过氧化物酶体增殖激活受体α(PPARα)基因突变对牛的背膘厚和胴体长的影响

A Mutation in PPARα Gene Impact Backfat Thickness and Carcass Length in Cattle

研究过氧化物酶体增殖激活受体α(PPARα)基因第7外显子SNP位点与牛的部分胴体、肉质性状的相关性。以6个牛品种(秦川牛、南阳牛、郏县红牛、鲁西牛、安格斯、夏南牛)共计717个个体为研究对象,采用PCR-SSCP结合DNA测序方法对PPARα基因第7外显子进行SNP检测,并该SNP位点与108头秦川牛的部分胴体、肉质性状的相关性进行分析。结果发现在PPARα基因第7外显子的184位检测到C→T突变,在南阳牛、秦川牛、郏县红牛、安格斯、鲁西牛、夏南牛这6个群体中等位基因E/F的频率分别是0.225/0.775,0.151/0.849,0.125/0.875,0.123/0.877,0.070/0.930,0.157/0.783;遗传学指标结果显示:秦川牛、郏县红牛、安格斯、鲁西牛和夏南牛这5个群体属于低度多态(PIC<0.25),南阳牛为中度多态(PIC=0.288);相关分析结果显示:该位点与秦川牛的背膘厚和胴体长两个性状显著相关,表现为FF基因型个体在背膘厚性状方面显著高于EE和EF基因型个体(P<0.05),FF基因型个体的胴体长显著高于EE基因型个体(P<0.05)。这一位点可能是影响牛背膘厚和胴体长的主效QTN或与之紧密连锁,可做为肉牛选育的候选分子标记。

To reveal the SNP of PPARa gene exon7 and evaluate its relationship with carcass traits and meat traits in cattle, a total of 717 individuals from six breeds （QC, NY, JX, LX, XN and Angus） were genotyped by PCR-SSCP and DNA sequencing in PPARa gene exon7 and analyzed its correlation of the SNP with some carcass traits and meat traits in 108 Qinchuan cattle. C→T mutation was detected at 184bp in PPARa gene exon7. Allele frequencies of PPARa-E/F in the six breeds were 0. 225/0. 775, 0. 151/0. 849, 0. 125/0. 875, 0. 123/0. 877, 0. 070/0. 930 and 0. 157/0. 783 for NY, QC, JX, Angus, LX and XN, respectively. Except for NY breed in moderate polymorphisms （PIC=0. 288）, other five breeds were in low genetic diversity in the locus（PIC〈0.25）. Correlation analysis showed that the mutation had significantly related to back fat thickness and carcass length in QC breed. Animals with the genotype FF had significantly higher traits than these with genotypes EE and EF in back fat thickness trait （P〈0.05）, and animals with the genotype FF had much higher than those with genotype EE （P〈0.05） in carcass length trait. In conclusion, this locus is likely to be a major QTN or tightly linked that affect production traits, it can be a candidate molecular marker for the beef cattle breeding.