Minisatellite DNA variation and stock identification of coho salmon (original) (raw)
Related papers
2003
Allele frequency data from eight microsatellite loci provide evidence of highly significant genetic differentiation among stocks of Atlantic salmon Salmo salar L. from the Bay of Fundy, eastern and north-western Nova Scotia and Newfoundland. Estimates of genetic structure (R ST and θ) were significant both among all samples taken from the different geographical locations and among samples from geographical regions for which more than one stock was sampled. Samples from the Bay of Fundy taken from stocks which are phenotypically and behaviourally diverse showed particularly high levels of genetic structure. Rogers', allele sharing and (δµ) 2 distances also revealed significant differences among stock samples and were significantly correlated [Rogers' and (δµ) 2 ] with sea distance between rivers. Results suggest that stocks of Atlantic salmon in eastern Canada are highly diverse genetically and that this should be an important consideration in any management programme for stocks in the area.
Journal of Fish Biology, 1998
Variation at four microsatellite loci was examined for three populations of Atlantic salmon Salmo salar from the Conne River, Newfoundland. Samples of wild parr were collected from the mainstem Conne River during 4 years, and from tributaries Twillick Brook and Bernard Brook during 2 years. No significant temporal variation was observed in allele frequencies at the Ssa14, Ssa197, Ssa202, and Ssa289 loci. No difference in allele frequencies was observed between parr from Bernard and Twillick brooks at any locus, but allele frequencies of mainstem Conne River parr were significantly different from those of the tributaries at Ssa14 and Ssa202, indicative of differentiation among local populations. Atlantic salmon from the Conne River system were well differentiated from those in Nova Scotia, Canada and from those in Europe.
Aquaculture, 1999
. Atlantic salmon Salmo salar were imported to Australia from the River Philip, Nova Scotia, in the mid-1960s. A population was established in New South Wales, and in the mid-1980s ova from this population were used to found the Tasmanian salmon aquaculture industry. An allozyme and mitochondrial DNA examination of the Tasmanian and parent Canadian populations in 1993 showed some small but significant allele frequency differences between the two samples for one of seven polymorphic allozymes and for mitochondrial DNA haplotypes. However, there was no evidence of reduced genetic variability in the Tasmanian sample. The same individual fish from both populations have now been examined for eight polymorphic microsatellite loci. Small but significant differences in allele frequencies between the two samples were found for four of the Ž eight loci, and there was evidence of a small overall loss of genetic variation both heterozygosity . and alleles in the Tasmanian sample. Mean heterozygosity per microsatellite locus was more than ) C orresponding author. 0044-8486r99r$ -see front matter q 1999 Elsevier Science B.V. All rights reserved.
Transactions of the American Fisheries Society, 2001
Variation at eight microsatellite loci and two linked exons of a major histocompatibility complex (MHC) locus was surveyed in approximately 21,000 coho salmon Oncorhynchus kisutch sampled from 138 localities ranging from southeast Alaska to the Columbia River, the majority of the sites being in British Columbia. The observed regional population structure enabled evaluation of the utility of using microsatellite and MHC variation for estimating the stock composition of coho salmon in mixed-stock fisheries. Both MHC exons were more effective for stock identification than any of the eight microsatellite loci examined. The two MHC exons combined were nearly as effective, on average, as the eight microsatellite loci combined. Some loci were particularly effective at discriminating stocks from specific regions. Mixed-stock analysis provided accurate estimates of contributions from the threatened Thompson River and upper Skeena River stocks, even when they composed less than 5% of the sampled fish. From about 17,000 coho salmon sampled from mixed-stock fisheries in British Columbia and Washington during 1997-1999, we found that the highest estimated proportions of coho salmon originating in southeast Alaska were in Canadian fishing areas adjacent to the international border in northern British Columbia; the highest proportions of Washington-origin coho salmon were observed closest to the international border in southern British Columbia. Within major river drainages, MHC variation within appropriately sampled fisheries can be used to determine the timing of spawning returns of specific stocks and the relative or absolute stock escapements.
Molecular Ecology, 2001
Atlantic salmon (n = 1682) from 27 anadromous river populations and two nonanadromous strains ranging from south-central Maine, USA to northern Spain were genotyped at 12 microsatellite DNA loci. This suite of moderate to highly polymorphic loci revealed 266 alleles (5 -37/locus) range-wide. Statistically significant allelic and genotypic heterogeneity was observed across loci between all but one pairwise comparison. Significant isolation by distance was found within and between North American and European populations, indicating reduced gene flow at all geographical scales examined. North American Atlantic salmon populations had fewer alleles, fewer unique alleles (though at a higher frequency) and a shallower phylogenetic structure than European Atlantic salmon populations. We believe these characteristics result from the differing glacial histories of the two continents, as the North American range of Atlantic salmon was glaciated more recently and more uniformly than the European range. Genotypic assignment tests based on maximum-likelihood provided 100% correct classification to continent of origin and averaged nearly 83% correct classification to province of origin across continents. This multilocus method, which may be enhanced with additional polymorphic loci, provides fishery managers the highest degree of correct assignment to management unit of any technique currently available.
Molecular Ecology Notes, 2005
Eleven microsatellite DNA loci were identified and characterized for Atlantic salmon (Salmo salar) collected from the Penobscot River, Maine, USA and the River Nith, Scotland, UK. The markers revealed high levels of genetic diversity (seven to 48 alleles per locus), heterozygosity (to 100%), and allelic heterogeneity (all comparisons). Considerable differentiation was observed as the genetic distance (chord) between the two collections was 0.680 and the pairwise F ST , 0.12, was highly significant. These findings are consistent with patterns of continental-level differentiation observed previously using an alternate suite of microsatellite loci. Locus-by-locus analyses of molecular variance suggested that most markers were suitable for delineating kinships and population genetic structure.
Transactions of the American Fisheries Society, 2006
The variation at 14 microsatellite loci and one major histocompatibility complex (MHC) locus was surveyed for over 48,000 sockeye salmon Oncorhynchus nerka sampled from 299 localities ranging from the Columbia River to Japan. For the microsatellite loci, the number of alleles observed at a locus was related to the power of the locus in providing accurate estimates of stock composition of single-population mixtures. In an analysis of single-population mixtures where the Pacific Rim baseline was used for estimation of stock identification, 80% accuracy for the average population was achieved by employing approximately 80 alleles in the analysis. Increasing the accuracy of estimated stock compositions to 90% for the average population required approximately 400 microsatellite alleles. When all loci were used to estimate stock compositions, estimates were above 80% for all sampling sites or populations, above 90% for the lake of origin, and generally above 95% for the region of origin. Analysis of known-origin samples indicated that accurate lake or regional estimates of stock composition were obtained. The accuracy of identification of individual fish to the correct lake of origin was above 90%, regardless of whether the lakes were geographically widespread or within a single watershed. The estimated stock compositions of mixed-fishery samples from the western Bering Sea, from the continental shelf near Kodiak Island in the Gulf of Alaska, from Southeast Alaska, and from Johnstone Strait in southern British Columbia were markedly different among samples. These stock compositions reflected geographical variation in fishery locations and variation in the migration pathways of either juvenile or maturing sockeye salmon. Variation of DNA enabled us to estimate accurately the origin of individual fish and the composition of mixed-stock samples from any location in the Pacific Rim distribution of sockeye salmon.