文摘
Korean field mouse (Apodemus peninsulae) is widely distributed throughout northeastern Asia, including the Russian Far East, northern China, the Korean Peninsula, Sakhalin, and Hokkaido. This mouse species is characterized by a high frequency of animals with B chromosomes differing in their number, morphology, and DNA composition in different geographical regions. For the first time a comparative analysis of DNA probes from B chromosomes with metaphase chromosomes of mice from Transbaikalia, the Far East (including the Russian Far East), Japan, and South Korea was conducted by in situ hybridization. B chromosomes in mice from the Russian Far East were shown to exhibit low variability in DNA content; however, the DNA composition of B chromosomes in species from Transbaikalia and Japan were highly variable. B chromosomes in A. peninsulae from the South Korean population demonstrate minor differences from those from the Russian Far East. We discuss the origin of B chromosomes in the studied region in comparison with previously obtained data for mice from Siberia and the Baikal region, as well as the dispersal routes of the Korean field mouse.