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 conc...