畜牧兽医学报 ›› 2015, Vol. 46 ›› Issue (2): 288-294.doi: 10.11843/j.issn.0366-6964.2015.02.016

• 预防兽医 • 上一篇    下一篇

绵羊肺炎支原体延伸因子Tu基因的分子特性分析

尹正军,岳华,汤承*   

  1. (西南民族大学生命科学与技术学院,成都 610041)
  • 收稿日期:2014-05-22 出版日期:2015-02-23 发布日期:2015-02-25
  • 通讯作者: 汤承,E-mail:tangcheng101@163.com
  • 作者简介:尹正军(1989-),男,江苏丹阳人,硕士,主要从事临床病原微生物快速检测技术的研究,E-mail:yinzhengjun1989@163.com
  • 基金资助:

    “十二五”高技术研究发展计划(863计划)(2012AA101304)

Molecular Characterization of the Elongation Factor Tu Gene in Mycoplasma ovipneumoniae

YIN Zheng-jun,YUE Hua,TANG Cheng*   

  1. (College of Life Science and Technology,Southwest University for Nationalities,Chengdu 610041,China)
  • Received:2014-05-22 Online:2015-02-23 Published:2015-02-25

摘要:

对绵羊肺炎支原体(Mycoplasma ovipneumoniae)参考菌株Y98株和11个临床分离株的tuf基因进行克隆、测序,生物信息学分析及构建进化树,分析绵羊肺炎支原体tuf基因的分子结构特性。结果表明:Y98株和11株分离株tuf基因编码区全长1 209 bp,编码402个氨基酸,氨基酸相似性为93.3%~100%,有较高的抗原指数和抗原表位,不含信号肽,平均GC含量为39.80%。Y98株与10个分离株延伸因子Tu存在1个跨膜区,含有6种不同的功能位点。而一分离株该蛋白质存在2个跨膜区,在271—274位点多出1个N-糖基化位点。12个菌株的tuf基因有117个单核苷酸突变位点,其中无义突变为41个,有义突变为76个,造成53个推导的氨基酸变化,主要发生在325—354位点靠近羧基端,有可能导致该蛋白质功能的改变。基于该基因的遗传进化与全基因组建立的进化关系一致,比16S rRNA基因更适合作为绵羊肺炎支原体进化关系的分子靶标。该基因种内保守同时也存在遗传多样性,作为分子分型的潜力值得进一步研究。

关键词: 绵羊肺炎支原体, tuf基因, 克隆, 分子特性, 遗传进化

Abstract:

This study aimed at analyzing the molecular characterization of the tuf gene in Mycoplasma ovipneumoniae.The tuf genes of the reference Y98 strain and 11 clinical isolates were cloned and sequenced,and then were used for bioinformatics analysis.A phylogenetic tree was constructed base on the tuf genes.The results showed that the open-reading frames (ORFs) of tuf genes in all the strains were 1 209 bp,which encoded 402 amino acids with 93.3%-100% amino acid identity and possessed higher antigenic index and higher lymphocyte epitopes.The average GC content of the protein coded by tuf gene was 39.80%.The Tuf proteins of reference Y98 strain and 10 clinical isolates contained one strong transmembrane region and were absence of signal peptide,and contained six different functional sites.While another isolate contained two transmembrane regions,with a additional N-glycosylation site in the site of 271-274.The genes from 12 strains were identified 117 single nucleotide polymorphisms (SNPs),consisting of 41 synonymous polymorphisms and 76 non-synonymous polymorphisms leading to 53 amino acid changes,mainly in 325-354 region near the carboxyl region,which maybe leading to change the function of this protein.The phylogenetic relationship of M.ovipneumoniae based on whole genome and that based on the tuf gene were consistent.So,the tuf gene is a better target than 16S rRNA gene for the phylogenetic analysis for M.ovipneumoniae.Despite of its conservation,the tuf gene still showed genetic diversity within the strains,making it potential for molecular typing.

Key words: Mycoplasma ovipneumoniae, elongation factor Tu gene, cloning, molecular characterization, phylogenetic

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