The Experts below are selected from a list of 369 Experts worldwide ranked by ideXlab platform
Adam D Leache - One of the best experts on this subject based on the ideXlab platform.
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do dams also stop Frogs assessing population connectivity of coastal Tailed Frogs ascaphus truei in the north cascades national park service complex
Conservation Genetics, 2017Co-Authors: Jared A Grummer, Adam D LeacheAbstract:We investigated the effects of three hydroelectric dams and their associated lakes on the population structure and connectivity of the coastal Tailed Frog, Ascaphus truei, in the North Cascades National Park Service Complex. Three dams were erected on the Skagit River in northern-central Washington state between 1924 and 1953 and subsequently changed the natural shape and movement of the Skagit River and its tributaries. We collected 183 Frogs and tadpoles from 13 tributaries and generated a dataset of >2500 loci (unlinked SNPs) using double digestion restriction site-associated DNA sequencing (ddRADseq). An analysis of molecular variance (AMOVA) identified $$\sim$$ 99% of the genetic variation within groups, and the remaining variation among groups separated by dams, or the Skagit River. All populations exhibited low F $$_{ST}$$ values with a maximum of 0.03474. A “de novo” discriminant analysis of principal components revealed two populations with no geographic structure. However, testing groups that were partitioned a priori by the dams revealed distinctiveness of groups down-river of the lowest dam (Gorge Dam). Coalescent-based analyses of recent migration suggest that up to 17.3% of each population is composed of migrants from other populations, and an estimation of effective migration rates revealed high levels of migration heterogeneity and population connectivity throughout the study area. Our results suggest that although the populations down-river from Gorge Dam are distinguishable using SNPs, A. truei population connectivity is high throughout the North Cascades National Park Service Complex.
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do dams also stop Frogs assessing population connectivity of coastal Tailed Frogs ascaphus truei in the north cascades national park service complex
bioRxiv, 2016Co-Authors: Jared A Grummer, Adam D LeacheAbstract:We investigated the effects of three hydroelectric dams and their associated lakes on the population structure and connectivity of the coastal Tailed Frog, Ascaphus truei, in the North Cascades National Park Service Complex. Three dams were erected on the Skagit River in northern-central Washington state between 1924 and 1953 and subsequently changed the natural shape and movement of the Skagit River and its tributaries. We collected 183 individuals from 13 tributaries and generated a dataset of >2,500 loci (unlinked SNPs) using double digestion restriction site-associated DNA sequencing (ddRADseq). An analysis of molecular variance (AMOVA) identified ~99% of the genetic variation within groups, and the remaining variation among groups separated by dams, or the Skagit River. All populations exhibited low FST values with a maximum of 0.03474. A "de novo" discriminant analysis of principal components revealed two populations with no geographic cohesiveness. However, testing groups that were partitioned a priori by the dams revealed distinctiveness of populations down-river of the lowest dam. Coalescent-based analyses of recent migration suggest that up to 17.3% of each population is composed of migrants from other populations, and an estimation of effective migration rates revealed high levels of migration heterogeneity and population connectivity in this area. Our results suggest that although the populations down-river from the lowest dam are distinguishable, a high level of A. truei population connectivity exists throughout the North Cascades National Park Service Complex.
Caren C. Helbing - One of the best experts on this subject based on the ideXlab platform.
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Attributes of coastal Tailed Frog tadpoles and Frogs.
2019Co-Authors: Jared Hobbs, Jessica M. Round, Michael J. Allison, Caren C. HelbingAbstract:A) Coastal Tailed Frog tadpoles have an adhesive oral-disc, or mouth, to attach to rocks in stream habitats. B) Defining features include, the vertical pupils, lack of an external ‘ear’ membrane, and long outer hind toes. C) Male (right) and female (left) adult Tailed Frogs are sexually dimorphic–the ‘tail’ is visible on the adult male (white arrow). Photo credits: Jared Hobbs.
