Mitochondrial DNA diversity in North American and European Atlantic salmon with emphasis on the Downeast rivers of Maine (original) (raw)
Related papers
Journal of Fish Biology, 1995
This study investigates the patterns of genetic diversity detected in allozymes, mtDNA, and microsatellites, in order to assess their relative efficacy to differentiate sympatric landlocked salmon populations and to estimate changes in genetic diversity between wild and firstgeneration hatchery fish. Overall, the three genetic markers indicated a genetic differentiation between two sympatric populations of Lake Saint-Jean, Quebec. MtDNA and microsatellites also showed significant differences between wild and first-generation hatchery fish originating from the same river. Allozyme analysis was the most limited approach due to the low genetic diversity detected and the necessity to kill specimens. Although low polymorphism was found in mtDNA, it was the most discriminant marker between wild populations. Microsatellite analysis appears to be a promising approach due to its high sensitivity in differentiating wild populations, in detecting changes in allele composition between wild and first-generation hatchery fish and its potential for increased resolution by augmenting the number of polymorphic loci. Given the benefits and disadvantages of the three methods, the combination of mtDNA and microsatellite analyses will best address our research objectives.
2004
Atlantic salmon (Salmo salar L.) populations from 30 spawning rivers along the northeastern European coast were analyzed for restriction site variation on the standard 2000 base pair fragment of mitochondrial DNA. Overall genetic diversity was higher than in the North Sea or Baltic Sea populations. Linear partitioning of the populations into three geographical areas contributed 27% to the total molecular variance. The Atlantic haplotypes dominate in the westernmost populations along the Barents Sea up to Svyatoi Nos. A haplotype belonging to the North American phylogenetic branch was also frequent along the western Barents coast. The Kola Peninsula rivers draining to the White Sea are dominated by haplotypes hypothesized to originate from the Komi Ice Lake, diluted by Atlantic immigrants. On the Karelian and Arkhangelsk coast of the White Sea, only two haplotypes were present, which are suggested to be derived directly from the freshwater refugium.
Annales Zoologici …, 2004
Atlantic salmon (Salmo salar L.) populations from 30 spawning rivers along the northeastern European coast were analyzed for restriction site variation on the standard 2000 base pair fragment of mitochondrial DNA. Overall genetic diversity was higher than in the North Sea or Baltic Sea populations. Linear partitioning of the populations into three geographical areas contributed 27% to the total molecular variance. The Atlantic haplotypes dominate in the westernmost populations along the Barents Sea up to Svyatoi Nos. A haplotype belonging to the North American phylogenetic branch was also frequent along the western Barents coast. The Kola Peninsula rivers draining to the White Sea are dominated by haplotypes hypothesized to originate from the Komi Ice Lake, diluted by Atlantic immigrants. On the Karelian and Arkhangelsk coast of the White Sea, only two haplotypes were present, which are suggested to be derived directly from the freshwater refugium.
The Atlantic salmon, Salmo salar, shows geographically structured differentiation at various classes of molecular genetic variation, among and within river stocks. Nuclear microsatellite locus variation at multiple loci has been exploited for more than a decade as a marker for the continental origin of fish caught at sea in distant-water fisheries. However, a simpler, more cost-effective, but still accurate, assignment can be obtained using a single microsatellite locus in combination with a mitochondrial DNA (mtDNA) single-nucleotide polymorphism (SNP) detected by restriction enzyme digestion. Following on from this, a preliminary study was made of the potential for using mtDNA SNP variation to enhance the resolving power and cost-effectiveness of within-continent assignment of European salmon as determined using microsatellites. Variation in 20 mtDNA regions, encompassing ?43% of this genome, in 330 salmon from 29 rivers across Europe, was analysed. High levels of inter-individual and inter-river variation were found, as well as evidence of regional differentiation paralleling observed microsatellite differentiation. The observations indicate scope for using mtDNA SNPs along with microsatellites for genetically based assignment of European salmon to region and river of natal origin, but further study is needed. Key words: Atlantic salmon, genetic stock identification, marine ecology, mitochondrial DNA, 454 sequencing
Canadian Journal of Fisheries and Aquatic Sciences, 1991
C ommercia% marine harvests of Atlantic sdmon (Salrno is a major fishery for Atlantic salmon off the west coast of salaa) represent a classic problem in fisheries biology, Greenland where the catch is composed almost entirely sf North namely that of managing a mixed-stock fishery. There American and Elgropm origin one-sea-winter age salmon. The fish originate from both wild-run rivers md enhancement prolconuibution of the Smithsonian Molecular Systematics Group. grams on both continents. For conservation and economic iea-2Author to whom correspondence should be addressed. Present SonS it is impomnt9 on a Year to Yea basis9 to determine the address: Smihsonim Tropical Research Instiate, APO Miami 34002-relative c0IIbib~tions that different stocks of ~t~~t i~ ~d m 0 n 001 1 or Apartado 2072, Balboa, Republlic of Panama.
