Data from: Imprints from genetic drift and mutation imply relative divergence times across marine transition zones in a pan-European small pelagic fish (Sprattus sprattus)

Geographic distributions of most temperate marine fishes are affected by post-glacial recolonisation events which have left complex genetic imprints on populations of marine species. This study investigated population structure and demographic history of European sprat (Sprattus sprattus L.) by combining inference from both mtDNA and microsatellite genetic markers throughout the species distribution. We compared effects from genetic drift and mutation for both genetic markers in shaping genetic differentiation across four transition zones. Microsatellite markers revealed significant isolation by distance and a complex population structure across the species' distribution (overall θST = 0.038, p < 0.01). Across transition zones markers indicated larger effects of genetic drift over mutations in the northern distribution of sprat contrasting a stronger relative impact of mutation in the species southern distribution in the Mediterranean region. These results were interpreted to reflect more recent divergence times between northern populations in accordance with previous findings. This study demonstrates the usefulness of comparing inference from different markers and estimators of divergence for phylogeographic and population genetic studies in species with weak genetic structure, as is the case in many marine species.

绝大多数温带海洋鱼类的地理分布受冰期后重新殖民事件的影响，这类事件已在海洋物种种群中留下了复杂的遗传印记。本研究结合线粒体DNA（mtDNA）与微卫星遗传标记的推断结果，对欧洲西鲱（Sprattus sprattus L.）在其整个分布范围内的种群结构与种群历史动态展开了探究。我们对比了两类遗传标记的遗传漂变与突变效应，以此解析四个过渡带内的遗传分化格局。微卫星遗传标记结果显示，在该物种的整体分布范围内存在显著的距离隔离效应，且种群结构较为复杂（整体θST=0.038，p<0.01）。过渡带的分析结果表明，在西鲱北部分布区，遗传漂变对种群分化的影响强于突变；而在地中海海域的南部分布区，突变的相对影响则更为显著。结合此前的研究结论，上述结果可被解读为北部种群间的分化时间更为晚近。本研究证实，针对遗传结构较弱的海洋物种（多数海洋物种均属此类），对比不同遗传标记与分化估算方法的推断结果，对系统地理学与种群遗传学研究具有重要价值。