quantity of DNA although the amplification efficiency was found to be similar regardless of sonication time. Overall, a 66% amplification efficiency was observed. Examination of post-sonicated material confirmed retention of morphological characters. Sonication was found to be a reliable DNA extraction approach for barcoding, providing sufficient quality template for polymerase chain reaction amplification as well as retaining the voucher specimen for post-barcoding morphological evaluation.
Correct taxonomy is a prerequisite for biological research, but currently it is undergoing a serious crisis, resulting in the neglect of many highly diverse groups of organisms. In nematodes, species delimitation remains problematic due to their high morphological plasticity. Evolutionary approaches using DNA sequences can potentially overcome the problems caused by morphology, but they are also affected by theoretical flaws. A holistic approach with a combination of morphological and molecular methods can therefore produce a straightforward delimitation of species. The present study investigates the taxonomic status of some highly divergent mitochondrial haplotypes in the Rhabditis (Pellioditis) marina species complex by using a combination of molecular and morphological tools. We used three molecular markers (COI, ITS, D2D3) and performed phylogenetic analyses. Subsequently, morphometric data from nearly all lineages were analysed with multivariate techniques. We included R. (P.) mediterranea and R. (R.) nidrosiensis to infer species status of the observed lineages. The results showed that highly divergent genotypic clusters were accompanied by morphological differences, and we created a graphical polytomous key for future identifications. This study indisputably demonstrates that R. (P.) marina and R. (P.) mediterranea belong to a huge species complex and that biodiversity in free-living marine nematodes may be seriously underestimated.
A re-examination of the holotype and mtDNA barcoding confirms Garzon-Ferreira and Acero’s separation of Coryphopterus tortugae from C. glaucofraenum. However, specimens matching the markings of their Santa Marta variant of C. tortugae comprise a distinct clade about 10% sequence divergent from true C. tortugae and C. glaucofraenum. The variant is described here as a new species, the sand canyon goby Coryphopterus bol, from specimens collected in Puerto Rico, the US Virgin Islands, and the Atlantic coast of Panama. The new species is abundant and widespread in the region and has not been recognized as distinct from the bridled goby, C. glaucofraenum. C. bol can be distinguished from C. tortugae by markings: a dark oval spot on the lower third of the pectoral-fin base, a chain-link pattern of melanophores on the top of the head, and a thick C-shaped basicaudal mark and scale-edges outlined in lines of tiny melanophores on well-marked individuals. Putative bridled gobies from three different reef types were sampled: a wide and clearly-zoned shelf in the Greater Antilles (off La Parguera, Puerto Rico), a narrower mixed-zone island of the Lesser Antilles (St. Thomas, US Virgin Islands), and narrow fringing continental reefs in the Southern Caribbean (the Atlantic coast of Panama near Portobelo). In all three locations, C. bol was found in deeper and more offshore reef areas with strong currents, i.e. in the channels of the buttress-canyon zone just inshore of the drop-off in Puerto Rico, around exposed rocky points in St. Thomas, and on wave-swept reefs just offshore of the sediment influenced coastline in Panama.
A re-examination of the holotype and mtDNA barcoding confirms Garzon-Ferreira and Acero’s separation of Coryphopterus tortugae from C. glaucofraenum. However, specimens matching the markings of their Santa Marta variant of C. tortugae comprise a distinct clade about 10% sequence divergent from true C. tortugae and C. glaucofraenum. The variant is described here as a new species, the sand canyon goby Coryphopterus bol, from specimens collected in Puerto Rico, the US Virgin Islands, and the Atlantic coast of Panama. The new species is abundant and widespread in the region and has not been recognized as distinct from the bridled goby, C. glaucofraenum. C. bol can be distinguished from C. tortugae by markings: a dark oval spot on the lower third of the pectoral-fin base, a chain-link pattern of melanophores on the top of the head, and a thick C-shaped basicaudal mark and scale-edges outlined in lines of tiny melanophores on well-marked individuals. Putative bridled gobies from three different reef types were sampled: a wide and clearly-zoned shelf in the Greater Antilles (off La Parguera, Puerto Rico), a narrower mixed-zone island of the Lesser Antilles (St. Thomas, US Virgin Islands), and narrow fringing continental reefs in the Southern Caribbean (the Atlantic coast of Panama near Portobelo). In all three locations, C. bol was found in deeper and more offshore reef areas with strong currents, i.e. in the channels of the buttress-canyon zone just inshore of the drop-off in Puerto Rico, around exposed rocky points in St. Thomas, and on wave-swept reefs just offshore of the sediment influenced coastline in Panama.
