| 摘要: |
| 【目的】 克隆和鉴定草鱼(Ctenopharyngodon idella)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1743 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. |
| 关键词: 真核翻译起始因子5A（eIF-5A） 基因克隆 基因表达 草鱼 Poly I:C |
| DOI： |
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| 基金项目:江西省重点科技攻关项目(20061B0260301) |
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| Cloning,tissue-specific expression and evolution of grass carp eIF-5A gene |
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| Abstract: |
| 【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 eIF-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 eIF-5A was 2 249 bp,which contained a 5′ untranslated region of 41 bp and a 3′ untranslated region 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-5A 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. eIF-5Awas constantly expressed among the heart,brain,muscle,gill,spleen,liver,intestine,kidney of grass carp,as well as by Poly I:C infected.【Conclusion】 eIF-5A is related to cell division and differentiation.The various eIF-5A forms suggest that they are extremely important to cell.According to the above results,the grass carp eIF-5A identified is eIF-5A1 rather than eIF-5A2. |
| Key words: eIF-5A gene cloning gene expression grass carp Poly I:C |
