论文部分内容阅读
家养山羊(Capra hircus)由野生山羊进化而来,我国家养山羊适应性强,分布范围广,品种资源丰富。长期的自然选择和人工选择,可能会导致南北地区家养山羊遗传多样性及分化有一定差别。为了了解中国南部地区和西北地区家养山羊遗传多样性及其起源分化,本研究对南部地区5个家养山羊品种69个个体线粒体DNA D-loop区进行了测序,结合所下载的西北地区3个品种33条山羊序列进行数据分析。结果发现,南部地区家养山羊平均单倍型多样性(haplotype diversity,Hd)和平均核苷酸多样性(nucleotide diversity,π)分别为0.954±0.005和0.019 57±0.002 10,西北地区山羊分别为0.919±0.106和0.019 08±0.001 15;不同群体的中性检验Fu′s Fs值为较大负值(P<0.05),离差平方和(sum of squares of deviations,SSD)与Raggedness值统计检验均差异不显著,表明核苷酸不配对分布未偏离群体扩张模型,通过核苷酸错配分布分析发现,对于整个单倍型群体来说在13、37、61碱基处各有一个峰值;NJ(neighbor-joining)聚类分析指出,所有山羊序列共分为两大支系(A支系和B支系),南部和西北地区山羊在两支系中均有分布。结果表明,中国南部地区山羊遗传多样性略高于西北地区山羊群体,但较几年前有所下降;对于整个单倍型群体以及A、B支系来说,均经历过群体扩张,对整个群体来说至少发生过3次扩张事件;捻角野山羊(C.aegagrus)是本研究所涉及的中国南部和西北地区家养山羊的野生祖先。本研究为进一步了解中国南部与西北地区山羊起源分化以及遗传多样性提供理论支持,并为地方山羊品种保护提供理论依据。
Domestic goats (Capra hircus) evolved from wild goats, my domestic goats adaptability, distribution of a wide range of species rich in resources. Long-term natural selection and artificial selection may lead to differences in the genetic diversity and differentiation of domestic goats in the north and south regions. In order to understand the genetic diversity and their differentiation of domestic goats in southern China and northwestern China, 69 mitochondrial DNA D-loop regions of 5 domestic goat breeds in southern China were sequenced. In this study, 33 goat sequences for data analysis. The results showed that the average haplotype diversity (Hd) and the average nucleotide diversity (π) of domestic goats in the southern area were 0.954 ± 0.005 and 0.019 57 ± 0.002 10, respectively, while that in the northwest area was 0.919 ± 0.106 and 0.019 08 ± 0.001 15, respectively. Fu’s Fs values of the neutral test in different groups were significantly negative (P <0.05), both of the sum of squares of deviations (SSD) and Raggedness value test The difference was not significant, indicating that the unpaired nucleotide distribution did not deviate from the population expansion model. According to the nucleotide mismatch distribution analysis, there was a peak at 13, 37, and 61 bases for the entire haplotype population. NJ (neighbor-joining) cluster analysis indicated that all the goat sequences were divided into two major branches (A branch and B branch), and the southern and northwestern goats were distributed in both branches. The results showed that the genetic diversity of goats in southern China was slightly higher than that of goats in northwestern China, but decreased from that of a few years ago. For the entire haplotype population and A and B branches, At least 3 dilations occurred in the population; C. aegagrus was the wild ancestor of the domestic goats in southern and northwestern China involved in this study. This study provides theoretical support for further understanding the origin and differentiation of goats and their genetic diversity in southern and northwestern China and provides a theoretical basis for the protection of local goat breeds.