Genetic diversity in Bhutanese yak (Bos grunniens) populations using microsatellite markers

摘要

Eight cattle microsatellite markers were used for genetic analyses of three Bhutanese yak (B. grunniens) populations (western, central and eastern). Theer was substantial genetic variability within yak populations, with average heterozygosity range of 0.644 to 0.680. Neighbour-joining tree constructed from Nei's standard genetic distances (Ds; Nei 1972) grouped western and central Bhutan yak in one clade (Ds = 0.01) separate from eastern Bhutan yak (Ds = 0.20 and 0.27, respectively). The genetic distances between the yak from eastern Bhutan and the other two regions suggest that the populations have been separated for at least 4000 years and that they have exchanged <2 migrants per generation. Based on these results, Bhutanese yak populations are categorised into two types: 1) western and central Bhutan yak, and 2) eastern Bhutan yak. Implications of these findings on yak conservation and breeding programmes are discussed.