猪MyoD1基因的多态性检测及与肉质性状的关联分析

PCR-RFLP Polymorphism Detection and Relationship with Meat Quality Traits of MyoD1 Gene in Pig

采用PCR-RFLP方法对通城、大白和长白3个纯种及长大通和大长通2个三元杂种共5个群体MyoD1基因第1内含子的多态性进行了研究,并对多态位点与生长、胴体和肉质性状进行了关联分析。结果发现第1内含子第257位存在1个A/C颠换,引起DdeⅠ酶切位点的改变。PCR产物经DdeⅠ酶切后,检测到2个等位基因,3种基因型,其中通城猪中C等位基因的分布占主要优势,大白、长白猪中2种等位基因的分布频率相近。关联分析结果表明,不同的基因型与肉色评分和失水率相关(P<0.05或P<0.01);CC基因型个体的肉色评分显著高于AA和AC基因型个体;而CC基因型个体的失水率极显著低于AA基因型个体。研究结果进一步证明MyoD1基因是一个重要的肉质性状候选基因,第1内含子第257位被DdeⅠ限制性内切酶识别的多态位点为猪肉质性状的标记辅助选择提供分子标记,CC基因型猪具有优良的肉质。

PCR-RFLP technique was applied in this study to analyze the polymorphism of intron 1 of porcine MyoD1 gene in 3 pure breeds（Tongcheng,Landrace,Yorkshire）and 2 crossbred breeds（LYT,YLT）.There was a base transition in the 257th nucleotides of intron 1（C-A）,which lead to the change of DdeⅠdigestion site.PCR products digested with DdeⅠindicated that there were two alleles,three genotypes.The C allele was predominant in Tongcheng pigs,while the frequency of A allele and C allele was close in other groups.The relationship with growth,carcass and meat quality traits revealed that different genotypes were related with meat color score and water loss rate（P〈0.05 or P〈0.01）.Meat color score with CC genotype was significant higher than AA and AC genotype（P〈0.05）,but the water loss rate was extremely significant lower than that with AA genotype（P〈0.01）.So the meat quality of individual with CC genotype was better.These results confirmed that MyoD1 gene was an important candidate gene for meat quality,and the polymorphism of the 257th nucleotides of intron 1 offered molecular marker for marker assisted selection of porcine meat quality.