Phylogeography of Lasiopodomys gregalis (Rodentia: Cricetidae) in the southern part of its geographic range

. The narrow-headed vole species complex (subgenus Stenocranius) is represented by at least two cryptic species: Lasiopodomys gregalis and L. raddei. One of L. gregalis lineages (lineage B, inhabiting northern Mongolia and neighbouring territories) forms a secondary contact zone with L. raddei. In the current study, we analysed phylogeographic structure of L. gregalis lineage B by means of sequences of mitochondrial cytochrome b and reconstructed ecological niches of both species at present and in the past. The source of the spread of L. gregalis lineage B was probably the territory of modern western Mongolia and southeastern Tuva. Despite seeming continuity of the geographic range of lineage B, mitochondrial clusters within it turned out to be allopatric or parapatric; the reasons for such spatial structure are not yet clear. Based on the ecological niche modelling, it can be hypothesised that the two studied species reacted differently to climatic fluctuations of the late Pleistocene, and the structure of the modern geographic range of L. gregalis lineage B has formed largely due to inter-specifi c competitive interactions with L. raddei.