草鱼TLR9基因全长cDNA的克隆及特征分析

采用同源克隆及快速扩增cDNA末端技术,从草鱼鳃组织中克隆了Toll样受体9(Toll-like receptor 9,TLR9)基因的cDNA全长。序列分析表明,草鱼TLR9 cDNA全长3 468 bp,编码1 058个氨基酸,其中包括18个氨基酸组成的信号肽、16个富含亮氨酸重复结构域(leucine rich repeat,LRR)、1个跨膜区和1个TIR结构域(Toll/IL-1 receptor)。该蛋白的分子量为121 921 u,等电点为8.80。氨基酸序列的同源性分析显示,草鱼TLR9与鲤TLR9的同源性最高(85%),依次为斑马鱼(82%)、大西洋鲑(55%)、虹鳟(55%)。在系统发生树上,草鱼TLR9首先与鲤科的鲤和斑马鱼聚类。通过半定量RT-PCR检测可知,草鱼TLR9在被检测的15个组织中都有表达,其中在鳃中的表达最高,其次为血、头肾等。这些结果为进一步深入研究TLR-9的功能及开发草鱼免疫增强剂奠定基础。

Cloning and characterization of grass carp (Ctenopharyngodon idella) Toll-like receptor 9

The full-length cDNA sequence of Toll-like receptor 9(CiTLR9)gene was identified from grass carp(Ctenopharyngodon idella)gill by homologous cloning and rapid amplification cDNA ends(RACE).The CiTLR9 cDNA was 3 468 bp,encoding 1 058 amino acid(aa)residues,including signal peptide,16 leucine rich repeat(LRR)motifs,one transmembrane zone and one Toll/IL-1 receptor(TIR)domain.The molecular weight of the deduced protein is 121 921 u,and the isoelectric point is 8.80.The amino acid sequence of CiTLR9 possessed 85...