Genetic diversity and bottleneck analysis of Yunnan mithun (Bos frontalis) using microsatellite loci

Abstract

Mithun or gayal (Bos frontalis) is endemic to the Gaoligongshan Mountains and Drung River Basin in Yunnan, China; a rare and endangered Bos species. To evaluate the genetic diversity and bottleneck effect of Yunnan mithun population, we screened 16 bovine microsatellite loci of Yunnan mithun (N = 34) to provide genetic information for its conservation strategies and breeding programmes. A total of 126 microsatellite alleles and large allele size variance were detected. All loci displayed low genetic diversity with overall mean of Na = 7.88, polymorphism information content (PIC) = 0.60, and H_E = 0.63, which were the lowest among the beef cattle breeds. Despite the smaller population size, the normal L-shaped distribution of allelic frequencies without any mode-shift indicate the absence of genetic bottleneck in Yunnan mithun population, suggesting that Yunnan mithun population might moderately have underwent gene introgression from zebu and yellow cattle.

Key words: Yunnan mithun (Bos frontalis), genetic diversity, bottleneck effect, microsatellite loci.