西藏牦牛mtDNA cytb基因的序列多态性及其系统进化分析

Genetic Diversity and Evolution Relationship of Tibet Yaks Inferred from mtDNA cytb

为从分子水平上探究西藏牦牛类群的亲缘关系、分类地位和遗传多样性,本研究测定了嘉黎牦牛、桑桑牦牛、桑日牦牛、工布江达牦牛、斯布牦牛、帕里牦牛、康布牦牛、江达牦牛、类乌齐牦牛、丁青牦牛、巴青牦牛等11个西藏牦牛类群共110头牦牛的细胞色素b基因全序列,分析了其多态性,并构建了11个类群的系统进化树。结果表明:11个西藏牦牛类群的细胞色素b基因全序列长均为1 140bp,共有单倍型53种,其中新发现的有49种,序列间共有14个SNPs多态位点,核苷酸变异类型包括转换和颠换,无插入和缺失,以同义突变为主,说明西藏牦牛具有较丰富的遗传多样性。西藏11个牦牛类群可分为:帕里牦牛系、江达牦牛系、巴青牦牛系、桑日牦牛系、类乌齐牦牛系等5大系。

In order to explore the classification status and genetic diversity of Tibet yak at the molecular level, the cytb gene sequences of Tibet yaks were determined; its sequence polymor- phism was analyzed; and the molecular phylogenetic tree was constructed for 110 yaks from 11 groups （Jiali, Sangsang, Sangri, Gongbujiangda, Sibu, Pali, Kangbu, Jiangda, Leiwuqi, Dingqing, Baqing yak）. The results showed that the size of cytochrome b gene sequences of 110 yaks are 1 140 bp. 53 haplotypes were identified, 49 haplotypes were newly discovered, 14 SNPs loci among 110 sequences were detected, nucleotide mutation types included conversion and transversion, no insertions and deletions, the main mutations was synonymous mutations, which indicated that Tibetan yaks had abundant genetic diversity. 11 species or groups of Tibet yak can be divided into 5 strains ： Pall, Jiangda, Baqing, Sangri, Leiwuqi yak.