高坡猪肌肉生长抑制素基因多态性及其与肉质性状的相关性分析

The Polymorphisms of MSTN Gene and Its Relationship with Meat Quanlity Traits in Gaopo Pig

为了探讨肌肉生长抑制素(myostatin,MSTN)基因的多态性对高坡猪肉质性状(水分、粗脂肪、粗蛋白质、粗灰分、眼肌面积、大理石纹、pH、肉色、嫩度、滴水损失、失水率)的影响,试验以MSTN基因作为肉质性状候选基因,以10月龄的50头高坡猪为研究对象,采用PCR扩增产物直接测序的方法对高坡猪MSTN基因3个外显子的单核苷酸多态性(SNP)进行研究,运用SPSS 20.0软件分析MSTN基因SNP与肉质性状的关联性。结果表明,仅在高坡猪MSTN基因第3外显子63bp处检测到1个C/T突变位点,该突变为同义突变,未引起编码氨基酸的改变。基因型分析发现,仅有3个个体在该位点发生突变,CC基因型为优势基因型,C为优势等位基因,无TT纯合基因型。经χ~2适合性检验分析,该SNP在研究群体中处于Hardy-Weinberg平衡状态(P>0.05)。群体遗传参数分析发现,C63T标记位点的杂合度(He)相对较低,表明其在高坡猪群体中的变异较小;就多态信息含量(PIC)而言,该位点属于低度多态(PIC<0.25),说明该遗传标记能够提供少量的遗传信息。将该位点的不同基因型与肉质性状指标进行关联分析表明,所有肉质性状指标在不同基因型间差异均不显著(P>0.05)。综上所述,MSTN基因外显子在高坡猪中存在多态性,但变异较少,相对保守,能否作为高坡猪肉质性状的遗传标记有待于扩大样本数量进一步研究。

To explore the influence of Gaopo pig myostatin （MSTN） gene polymorphism on meat quanlity traits （moisture,crude fat,crude protein,crude ash, loin muscle area, marbling score, pH value, color of meat,tenderness,drip loss, water loss rate）, MSTN gene was chosen as a candidate gene for research meat quality traits in this study. 50 Gaopo pigs at 10 months old were selected,the single nucleotide polymorphism （SNP） of three exons of MSTN gene in Gaopo pig were detected by direct sequencing of PCR amplification products, and the correlation between MSTN gene SNP and meat quality traits was analyzed using SPSS 20.0 software. The results showed that a C/T mutation had been found at 63 bp of MSTN gene exon 3,the site was silent mutation, and did not caused changes of encoding amino acid. Genotype analysis showed only three samples had mutations in the site, CC genotype was the dominant type and allele C was the dominant gene, but there was no TT homozygous genotype. The test of Hardy-Weinberg equilibrium showed the research group obeyed the genetic equilibrium （P〉0.05）. Population genetic parameter analysis showed the heterozygosity （He） of C63T was lower, and had a low variation in Gaopo pig population. Polymorphism information content （PIC） analysis showed that it was a low polymorphic loci （PIC〈0.25）, and the site could provide a little genetic imformation. There was no significant difference between the different genotypes and meat quality traits （P〉0.05）.Given the above, the polymorphism of MSTNgene exon was found in Gaopo pig, with less variation and relatively conservative.It＇s needed to expand the number of sample for further explore whether the site could be considered as genetic markers for meat quality traits of Gaopo pig or not.