GHSR基因变异及其与贵州黑山羊体重体尺的关联研究

Study on the GHSR Gene Mutation and its Relationships with Body Weight and Body Size Traits in Guizhou Black Goats

本实验以82只贵州黑山羊为研究对象,采用DNA池结合PCR产物测序及PCR-SSCP技术检测GHSR基因的单核苷酸多态性,探讨GHSR基因SNP与山羊体重、体尺性状的关联性。结果表明:在GHSR基因外显子2′和3′UTR区分别检测到1个SNP位点(G996A和T1424C),而在外显子1′和5′UTR区未发现多态性;G996A为错义突变位点,表现为3种基因型,分别命名为GG、GA和AA,其基因型频率分别为0.2317、0.5122和0.2561,等位基因G和A的频率分别为0.4878和0.5122;χ2适合性检验表明,贵州黑山羊GHSR基因外显子2等位基因的分布符合HardyWeinberg平衡。基因型分型后个体体重体尺性状间差异显著性分析显示,GG基因型个体的体重与AA基因型个体的体重间差异显著;GA基因型个体的体高和体斜长与AA基因型个体间均存在显著差异(P<0.05);而3种基因型个体的胸围、管围间的差异不显著(P>0.05)。综上说明,G996A位点突变与贵州黑山羊体重、体高和体斜长间有一定的相关性,但与胸围、管围间没有明显的关联。

The polymorphism of GHSR gene of Guizhou black goat was analyzed using the DNA pooling technology, direct sequencing of PCR products and PCR-SSCP. A total of 82 Guizhou black goats were used as experimental animal. The result showed that mutations of G996A and T1424C were detected in exon 2 and 3＇UTR but no SNP in exonl and 5＇UTR of GHSR gene. The SNP （G996A） was a missense mutation, and there were 3 genotypes including GG, GA and AA. The frequencies of these genotypes were 0.2317, 0.5122 and 0.2561 for GG, GA and AA respectively. The frequencies of allel G and A were 0.4878 and 0.5122. The result of Chi-Square test indicated that the frequencies of exon 2 of GHSR gene fitted into Hardy-Weinberg equilibrium in this population. The correlation analysis of polymorphism between genotype and body weight and size traits revealed that, significant differences existed in individual body weight between GG genotype and AA genotype （P〈0.05）, in body height （body length） between GA genotype and AA genotype （P〈0.05）; however no significant differences was found in chest girth or hucklebone width among genotypes （P〉0.05）. In conclusion, correlationship might exist between G996A and body traits such as body weight, height, length, but not body chest girth or hucklebone width.