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Expansion of the known distribution of the coastal Tailed Frog, Ascaphus truei, in British Columbia, Canada, using robust eDNA detection methods
2019Co-Authors: Jared Hobbs, Jessica M. Round, Michael J. Allison, Caren C. HelbingAbstract:The coastal Tailed Frog (Ascaphus truei) is endemic to the Pacific Northwest of North America and is listed as a species of Special Concern under the Canadian Species at Risk Act. Its range is limited to British Columbia where it occurs widely west of the Coast Mountain Ranges extending north almost to the Alaskan Panhandle. The present study focused on surveying within the Cayoosh, Bridge (Shulaps), Seton, Anderson, Carpenter, and Downton Lake drainages. Four years of previous inventory efforts using conventional time-constrained search (TCS) methods detected Tailed Frog at 23/292 discrete sites (7.9% detection rate) in seven watersheds. Non-invasive environmental DNA (eDNA) methods hold promise for cryptic and low-abundance species detection. We rigorously validated a quantitative real-time polymerase chain reaction (qPCR)-based tool for detecting coastal Tailed Frog eDNA in water samples. This eASTR4 test is highly specific and sensitive. We applied a two-step targeted eDNA analysis approach on duplicate filtered water samples from a total of 72 sites collected over five days. The first IntegritE-DNA step mitigates false negative results and tests all DNA samples for the ability to support amplification from endogenous plant chloroplast DNA as a measure of sample viability. Three DNA samples failed this step even after inhibitor clean up suggesting that these samples were poor quality and not reliable for targeted species’ DNA analyses. All other DNA samples were deemed viable and were then tested for species-specific DNA. Coastal Tailed Frog eDNA was detected in 55/72 (76%) discrete stream reaches; nine sites with historical known occurrence were all eDNA positive. The false negative rate for TCS compared to eDNA methods was 58%. The results expand known coastal Tailed Frog distribution to 24 watersheds effectively more than tripling extant occurrences and confirm a previously suspected, apparently isolated coastal Tailed Frog metapopulation in the Shulaps drainage.
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Selectivity in detection following development of species-specific qPCR primer sets.
2016Co-Authors: Nik Veldhoen, Jared Hobbs, Georgios Ikonomou, Michael Hii, Mary Lesperance, Caren C. HelbingAbstract:The species-specific primer sets included eLICA1 (white bar), eLICA2 (grey bar), eASMO (black bar), and eASMO9 (hatched bar). DNA template included in species-specific amplification reactions comprised bullFrog (LICA), leopard Frog (LIPI), tree Frog (PSRE), clawed Frog (XELA), Tailed Frog (ASMO), and human (HOSA). Additionally, all primer sets were evaluated in a qPCR reaction with no DNA template present (NTC). Multiple qPCR reactions (n = 23 to 27) were performed for each primer set and DNA template combination with the mean abundance and standard error of the mean determined and presented as described in Fig 1.
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Field validation of species-specific eDNA assays directed towards bullFrog and Tailed Frog.
2016Co-Authors: Nik Veldhoen, Jared Hobbs, Georgios Ikonomou, Michael Hii, Mary Lesperance, Caren C. HelbingAbstract:Field validation of species-specific eDNA assays directed towards bullFrog and Tailed Frog.
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Field validation of eDNA qPCR assays directed towards bullFrog and Tailed Frog.
2016Co-Authors: Nik Veldhoen, Jared Hobbs, Georgios Ikonomou, Michael Hii, Mary Lesperance, Caren C. HelbingAbstract:Sampling sites were chosen in southern British Columbia (BC), Canada, which included known locations of habitation (star) as well as regions where the target species is absent (circle). Sites selected for validation of the Tailed Frog eDNA assay were located in the east Kootenay region of southeastern BC. Geographic areas across south Vancouver Island outlined by a dashed line represent locales with historical populations of bullFrog (British Columbia Ministry of Environment, BC Frogwatch Atlas (http://maps.gov.bc.ca/ess/sv/bcfa/) and BullFrogControl.com Inc (http://www.bullFrogcontrol.com/index.html).
Andrew Storfer - One of the best experts on this subject based on the ideXlab platform.
