哈萨克羊DQB2基因外显子2多态性及遗传变异分析  

Polymorphisms and Its Genetic Variation Analysis of DQB2 Gene Exon 2 in Kazakh Sheep

作　　者：王元元 严国 罗成 齐江姣 周光普 谭君 高剑峰[1] WANG Yuan-yuan;YAN Guo;LUO Cheng;QI Jiang-jiao;ZHOU Guang-pu;TAN Jun;GAO Jian-feng(College of Life Science, Shihezi University, Shihezi 832003,China)

机构地区：[1]石河子大学生命科学学院,石河子832003

出　　处：《中国畜牧兽医》2017年第12期3543-3553,共11页China Animal Husbandry & Veterinary Medicine

基　　金：国家重点基础研究发展计划(973计划)(2010CB530200)

摘　　要：试验旨在研究DQB2基因外显子2多态性与哈萨克羊布鲁氏菌病易感性的相关性。通过PCR-SSCP技术对146只布鲁氏菌阴性哈萨克羊血液样本和28只布鲁氏菌阳性哈萨克羊血液样本中的白细胞表面抗原DQB2基因外显子2的多态性进行研究,挑取不同的等位基因进行克隆测序,经卡方检验分析每个SNP位点的基因频率、基因型频率及其多态性与布鲁氏菌病易感性的相关性,应用生物信息学软件分析与哈萨克羊布鲁氏菌病易感性相关的不同等位基因的mRNA二级结构及蛋白质的二级结构、三级结构和抗原表位。结果发现,在270bp的外显子2序列中共检测到33个SNPs,其中C9G、A180G位点的基因频率在病例组和对照组中的分布具有极显著性差异(P<0.01),其基因型频率在病例组和对照组中存在显著差异(P<0.05);A13T、C133G位点的基因频率在病例组和对照组中存在显著差异(P<0.05);进一步分析发现,A180G突变位点的最小自由能最低,其mRNA二级结构最稳定;A13T和C133G2个突变位点均引起mRNA二级结构及蛋白质二级结构、三级结构和抗原表位的改变。本试验结果表明DQB2基因外显子2多态性与哈萨克羊布鲁氏菌病易感性呈显著相关。This study was aimed to investigate the association between the polymorphism of DQB2gene exon2and the susceptibility to Kazakh sheep brucellosis.The DQB2gene exon2of Kazakh sheep lymphocyte antigen was amplified by PCR-SSCP method from146healthy and28infected with Brucella Kazakh sheep,and the single nucleotide polymorphisms(SNP)was analyzed,then the different alleles were selected for cloning and sequencing.In order to analyze its correlation with brucellosis susceptibility,the differences in gene frequency and genotype frequency of each SNP locus were analyzed by Chi-square test.Bioinformatics softwares were used to analyze the secondary structure of mRNA,the secondary structure,tertiary structure and epitope of protein.The sequencing result showed that33SNPs were detected in270bp DNA sequence,the gene frequencies of C9G and A180G were extremely significantly different in case group and control group(P<0.01),and its genotype frequencies presented significantly difference(P<0.05).Similarly,A13T and C133G loci were significant difference in case group and control group(P<0.05).Further analysis result showed that the minimum free energy of the A180G mutation site was the lowest and its mRNA secondary structure was the most stable;Both A13T and C133G mutation sites caused the changes of mRNA secondary structure,protein secondary,tertiary structure and antigenic epitope of protein,respectively.The results showed that the polymorphism of DQB2gene exon2might be significantly correlated with brucellosis susceptibility in Kazakh sheep.

关 键 词：DQB2基因 PCR-SSCP SNPS 布鲁氏菌病 易感性 生物信息学 

分 类 号：S813.3[农业科学—畜牧学]