草鱼GSTR基因外显子1、外显子2的SNPs筛选及其与生长性状的关联分析

SNPs in exon 1,exon 2 of GSTR gene and its relationship with growth traits in grass carp

根据草鱼EST数据库中的rho型谷胱甘肽硫转移酶基因cDNA序列设计引物,扩增预计存在的SNP位点。采用PCR产物测序法和PCR-RFLP法,在珠江水系草鱼养殖群体中筛选到2个SNP位点,分别位于外显子1和外显子2上,为C-T突变,且属于同义突变,统计了多态位点在群体中的分布:C+129T位点CC型占0.69%,TC型占8.75%,TT型占80.56%;C+192T位点CC型占25.4%,TC型占48.6%,TT型占26.1%。利用一般线性模型将SNPs与草鱼6个生长性状进行关联分析,结果表明,C+129T位点TT型个体6个生长性状均值比TC型高(P>0.05);C+192T位点TT型个体体质量均值高于TC型和CC型个体(P<0.05)。双倍型关联分析表明D1型个体的体质量均值明显高于D3型和D6型(P<0.05),因而可以考虑将GSTR基因作为影响草鱼体质量等生长性状的候选基因,应用于草鱼分子辅助育种。

Primers were designed according to glutathione S-transferase-rho gene from EST database of grass carp.The PCR products were sequenced for detecting polymorphisms in cultured population and two SNPs sites were found：C＋129T in exon 1 and C＋192T in exon 2.Both SNPs are synonymous mutation.The polymorphisms were genotyped by PCR-RFLP methods.The percentage of CC,TC and TT genotype in C＋129T site was 0.69%,18.75% and 80.56%,respectively.The percentage of CC,TC,and TT genotype in C＋192T site was 25.4%,48.6% and 26.1%,respectively.A general linear model was used to analyze relationship between GSTR gene polymorphisms and 6 major growth traits.The results indicated that the average value of growth character TT genotype was higher than that of TC genotype in C＋129T site,although no significant difference was observed.The average body weight of TT genotype was higher than that of TC and CC genotype in C＋192T site（P〈0.05）.Six diplotypes were constructed based on two SNPs in the experiment population and the average body weight of diplotype D1 was higher than that of D3 diplotypes and D6 diplotypes（P〈0.05）.GSTR gene could be recommended as a candidate gene for characterizing grass carp growth traits which could be useful for molecular breeding.