阿勒泰羊MyoD基因的遗传多态性及其与产肉性状的关联分析

Association Analysis between MyoD Gene Polymorphisms and Meat Performance in Xinjiang Altay Sheep

利用分子生物学手段研究MyoD基因遗传多态性与阿勒泰羊产肉量的关系,旨在为今后用分子标记辅助育种方法提高阿勒泰羊产肉性能提供科学依据。本试验以120只阿勒泰羊周岁公羊为研究对象,选取MyoD基因的5′调控区和外显子1的部分片段,采用PCR-SSCP技术检测其遗传多态性,并与周岁体重进行关联分析,研究MyoD基因的多态性与阿勒泰羊产肉性能的关系。结果表明,MyoD-P1基因座(MyoD基因5′调控区)无多态性;MyoD-P2基因座(外显子1)有多态性,存在3种基因型:AA、AB和BB,测序结果显示该处发生了碱基突变A→G,为错义突变,该突变导致其编码的氨基酸由组氨酸变为丙氨酸,经关联分析发现,该突变对阿勒泰羊产肉性能有显著影响(P<0.05)。阿勒泰羊MyoD基因外显子1上的点突变可能是影响阿勒泰羊产肉性能的重要位点,MyoD基因可望作为阿勒泰羊产肉性能的候选基因。

In this study, the relationship of MyoD gene polymorphisms and meat yield was studied by molecular biology methods. The aim was to provide scientific basis for improving meat performance of Altay sheep by molecular marker assisted breeding methods. One year old ram of Altay （n= 120） were chosen in representative area to jugular vein blood, MyoD gene 5′ control region and the part of the exon 1 pieces were selected to detect genetic polymorphism by PCR-SSCP, and the effects on weight traits were analyzed. It was used to research the relationship between MyoD genetic polymorphisms and meat performance. There was no polymorphism in MyoD-P1 gene locus （5′ flanking region ）;There was polymorphism in MyoDP2 gene locus （326-542 bp in exon 1）, the primer MyoD P2 gene locus existence three kinds of genotypes of AA, AB and BB. Sequencing results showed that there was a base mutation A→G in location 408 bp in MyoD gene exon 1. The mutation causesd its coding changing from histidine into alanine. By correlation analysis it was found that the individual weight of AA genotype were much higher than BB genotype （P〈0.05）. Mutational site exon 1 of MyoD gene might be the important site of Altay sheep＇s meat performance, MyoD gene might be the candidate genes of Ahay sheep＇s meat performance.