中国黑白花奶牛干扰素-τ成熟蛋白基因的克隆与序列分析及牛干扰素-τ的分类  

Cloning and Sequence Analysis of Mature Interferon-τ Gene from Chinese Holstein and a Classification for Bovine Interferon-τ

作　　者：张明[1] 管晓斌[1] 朱庆[1] 刘学方[1] 冯玉梅[1] 赖松家[1] 

机构地区：[1]四川农业大学动物科技学院,雅安625014

出　　处：《畜牧兽医学报》2007年第5期417-424,共8页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：四川省教育厅"牛干扰素-τ多态性及其与繁殖性状的相关性研究"项目;四川农业大学动物遗传与繁殖重点学科博士点基金

摘　　要：通过PCR克隆测序首次测定了黑白花奶牛干扰素-τ成熟蛋白的完整基因序列（GenBank登录号：DQ680846、DQ680847）,其CDS长度为519 bp,编码含有172个氨基酸的牛干扰素-τ成熟蛋白。对所有牛干扰素-τ序列进行聚类分析,可将其聚为4类,发现了一类新的牛干扰素-τ（τ4）和6种新亚型（τ1e、τ3f、τ3g、τ3h、τ4a、τ4b）。DQ680846属于τ4类的一种亚型,标记为τ4a;DQ680847属于τ3类的一种亚型,标记为τ3f。各牛干扰素-τ基因核苷酸序列间的同源性在92.7%-99.8%之间,推导氨基酸序列间的同源性在88.5%-99.4%之间;τ4a、τ3f与其他牛干扰素-τ基因核苷酸序列间的同源性分别在94.0%-97.1%、92.9%-99.6%之间,推导氨基酸序列间的同源性分别在91.4%-96.0%、88.5%-99.4%之间。这一结果反应了牛干扰素-τ基因在进化过程中的高度保守性。二级结构预测发现牛干扰素-τ成熟蛋白是以5个α-螺旋（A-E螺旋）为基础构成的。Asn78、Cys1、Cys29、Cys99、Cys139I、le143、Lys160和C-末端的11个氨基酸为高度保守区,它们是维持牛干扰素-τ的结构和功能所必需的。Complete sequence of mature interferon-τ gene from Chinese Holstein was cloned and sequenced for the first time（GenBank accession number： DQ680846, DQ680847）. Its CDS sequence is 519 bp, encoded 172 amino acid residues of bovine mature interferon-τ protein. All bovine interferon-τ sequences is divided into four groups by cluster analysis. A novel group（τ4） and six novel variant forms（r1e,τ3f, τ3g, τ3h, τ4a, τ4b） were found. DQ680846 is a variant forms in τ4, signed τ4a; DQ680847 is a variant forms in τ3, signed τ3f. The nucleotide sequence homology of all bovine interferon-τ genes are 92.7%-99.8%, and the amino acid sequence homology of all bovine interferon-τ protein are 88.5 %-99.4%. The nucleotide sequence homology between interferon-τ4a and other bovine interferon-τ is 94.0% -97.1%. The nucleotide sequence homology between interferon-τ3f and other bovine interferon-τ is 92.9%-99.6%. The amino acid sequence homology between interferon-τ4a and other bovine interferon-τ, interferon-τ3f and other bovine interferon-τ is 91.4%-96.0% and 88.5%-99.4% respectively. The results suggested bovine interferon-τ gene is high-degree conservation during the evolution. The secondary structure of bovine interferon-τ mature protein was predicted by MLRC and the results showed that five a-helices （A-E） is substructure of interferon-τ mature protein, and Asn78, Cys1, Cys29, Cys99, Cys139, Ile143, Lys160 and the 11 amino acid residues from carboxyl terminus are high-degree conservation region, which are essential for structure and function of bovine interferon-τ.

关 键 词：干扰素-τ 黑白花奶牛 分子克隆 序列分析 分类 

分 类 号：S823.912[农业科学—畜牧学]