Differing Y chromosome versus mitochondrial DNA ancestry, phylogeography, and introgression in the house mouse

We used Y chromosome microsatellites to infer the phylogeography of the house mouse (Mus musculus; predominantly the domesticus subspecies) across western Europe, and compared this with mitochondrial (mt)DNA phylogeography for the same samples. Overall, the distributions of mtDNA and Y haplotype lineages within M.m. domesticus were discordant, probably as a result of behavioural differences between males and females. In island contexts, there is evidence for a greater number of Y chromosome introductions compared to mtDNA introductions, indicating that island populations are more resistant to incoming females than males. This contrasts with a subspecies hybrid zone, which acts as a nonpermeable barrier to the Y chromosome but is relatively porous to mtDNA. Interestingly, within Norway, where Mus musculusY chromosomes are prevalent in the resident domesticus populations, the musculusY is apparently of a single, recent origin, with a distribution that is likely the result of a positive selection allowing the subspecies barrier to be crossed. Overall, we confirm the utility of Y chromosome microsatellites for inferring global ancestry and phylogeography in the house mouse.(c) 2015 Crown copyright. Biological Journal of the Linnean Society (c) 2015 The Linnean Society of London, 2015, 115, 348-361.