We describe a novel method of species identification, fluorescent fragment length barcoding, based on length variation in regions of the 18S and 28Salpha ribosomal DNA. Fluorescently tagged primers, designed in conserved regions of the 18S and 28Salpha ribosomal DNA, were used to amplify fragments with inter-species size variation, and sizes determined accurately using an automated DNA sequencer. By using multiple regions and different fluorochromes, a barcode unique to each species was generated. The technique was developed for the identification of African tsetse-transmitted trypanosomes and validated using DNA from laboratory isolates representing known species, subspecies and subgroups. To test the methodology, we examined 91 trypanosome samples from infected tsetse fly midguts from Tanzania, most of which had already been identified by species-specific and generic PCR tests. Identifications were mainly in agreement, but the presence of an unknown trypanosome in several samples was revealed by its unique barcode. Phylogenetic analyses based on 18S rDNA and glycosomal glyceraldehyde phosphate dehydrogenase gene sequences confirmed that this trypanosome is a new species and it is within the Trypanosoma brucei clade, as a sister group of subgenus Trypanozoon. The overall identification rate of trypanosome-infected midgut samples increased from 78 to 96% using FFLB instead of currently available PCR tests. This was due to the high sensitivity of FFLB as well as its capacity to identify previously unrecognised species. FFLB also allowed the identification of multiple species in mixed infections. The method enabled high-throughput and accurate species identification and should be applicable to any group of organisms where there is length variation in regions of rDNA.
The use of a DNA-based identification system (DNA barcoding) founded on the mitochondrial gene cytochrome c oxidase subunit I (COI) was investigated for updating the U.S. Food and Drug Administration Regulatory Fish Encyclopedia (RFE; http://www.cfsan.fda.gov/-frf/rfe0.html). The RFE is a compilation of data used to identify fish species. It was compiled to help regulators identify species substitution that could result in potential adverse health consequences or could be a source of economic fraud. For each of many aquatic species commonly sold in the United States, the RFE includes high-resolution photographs of whole fish and their marketed product forms and species-specific biochemical patterns for authenticated fish species. These patterns currently include data from isoelectric focusing studies. In this article, we describe the generation of DNA barcodes for 172 individual authenticated fish representing 72 species from 27 families contained in the RFE. These barcode sequences can be used as an additional identification resource. In a blind study, 60 unknown fish muscle samples were barcoded, and the results were compared with the RFE barcode reference library. All 60 samples were correctly identified to species based on the barcoding data. Our study indicates that DNA barcoding can be a powerful tool for species identification and has broad potential applications.
The use of a DNA-based identification system (DNA barcoding) founded on the mitochondrial gene cytochrome c oxidase subunit I (COI) was investigated for updating the U.S. Food and Drug Administration Regulatory Fish Encyclopedia (RFE; http://www.cfsan.fda.gov/-frf/rfe0.html). The RFE is a compilation of data used to identify fish species. It was compiled to help regulators identify species substitution that could result in potential adverse health consequences or could be a source of economic fraud. For each of many aquatic species commonly sold in the United States, the RFE includes high-resolution photographs of whole fish and their marketed product forms and species-specific biochemical patterns for authenticated fish species. These patterns currently include data from isoelectric focusing studies. In this article, we describe the generation of DNA barcodes for 172 individual authenticated fish representing 72 species from 27 families contained in the RFE. These barcode sequences can be used as an additional identification resource. In a blind study, 60 unknown fish muscle samples were barcoded, and the results were compared with the RFE barcode reference library. All 60 samples were correctly identified to species based on the barcoding data. Our study indicates that DNA barcoding can be a powerful tool for species identification and has broad potential applications.
