大口黑鲈HSC70-1基因多态性及其双倍型与生长性状的关联分析

Association analysis of SNPs and diplotype of HSC70-1 gene with growth traits in largemouth bass (Micropterus salmoides)

为了探讨HSC70-1基因对大口黑鲈(Micropterus salmoides)生长性状的影响作用,开发与生长性状相关的分子标记,该研究采用PCR技术扩增得到HSC70-1基因的cDNA和DNA全序列,编码区cDNA序列长1 953 bp,编码650个氨基酸,其DNA全序列长3 390 bp,包含8个外显子和7个内含子。采用直接测序法在该基因上筛选到4个单核苷酸多态性(SNP)位点,分别位于核苷酸序列中的第821、第1 105、第1 200和第2 804碱基处,且处于内含子上。SNP标记与性状的关联分析结果表明,C-821G位点上CC基因型个体的体质量和全长均显著高于CG和GG基因型(P<0.05)。A-2804T位点上TT基因型个体的体质量和全长均显著高于AT和AA基因型(P<0.05)。其他位点不同基因型个体间的生长性状均不存在显著差异(P>0.05)。通过合并基因型发现,双倍型D1 (CC--CCTT)的各个生长性状表现最优,在体高和全长上显著高于D5。C-821G、A-2804T和D1与生长性状显著相关,可作为大口黑鲈分子标记辅助育种的候选标记。

In order to explore the effects of HSC70-1 gene on growth traits of largemouth bass(Micropterus salmoides)and develop growth-related SNPs,we obtained the cDNA of coding region and the complete sequence of HSC70-1 gene by PCR amplification.The encoding region cDNA sequence of HSC70-1 gene was 1 953 bp,encoding 650 amino acids.Its complete sequence was 3 390 bp in length,consisting of 8 exons and 7 introns.We screened four SNPs(at 821,1 105,1 200 and 2 804 bp on the introns)by direct sequencing,and found that the individuals with CC genotype of C-821G site had significantly higher values of body mass or total length than those with CG or GG genotypes(P<0.05).At the position of A-2804T,the individuals with TT genotype had significantly higher values of body mass or total length than those with AT or AA genotypes(P<0.05).The other two SNP loci were not significantly correlated with growth traits(P>0.05).The optical combined genotype of HSC70-1 gene was D1(CC--CCTT),which had significantly higher values of body height or total length than those with D5.The growth-related C-821G,A-2804T and D1 can be useful candidate molecular markers for largemouth bass molecular marker-assisted selection.