草鱼(Ctenopharyngodon idella)组织蛋白酶L基因克隆及表达特性分析

Gene Cloning and Expression Analysis of Cathepsin L Gene in Ctenopharyngodon idella

为探究组织蛋白酶L(Cathepsin L,CtsL)是否在草鱼(Ctenopharyngodon idella)体内发挥免疫功能,根据已构建的草鱼肌肉转录组数据库中unigene序列,采用RACE技术首次克隆得到全长为1 496 bp的草鱼组织蛋白酶L基因(CiCtsL)cDNA序列。序列分析和同源建模显示该基因编码的蛋白具备组织蛋白酶前体抑制结构域I29和木瓜蛋白酶家族半胱氨酸蛋白酶Pept_C1结构域。系统进化分析表明,CiCtsL与斑马鱼CtsL聚为一支。CiCtsL mRNA在7个组织中均有表达,其中肝脏中的相对表达水平最高。感染GCRV后,CiCtsL在各组织中的表达量显著上调,呈现先上升后下降的趋势。研究表明CiCtsL参与了草鱼抵抗GCRV的免疫应答反应,可在草鱼先天免疫调控中发挥重要作用。

In order to investigate the immune function of Cathepsin L in Ctenopharyngodon idella(CiCtsL),according to the constructed unigene sequence in the muscle transcriptome database of Ctenopharyngodon idella,in this work,we closed the full cDNA sequence of CiCtsL(1 496 bp).The CiCtsL protein possessed cathepsin propeptide inhibitor domain I29 and papain family cysteine protease Pept_C1 domain,and clustered together with Danio rerio.CiCtsL mRNAs were expressed in tested tissues,with the highest expression level found in liver.After GCRV infection,the expression level of CiCtsL in each tissue was significantly up-regulated,and showed an overall tendency of being firstly up-regulated and then decreased.Our present results confirmed that CiCtsL was involved in the immune response to GCRV and played an important role in the innate immune regulation of Ctenopharyngodon idella.