Data from: Scale-specific sex-biased dispersal in the Valais shrew unveiled by genetic variation on the Y chromosome, autosomes, and mitochondrial DNA

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 bi-parentally 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, while the opposite was observed on other markers. In addition, there was no pattern of isolation-by-distance for the Y, while 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 micro-evolutionary 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, while it is mildly biased in favour 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.

本研究针对呈层级分布的山地栖息物种瓦莱鼩鼱（Sorex antinorii），探究了塑造其Y染色体（Y chromosome）、常染色体（autosome）与线粒体DNA（mitochondrial DNA, mtDNA）遗传结构模式的演化过程中的性别特异性差异。分层方差分析与距离隔离（isolation-by-distance）分析均显示，种群遗传结构模式在母系、父系及双亲遗传的分子标记间并不一致。相较于常染色体微卫星（microsatellite）与线粒体DNA，Y染色体微卫星的遗传分化程度低于预期，且其分化主要源于山谷内种群间的遗传变异；而其他分子标记则呈现相反的模式。此外，Y染色体未表现出距离隔离模式，而线粒体DNA与常染色体则呈现显著的距离隔离特征。本研究采用共祖动态层级岛屿模型（hierarchical island model of coancestry dynamics），探讨了可能诱发此类遗传结构模式的微观演化力量的相对作用。研究结论认为，性别偏向性扩散（sex-biased dispersal）是观测到的遗传结构的核心驱动因素，但存在一个有趣的矛盾现象：在大空间尺度下扩散呈现强烈的雄性偏向，而在局域尺度下则表现为轻微的雌性偏向。本研究结果补充了近期关于尺度依赖型性别偏向性扩散模式的相关报道，并强调了结合Y染色体、线粒体DNA与常染色体来推断性别特异性遗传特征的有效性。