[The B-chromosome system--a marker of Apodemus peninsulae (Rodentia, Muridae) populations in the Baĭkal region].

Karyological studies of 56 Apodemus peninsulae mice from 6 points in the neighbourhood of the Baikal lake revealed both considerable likeness and difference in the variants of the B-chromosomes system of this species. The mice from the regions situated at a distance of 150 kilometers from each other have similar karyotype variants, which allowed to consider these animals as one geographical population. The mice from the south-west, South Pribaikal and south-east regions considerably differ in the variants of the B-chromosomes system and may belong to 3 separate geographical populations.