4个绵羊品种LHCGR基因单核苷酸多态性分析

Single Nucleotide Polymorphism Analysis of LHCGR Gene in 4 Sheep Breeds

为探究绵羊LHCGR基因在4个绵羊品种之间的多态性与基因功能,本研究以杜泊羊、滩羊、小尾寒羊、滩羊和小尾寒羊杂交羊4个绵羊品种为研究对象,利用Sequenom MassARRAY®SNP技术对4个绵羊品种LHCGR基因g.75747421A>C、g.75748200T>A 2个位点进行检测,并利用相关生物信息学软件预测分析2个位点突变前后mRNA二级结构与其编码蛋白的理化性质、结构和蛋白互作等。结果表明,LHCGR基因g.75747421A>C位点在4个品种中存在3种基因型,分别是CC、CA和AA;g.75748200T>A位点在4个品种中存在AA、AT和TT 3种基因型;χ^(2)适合性检验表明,g.75747421A>C、g.75748200T>A 2个位点在4个绵羊品种中均处于Hardy-Weinberg平衡状态(P>0.05)。生物信息学分析表明,该基因编码蛋白的相对分子质量为73599.70,理论等电点为8.30,脂肪系数为98.90,总平均亲水性为0.191,推测该蛋白为疏水性蛋白;突变前后LHCGR基因的mRNA二级结构、编码蛋白二级结构及三级结构均发生了变化;蛋白互作的结果表明,与LHCGR蛋白相互作用的蛋白质主要包括骨形态发生蛋白15(BMP15)、嗜铬粒蛋白A(CGA)、甲羟戊酸激酶(MVK)、胆固醇侧链裂解酶(CYP11A1)、鸟嘌呤核苷酸结合蛋白α亚基(GNAS)等。本研究成功筛选出4个绵羊品种LHCGR基因多态位点,为绵羊繁殖力的标记辅助选择和育种提供一定的理论依据。

To explore the polymorphism and gene function of LHCGR gene of 4 sheep breeds,the 2 loci(g.75747421A>C and g.75748200T>A)of LHCGR gene among Dorper sheep,Tan sheep,Small-tailed Han sheep and Tan×Han hybrid sheep were detected by Sequenom MassARRAY®SNP.The secondary structure of mRNA and the physicochemical properties,structure and protein interaction between the 2 sites before and after the mutation were predicted and analyzed by bioinformatics software.The results showed that there were 3 genotypes of LHCGR gene g.75747421A>C in 4 breeds,which were CC,CA and AA.g.75748200T>A had 3 genotypes of AA,AT and TT in 4 breeds.χ^(2) test indicated that g.75747421A>C and g.75748200T>A were in Hardy-Weinberg equilibrium in 4 sheep breeds(P>0.05).Bioinformatics analysis showed that the relative molecular weight of LHCGR gene was 73599.70,the theoretical isoelectric point was 8.30,the fat coefficient was 98.90,and the total average hydrophilicity was 0.191,which was an unstable hydrophobic protein.The secondary structure of LHCGR gene mRNA and the secondary structure and tertiary structure of the encoded protein were all changed before and after mutation.The results of protein-protein interaction showed that the proteins interacting with LHCGR protein mainly included bone morphogenetic protein 15(BMP15),chromogranin A(CGA),mevalonate kinase(MVK),cholesterol side chain cleavage enzyme(CYP11A1),guanine nucleotide binding proteinαsubunit(GNAS).This study successfully screened the LHCGR gene polymorphism loci of 4 sheep breeds,which could provide a certain theoretical basis for the marker-assisted selection and breeding of sheep fecundity.