The use of a DNA-based identification system (DNA barcoding) founded on the mitochondrial gene cytochrome c oxidase subunit I (COI) was investigated for updating the U.S. Food and Drug Administration Regulatory Fish Encyclopedia (RFE; http://www.cfsan.fda.gov/-frf/rfe0.html). The RFE is a compilation of data used to identify fish species. It was compiled to help regulators identify species substitution that could result in potential adverse health consequences or could be a source of economic fraud. For each of many aquatic species commonly sold in the United States, the RFE includes high-resolution photographs of whole fish and their marketed product forms and species-specific biochemical patterns for authenticated fish species. These patterns currently include data from isoelectric focusing studies. In this article, we describe the generation of DNA barcodes for 172 individual authenticated fish representing 72 species from 27 families contained in the RFE. These barcode sequences can be used as an additional identification resource. In a blind study, 60 unknown fish muscle samples were barcoded, and the results were compared with the RFE barcode reference library. All 60 samples were correctly identified to species based on the barcoding data. Our study indicates that DNA barcoding can be a powerful tool for species identification and has broad potential applications.
The use of a DNA-based identification system (DNA barcoding) founded on the mitochondrial gene cytochrome c oxidase subunit I (COI) was investigated for updating the U.S. Food and Drug Administration Regulatory Fish Encyclopedia (RFE; http://www.cfsan.fda.gov/-frf/rfe0.html). The RFE is a compilation of data used to identify fish species. It was compiled to help regulators identify species substitution that could result in potential adverse health consequences or could be a source of economic fraud. For each of many aquatic species commonly sold in the United States, the RFE includes high-resolution photographs of whole fish and their marketed product forms and species-specific biochemical patterns for authenticated fish species. These patterns currently include data from isoelectric focusing studies. In this article, we describe the generation of DNA barcodes for 172 individual authenticated fish representing 72 species from 27 families contained in the RFE. These barcode sequences can be used as an additional identification resource. In a blind study, 60 unknown fish muscle samples were barcoded, and the results were compared with the RFE barcode reference library. All 60 samples were correctly identified to species based on the barcoding data. Our study indicates that DNA barcoding can be a powerful tool for species identification and has broad potential applications.
Partial mitochondrial COI sequences (barcoding fragment) were explored for the understanding of the species boundaries of Baetis vernus group taxa (Ephemeroptera, Baetidae) in northern Europe. We sampled all species of this group occurring in Finland, but focused on taxa for which morphological and taxonomical confusion have been most apparent. The sequence matrix comprised 627 nucleotides for 96 specimens, and was analysed using parsimony. Results provided strong evidence that Baetis macani Kimmins and B. vernus Curtis comprise morphologically cryptic but molecularly distinct taxa, as intraspecific uncorrected divergences within haplogroups ranged between 0.3% and 1.4% and interspecific divergences were from 13.1% to 16.5%. These interesting findings prompt for further taxonomic studies of B. vernus taxa using more extensive specimen sampling from the known distributional areas in the Palaearctic/Holarctic region for better understanding of haplotype distributions. We stress the importance of integration of morphological and molecular data, and the necessity to employ additional nuclear DNA sequence data.
