甘肃西门塔尔牛甘州类群MSTN基因外显子多态性分析

摘要

PCR-SSCP(single-strand conformational polymorphism)was used to detect the genetic polymorphism in 3 exons of myostatin (MSTN)gene in 50 individuals of Ganzhou Simmental cattle in Gansu. The alleles in a population were verified by sequencing, which provided the theoretical evidences for investigating the correlation betweenMSTN gene of Simmental cattle and meat quality. The results showed that the polymorphism in the exon 2 was controlled by B and C alleles, which formed 3 genotypes of BB, CC and BC with the frequencies at 0. 22(11/50), 0. 64(32/50)and 0. 14(7/50)respectively. The polymorphism in the exon 1 and exon 3 was controlled by A and D allele respectively, which formed AA and DD genotypes with frequencies at 1(50/50). Sequence analysis indicated that there was one single nucleotide mutation of C to T at 41st nucleotide in the exon 2 of Ganzhou Simmental cattle;however this did not lead to the amino acid changed, so it was a synonymous mutation. There were no mutations in the exon 1 and exon 3. The statistical results showed that the exon 2 ofMSTN gene in 50 individuals of Ganzhou Simmental cattle had a moderate level of polymorphism, and the exon 1 and exon 3 had no polymorphism.%采用PCR-SSCP方法检测50头甘肃西门塔尔牛甘州类群MSTN基因3个外显子的遗传多态性，并对群体内各等位基因进行测序，旨为探讨西门塔尔牛MSTN基因与肉质性状关联等方面的研究提供理论依据。结果显示，甘肃西门塔尔牛甘州类群MSTN基因3个外显子中，外显子2受B、C等位基因控制，形成BB、CC和BC 3种基因型，基因型频率分别为0.22（11/50）、0.64（32/50）、0.14（7/50）；外显子1和外显子3分别受A等位基因与D等位基因控制，形成AA和DD基因型，基因型频率均为1（50/50）。序列分析表明，甘肃西门塔尔牛甘州类群MSTN基因3个外显子中，外显子2在第41 bp处发生了C→T的突变，但并没有导致氨基酸发生改变，属于同义突变；外显子1和3均无突变。统计结果表明，甘肃西门塔尔牛甘州类群MSTN基因3个外显子中，外显子2为中度多态，其余均无变化。