原核生物eno基因在系统进化中应用及水平转移分析  

Phylogenetic application and analysis of horizontal transfer based on the prokaryote eno gene

作　　者：刘庆辉[1] 郭振国[1] 任嘉红[2,3] 

机构地区：[1]河北大学生命科学学院,保定071002 [2]长治学院生物科学与技术系,长治046011 [3]南京林业大学森林资源与环境学院,南京210037

出　　处：《遗传》2012年第7期907-918,共12页Hereditas（Beijing)

基　　金：国家自然科学基金项目(编号:31100471)资助

摘　　要：多基因系统发育研究方法是系统发育分析中的一个重要手段,基因树冲突已成为分子系统发育研究中日益突出的问题。烯醇化酶基因(eno)及其编码的蛋白广泛存在于五界系统中,烯醇化酶为糖酵解途径中重要酶类。文章选取原核生物已注释的eno基因序列进行了系统发育分析。对其中的138个模式菌株的eno基因序列进行系统发育分析和同源性搜索,发现19个模式菌株的eno基因是通过水平转移而来;并通过核苷酸组成、密码子偏好性和基因排列等基因特征分析,进一步验证了水平转移基因的外源性。结果表明:原核生物eno序列具有较高保守性,其大小适中,是研究原核生物系统发育的良好材料。文章在对基因水平转移的供体和受体菌株生活习性、进化历史以及烯醇化酶的结构和功能的研究过程中提供重要参考价值。The phenomenon of conflicting gene trees has become a remarkable and difficult problem. Application of multiple genes has been a widespread practice to reconstruct phylogenies in phylogenetic studies. Enolase is a key glyco- lyric enzyme, The enzymes from a large variety of organisms, including archaebacteria, eubacteria and eukaryotes, were studied. We downloaded eno sequences from the genomes of bacteria and archaea that have been completely sequenced. The comprehensive homology search and phylogenetic analysis of the eno were used, and nineteen horizontally transferred genes were identified. The results of analysis showed lots of differences between the features of horizontal transferred genes and the ones of whole genomic genes, such as nucleotide composition, gene combination, codon usage bias, and selection pressure. These results reconfirmed that the horizontally transferred genes were exogenous. The result revealed that prokaryote eno genes were highly conserved, medium-sized, is a good material in the phylogenetic. This paper can provide a reference in study of life habit and evolutionary history of donor and receptor, and enolase structure and function.

关 键 词：eno基因 系统发育 基因水平转移 

分 类 号：Q93[生物学—微生物学]