Sorex bedfordiae has the Smallest Diploid Chromosome Number of the XY Group in the Genus Sorex (Mammalia, Soricidae)

Abstract

Karyological data on the lesser stripe-backed shrew, Sorex bedfordiae, were obtained from four specimens collected on Mt. Laojun, Lijiang District, Yunnan Province, China. Three of the four S. bedfordiae specimens had karyotypes consisting of 2n=26, NFa=44, with 4 metacentric, 4 submetacentric, 2 subtelocentric, and 2 acrocentric pairs, and 1 acrocentric X and acrocentric Y. This karyotype has the smallest diploid chromosome number in the XY group in the genus Sorex. The fourth specimen of S. bedfordiae had a different karyotype consisting of an additional pair of medium-sized metacentric chromosomes, i.e., 2n=28, NFa=48. These supernumerary chromosomes appear to constitute a new chromosome group in the genus Sorex and might provide new information concerning the taxonomy of soricid species.