The use of a DNA-based identification system (DNA barcoding) founded on the mitochondrial gene cytochrome c oxidase subunit I (COI) was investigated for updating the U.S. Food and Drug Administration Regulatory Fish Encyclopedia (RFE; http://www.cfsan.fda.gov/-frf/rfe0.html). The RFE is a compilation of data used to identify fish species. It was compiled to help regulators identify species substitution that could result in potential adverse health consequences or could be a source of economic fraud. For each of many aquatic species commonly sold in the United States, the RFE includes high-resolution photographs of whole fish and their marketed product forms and species-specific biochemical patterns for authenticated fish species. These patterns currently include data from isoelectric focusing studies. In this article, we describe the generation of DNA barcodes for 172 individual authenticated fish representing 72 species from 27 families contained in the RFE. These barcode sequences can be used as an additional identification resource. In a blind study, 60 unknown fish muscle samples were barcoded, and the results were compared with the RFE barcode reference library. All 60 samples were correctly identified to species based on the barcoding data. Our study indicates that DNA barcoding can be a powerful tool for species identification and has broad potential applications.
The marine bryozoan Celleporella hyalina is a species complex composed of many highly divergent and mostly allopatric genetic lineages that are reproductively isolated but share a remarkably similar morphology. One such lineage commonly encrusts macroalgae throughout the NE Atlantic coast. To explore the processes leading to geographical diversification, reproductive isolation and speciation in this taxon, we (i) investigated NE Atlantic C. hyalina mitochondrial DNA phylogeography, and (ii) used breeding trials between geographical isolates to ascertain reproductive isolation. We find that haplotype diversity is geographically variable and there is a strong population structure, with significant isolation by distance. NE Atlantic C. hyalina is structured into two main parapatric lineages that appear to have had independent Pleistocene histories. Range expansions have resulted in two contact zones in Spain and W Ireland. Lineage 1 is found from Ireland to Spain and has low haplotype diversity, with closely related haplotypes, suggesting a recent population expansion into the Irish Sea, S Ireland, S England and Spain. Lineage 2 is found from Iceland to Spain and has high haplotype diversity. Complete reproductive isolation was found between some geographical isolates representing both lineages, whereas it was incomplete or asymmetric between others, suggesting these latter phylogeographical groups probably represent incipient species. The phylogeographical distribution of NE Atlantic C. hyalina does not fall easily into a pattern of southern refugia, and we discuss likely differences between terrestrial and marine system responses to Pleistocene glacial cycles.
The genus Eumicrotremus comprises 16 lumpsucker species distributed in the Arctic and northern Atlantic and Pacific Oceans. The most common species in the North Atlantic is Eumicrotremus spinosus, described in 1776, and characterized partly by numerous bony tubercles on the head and body. Another Atlantic species, Eumicrotremus eggvinii, described in 1956, remained known only from a single specimen until additional specimens were recently recovered. To reassess the status of E. eggvinii, 21 meristic and 32 morphometric characters were analysed for a total of 83 specimens of E. spinosus and E. eggvinii. Mitochondrial (COI, COII and cyt-b) and nuclear (Tmo-4C4) genes were also sequenced for both species, along with Eumicrotremus derjugini. The results indicate that although E. spinosus and E. eggvinii are clearly separated by a considerable number of morphological characters, they in fact constitute a single, sexually dimorphic species. Thirteen specimens of E. eggvinii (including the holotype) and 59 E. spinosus could be sexed; all individuals of E. eggvinii turned out to be males and all E. spinosus were females. Identical DNA sequences were found in all E. eggvinii and E. spinosus for COI, COII and Tmo-4C4, and a single shared synonymous substitution found in cyt-b. In contrast, E. spinosus, E. eggvinii and E. derjugini differed by 5.9% for COI and COII, 1.2% for Tmo-4C4 and 8.3% for cyt-b.
