豫西黑猪线粒体Cytb基因遗传多样性分析

Genetic diversity analysis of mitochondrion Cytb gene in Yuxi black pig

为了评估河南省地方类群豫西黑猪的种质资源,分析其遗传多样性和基因混杂情况,试验以长白猪为对照,采用PCR扩增的方法,并用最大似然法(ML法)和邻接法(NJ法)构建分子进化树,对豫西黑猪线粒体Cytb基因进行了研究,并与GenBank中37个其他品种猪进行比对。结果表明:PCR扩增得到的线粒体Cytb基因条带明亮,大小为873 bp。去除差异序列获得的长度为769 bp的豫西黑猪线粒体Cytb基因片段中共有10个变异位点,其中有1个变异位点可造成蛋氨酸与苏氨酸之间的非同义突变;长白猪线粒体Cytb基因片段中共有8个变异位点。豫西黑猪与GenBank中已公布的37个其他品种猪序列进行比对后共发现25个变异位点,其中有4个变异位点(58,94,173,183位)可造成氨基酸突变。在构建的两种分子进化树中,豫西黑猪和长白猪均分布在两大支系中。说明豫西黑猪具有遗传多样性,并且与其他品种猪之间存在基因混杂情况。

In order to evaluate the germplasm resources of Yuxi black pig, a local group in Henan Province, and analyze its genetic diversity and gene hybridization, in this study, the mitochondrial Cytb gene of Yuxi black pig was studied by PCR amplification, maximum likelihood(ML) and neighbour-joining(NJ) methods to construct molecular phylogenetic trees. Landrace pigs were used as the control and compared with 37 other breeds of pigs in GenBank. The results showed that the mitochondrion Cytb gene amplified by PCR had a bright band of 873 bp. There were ten mutation sites in the 769 bp mitochondrion Cytb gene fragments of Yuxi black pig after removing differential sequences, one of which could cause non synonymous mutation between methionine and threonine. There were eight mutation sites in the mitochondrial Cytb gene fragments of Landrace. A total of 25 mutation sites were found after sequences alignment between Yuxi black pig and 37 other breeds of pig published in GenBank. Among them, four mutation sites(58, 94, 173, 183) could cause amino acid mutation. In the two molecular phylogenetic trees, Yuxi black pigs and Landrace were distributed in two major branches.The results indicated that there were genetic diversities in Yuxi black pig, and there was gene hybridization between Yuxi black pig and other breeds of pig.