【作者】 王荣华； 李伟； 汪小冬； 刘巧林； 彭慧珍； 曾令兵； 肖调义；

【Author】 WANGRonghua;LIWei;WANGXiaoDong;LIU Qiaolin;PENG Huizhen;ZENG Lingbing;XIAO Tiaoyi;Hunan Engineering Research Center for Utilization of Characteristics of Aquatic resources, Hunan Agricultural University;Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences;

【机构】 湖南省特色水产资源利用工程技术研究中心湖南农业大学； 中国水产科学研究院长江水产研究所；

【摘要】 赤眼鳟具有比草鱼更好的GCRV抗性,本文为探讨赤眼鳟和草鱼TLR22的结构和表达特性与GCRV敏感性的关系,克隆了赤眼鳟TLR22基因cDNA全长,并对比分析了草鱼和赤眼鳟TLR22结构和表达特性。结果显示ScTLR22 cDNA全长3504个碱基,共编码960个氨基酸。ScTLR22由胞外起识别作用的18个富亮氨酸结构域、跨膜结构域和胞内传递信号的TIR结构域组成。结构方面:ScTLR22最后一个LRR距离LRR-CT结构域12个氨基酸,且ScTLR22的TIR结构域中Box1和Box2中均有一个氨基酸突变,和斑马鱼、鲫鱼相同,而和草鱼不同,而赤眼鳟和其他鲤科鱼类表现出对GCRV良好的抗性,而草鱼对GCRV敏感。表达特性方面:GCRV感染后,赤眼鳟和草鱼肝脏、脾脏、头肾和体肾组织中TLR22的表达水平有显著的上调,且和0h相比,整个实验周期中赤眼鳟的上调比例均要显著高于草鱼。过表达ScTLR22的CIK细胞中,IFN的表达水平显著高于正常CIK细胞,且GCRV的TCID50也要低于正常CIK细胞。结果表明,TLR22在赤眼鳟抗GCRV中发挥了识别作用,并通过诱导IFN的表达抵抗GCRV入侵;赤眼鳟与草鱼TLR22结构和表达特性的差异分析,有助于解释赤眼鳟比草鱼具有更强抗GCRV的特性。更多还原

【Abstract】 Studies of our laboratory have demonstrated that barbel chub Squaliobarbus curriculus exhibits greater resistance against grass carp reovirus(GCRV) than grass carp Ctenopharyngodon idella. To understand the difference sensitivity to GCRV in structure and expression feature of barbel chub and grass carp Toll-like receptor 22(TLR22), the full cDNA sequence of TLR22 from barbel chub was cloned by RACE-PCR method, and the difference in structure and expression feature between S.curriculus TLR22(ScTLR22) and C.idella TLR22(Ci TLR22) were studied.The complete cDNA sequence of ScTLR22 is 3504 bp, encodes 960 amino acid residues. The protein possesses 18 leucine-rich repeats(LRRs), transmembrane domain and a Toll/interleukin(IL)-1 receptor(TIR) domain. For structure aspect, the last LRR domain of ScTLR22 had 12 amino acids before the LRRCT domain that was same with D. rerio and C. carpio that show resistance to GCRV infection, but it was different with grass carp, which is more susceptible to GCRV infection. In TIR domain, three particularly conserved regions were observed, which were completely consistent withthe tested species of Cyprinidae except grass carp, one amino acid mutation was found in Box 1 and 2. Quantitative RT-PCR analysis showed that the highest expression levels of ScTLR22 were observed in the head kidney and the lowest expression levels in the brain. After GCRV infection, the ScTLR22 expression level was up-regulation in four tested tissues, which were significantly higher than Ci TLR22.更多还原