中国地方猪品种的遗传多样性与聚类分析

Diversity and cluster analysis of China local pig breeds

我国拥有丰富的地方猪资源,也是世界上家猪驯化较早的中心之一。但近40年,地方猪品种受到国外引进猪种的强烈冲击,在数量和规模上均显著降低,遗传资源受到威胁。本研究利用线粒体基因组序列,对我国21个地方猪品种共计86个个体的遗传多样性进行了分析,并构建了43个地方猪品种的分子进化树。结果表明:中国地方猪线粒体D-Loop区存在序列长度多态性。86个序列共检测到32种单倍型,平均单倍型多样性(Hd)为0.966±0.006,平均核苷酸多样性(Pi)为0.00592±0.00023,遗传多样性贫乏。32种单倍型可明显的聚为2大类,但是单倍型的聚类与地理分布没有显著相关性。分子进化树显示中国地方猪与国外猪种处于2个明显不同的分支上;由于受到人类迁徙活动以及不同猪种间基因交流的影响,猪种的聚类关系与地理分布同样不存在显著相关,很难利用线粒体基因组序列对中国地方猪品种进行准确分类。

China has rich local pig breeds and is one of the earliest pig domestication centers in the world. However,recently forty years,China local pig breeds were strong impacted by foreign pig breeds. The number and scale of China local breeds were all significantly decline.The genetic resources are threatened. In the present study,21 China local pig breeds,86 individual mitochondria sequences were used to analysis the genetic diversity. The molecular evolutionary tree was constructed by 43 local pig breeds. The results showed that there was a sequence length polymorphism in the D- Loop region. Thirty- two haplotypes were found in 86 sequences. The average haploid type diversity is 0. 966 ± 0. 006 and the average nucleotide diversity is 0. 005 92 ± 0. 000 23. Genetic diversity is poor. Thirty- two haplotypes were clustered two classes,but the cluster was not significantly associated with the geographic distribution. Through the evolutionary tree,China local pig breeds and foreign pig breeds were in the different branch. China local pig breeds were affected by the people movement and gene exchange among different pig breeds,the cluster relationship was also not significantly associated with the geographic distribution. It is difficult to accuracy classify the China local pig breeds by mitochondria sequences.