MSTN基因突变对优质鸡肌肉生长的影响

The myostatin gene(MSTN) and its relationship with muscle fiber traits in chickens

为了研究肌肉生长抑制素基因(MSTN)在优质鸡群体中的遗传变异及其对肌肉生长特性的影响,以优质鸡S3系为研究对象,采用PCR-SSCP及测序技术进行多态性检测。结果发现MSTN基因G195C和A234G 2个突变位点。公鸡群体在G195C处于Hardy-Weinberg不平衡状态(P<0.05),各群体在G195C和A234G位点均处于Hardy-Weinberg平衡状态(P>0.05)。最小二乘方差分析显示,在G195C位点处,S3系优质母鸡的CC基因型个体胸肌重、腿肌重、肌纤维密度与GG基因型个体差异显著(P<0.05),肌纤维面积CC基因型个体极显著高GG基因型个体(P<0.01)。在A234G位点处,肌纤维密度GG型个体显著小于AA基因型个体(P<0.05),肌纤维面积极显著高AA基因型个体(P<0.01)。基因组合CCGG型个体屠体重、胸肌重、腿肌重显著高于GGAA型个体(P<0.05),肌纤维面积和肌纤维密度间差异极显著(P<0.01)。在G195C和A234G位点处,S3系优质公鸡突变型CC和GG基因型个体在屠体重、胸肌重和腿肌重间差异不显著(P>0.05)。在A234G位点处肌纤维密度GG型个体显著小于AA基因型个体(P<0.05),肌纤维面积极显著高于AA基因型个体(P<0.01)。基因组合CCGG型个体屠体重、胸肌重、腿肌重显著高于GCAA型个体(P<0.05),肌纤维面积和肌纤维密度间差异极显著(P<0.01)。因此,MSTN是影响鸡肌肉生长的一个主效基因,基因突变显著影响优质鸡肌肉的生长,为优质鸡肌肉生长性状的选育提供遗传学依据,其肌肉生长性状的分子遗传学基础需进一步研究。

To investigate the influence of the MSTN gene on muscle fiber traits of quality chickens, polymorphisms of the myostatin（MSTN） gene from S3 line quality chickens was detected by PCR-SSCP and sequencing technology. Two SNPs were identified at G195 C and A234 G of the MSTN gene. Both SNPs were in Hardy-Weinberg balance（P〉0.05） in all the chicken populations except for the G195 C locus in the cock population. The effects of these polymorphisms of the MSTN gene on fiber traits were analyzed. The result showed that there were significant differences in breast muscle weight, thigh muscle weight and muscle fiber density between the genotype CC and GG hens of S3 line at G195C（P〈0.05）. The genotype CC was significantly higher in muscle fiber area than that of GG genotype（P〉0.01）.The muscle fiber density of GG genotype was less than the AA genotype（P〈0.05）, and muscle fiber area was significantly higher than AA genotype at A234G（P〈0.01）.The haplotype effects of CCGG on carcass weight, breast muscle weight, thigh muscle weight, muscle fiber density and muscle fiber area were greater than that of haplotype genotype GGAA（P〈0.05）. There was no difference between genotype CC and GGAA on carcass weight, breast muscle weight and thigh muscle weight at G195 C and A234 G of cocks（P〈0.05）. The muscle fiber density of GG genotype was less than the AA genotype（P〈0.05）, and muscle fiber area was significantly higher than the AA genotype at A234G（P〈0.01）. The haplotype effects of CCGG on carcass weight, breast muscle weight, thigh muscle weight were greater than that of haplotype genotype GGAA（P〈0.05）, and haplotype genotypes of CCGG and GGAA showed significant difference between muscle fiber area and density of muscle fiber（P〈0.01）.These results preliminarily showed that MSTN was a major gene that influences the skeletal muscle growth of chicken and provided genetic information on muscle growth in quality chickens. The genetic basis of muscle growth affected by MSTN in chickens should be further studied.