艾维茵商品肉用鸡白细胞介素-2基因的克隆及其二级结构分析  

Cloning and secondary structure analysis of avian commercial broiler chicken interleukin-2 gene

作　　者：陈吉刚[1] 周继勇[1] 王金勇[1] 程丽琴[1] 陈庆新[1] 叶菊秀[1] 郑肖娟[1] 商绍彬[1] 

机构地区：[1]浙江大学动物预防医学研究所,浙江杭州310029

出　　处：《中国兽医科技》2003年第1期19-24,共6页Chinese Journal of Veterinary Science and Technology

基　　金：杭州市科委重大攻关项目 (2 0 112A0 7)

摘　　要：根据Sundick等发表的鸡白细胞介素 2 (IL 2 )基因序列设计一对特异性引物 ,从伴刀豆球蛋白A (ConA)体外激活的脾淋巴细胞中提取mRNA ,通过RT PCR方法获得艾维茵商品肉用鸡IL 2cDNA基因。将其连接到测序载体 pGEM TEasyVector ,测序后用Pcgene和DNAstar软件分析。结果显示 ,艾维茵商品肉用鸡IL 2基因长 734bp ,编码一由 14 3个氨基酸组成的前体蛋白 ,与来自GenBank的另外 3个品系 (Kestrelleghorn ,Obese和SC)鸡IL 2比较 ,其核苷酸和氨基酸序列同源性为 98.9%～ 10 0 %和 97.2 %～ 10 0 %。二级结构预测表明 ,艾维茵商品肉用鸡IL 2N端存在一条由 2 2个氨基酸组成的前导肽及 4个半胱氨酸形成的链内二硫键 ,并存在类似人IL 2的 4个α螺旋 ,这些结构很可能在维持IL 2生物学活性中发挥重要作用。基因系统进化树分析表明 ,艾维茵商品肉用鸡与SC鸡IL 2的亲缘关系较近 ,与火鸡、Kestrelleghorn和Obese鸡IL 2的亲缘关系较远。Chicken interleukin 2(IL 2) was a kind of recently discovered cell factor. One specific pair of primers were designed according to IL 2 gene sequence published by Sundick et al. IL 2 cDNA gene was amplified by RT PCR method with the primers according to mRNA which was extracted from Avian commercial broiler chicken spleen cells stimulated by ConA. The gene was cloned into pGEM T Easy Vector and sequenced by the dideoxy mediated chain termination method. The results indicated that the full length chicken IL 2 cDNA was 734bp, encoding 143 amino acids. Compared with other 3 kinds of breed (Kestrel leghorn, Obese and SC ) chicken IL 2 from GenBank, the homology of nucleotide and dedued amino acid was 98.9%-100% and 97.2%-100% ,respectively . The predicted protein had a leader sequence composed of 22 amino acids, and four conserved cysteines allowing the formation of two intrachain disulfid bonds. Like mammalian IL 2, chicken IL 2 had four α helices. Phylogenetic tree analysis indicated that the Avian commercial broiler chicken IL 2 had closer relationship with SC chicken IL 2 than Turkey, Kestrel leghorn and Obese chicken IL 2.

关 键 词：艾维菌 商品肉用鸡 白细胞 介素-2 基因 克隆 二级结构 基因系统进化树 

分 类 号：S831[农业科学—畜牧学]