鸡主要组织相容性复合体Ⅰβ微球蛋白(β2m)基因的克隆及序列分析  

Cloning and Sequence Analysis of MHC Ⅰβ2m Gene in Chicken

作　　者：戴银[1] 张丹俊[1] 胡晓苗[1] 赵瑞宏[1] 侯宏艳[1] 潘孝成[1] 周学利[1] 沈学怀[1] 

机构地区：[1]安徽省农业科学院畜牧兽医研究所,安徽合肥230031

出　　处：《中国畜牧兽医》2014年第10期28-32,共5页China Animal Husbandry & Veterinary Medicine

基　　金：国家自然科学基金项目(31302044);国家蛋鸡产业技术体系项目(CARS-41);安徽省现代农业肉禽产业发展资金项目;院科技创新团队(11C0404)

摘　　要：为深入了解鸡主要组织相容性复合体Ⅰ（major histocompatibility complex classⅠ,MHCⅠ）β微球蛋白（β2m）分子的特征,研究β2m的免疫作用机理,试验通过RT-PCR技术获得了15条3个地方品种鸡完整的典型的MHCⅠβ2 m基因,将该序列与GenBank数据库中登录的鸭、人、鼠、鱼、猴、马和猪7个不同物种的MHCⅠβ2m分子序列进行了比对分析。结果显示,15条鸡β2m氨基酸序列同源性在98.0%~100%之间,大部分序列完全一致。鸡β2m氨基酸序列与鸭同源性最高,为60.6%;最低的则是来源于草鱼的β2m氨基酸序列,仅为33.3%。遗传进化分析进一步证实鸡与鸭的MHCⅠβ2m亲缘关系较近,与其他物种则遗传距离较远。此外,序列分析发现鸡β2 m基因高度保守,仅个别碱基发生突变。其成熟肽序列的第24和79位为半胱氨酸,在所比对的动物中均未发生突变;同时在成熟肽的第77~83位之间存在免疫球蛋白超基因家族的特征基序＂YXCXVXH＂。研究结果表明,鸡与其他物种的MHCⅠβ2m分子具有相同的免疫功能基本单位,同时又具备独特的结构特点。In order to further understand molecular characteristics and immune mechanisms of chicken major histocompatibility complex classⅠ（MHCⅠ）β2 mgene,the 15 sequence of chicken MHCβ2 mgene from three local breeds was cloned by RT-PCR.We compared these sequences with seven MHCⅠβ2 mgenes of human,mouse and other animals in the GenBank database.The results showed that the amino acid homology among chicken MHCⅠβ2mranged from 98.0%to 100%,the most sequences were identical.Chicken MHCⅠβ2mshared a 60.6%amino acid homology with duck,the highest degree of homology indicated a close genetic relationship,and the grasscarp had the lowest homology,33.3%.It could be further confirmed by phylogenetic analysis.Moreover,alignment of 10β2msequences of mature protein,two cysteines were located in sites 24and79,and there was the＂YXCXVXH＂Ig-motif character between the sites 77 and 83of chickenβ2m.The results showed that MHCⅠβ2mof chicken and other species had the same basic unit of immune function,and they had the unique structural features.

关 键 词：鸡主要组织相容性复合体 β微球蛋白基因 序列分析 

分 类 号：Q78[生物学—分子生物学]