Abstract:

Using PCR-SSCP and DNA sequencing techniques, the genetic polymorphism of 257 C/G mutation in THRSP gene exon 1 and its relationship with meat quality traits were studied on five cattle breeds, including Qinchuan cattle, Xianan cattle, Nanyang cattle, Jiaxian red cattle and Luxi cattle. The results showed that this mutation had led to a synonymous mutation in the 75th amino acids. The allele frequency was consistent in 5 cattle breeds. The PIC of this locus is the highest in Nangyang cattle, which belonged to moderate polymorphisms, and that of the other cattle breeds belonged to low polymorphisms. The χ2 adaptability test indicated that the polymorphic of site 257 was in accordance with Hardy-Weinberg equilibrium (P>0.05) in five breeds. Associate analysis showed that carcass length and loin muscle area is significantly different between AA and AB genotypes in this locus. This locus is probably a mutation that affects carcass length and loin muscle area, or tightly linked to it. It could be a candidate molecular marker for beef cattle breeding.

Key words: THRSP gene, PCR-SSCP, Qinchun cattle, molecular marker

摘要：

采用PCR-SSCP技术及测序技术,研究了秦川牛、夏南牛、南阳牛、郏县红牛和鲁西牛五个牛品种THRSP基因第一外显子257 bp处C/G突变的遗传多态性及其与肉质性状的关系。结果显示,该位点引发THRSP基因第75位氨基酸发生同义突变,五个牛品种基因频率一致,多态信息含量以南阳牛最高,属于中度多态,其他牛品种属于低度多态。经χ2适合性检验,五个牛品种群体257C/G位点的突变均达到Hardy-Weinberg平衡状态(P>0.05)。关联分析结果显示,AA,AB基因型个体的胴体长、眼肌面积差异显著。该位点可能是影响胴体长和眼肌面积的突变位点或与之紧密连锁,可做为肉牛肉质选育的候选分子标记。

关键词: THRSP基因;PCR-SSCP;秦川牛;分子标记