Cai Xin, Chen Hong, Lei Chuzhao, Wang Shan, Xue Kai, Zhang Bao
College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Agricultural Molecular Biology, Yangling, Shaanxi, 712100, China.
Genetica. 2007 Oct;131(2):175-83. doi: 10.1007/s10709-006-9129-y.
In order to clarify the origin and genetic diversity of indigenous cattle breeds in China, we carried out phylogenetic analysis of representatives of those breeds by employing mitochondrial gene polymorphism. Complete cyt b gene sequences, 1140 bp in length, were determined for a total of 136 individuals from 18 different breeds and these sequences were clustered into two distinct genetic lineages: taurine (Bos taurus) and zebu (Bos indicus). In analysis of the cyt b gene diversity, Chinese cattle showed higher nucleotide (0.00923) and haplotype diversity (0.848) than the reports from other studies, and the animals from the taurine lineage indicated higher nucleotide diversity (0.00330) and haplotype diversity (0.746) than the ones from the zebu lineage (0.00136; 0.661). The zebu mtDNA dominated in the southern breeds (63.3-100%), while the taurine dominated in the northern breeds (81.8-100%). Six cattle breeds from the central area of China exhibited intermediate frequencies of zebu mtDNA (25-71.4%). This polymorphism revealed a declining south-to-north gradient of female zebu introgression and a geographical hybrid zone of Bos taurus and Bos indicus in China.
为了阐明中国本土牛品种的起源和遗传多样性，我们利用线粒体基因多态性对这些品种的代表进行了系统发育分析。测定了来自18个不同品种的136个个体的完整细胞色素b（cyt b）基因序列，长度为1140 bp，这些序列被聚类为两个不同的遗传谱系：普通牛（Bos taurus）和瘤牛（Bos indicus）。在对cyt b基因多样性的分析中，中国牛的核苷酸多样性（0.00923）和单倍型多样性（0.848）高于其他研究报告，普通牛谱系的动物比瘤牛谱系的动物表现出更高的核苷酸多样性（0.00330）和单倍型多样性（0.746）（瘤牛谱系分别为0.00136和0.661）。瘤牛线粒体DNA在南方品种中占主导地位（63.3 - 100%），而普通牛在北方品种中占主导地位（81.8 - 100%）。来自中国中部地区的6个牛品种表现出瘤牛线粒体DNA的中间频率（25 - 71.4%）。这种多态性揭示了瘤牛母系基因渗入从南到北的递减梯度以及中国普通牛和瘤牛的地理杂交带。
