Lai Song-Jia, Wang Ling, Liu Yi-Ping, Li Xue-Wei
College of Animal Science and Technology, Sichuan Agriculture University, Ya'an 625014, China.
Yi Chuan Xue Bao. 2005 May;32(5):463-70.
This study determined yak's complete sequence of mitochondrial DNA control region (D-loop) of 35 individuals in 5 yak breeds at the first time. The result showed that the length of D-loop in yak was 891 -895 bp. Content of nucleotide T, C, A, G were 28.5%, 25.3%, 32.5% and 13.7% respectively. There were 55 polymorphic sites (6.16% in total analyzed sites). The transition,transversion and insertion/deletion were found in this region.24 haplotypes was defined in this study, in which haplotype H4 and H6 were major haplotypes of Chinese yak. The distribution of all the haplotypes among the breeds was disequilibrium. The average diversity of haplotypes were 0.9697 +/-0.0180, indicating the abundance of haplotypes of yak's D-loop. The average nucleotide difference and the nucleotide diversity in Chinese yak breeds were 10.936% and 1.231% respectively. Nucleotide divergence and Kimura 2-parameter distance between yak breeds were 0.760% -2.155%, and 0.000-0.029 respectively. The results indicated that the genetic diversity of Chinese yak was very abundant. Analysis of molecular variance and network construction results indicated that there was significant divergence among Chinese yak breeds. The network construction indicated that Chinese yak had been divided into 2 types and had probably 2 maternal origins or 2 domesticated places.
本研究首次测定了5个牦牛品种35头牦牛的线粒体DNA控制区（D-loop）全序列。结果表明，牦牛D-loop长度为891 - 895 bp。核苷酸T、C、A、G的含量分别为28.5%、25.3%、32.5%和13.7%。共有55个多态性位点（占总分析位点的6.16%）。该区域存在转换、颠换和插入/缺失。本研究定义了24种单倍型，其中单倍型H4和H6是中国牦牛的主要单倍型。所有单倍型在品种间的分布不均衡。单倍型的平均多样性为0.9697±0.0180，表明牦牛D-loop单倍型丰富。中国牦牛品种的平均核苷酸差异和核苷酸多样性分别为10.936%和1.231%。牦牛品种间的核苷酸分歧和Kimura双参数距离分别为0.760% - 2.155%和0.000 - 0.029。结果表明中国牦牛的遗传多样性非常丰富。分子方差分析和网络构建结果表明中国牦牛品种间存在显著分歧。网络构建表明中国牦牛已分为2种类型，可能有2个母系起源或2个驯化地。
