延边黄牛ATF3基因组织表达及其多态性与肉质性状的相关性分析

Tissue Expression and Polymorphism of ATF3 Gene and Its Association with Meat Quality Traits in Yanbian Yellow Cattle

本研究旨在分析转录激活因子3(activating transcription factor 3,ATF3)基因在延边黄牛各组织中的表达差异及其多态性与肉质性状的相关性。以70头30月龄的健康延边黄牛为研究对象,用实时荧光定量PCR比较ATF 3基因在延边黄牛心脏、肝脏、脾脏、肺脏、肾脏、后腿肌、眼肌、西冷、上脑和皮下脂肪10个部位的表达水平差异;进一步对ATF 3基因的第4外显子进行PCR扩增,通过Sanger直接测序筛选出SNPs位点,用PCR-RFLP对筛选出的SNPs进行酶切验证,并与肉质性状进行关联分析。结果发现,ATF 3基因在延边黄牛10个组织中均有表达,其中在皮下脂肪组织中表达量极显著高于其他组织(P<0.01);西冷中ATF 3基因相对表达量与肌内脂肪(IMF)含量呈极显著正相关(P<0.01),相关系数为0.996;眼肌中ATF 3基因表达量与IMF含量呈显著正相关(P<0.05),相关系数为0.999;上脑和后腿肌中ATF 3基因表达量与IMF含量无显著相关(P>0.05),相关系数分别为0.757和0.658。ATF 3基因1428 bp处存在G→C突变,存在3种基因型:GG、GC、CC,其中GC和CC基因型的脂肪含量、背膘厚均显著高于GG基因型(P<0.05);大理石花纹等级极显著优于GG基因型(P<0.01)。说明该突变位点可作为延边黄牛肉质性状潜在的分子标记,ATF 3基因可能是影响延边黄牛脂肪沉积的候选基因。

The aim of this study was to elucidate the association between tissue expression level and polymorphism of ATF 3 gene and meat quality traits in Yanbian Yellow cattle.Using 70 healthy 30-month-old Yanbian Yellow cattle as the research object,Real-time PCR was used to compare the expression of ATF 3 gene in 10 tissues including heart,liver,spleen,lung,kidney,hind leg muscle,eye muscle,sirloin,upper brain and subcutaneous fat tissue.The exon 4 of ATF 3 gene was amplified,SNP was screened and verified by Sanger direct sequencing and PCR-RFLP methods,and the association with meat quality traits was analyzed.The results showed that the expression of ATF 3 gene was detected in 10 tissues of Yanbian Yellow cattle,and the expression of ATF 3 gene in subcutaneous adipose was extremely significantly higher than other tissues(P<0.01).The relative expression of ATF 3 gene in sirloin was extremely significantly positively correlated with IMF content(P<0.01),and the coefficient of correlation was 0.996;There was a significant positive correlation between ATF 3 gene expression and IMF content in eye muscle(P<0.05),and the coefficient of correlation was 0.999.There were no significant correlation between the expression of ATF 3 gene and IMF content in the upper brain and hind leg muscle(P>0.05),and the correlation coefficients were 0.757 and 0.658,respectively.There was a G→C mutation at 1428 bp of ATF 3 gene,contained three genotypes:GG,GC and CC.The fat content and back fat thickness of GC and CC genotypes were significantly higher than GG genotype(P<0.05),the marbling grade of GC and CC genotypes were extremely significantly better than GG genotype(P<0.01).The results demonstrated that the mutation site could be used as a potential molecular marker for meat quality traits,and ATF 3 gene might be a candidate gene for fat deposition in Yanbian Yellow cattle.