Department of Ecology and Evolution, University of Lausanne, and Service de Médecine Préventive Hospitalière, Centre Hospitalier Universitaire Vaudois, CH-1015 Lausanne, Switzerland.
Evolution. 2012 Jun;66(6):1737-50. doi: 10.1111/j.1558-5646.2011.01554.x. Epub 2012 Mar 3.
We investigated sex specificities in the evolutionary processes shaping Y chromosome, autosomes, and mitochondrial DNA patterns of genetic structure in the Valais shrew (Sorex antinorii), a mountain dwelling species with a hierarchical distribution. Both hierarchical analyses of variance and isolation-by-distance analyses revealed patterns of population structure that were not consistent across maternal, paternal, and biparentally inherited markers. Differentiation on a Y microsatellite was lower than expected from the comparison with autosomal microsatellites and mtDNA, and it was mostly due to genetic variance among populations within valleys, whereas the opposite was observed on other markers. In addition, there was no pattern of isolation by distance for the Y, whereas there was strong isolation by distance on mtDNA and autosomes. We use a hierarchical island model of coancestry dynamics to discuss the relative roles of the microevolutionary forces that may induce such patterns. We conclude that sex-biased dispersal is the most important driver of the observed genetic structure, but with an intriguing twist: it seems that dispersal is strongly male biased at large spatial scale, whereas it is mildly biased in favor of females at local scale. These results add to recent reports of scale-specific sex-biased dispersal patterns, and emphasize the usefulness of the Y chromosome in conjunction with mtDNA and autosomes to infer sex specificities.
我们研究了性特异性在塑造瓦莱州鼩鼱（Sorex antinorii）Y 染色体、常染色体和线粒体 DNA 遗传结构模式进化过程中的作用，瓦莱州鼩鼱是一种具有分层分布的山地栖息物种。分层方差分析和隔离距离分析都揭示了种群结构模式，这些模式在母系、父系和双亲遗传标记上不一致。Y 微卫星的分化低于与常染色体微卫星和 mtDNA 比较的预期，这主要是由于山谷内种群之间的遗传方差，而在其他标记上则观察到相反的情况。此外，Y 染色体没有隔离距离模式，而 mtDNA 和常染色体则存在强烈的隔离距离模式。我们使用亲缘关系动态的分层岛屿模型来讨论可能导致这种模式的微观进化力量的相对作用。我们得出结论，性别偏向的扩散是观察到的遗传结构的最重要驱动因素，但有一个有趣的转折：在大空间尺度上，扩散似乎强烈偏向雄性，而在局部尺度上则偏向雌性。这些结果增加了最近关于特定尺度性别偏向扩散模式的报告，并强调了 Y 染色体与 mtDNA 和常染色体结合使用来推断性别特异性的有用性。
