早胜牛遗传多态性与母系遗传背景分析

The Analysis of Genetic Polymorphism and Maternal Genetic Background of Zaosheng Cattle

[目的]为评价和挖掘早胜牛遗传资源及种质资源,开展了早胜牛母系遗传背景及分子遗传特性研究。[方法]以早胜牛mtDNA D-Loop区为标记位点,对基因组DNA进行了PCR扩增和测序;以8个中国地方黄牛品种和5个引进品种的mtDNA D-Loop区核苷酸序列为对照,分析了核苷酸多态位点、核苷酸多样性、单倍型数等遗传多态性指标,构建了系统发育树。[结果]早胜牛及其杂交类群mtDNA D-Loop区富含A和T,检测到80个核苷酸变异位点,存在转换、颠换、转换和颠换共存3种突变类型,且以转换为主;界定了59个单倍型,其中8个共享单倍型,51个特有单倍型;我国地方黄牛分为两大支系,多数与非洲瘤牛、欧洲普通牛聚为一类,少数与印度瘤牛聚为一类;与其他地方黄牛品种相比,早胜牛及其杂交类群与秦川牛的亲缘关系最近。[结论]早胜牛及其杂交类群mtDNA D-Loop区核苷酸变异丰富,群体变异程度较高,与秦川牛的亲缘关系最近。

[Objective] In order to evaluate and excavate genetic resources and germplasm resources of Zaosheng cattle, this study studied the genetic polymorphism and maternal genetic background of Zaosh- eng cattle. [Method] PCR amplification and sequencing of genome DNA were conducted based on the marker sites within mtDNA D-Loop region. And further this study analyzed genetic polymorphism inde- xes, such as nucleotide polymorphism loci, nucleotide diversity and number of haplotype of the nucleotide sequence of mtDNA D-Loop of 8 indigenous yellow cattle species and 5 introduced species as control, and constructed phylogenetic tree. [Result] mtDNA D-Loop of Zaosheng cattle and Zaosheng cattle hybrid groups were rich in nucleotide A and T. A total of 80 nucleotide mutation loci were detected in this region, containing three types, base transition, transversion and both the two types coexist, in which transition was the main mutation types. Moreover, 59 haplotypes were defined, which contained 8 shared haploid types and 51 unique haploid type. In China, most of indigenous yellow cattle were clustered into African zebu and Common European cattle, and a few was clustered into India zebu. Zaosheng cattle and Hybrid groups had closest relationship with Qinchuan cattle, comparing with other local yellow cattle breed in China. [Conclusion] Zaosheng cattle and Zaosheng hybrid groups were rich in nucleotides mutations and higher population variation degree, and which had the closest genetic relationship with Qinchuan cattle.