猪OLR1基因克隆及其与生产性状的关联、表达分析

Cloning,association with production traits and expression analysis of the porcine OLR1 gene

为鉴定对猪生产性状有重要影响的新分子标记,采用电子克隆技术结合PCR方法获得了猪氧化型低密度脂蛋白受体1（oxidized low-density lipoprotein receptor 1,OLR1）基因编码区序列,在OLR1基因第4内含子246bp处发现了1个新SNP位点A246G,并建立了PCR-Pag1-RFLP基因分型方法,分析了4个不同品种猪群中该等位基因频率,发现国外品种大白、长白猪群G等位基因频率高于A等位基因频率,而国内品种梅山、大梅群体A等位基因频率高于G等位基因频率。在大梅猪群体中的关联分析结果发现,A246G位点与胸腰椎间膘厚、平均背膘、背最长肌含水量、背最长肌肌内脂肪含量、屠宰率、板油质量、6-7腰椎间膘厚、背最长肌大理石纹、股二头肌大理石纹显著或极显著相关。通过RT-PCR分析发现,OLR1在恩施黑猪和大白猪群中心脏表达量最高,其次是背脂,同品种不同组织间表达量差异大,表明OLR1基因是脂肪相关的候选基因。

To identify new DNA markers which have significant impact on pig production traits, full coding sequence of the porcine OLR1 （oxidized low-density lipoprotein receptor 1） gene were isolated using in silico cloning and PCR. A single nucleotide polymorphism （SNP, A246G） in intron 4 were found and the PCR-Pagl-RFLP method was used to genotype the polymorphic site. In all the four detected pig populations,the western commercial pig breeds （Large White and Landrace） had higher frequencies of the G allele, and the Chinese indigenous breeds （Meishan and Large White X Meishan） had higher fre- quencies of the A allele. Association analysis showed that the polymorphic site had a significant or domi- nant significant effect on thorax-waist fat thickness,average backfat thickness,water content of longissi- mus dorsi, intramuscular fat of longissimus dorsi, dress percentage, leaf fat weight, 6-7 rib fat thickness, meat marbling of longissimus dorsi and meat marbling of biceps femoris. Quantitative real-time PCR （qRT-PCR） analyses showed that the porcine OLR1 gene was highly expressed in the heart tissue, followed by the back fat in Enshi black and Large White pigs, and it was differentially expressed in different tissues. These results indicated that the OLR1 is a fat relevant candidate gene.