Genomic Insights into the Hybridization of House Mouse Subspecies in East Asia

House mice (Mus musculus), one of the most important experimental animals for biomedical research, are commensal to humans and have spread throughout the world with human activity. A complex and extensive genetic admixture pattern between two subspecies, M. musculus castaneus and musculus in East Asia has been documented. A genome-level understanding of how they spread and interbred in East Asia would provide important insights into human prehistory and the genetic processes of interbreeding among genetically divergent subspecies. In this study, we newly sequenced 37 wild house mouse samples, mainly collected in East Asia. We determine the extent to which the genetic admixture event is widespread among East Asian subspecies and how the sex-linked loci of each subspecies are genetically differentiated. In addition, we detect natural selection acting on the samples from Japanese archipelago, where a mixture of the two subspecies is abundant.