Phylogenetic analysis of Alpine voles of the Microtus multiplex complex using the mitochondrial control region

Abstract

To elucidate the phylogenetic relationships of Alpine voles comprising the Microtus multiplex complex and related species the mitochondrial control region (CR) was employed as a genetic marker. Forty specimens were analysed representing the taxa Microtus liechtensteini, Microtus multiplex, and Microtus bavaricus (samples from 11 geographic regions) as well as specimens of Microtus subterraneus, Microtus tatricus, Microtus arvalis, Microtus agrestis, Microtus oeconomus, and Chionomys nivalis. The haplotypes from Tuscany and the Swiss canton of Valais can be ascribed to M. multiplex, whereas the haplotypes isolated from the geographic samples from Croatia, Slovenia, Carinthia, Styria, East Tyrol, and South Tyrol represent M. liechtensteini. The molecular data indicate that the distribution range of M. liechtensteini extends further to the north (Upper Styria) than has been assumed earlier. The haplotypes of M. bavaricus, together with the populations from North Tyrol, form a cluster clearly separated from M. liechtensteini. This result suggests that the North Tyrolean samples belong to M. bavaricus, a species thought to be extinct. Microtus tatricus splits off at the basis of the multiplex complex. Our sequence data do not support a close relationship between M. bavaricus and M. tatricus. The phylogenetic relationships deduced from the sequence data favour a hypothesis assuming three glacial refugia, in which M. multiplex, M. liechtensteini and M. bavaricus, respectively, survived the last one or two Alpine glaciations.