延边黄牛α-肌动蛋白1基因的多态性及其与生长性状的相关分析

试验旨在寻找肌内脂肪含量差异极显著的两组个体延边黄牛背最长肌组织差异表达基因,并分析其遗传多态性对生长性状的影响。应用引物退火技术获得了在肌内脂肪含量差异极显著的两组个体背最长肌组织差异表达α-肌动蛋白1(actin alpha 1,ACTA1)基因及其全长cDNA序列,该基因主要在心脏和背最长肌中表达。序列比对结果发现,在5'端非编码区193 bp处存在1个突变。采用PCR-RFLP方法对100头延边黄牛群体进行检测,发现AA、AG、GG 3种基因型,基因型频率分别为0.24、0.50、0.26;A、G等位基因频率分别为0.37、0.63。对该突变位点的多态性与生长性状的关联性进行分析,结果发现,在体长、体重和平均日增重上,GG基因型个体显著高于AA和AG基因型个体(P＜0.05);在胸围上,GG基因型个体显著高于AG基因型个体,但与AA基因型个体差异不显著(P＞0.05);在体高上,不同基因型之间差异不显著(P＞0.05)。初步认为GG基因型是提高延边黄牛体质量和体尺指标性状的有利基因型,提示ACTA1基因有可能作为延边黄牛生长性状的候选基因。

Genetic Polymorphism and Correlation Analysis with Growth Traits of ACTA1 Gene in Yanbian Yellow Cattle

To search for differentially expressed genes and analysis its genetic effections,in this study,actin alpha 1 (ACTA1) gene was found differentially expressed in longissimus dorsi of Yanbian Yellow cattle,which had significant difference on intramuscular fat (IMF) content, and its full-length cDNA sequence was obtained from Yanbian Yellow cattle. The tissue expression analysis indicated that the ACTA1 gene was highly expressed in muscle and longissimus dorsi. One SNP was detected by sequence comparison in 5' non-coding region.The polymorphisms of ACTA1 were detected in a 100 Yanbian Yellow cattles population by PCR-RFLP and the association of genotype with growth traits,which result in 3 genotypes named AA,AG and GG respectively,the genotype frequency of AA,AG and GG were 0.24,0.50 and 0.26;Allele frequencies of A and G were 0.37 and 0.63. Variance analysis showed: some indexes of the individuals with GG genotype were higher than that with genotype AA and AG, such as the indexes of body length, body weight and average day gain(P＜0.05); the heart girth of individuals with GG genotype was extremely higher than AG genotype (P<0.05); there were not significantly differences in the wither height individuals with different genotype.The GG genotype may have positive effect on growth traits. This indicated that ACTA1 gene as marker can be used to selection of growth trait in Yanbian Yellow cattle.