青海高原牦牛mtDNACytb基因和D-loop区遗传多样性及系统进化分析  

Genetic Diversity and Phylogenetic Analysis of mtDNA Cytb Gene and D-loop Region in Yak of Qinghai Plateau

作　　者：王兴东 郭宪[2] 吴晓云[2] 马启财 张振宇 叶娜 阎萍[2] 潘和平[1] Wang Xingdong;Guo Xian;Wu Xiaoyun;Ma Qicai;Zhang Zhenyu;Ye Na;Yan Ping;Pan Heping(School of Life Science and Engineering,Northwest Minzu University,Lanzhou,730030;Lanzhou Institute of Husbandry and Pharmaceutical Sciences of CAAS,Lanzhou,730050)

机构地区：[1]西北民族大学生命科学与工程学院,兰州730030 [2]中国农业科学院兰州畜牧与兽药研究所,兰州730050

出　　处：《基因组学与应用生物学》2021年第1期9-17,共9页Genomics and Applied Biology

基　　金：中国农业科学院创新工程项目(CAAS-ASTIP-2014-LIHPS-01)资助。

摘　　要：为探究青海高原牦牛的遗传多样性和起源进化关系,本研究通过测定和分析青海高原牦牛155个个体细胞色素b基因(Cytb)和D-loop区全序列,分析多态性及构建系统进化树。结果表明:青海高原牦牛Cytb基因全序列长度为1 140 bp,个体间序列长度无差异,4种核苷酸T、A、G、C的含量分别为26.26%、31.73%、13.09%、28.920%;发现13个SNP位点,全部为转换,符合Cytb基因保守的特征;核苷酸多样性(Pi)为0.002 88,单倍型数(H)为9,单倍型多样性(Hd)为0.645;D-loop区序列长度在892~895 bp之间,不同个体间存在序列长度差异;4种核苷酸T、A、G、C的平均比例分别为28.69%、32.22%、13.75%、25.34%,A+T含量为60.91%,G+C含量为39.09%。在155个个体中共统计出41个SNP位点,其中转换38个,颠换3个,缺失5个,插入3个。其核苷酸多样性(Pi)为0.012 44,分析得到的单倍型数(H)为38,单倍型多样性(Hd)为0.881。在基于Cytb基因的系统进化树中,青海高原牦牛首先与野牦牛和巴州牦牛聚在一起,紧接着与美洲野牛聚在一起;在D-loop区的系统进化分析中,青海高原牦牛首先与西藏牦牛和野牦牛聚在一起,展示出丰富的遗传多样性,同时进一步支持了牦牛和野牦牛划为牛亚科牦牛属(Bovidae)的观点。本研究结果为牦牛改良及育种工作提供了科学依据。In order to investigate the genetic diversity and origin of evolutionary relationship of Qinghai Plateau yak, the complete sequence of 155 individuals Cytb gene and D-loop, and its sequence polymorphism were analyzed, the phylogenetic tree was constructed. Results of Cytb gene showed that the length of the nucleotide sequence of Cytb gene of 155 individuals was 1 140 bp, and there was no difference in the length between the individuals. With nucleotide frequencies of 26.26%, 31.73%, 13.09% and 28.92% for T, A, G and C respectively;Nine haplotypes were identified in 155 individuals, all thirteen polymorphic sites were conversions, which was consistent with the conserved characteristics of Cytb gene;and nucleotide diversity was 0.002 88, the haplotype diversity was 0.645. Results of D-loop region showed that the length of the nucleotide sequence was between 892 bp and 895 bp, and there were differences in sequence length between different individuals. With nucleotide frequencies of 28.69%, 32.22%, 13.75%, and 25.34% for T, A, G, and C respectively. The content of A+T was 60.91%;G+C was 39.09%, and there were also obvious base preferences. Thirty eight haplotypes were identified in 155 individuals, with 41 polymorphic sites, including 38 conversions, 3 transversions, 5 deletions and 3 insertion. The nucleotide diversity was 0.012 44, the haplotype diversity was 0.881. In the phylogenetic tree based on Cytb gene,Qinghai Plateau yaks first congregated with wild yaks and Bazhou yaks, followed by American bison. In the phylogenetic analysis of D-loop region, Qinghai plateau yaks first gathered with Tibetan yaks and wild yaks, showing rich genetic diversity. At the same time, it further supported the view that yak and wild yak were classified into the yak genus of Bovidae. The results of this study provided scientific basis for yak improvement and breeding.

关 键 词：青海高原牦牛 CYTB D-LOOP 遗传多样性 系统进化 

分 类 号：S823.85[农业科学—畜牧学]