Y chromosome polymorphism found among house shrew populations in Myanmar

The house shrew (Suncus murinus) is a small mammalian species that is widespread in South Asia and Southeast Asia. Preceding analyses of mitochondrial DNA polymorphisms revealed two major groups among the wild populations of this species, continental and insular, and the division was inferred to lie in the central part of Myanmar. However, the wild house shrew populations in Myanmar are also known to comprise more than two groups. Considering this information, the present study attempted to further elucidate the wild population structure of house shrews in regions around Myanmar. We prepared chromosomal samples from the house shrews captured in several localities in Myanmar and compared the band patterns. The autosomal and X-chromosomal band patterns obtained from these animals resembled those of the standard suncus karyotype (continental type). In contrast, Y chromosomes revealed a considerable range of inter-individual variations. The absence of any common regionality in the distribution of Y chromosome polymorphisms suggests that the wild populations of house shrews in Myanmar are formed through a more complicated process than formerly postulated