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landscape genetic structure of coastal Tailed Frogs ascaphus truei in protected vs managed forests
Molecular Ecology, 2008Co-Authors: Stephen F. Spear, Andrew StorferAbstract:Habitat loss and fragmentation are the leading causes of species’ declines and extinctions. A key component of studying population response to habitat alteration is to understand how fragmentation affects population connectivity in disturbed landscapes. We used landscape genetic analyses to determine how habitat fragmentation due to timber harvest affects genetic population connectivity of the coastal Tailed Frog (Ascaphus truei), a forestdwelling, stream-breeding amphibian. We compared rates of gene flow across old-growth (Olympic National Park) and logged landscapes (Olympic National Forest) and used spatial autoregression to estimate the effect of landscape variables on genetic structure. We detected higher overall genetic connectivity across the managed forest, although this was likely a historical signature of continuous forest before timber harvest began. Gene flow also occurred terrestrially, as connectivity was high across unconnected river basins. Autoregressive models demonstrated that closed forest and low solar radiation were correlated with increased gene flow. In addition, there was evidence for a temporal lag in the correlation of decreased gene flow with harvest, suggesting that the full genetic impact may not appear for several generations. Furthermore, we detected genetic evidence of population bottlenecks across the Olympic National Forest, including at sites that were within oldgrowth forest but surrounded by harvested patches. Collectively, this research suggests that absence of forest (whether due to natural or anthropogenic changes) is a key restrictor of genetic connectivity and that intact forested patches in the surrounding environment are necessary for continued gene flow and population connectivity.
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© 2008 The Authors Journal compilation © 2008 Blackwell Publishing Ltd
2008Co-Authors: Stephen F. Spear, Andrew StorferAbstract:Habitat loss and fragmentation are the leading causes of species ’ declines and extinctions. A key component of studying population response to habitat alteration is to understand how fragmentation affects population connectivity in disturbed landscapes. We used land-scape genetic analyses to determine how habitat fragmentation due to timber harvest affects genetic population connectivity of the coastal Tailed Frog (Ascaphus truei), a forest-dwelling, stream-breeding amphibian. We compared rates of gene flow across old-growth (Olympic National Park) and logged landscapes (Olympic National Forest) and used spatial autoregression to estimate the effect of landscape variables on genetic structure. We detected higher overall genetic connectivity across the managed forest, although this was likely a historical signature of continuous forest before timber harvest began. Gene flow also occurred terrestrially, as connectivity was high across unconnected river basins. Autoregressive models demonstrated that closed forest and low solar radiation were corre-lated with increased gene flow. In addition, there was evidence for a temporal lag in the correlation of decreased gene flow with harvest, suggesting that the full genetic impact may not appear for several generations. Furthermore, we detected genetic evidence of population bottlenecks across the Olympic National Forest, including at sites that were within old-growth forest but surrounded by harvested patches. Collectively, this research suggests that absence of forest (whether due to natural or anthropogenic changes) is a key restrictor of genetic connectivity and that intact forested patches in the surrounding environment are necessary for continued gene flow and population connectivity
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© 2008 The Authors Journal compilation © 2008 Blackwell Publishing Ltd Blackwell Publishing LtdPERMANENT GENETIC RESOURCES Newly developed polymorphic microsatellite markers for
2007Co-Authors: Stephen F. Spear, Jason Baumsteiger, Andrew StorferAbstract:Thirteen polymorphic microsatellite loci were identified and developed for the coastal Tailed Frog, Ascaphus truei, from sites within the Olympic Peninsula of Washington, USA. These tetranucleotide repeat loci were highly variable, averaging 19 alleles per locus and expected heterozygosity of 0.91. In addition, these loci cross-amplify in the sister species, Ascaphus montanus. These markers will prove useful in identifying fine-scale genetic structure, as well as provide insight into the evolution and conservation of this group across fragmented landscapes
J Michael Conlon - One of the best experts on this subject based on the ideXlab platform.
