八眉猪DRA基因编码区多态性及生物信息学分析

Cloning and Bioinformatics Analysis on Coding Regions of DRA Gene in Bamei Pigs

为了探讨八眉猪DRA基因的遗传特性及其在抗病育种和猪-人异种器官移植中的应用前景,采用克隆测序的方法对该基因编码区进行多态性分析,并利用生物信息学方法预测该基因编码氨基酸的理化特性和结构功能,同时对该基因进行同源性分析。结果显示,八眉猪DRA基因编码252个氨基酸,编码区有5个核苷酸和2个氨基酸变异位点。DRA基因编码产物是一种不稳定的不可溶蛋白,二级结构为混合型,无规则卷曲所占比例最高。蛋白质功能预测结果显示,DRA基因免疫应答几率最高(4.405)。同源性分析发现,八眉猪DRA氨基酸与其他猪种的相似度在98%以上,与人的相似度达到83%,在CD4分子结合部位与人类相应的DRA仅存在1个氨基酸差异,具有在异种移植排斥反应中利用的潜力。研究结果为八眉猪的抗病分子育种和猪-人异种器官移植提供理论依据。

The study aimed to elucidate the genetic characters of DRA gene in Bamei pigs and the potential in disease-resistance breeding and pigs to humans xenotransplantation,polymorphism of DRA gene coding regions in Bamei pigs were analyzed by DNA sequencing analysis,and further physicochemical characteristics,protein struc-tures and functions were predicted using the bioinformatics tools and the homologies of amino acid sequences be-tween SLA and HLA were compared.The results showed that DRA gene encoded 252 amino acids,there were only 5 nucleotide and 2 amino acid substitutions in DRA gene coding regions.Encoding product of DRA gene was a kind of instable and insoluble protein,the putative secondary structure of DRA was mixed,and the percent of random coil was highest.The putative result of DRA protein function showed that the odds of immune response were highest （4.405）.The homologies of DRA amino acid sequences between Bamei and other pig breeds were more than 98%, and the homologies between Bamei and human were 83%,the position which bind to human CD4 showed only one difference with HLA-DRA,which had potential using in xenograft rejection.These results would provide a basis for the study of molecular breeding in disease resistance and xenotransplantation.