斜带石斑鱼TLR5S基因结构及功能分析  

Characterization and Analysis of TLR5S Gene from Epinephelus coioides

作　　者：林克冰[1] 葛辉[1] 林琪[1] 吴建绍[1] 何丽斌[1] 方琼珊[1] 周宸[1] 

机构地区：[1]福建省水产研究所,福建厦门361013

出　　处：《厦门大学学报（自然科学版）》2013年第1期109-115,共7页Journal of Xiamen University：Natural Science

基　　金：福建省种业创新与产业化工程项目(闽种石斑004号)

摘　　要：Toll样受体5(Toll-like receptor 5,TLR5)属于先天免疫系统中的一种模式识别受体(PRR),可分为可溶型和跨膜型2种.它可以识别病原体相关分子模式(pathogen-associated molecular patterns,PAMP),从而启动信号转导.本研究从NCBI数据库中得到斜带石斑鱼(Epinephelus coioides)可溶型TLR5(ECTLR5S)cDNA全长序列(Genbank登录号:GQ396667).其cDNA序列全长2 439bp,包括69bp的5′UTR,435bp的3′UTR和1 935bp的开放阅读框,共编码644个氨基酸,预测编码蛋白质分子质量为72.28ku,等电点为6.37.将ECTLR5S基因氨基酸序列与其他脊椎动物的TLR5S基因氨基酸序列进行比对,结果显示出很高的相似性,其中与牙鲆相似度可达69%.Real time PCR检测结果显示ECTLR5S基因在斜带石斑鱼不同器官中均有表达,其中在肝脏中的表达量最高,其次是脾脏、血淋巴、肾脏等.Realtime PCR检测ECTLR5S基因在哈维氏弧菌(Vibrio harveyi)感染3,6,12,24,48h后的肝脏中表达情况,结果显示ECTLR5S基因在3,6,12,24h时表达量显著上调(p<0.05),而在48h下降至初始水平.这些结果说明ECTLR5S基因可能参与到斜带石斑鱼抗弧菌感染的免疫反应中,并且肝脏是其发挥作用的重要器官.TLR5 （Toll-like receptor 5） is an evolutionarily conserved component of the innate immune system that responds to spe- cific pathogen-associated molecular patterns （PAMP） during infections. By now, two types of TLR5 were found in fish, one was membrane form and the other one was soluble form. In this report,the Epinephelus coioide soluble TLR5 （ECTLRSS） cDNA se- quence was screened from the NCBI database （GenBank number：GQ396667）. The full-length cDNA o{ ECTLRSS was of 2 439 bp, including a 5＇-terminal untranslated region （UTR） of 69 bp, a 3＇-terminal UTR of 435 bp and an open reading frame （ORF） of 1 935 bp encoding a polypeptide of 644 amino acid residues. The molecular mass of the deduced protein was approximately 72.28 ku with an estimated pI of 6.37,and showed highest identity （69% ） to Paralichthys olivaceus. Quantitative Real time PCR analysis re- vealed a broad expression of ECTLRSS in most tissues,with the predominant expression in the liver. The expression of ECTLRSS after injection with Vibrio harveyi was tested in liver. The results indicated that ECTLRSS could be induced in liver by injection with Vibrio harveyi. ECTLRSS expression was significantly upregulated at 3,6,12 and 24 h （p〈0.05）. Our results suggested that ECTLRSS might play an important role in fish＇s defense against bacterial infection,and liver might be the vital organs of the actions.

关 键 词：斜带石斑鱼 TLR5S 哈维氏弧菌 REAL TIME PCR 

分 类 号：S965[农业科学—水产养殖]