1B-03 Toward establishment of a novel system for analyses of genome dynamics for short- and long-term evolutionary changes with three speciose groups of rats, house mice and field mice

In rat and mouse, where genome analyses are well advanced, comparative analyses with a large taxon set of related species can provide novel insights into genome evolutionary dynamics. We analyzed phylogenetic relationships of 17 species of Mus and more than 40 species of Rattus and closely related genera, using nucleotide sequences. Pilot tests with the MC1R gene and a duplicated copies of olfactory receptor genes demonstrate the utility of these taxon sets to elucidate the evolutionary history of genomic changes. Given that an explosion of knowledge regarding gene functions can be anticipated for rat and mouse, we suggest that, the murine genus Apodemus might be a useful tool for understanding evolutionary dynamics within populations under natural selection. In particular, A. specious, a Japanese endemic, distributed from subarctic (e. g. Hokkaido) through to temperate (e. g. Honshu) and subtropical regions (e. g. Satsunan Islands) would be a useful subject to monitor short-term evolutionary changes. We examined genetic diversity in this species and found substantial amount of genetic diversity, within and between local populations, in various nuclear gene markers.