牦牛Myf-5基因的克隆测序及其系统进化研究  

Cloning,Sequence and Phylogenetic Evolution Research on Myf-5 Gene of Yak

作　　者：陈雪梅[1] 陈玉红[1] 钟金城[1] 马志杰[2] 杨孔[1] 

机构地区：[1]西南民族大学生命科学与技术学院,成都610041 [2]青海省畜牧兽医科学院畜牧研究所

出　　处：《四川动物》2008年第4期528-533,共6页Sichuan Journal of Zoology

基　　金：四川省应用基础研究项目资助(03JY029-034)

摘　　要：本研究对牦牛(九龙牦牛)的生肌决定因子5(Myf-5)基因进行了T-A克隆测序和分析,并与多个物种的相应基因编码区核苷酸序列、氨基酸序列进行了比对分析,构建了物种间的系统进化树。结果表明:①牦牛的Myf-5基因大小为3313 bp,由3个外显子和2个内含子组成,与普通牛等9个物种比较,在基因大小上有较大的差异,但外显子和内含子的组成一致。②牦牛、大额牛、瘤牛、水牛、普通牛、人、恒河猴、黑猩猩、狗、家鼠、软体贝壳、鸡、斑马鱼等物种间Myf-5基因编码区的核苷酸序列同源性较高,其中,牦牛、大额牛、瘤牛、水牛、普通牛间的同源性最高,达98.4%以上,说明Myf-5基因编码区核苷酸序列在动物物种间具有较高的保守性。③牦牛、大额牛、瘤牛、水牛、普通牛、黑猩猩、恒河猴、人、狗、家鼠、软体贝壳、鸡、斑马鱼等物种间Myf-5基因编码蛋白的氨基酸序列具有较高的同源性,保守性强,这一结果与编码区核苷酸序列的比对结果基本一致。④根据核苷酸序列,用NJ法构建的牦牛、大额牛、瘤牛、水牛、普通牛、人、恒河猴、黑猩猩、狗、家鼠、软体贝壳、鸡、斑马鱼等13个物种的分子系统进化树显示:牦牛、普通牛、瘤牛、水牛和大额牛在较近的亲缘关系下聚为一大类,人、黑猩猩和恒河猴聚为另一大类,然后这两类再和其他物种相聚。这一分类结果与各物种的动物学分类结果和血液蛋白、mtDNA水平上的聚类结果基本一致,支持牦牛、普通牛和瘤牛3个物种间不应该是属间或亚属间关系,而应是同一属下的不同种,将牦牛、普通牛和瘤牛划分在同一个属———牛属(Bos),而将水牛划分在另一个单独的属的观点。同时也显示该基因序列适合用于动物学分类。Yaks （Jiulong） Myf-5（ myogenic factor 5 ） gene were cloned by the T-A method and then sequenced. Arrays of Myf-5 gene were analyzed and blasted with other species in the GenBank at the nucleoside acid and amino acid levels, and the phylogenetic tree between four bovine species and the other species was constructed. The result showed that： （1）The size of Myf-5 gene in yak was 3313 bp, consisted by 3 exons and 2 introns. （2）The homology rates of nucleotide sequences of the cod- ing region of Mff-5 gene between yak, gayal, zebu, buffalo, cattle, chimpanzee, rhesus monkey, human, dog, house mouse, Chinese softshell, chicken and zebrafish were higher. The homology rates of yak, gayal, zebu, buffalo and cattle were the highest, reached to 98.4%. This result showed that the nucleotide sequence of the coding region of Myf-5 gene between these species had higher conservativeness. （3）The amino acid sequences of Myf-5 gene between yak, gayal, zebu, buffalo, cattle, chimpanzee, rhesus monkey, human, dog, house mouse, Chinese softshell, chicken and zebrafish were quite conservative. This result was essentially consistent with the comparion of the nucleotide sequence of the coding region. （4）Molecular phyloge- netic tree was constructed by NJ method, including 13 species： yak, gayal, zebu, buffalo, cattle, chimpanzee, rhesus mon- key, human, dog, house mouse, Chinese softshell, chicken and zebrafish. The result showed that： the cattle, zebu, yak, buffalo and gayal were clustered together firstly because of closer relationship, chimpanzee, rhesus monkey and human clus- tered together, then together with each other, followed by other species. The clustering result was accordance with mtDNA function genes and the zoological classification result, and suggested that the cattle, zebu, yak should be different species in genus Bos. This also indicated that Myf-5 gene fitted to constructed molecular phylogenetic tree.

关 键 词：牦牛 Myf-5基因 克隆测序 系统进化 

分 类 号：Q78[生物学—分子生物学] Q951[农业科学—畜牧学] S823[农业科学—畜牧兽医]