中文摘要：

本试验旨在研究绵羊和人的主要组织相容性复合体（MHC）DRB1基因外显子2（exon2）单核苷酸多态性（SNPs）和单氨基酸多态性（SAPs），并进行生物信息学分析。运用生物基因组学数据库，利用生物信息学及比较基因组学方法对人与绵羊MHGDRB1基因exon2序列多态性进行分析，采用生物信息学软件对绵羊MHC-DRE1的蛋白质结构及生物学功能进行预测和分析。结果显示，人主要组织相容性复合体（HLA）和绵羊主要组织相容性复合体（OLA）的DRB1 exon2均存在丰富的SNPs位点和SAPs位点，单一多态位点和简约多态位点数不尽相同，二者相比仅有14个SNPs位点相同，其余位点均不同。序列分析结果表明，二者MHC—DRB1 exon2序列具有高度相似性。进一步生物信息学分析结果显示序列变异引起的单氨基酸变化引发了蛋白质二级结构和三级结构的改变，可能因此会引起基因功能的异常，从而引发抗病性和疾病易感性的变异。

英文摘要：

This study was aimed to detect the single nucleotide polymorphisms （SNPs） and single amino acid polymorphisms （SAPs） of Ovis aries and Homo sapiens DRB 1 genes exon2, and analyze the structure and characteristic change of OLA-DRB1 protein exon2 by bio-informatics. The sequence polymorphisms of Homo sapiens and Ovis aries MHC-DRB1 exon2 were analyzed with comparative genomics and biological databases. The protein structures and functions of Ovis aries MHC-DRB1 were predicted and analyzed with bio-informatics softwares. The result showed that there were rich polymorphisms and SAPs both in HLA DRB1 and OLA-DRB1 exon2. The number of singleton polymorphic and parsimony informative polymorphic sites were different from each other. There were only 14 same SNPs loci compared with each other, the rest of the site were different. Sequence analysis indicated that they were highly homology on MHC-DRB1 exon2. The results of the bio-informatics analysis indicated that caused by sequence variation of single amino acid triggering protein structure＇s change secondary structure and tertiary structure, could lead to obnorma[ gene function, and result in disease resistance and disease susceptibility mutation.