Environmental Biology of Fishes, 2004
We examined the genetic population structure of chum salmon, Oncorhynchus keta, in the Pacific Rim using mitochondrial (mt) DNA analysis. Nucleotide sequence analysis of about 500 bp in the variable portion of the 5′ end of the mtDNA control region revealed 20 variable nucleotide sites, which defined 30 haplotypes of three genealogical clades (A, B, and C), in more than 2,100 individuals of 48 populations from Japan (16), Korea (1), Russia (10), and North America (21 from Alaska, British Columbia, and Washington). The observed haplotypes were mostly associated with geographic regions, in that clade A and C haplotypes characterized Asian populations and clade B haplotypes distinguished North American populations. The haplotype diversity was highest in the Japanese populations, suggesting a greater genetic variation in the populations of Japan than those of Russia and North America. The analysis of molecular variance and contingency χ2 tests demonstrated strong structuring among the three geographic groups of populations and weak to moderate structuring within Japanese and North American populations. These results suggest that the observed geographic pattern might be influenced primarily by historic expansions or colonizations and secondarily by low or restricted gene flow between local groups within regions. In addition to the analysis of population structure, mtDNA data may be useful for constructing a baseline for stock identification of mixed populations of high seas chum salmon.
Over the last 50 years, Spanish Atlantic salmon (Salmo salar) populations have been in decline. In order to bolster these populations, rivers were stocked with fish of northern European origin during the period 1974-1996, probably also introducing the furunculosis-inducing pathogen, Aeromonas salmonicida. Here we assess the relative importance of processes influencing mitochondrial (mt)DNA variability in these populations from 1948-2002. Genetic material collected over this period from four rivers in northern Spain (Cantabria) was used to detect variability at the mtDNA ND1 gene. Before stocking, a single haplotype was found at high frequency (0.980). Following stocking, haplotype diversity (h) increased in all rivers (mean h before stocking was 0.0411, and 0.2453 afterwards). These increases were due principally to the dramatic increase in frequency of a previously very low frequency haplotype, reported at higher frequencies in northern European populations proximate to those used to stock Cantabrian rivers. Genetic structuring increased after stocking: among-river differentiation was low before stocking (1950s/1960s ÖST = –0.00296-0.00284), increasing considerably at the height of stocking (1980s ÖST = 0.18932) and decreasing post-stocking (1990s/2002 ÖST = 0.04934-0.03852). Gene flow from stocked fish therefore seems to have had a substantial role in increasing mtDNA variability. Additionally, we found significant differentiation between individuals that had probably died from infectious disease and apparently healthy, angled fish, suggesting a possible role for pathogen-driven selection of mtDNA variation. Our results suggest that stocking with non-native fish may increase genetic diversity in the short term, but may not reverse population declines.Keywords: Salmo salar, stocking, mitochondrial DNA, conservation genetics, foreign gene introgression
2014
Genetic relationships between homing anadromous and matured non-anadromous forms of masu salmon (Oncorhynchus masou) from one river of Hokkaido, Japan, and two rivers of Sakhalin, Russia, collected in 2001 to 2008 were examined using nucleotide sequence variation in the mitochondrial (mt) DNA NADH dehydrogenase subunit 5 gene (ND5) region and allelic polymorphisms at six microsatellite (ms) DNA loci. All the non-anadromous samples examined were genetic males identifi ed with GH-Y pseudogene. Signifi cant difference between anadromous and non-anadromous samples within the Shari and Sukhopletka Rivers was suggested with FST estimates and neighbor-joining trees using msDNA but not mtDNA marker. Analyses of mtDNA and msDNA also suggested that the genetic divergence among allopatric samples in Hokkaido and Sakhalin was larger than that between two life-history forms in the same river. The present fi ndings imply a possible genetic differentiation between the two life-history forms of mas...
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.
Conservation Genetics, 2008
In wild populations, defining the spatial scale at which management and conservation practices should focus remains challenging. In Atlantic salmon, compelling evidence suggests that genetic structure within rivers occurs, casting doubt on the underlying premise of the river-based management approach for this species. However, no comparisons of within-river genetic structure across different systems have been performed yet to assess the generality of this pattern. We compared the within-river genetic structure of four important salmon rivers in North America and evaluated the extent of genetic differentiation among their main tributaries. We found a hierarchical genetic structure at the river and tributary levels in most water systems, except in the Miramichi where panmixia could not be rejected. In the other cases, genetic differentiation between most tributaries was significant and could be as high as that found between rivers of the same geographical region. More importantly, the extent of genetic differentiation between tributaries varied greatly among water systems, from well differentiated (h ST = 0.035) to undifferentiated (h ST =-0.0003), underlying the difficulty in generalizing the ubiquity of within-river genetic structure in Atlantic salmon. Thus, this study underlines the importance of evaluating the genetic structure of Atlantic salmon in large water systems on a case by case basis in order to define the most appropriate spatial scale and focal unit for efficient management and conservation actions. The potential consequences of management at an inappropriate spatial scale are discussed.