草鱼eIF-5A的克隆、组织表达和进化分析  

Cloning,tissue-specific expression and evolution of grass carp eIF-5A gene

作　　者：王军花[1] 陈琼[1] 马梅生[1] 王丽坤[1] 胡成钰[1] 

机构地区：[1]南昌大学生命科学与食品工程学院,江西南昌330031

出　　处：《西北农林科技大学学报（自然科学版）》2009年第8期48-54,62,共8页Journal of Northwest A&F University(Natural Science Edition)

基　　金：江西省重点科技攻关项目(20061B0260301)

摘　　要：【目的】克隆和鉴定草鱼(Ctenopharyngodonidella)的eIF-5A基因,并分析其组织表达和适应性进化。【方法】在克隆草鱼eIF-5A全长cDNA的基础上,利用ORF finder、SMART等在线软件对草鱼eIF-5A的分子特征进行分析,并利用PAML 3.15软件包中的密码子替换模型检测eIF-5A的分子适应性进化;RT-PCR分析eIF-5A在草鱼心、脑、肌肉、鳃、脾、肝、肠、肾等组织中的本底表达和Poly I:C诱导表达。【结果】草鱼eIF-5A全长cDNA为2 249 bp,其中包含5′非编码区41 bp,3′非编码区1 743 bp;最大开放阅读框为465 bp,编码1个由155个氨基酸残基组成的蛋白质;草鱼eIF-5A分子质量为16.856 ku,等电点pI为5.18,N端含有eIF-5A家族共有的羧腐胺赖氨酸,C端包含一段富含亮氨酸的结构域。草鱼eIF-5A与人及其他动物具有较高的同源性,只有少数氨基酸残基发生替换;适应性进化分析也表明,eIF-5A不但具有结构的保守性,还具有功能的保守性;eIF-5A在草鱼心、脑、肌肉、鳃、脾、肝、肠、肾等组织中恒量表达,并且其表达不因Poly I:C的诱导而发生变化。【结论】eIF-5A是一类与细胞分裂和分化密切相关的蛋白质,在生物体中具有多种剪切体,提示eIF-5A对维持细胞生存非常重要;鉴定的草鱼eIF-5A为eIF-5A1,而非eIF-5A2。【Objective】 The eIF-5A gene was cloned and identified in Ctenopharyngodon idella.The tissue-specific expression and adaptive evolution of grass carp eIF-5A gene was analyzed.【Method】 After the full length cDNA of eIF-5A had been cloned from grass carp,the molecule characterization of grass carp eIF-5A was predicted by ORF finder,SMART on-line softwares and so on.The adaptive evolution of the eIF-5A had been studied by codon substitution model in PAML 3.15 software package.The background expression and Poly I. C induced expression of elF- 5A in heart, brain, muscle, gill, spleen, liver, intestine and kidney of grass carp were detected by RT-PCR. [Result] The full length cDNA sequence of grass carp elF-SA was 2 249 bp,which contained a 5r untranslated region of 41 bp and a 3＇ untranslated re- gion of 1 743 bp. The open reading frame was 465 bp,which could code a 155 amino acid polypeptide with a molecular mass of 16. 856 ku and pI 5. 18. Grass carp eIF-SA contained the unusual basic amino acid hypusine that conserved in eIF-5A family at the N-terminal region and a leucine-rich stretch at the C-terminal region. Only several amino acid residues were substituted, the amino acid sequence shared identity with eIF-5A from human and other species. Adaptive evolution analysis also indicated that eIF-5A was not only conserved in structure but also in function, elF-5A was constant cle, gill, spleen, liver, intestine, kidney of grass carp, as well as by related to cell division and tant to cell. According to 5A2. ly expressed among the heart, brain, musPoly I. C infected. [Conclusion] elF-5A is differentiation. The various eIF-5A forms the above results, the grass carp elF-SA suggest that they are extremely impor identified is eIF-5A1 rather than eIF 5A2.

关 键 词：真核翻译起始因子5A(eIF-5A) 基因克隆 基因表达 草鱼 PolyI:C 

分 类 号：Q785[生物学—分子生物学] S965.112[农业科学—水产养殖]