The genus Eumicrotremus comprises 16 lumpsucker species distributed in the Arctic and northern Atlantic and Pacific Oceans. The most common species in the North Atlantic is Eumicrotremus spinosus, described in 1776, and characterized partly by numerous bony tubercles on the head and body. Another Atlantic species, Eumicrotremus eggvinii, described in 1956, remained known only from a single specimen until additional specimens were recently recovered. To reassess the status of E. eggvinii, 21 meristic and 32 morphometric characters were analysed for a total of 83 specimens of E. spinosus and E. eggvinii. Mitochondrial (COI, COII and cyt-b) and nuclear (Tmo-4C4) genes were also sequenced for both species, along with Eumicrotremus derjugini. The results indicate that although E. spinosus and E. eggvinii are clearly separated by a considerable number of morphological characters, they in fact constitute a single, sexually dimorphic species. Thirteen specimens of E. eggvinii (including the holotype) and 59 E. spinosus could be sexed; all individuals of E. eggvinii turned out to be males and all E. spinosus were females. Identical DNA sequences were found in all E. eggvinii and E. spinosus for COI, COII and Tmo-4C4, and a single shared synonymous substitution found in cyt-b. In contrast, E. spinosus, E. eggvinii and E. derjugini differed by 5.9% for COI and COII, 1.2% for Tmo-4C4 and 8.3% for cyt-b.
Phylogenetic reconstructions of relations within the phylum Nematoda are inherently difficult but have been advanced with the introduction of large-scale molecular-based techniques. However, the most recent revisions were heavily biased towards terrestrial and parasitic species and greater representation of clades containing marine species (e.g. Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, Enoplida, and Monhysterida) is needed for accurate coverage of known taxonomic diversity. We now add small subunit ribosomal DNA (SSU rDNA) sequences for 100 previously un-sequenced species of nematodes, including 46 marine taxa. SSU rDNA sequences for >200 taxa have been analysed based on Bayesian inference and LogDet-transformed distances. The resulting phylogenies provide support for (i) the re-classiWcation of the Secernentea as the order Rhabditida that derived from a common ancestor of chromadorean orders Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, and Monhysterida and (ii) the position of Bunonema close to the Diplogasteroidea in the Rhabditina. Other, previously controversial relationships can now be resolved more clearly: (a) Alaimus, Campydora, and Trischistoma belong in the Enoplida, (b) Isolaimium is placed basally to a big clade containing the Axonolaimidae, Plectidae, and Rhabditida, (c) Xyzzors belongs in the Desmodoridae, (d) Comesomatidae and Cyartonema belongs in the Monhysterida, (e) Globodera belongs in the Hoplolaimidae and (f) Paratylenchus dianeae belongs in the Criconematoidea. However, the SSU gene did not provide signiWcant support for the class Chromadoria or clear evidence for the relationship between the three classes, Enoplia, Dorylaimia, and Chromadoria. Furthermore, across the whole phylum, the phylogenetically informative characters of the SSU gene are not informative in a parsimony analysis, highlighting the short-comings of the parsimony method for large-scale phylogenetic modelling.
The scope of the present research was to initiate and apply DNA barcoding in Greek freshwater fish species aiming to reveal new approaches on their protection and sustainable management as well as unmask look-alikes to prevent falsification. In the present study DNA barcoding was carried out in a total of 141 individuals, representing 18 fish species from both lakes Doirani and Volvi (Northern Greece). A 655bp region of the mitochondrial cytochrome oxidase subunit I (cox1) was sequenced using universal primers. Average within-species, -family and -order Kimura two parameter (K2P) distances were 0.41%, 14.9% and 15.6% respectively. All species could be differentiated by their cox1 sequence. Barcoded common species from both lakes had lake-specific haplotypes, indicating that location-based discrimination of species is possible. After constructing neighbor joining phylogenetic trees, the clades revealed generally corresponded well with expectations. Our study supports previous studies on the conclusion that cox1 sequencing, or ‘barcoding’, can be used to identify fish species.
