日本鳗鲡TLR21基因的鉴定、免疫应答与启动子分析  

MOLECULAR CLONING AND CHARACTERIZATION OF TLR21 GENE FROM JAPANESE EEL, ANGUILLA JAPONICA

作　　者：李春艳[1,2] 黄贝[1,2] 熊静[1,2] 彭喜霞 梁英[1,2] 聂品[1,3] 黄文树[1,2,4] 

机构地区：[1]集美大学水产学院,厦门361021 [2]鳗鲡现代产业技术教育部工程研究中心,厦门361021 [3]中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,武汉430072 [4]福建省海洋生物资源开发利用协同创新中心,厦门361005

出　　处：《水生生物学报》2017年第2期296-305,共10页Acta Hydrobiologica Sinica

基　　金：福建省自然科学基金(2014J05042;2012J06008);国家自然科学基金(31402329;31174238和U1205123)资助~~

摘　　要：为研究TLR21(Toll like receptor 21)在低等脊椎动物中的功能及表达调控机制,我们扩增获得了日本鳗鲡TLR21(Aj TLR21)c DNA序列,其编码的蛋白具有TLR家族的共同特征。Aj TLR21基因结构与其他鱼类和两栖类TLR21相同,由单个外显子编码。荧光定量结果显示,Aj TLR21在血液、鳃、脾脏、中肾等11个组织/器官中转录表达,其中在血液中表达量最高。经Poly I:C诱导后8h,Aj TLR21在脾脏和中肾中的表达量显著性上调;诱导后16h,Aj TLR21在血液、鳃、肠和脾脏中的表达量显著性上调(P<0.05)。双荧光素酶报告基因结果显示,在Aj TLR21 5′上游调控序列–1179 bp到+117 bp存在Poly I:C调节的正调控元件。经Edwardsiella tarda诱导后16h和72h,Aj TLR21分别在血液和中肾组织的表达量显著性上调,表明Aj TLR21同时也参与了抗细菌免疫应答,其在机体免疫系统中的功能具有多样性。研究对于理解日本鳗鲡Aj TLR21的免疫学功能具有重要的理论意义和应用价值。Toll like receptor 21（TLR21） is a non-mammalian Toll-like receptor that recognizes unmethylated Cp G DNA to trigger innate immune responses against pathogenic microorganism infection. The present study cloned the full-length c DNA sequence of TLR21（Aj TLR21） from Japanese eel, Anguilla japonica, which had the common characteristics of Toll like receptors（TLRs）. The intronless Aj TLR21 shared similar gene structure with other vertebrate TLR21 genes. Aj TLR21 widely expressed in all examined tissues/organs with the highest expression in blood. Poly I：C treatment significantly induced the expression of Aj TLR21 in spleen and kidney at 8 hours and in blood, gill, intestine and spleen at 16 hours（P〈0.05）. Luciferase reporter assay exhibited that the 5′ flanking region of the Aj TLR21 contains positive regulatory elements for Poly I：C induced Aj TLR21 expression. The stimulation of Edwardsiella tarda also increased the expression of Aj TLR21 in blood and kidney at both 16 h and 72 h, suggesting an important role in anti-bacterium immune response. Our results revealed multiple effects of teleosts TLR21 in immune system, which has important theoretical significance and application value to understand the immunological function of Aj TLR21.

关 键 词：日本鳗鲡 TLR21 基因表达 免疫应答 启动子 

分 类 号：Q344.1[生物学—遗传学]