Wilson A J, Gíslason D, Skúlason S, Snorrason S S, Adams C E, Alexander G, Danzmann R G, Ferguson M M
Department of Zoology, University of Guelph, Guelph, Ontario, Canada.
Mol Ecol. 2004 May;13(5):1129-42. doi: 10.1111/j.1365-294X.2004.02149.x.
To examine the population genetic structure of lake-resident Arctic charr, Salvelinus alpinus from northwest Europe on multiple spatial scales, 2367 individuals from 43 lakes located in three geographical regions (Iceland, the British Isles and Scandinavia) were genotyped at six microsatellite loci. On a large scale, data provided little evidence to support clustering of populations according to geographical region. Hierarchical analysis of molecular variance indicated that, although statistically significant, only 2.17% of the variance in allelic frequencies was partitioned at the among-region level. Within regions, high levels of genetic differentiation were typically found between lakes regardless of the geographical distance separating them. These results are consistent with the hypothesis of rapid postglacial recolonization of all of northwest Europe from a single charr lineage, with subsequent restriction of gene flow. On a smaller scale, there was evidence for close genetic relationships among lakes from within common drainage basins in Scotland. Thus, interlake genetic structure reflects localized patterns of recent (or contemporary) gene flow superimposed onto a larger scale structure that is largely a result of historical processes. There was also evidence for widespread genetic structuring at the within-lake level, with sympatric populations detected in 10 lakes, and multilocus heterozygote deficits found in 23 lakes. This evidence of the Wahlund effect was found in all lakes known to contain discrete phenotypic morphs, as well as many others, suggesting that morphs may often represent separate breeding populations, and also that the phenomenon of polymorphism in this species may be more widespread than is currently realized.
为了在多个空间尺度上研究西北欧湖泊型北极红点鲑（Salvelinus alpinus）的群体遗传结构，对来自三个地理区域（冰岛、不列颠群岛和斯堪的纳维亚）43个湖泊的2367个个体进行了6个微卫星位点的基因分型。在大尺度上，数据几乎没有提供证据支持根据地理区域对群体进行聚类。分子方差的层次分析表明，尽管具有统计学意义，但等位基因频率的方差中只有2.17%在区域间水平上进行了划分。在区域内，无论湖泊之间的地理距离如何，通常都能发现湖泊之间存在高水平的遗传分化。这些结果与以下假设一致：西北欧所有地区都是由单一的红点鲑谱系在冰期后迅速重新定殖，随后基因流动受到限制。在较小尺度上，有证据表明苏格兰共同流域内的湖泊之间存在密切的遗传关系。因此，湖泊间的遗传结构反映了近期（或当代）基因流动的局部模式叠加在一个更大尺度的结构上，而这个更大尺度的结构在很大程度上是历史过程的结果。在湖泊内部水平上也有广泛遗传结构的证据，在10个湖泊中检测到同域分布的群体，在23个湖泊中发现多位点杂合子缺失。在所有已知包含离散表型形态的湖泊以及许多其他湖泊中都发现了这种瓦伦德效应的证据，这表明形态可能常常代表不同的繁殖群体，也表明该物种的多态现象可能比目前所认识到的更为普遍。
