关键词: 喀喇昆仑-帕米尔地区, 牦牛, mtDNA Cytb, 遗传多样性, 系统进化

Abstract: Yak is an important breeding resource in the Karakorum-Pamir Region, and there are few reports on the genetic diversity and phylogenetic evolution of yak in this region. In this study, the genetic diversity of mtDNA Cytb gene in yak in Karakoram-Pamir Region was analyzed. The results showed that the full length of mtDNA Cytb gene was 1 140 bp, and the average contents of T, C, A and G bases were 26.2%, 29.0%, 31.7%, and 13.1%, respectively, and the A+T base content (57.9%) was greater than C+G base content (42.1%), presence of base Basis bias; a total of 10 polymorphic loci with 5 haplotypes were detected, and only the transformed variant type was obtained; the average haplotype diversity, nucleotide difference, and nucleoside acid diversity were 0.599±0.001 23, 3.363 and 0.002 59, respectively. The results based on the construction of phylogenetic trees in the domestic yak population which indicated that the yak in the Karakoram-Pamir Region is closely related to the wild yak, and has a close relationship with the Bazhou yak; using the representative sequence of yak and bovine subfamily submitted by GenBank, the phylogenetic tree was constructed by the maximum likelihood method. The results showed that the yak was closely related to the American bison and had a close relationship with the common cattle.

Key words: Karakorum-Pamir Region, yak, mtDNA Cytb, genetic diversity, phylogenetic