The marine bryozoan Celleporella hyalina is a species complex composed of many highly divergent and mostly allopatric genetic lineages that are reproductively isolated but share a remarkably similar morphology. One such lineage commonly encrusts macroalgae throughout the NE Atlantic coast. To explore the processes leading to geographical diversification, reproductive isolation and speciation in this taxon, we (i) investigated NE Atlantic C. hyalina mitochondrial DNA phylogeography, and (ii) used breeding trials between geographical isolates to ascertain reproductive isolation. We find that haplotype diversity is geographically variable and there is a strong population structure, with significant isolation by distance. NE Atlantic C. hyalina is structured into two main parapatric lineages that appear to have had independent Pleistocene histories. Range expansions have resulted in two contact zones in Spain and W Ireland. Lineage 1 is found from Ireland to Spain and has low haplotype diversity, with closely related haplotypes, suggesting a recent population expansion into the Irish Sea, S Ireland, S England and Spain. Lineage 2 is found from Iceland to Spain and has high haplotype diversity. Complete reproductive isolation was found between some geographical isolates representing both lineages, whereas it was incomplete or asymmetric between others, suggesting these latter phylogeographical groups probably represent incipient species. The phylogeographical distribution of NE Atlantic C. hyalina does not fall easily into a pattern of southern refugia, and we discuss likely differences between terrestrial and marine system responses to Pleistocene glacial cycles.
The scope of the present research was to initiate and apply DNA barcoding in Greek freshwater fish species aiming to reveal new approaches on their protection and sustainable management as well as unmask look-alikes to prevent falsification. In the present study DNA barcoding was carried out in a total of 141 individuals, representing 18 fish species from both lakes Doirani and Volvi (Northern Greece). A 655bp region of the mitochondrial cytochrome oxidase subunit I (cox1) was sequenced using universal primers. Average within-species, -family and -order Kimura two parameter (K2P) distances were 0.41%, 14.9% and 15.6% respectively. All species could be differentiated by their cox1 sequence. Barcoded common species from both lakes had lake-specific haplotypes, indicating that location-based discrimination of species is possible. After constructing neighbor joining phylogenetic trees, the clades revealed generally corresponded well with expectations. Our study supports previous studies on the conclusion that cox1 sequencing, or ‘barcoding’, can be used to identify fish species.
Phylogenetic reconstructions of relations within the phylum Nematoda are inherently difficult but have been advanced with the introduction of large-scale molecular-based techniques. However, the most recent revisions were heavily biased towards terrestrial and parasitic species and greater representation of clades containing marine species (e.g. Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, Enoplida, and Monhysterida) is needed for accurate coverage of known taxonomic diversity. We now add small subunit ribosomal DNA (SSU rDNA) sequences for 100 previously un-sequenced species of nematodes, including 46 marine taxa. SSU rDNA sequences for >200 taxa have been analysed based on Bayesian inference and LogDet-transformed distances. The resulting phylogenies provide support for (i) the re-classiWcation of the Secernentea as the order Rhabditida that derived from a common ancestor of chromadorean orders Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, and Monhysterida and (ii) the position of Bunonema close to the Diplogasteroidea in the Rhabditina. Other, previously controversial relationships can now be resolved more clearly: (a) Alaimus, Campydora, and Trischistoma belong in the Enoplida, (b) Isolaimium is placed basally to a big clade containing the Axonolaimidae, Plectidae, and Rhabditida, (c) Xyzzors belongs in the Desmodoridae, (d) Comesomatidae and Cyartonema belongs in the Monhysterida, (e) Globodera belongs in the Hoplolaimidae and (f) Paratylenchus dianeae belongs in the Criconematoidea. However, the SSU gene did not provide signiWcant support for the class Chromadoria or clear evidence for the relationship between the three classes, Enoplia, Dorylaimia, and Chromadoria. Furthermore, across the whole phylum, the phylogenetically informative characters of the SSU gene are not informative in a parsimony analysis, highlighting the short-comings of the parsimony method for large-scale phylogenetic modelling.
The year in science and medicine - WHAT LIES BENEATH
The micro-endemic Spotted Handfish, Brachionichthys hirsutus (Lacepède), which