Stocking may increase mitochondrial DNA diversity but fails to halt the decline of endangered Atlantic salmon populations
Stocking may increase mitochondrial DNA diversity but fails to halt the decline of endangered Atlantic salmon populations
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DOI：
10.1007/s10592-007-9286-2
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发表时间：
2007-12-01
影响因子：
2.2
通讯作者：
Jordan, W. C.
中科院分区：
文献类型：
--
作者：
Ciborowski, K. L.;Consuegra, S.;Jordan, W. C.
过去 50 年来，西班牙大西洋鲑鱼 (Salmo salar) 的数量一直在下降。为了增加这些种群的数量，1974 年至 1996 年间，河流中放养了源自北欧的鱼类，可能还引入了诱发疖病的病原体——杀鲑气单胞菌。在这里，我们评估了从 1948 年到 2002 年影响这些人群线粒体 (mt)DNA 变异的过程的相对重要性。在此期间从西班牙北部（坎塔布里亚）的四条河流收集的遗传材料用于检测 mtDNA ND1 基因的变异。在放养之前，以高频率发现了单一单倍型（0.980）。放养后，所有河流的单倍型多样性 (h) 均增加（放养前的平均 h 为 0.041，放养后为 0.245）。这些增加主要是由于以前频率非常低的单倍型的频率急剧增加，据报道，在靠近坎塔布连河流放养的北欧人群中频率较高。放养后遗传结构增加：放养前河间分化较低（1950s/1960s Phi(ST) = -0.00296-0.00284），放养高峰期显着增加（1980s Phi(ST) = 0.18932），放养后下降（1990s/2002 Phi(ST) = 0.04934-0.03852)。因此，来自放养鱼类的基因流似乎在增加线粒体 DNA 变异性方面发挥了重要作用。此外，我们发现可能死于传染病的个体和表面上健康的角鱼之间存在显着差异，这表明病原体驱动的 mtDNA 变异选择可能发挥作用。我们的结果表明，放养非本地鱼类可能会在短期内增加遗传多样性，但可能无法扭转种群下降的趋势。
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 to 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 0.041, and 0.245 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 Phi(ST) = -0.00296-0.00284), increasing considerably at the height of stocking (1980s Phi(ST) = 0.18932) and decreasing post-stocking (1990s/2002 Phi(ST) = 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.