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Peptidomic analysis of skin secretions supports separate species status for the Tailed Frogs, Ascaphus truei and Ascaphus montanus
Comparative Biochemistry and Physiology - Part D: Genomics and Proteomics, 2007Co-Authors: Catherine Bevier, Laurent Coquet, Jérôme Leprince, Thierry Jouenne, Hubert Vaudry, Blake Hossack, J Michael ConlonAbstract:The Tailed Frog Ascaphus truei Stejneger, 1899 is the most primitive extant anuran and the sister taxon to the clade of all other living Frogs. The species occupies two disjunct ranges in the Northwest region of North America: the Cascade Mountains and coastal area from British Columbia to Northern California, and an inland range in the northern Rocky Mountains and the Blue and Wallowa mountains. A previous study led to the isolation of eight peptides with antimicrobial activity (termed the ascaphins) from skin secretions of A. truei from the coastal range. The present study has used peptidomic analysis to identify the products of orthologous ascaphin genes in electrically-stimulated skin secretions from inland range specimens. Structural characterization of the peptides demonstrated that ascaphins from the inland range contained the following amino acid substitutions compared with orthologs from the coastal range Frogs: ascaphin-1 (Ala(12)-->Glu), ascaphin-3 (Asp(4)-->Glu), ascaphin-4 (Ala(19)-->Ser), ascaphin-5 (Lys(12)-->Thr), and ascaphin-7 (Gly(8)-->Ser and Ser(20)-->Asn). Orthologs of ascaphins-2, -6, and -8 were not identified but a paralog of ascaphin-5, identical to ascaphin-5 from coastal range Frogs, was found. The data support the claims, derived from analysis of the nucleotide sequences of mitochondrial genes, that the inland populations of the Tailed Frog should be recognized as a distinct species, the Rocky Mountain Tailed Frog Ascaphus montanus and that the divergence of the species from A. truei probably occurred in the late Miocene (approximately 10 Mya).
Jared A Grummer - One of the best experts on this subject based on the ideXlab platform.
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do dams also stop Frogs assessing population connectivity of coastal Tailed Frogs ascaphus truei in the north cascades national park service complex
Conservation Genetics, 2017Co-Authors: Jared A Grummer, Adam D LeacheAbstract:We investigated the effects of three hydroelectric dams and their associated lakes on the population structure and connectivity of the coastal Tailed Frog, Ascaphus truei, in the North Cascades National Park Service Complex. Three dams were erected on the Skagit River in northern-central Washington state between 1924 and 1953 and subsequently changed the natural shape and movement of the Skagit River and its tributaries. We collected 183 Frogs and tadpoles from 13 tributaries and generated a dataset of >2500 loci (unlinked SNPs) using double digestion restriction site-associated DNA sequencing (ddRADseq). An analysis of molecular variance (AMOVA) identified $$\sim$$ 99% of the genetic variation within groups, and the remaining variation among groups separated by dams, or the Skagit River. All populations exhibited low F $$_{ST}$$ values with a maximum of 0.03474. A “de novo” discriminant analysis of principal components revealed two populations with no geographic structure. However, testing groups that were partitioned a priori by the dams revealed distinctiveness of groups down-river of the lowest dam (Gorge Dam). Coalescent-based analyses of recent migration suggest that up to 17.3% of each population is composed of migrants from other populations, and an estimation of effective migration rates revealed high levels of migration heterogeneity and population connectivity throughout the study area. Our results suggest that although the populations down-river from Gorge Dam are distinguishable using SNPs, A. truei population connectivity is high throughout the North Cascades National Park Service Complex.
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do dams also stop Frogs assessing population connectivity of coastal Tailed Frogs ascaphus truei in the north cascades national park service complex
bioRxiv, 2016Co-Authors: Jared A Grummer, Adam D LeacheAbstract:We investigated the effects of three hydroelectric dams and their associated lakes on the population structure and connectivity of the coastal Tailed Frog, Ascaphus truei, in the North Cascades National Park Service Complex. Three dams were erected on the Skagit River in northern-central Washington state between 1924 and 1953 and subsequently changed the natural shape and movement of the Skagit River and its tributaries. We collected 183 individuals from 13 tributaries and generated a dataset of >2,500 loci (unlinked SNPs) using double digestion restriction site-associated DNA sequencing (ddRADseq). An analysis of molecular variance (AMOVA) identified ~99% of the genetic variation within groups, and the remaining variation among groups separated by dams, or the Skagit River. All populations exhibited low FST values with a maximum of 0.03474. A "de novo" discriminant analysis of principal components revealed two populations with no geographic cohesiveness. However, testing groups that were partitioned a priori by the dams revealed distinctiveness of populations down-river of the lowest dam. Coalescent-based analyses of recent migration suggest that up to 17.3% of each population is composed of migrants from other populations, and an estimation of effective migration rates revealed high levels of migration heterogeneity and population connectivity in this area. Our results suggest that although the populations down-river from the lowest dam are distinguishable, a high level of A. truei population connectivity exists throughout the North Cascades National Park Service Complex.