鸡大肠杆菌FimH基因C端结构域克隆及特性分析  

Cloning and characterization of C terminal domain of avian E.coli' Fim H gene

作　　者：白宇琛 谢金峰[1] 周广防 冯秀丽[1] 

机构地区：[1]南京农业大学,动物医学院,江苏南京210095

出　　处：《山西农业大学学报（自然科学版）》2016年第7期467-471,505,共6页Journal of Shanxi Agricultural University(Natural Science Edition)

基　　金：江苏省自然科学基金青年基金项目(BK20130682);江苏省高校优势学科建设工程资助项目(PAPD)

摘　　要：[目的]通过进一步研究禽大肠杆菌I型菌毛主要结构基因FimH的基因结构及其抗原特性,为深入探索鸡大肠杆菌致病机理及研制基因工程疫苗奠定必要的理论基础。[方法]本文以已发表的Fim H基因C端核酸序列为参考序列,设计并合成引物,扩增鸡大肠杆菌JS1、JS2、JS6三个菌株的Fim H相应基因,使用Lasergene软件对其进行序列比对、蛋白质结构预测以及进化树的绘制等。[结果]JS1、JS2、JS6三个菌株的核酸同源性分别为97.3%、97.7%和97.3%,而氨基酸序列的相似性分别为95.3%、97.6%和95.3%。此外,其抗原决定簇基本相似,但在第78和79位抗原决定簇不同,这说明本研究中的3个鸡大肠杆菌菌株的Fim H基因序列及氨基酸序列的变异可能对Fim H蛋白抗原结构产生了轻微影响。进化树分析发现,本实验室分离的3株鸡大肠杆菌菌株FimH基因与选择的国内鸡大肠杆菌菌株的Fim H基因同源性比较高,同处于一个进化分支中。[结论]本研究结果表明鸡大肠杆菌I型菌毛Fim H基因未发生明显变异,这为后续研究Fim H基因的功能及其基因工程亚单位疫苗研发提供了重要的实验基础。[Objective]Through further study of Firn H, the the main structure gene of avian Escherichia coli type I, the research aimed to provide necessary theoretical foundation for pathogenic mechanism of avian E. coli and develop- ment of gene engineering vaccinE. [Methods] Based on the published C terminal domain nucleotide sequence of Fire H gene for reference, this research designed and synthesized primers, amplified three strains of the relevant Fire H genes in avian E. coli including JS1, JS2 and JS6, used Lasergene software for sequence alignment and protein structure pre- diction, and the evolutionary tree was drew, etc. [Results] The results showed that the homology of gene nucleotide sequences between Reference strain and JS1, JS2 or JS6 were 97.3%, 97.7% and 97.30//00, and their amino acid se- quences was 95.3%, 97.6% and 95.3%, respectively. Although their Fire H antigenic nucleotide sequences between Reference strain and JS1, JS2 or JS6 were 97.3%, 97.7% and 97.3%, and their amino acid sequences was 95.3%, 97.6% and 95.3%, respectively. Although their Fire H antigenic determinants are basically similar, amino acids changes at 78th and 79th caused the different antigenic determinant at C terminal domain of Fire H, which indicated that amino acid variation of Fire H sequences might have the minor effect on the antigenic property of Fire H. Further- more, the evolutionary tree analysis showed the close evolutionary relationship among three isolated strains and the do- mestic avian E. coli strains. [Conclusion] The results indicated that the Fim H gene of avian E. coli had no significant variation, which makes important foundation for further research on molecular mechanism of avian E. coli and the con- trol strategies against pathogenic avian E. coll.

关 键 词：鸡大肠杆菌 FIM H基因 克隆 特性分析 

分 类 号：S852.61[农业科学—基础兽医学]