草鱼C1qC基因的克隆及表达分析

Cloning and expression of C1qC gene in grass carp(Ctenopharyngodon idella)

为了研究C1qC基因在草鱼(Ctenopharyngodon idella)免疫过程中所起的作用,利用RT-PCR和RACE方法克隆获得了C1qC基因cDNA全长序列,经序列分析表明,所克隆的C1qC cDNA全长为916 bp,包括开放阅读框(open reading frame,ORF)735 bp,5′端非编码区(untranslated region,UTR)89 bp和3′端非编码区(UTR)92 bp。735 bp的ORF共编码244个氨基酸,相对分子量为26 162.5 U。同源性分析表明,草鱼与斑马鱼(Danio rerio)的相似度最高,达到71%。经草鱼呼肠孤病毒(grass carp reovirus,GCRV)诱导后,草鱼C1qC基因在鳃、皮肤、肌肉、肝、中肾、心脏、头肾等组织中的mRNA表达水平均显著上调。在草鱼胚胎发育的各个阶段都能检测到C1qC mRNA的表达,说明该基因可能在草鱼胚胎和鱼苗的免疫反应和早期发育中起重要作用。本研究将为今后在草鱼免疫功能方面深入研究C1qC基因提供基础资料。

We evaluated the immune function of C1qC in grass carp（Ctenopharyngodon idella）.The full-length C1qC cDNA was successfully cloned by RT-PCR and rapid amplification of cDNA ends（RACE）.The full-length C1qC cDNA was 916 bp,consisting of a 735 bp open reading frame（ORF） encoding 244 amino acids,a 89 bp 5′untranslated region（5′ UTR）,and a 92 bp 3′ untranslated region（3′ UTR）.The molecular weight of this mature peptide was estimated to be 26 162.5U.Multiple alignment analysis revealed that grass carp C1qC shares the highest identity with zebrafish C1qC（71%）.We constructed a phylogenetic tree using the neighbor-Joining（NJ） method.Grass carp were grouped most closely with zebrafish（Danio rerio）.The expression of grass carp C1qC was significantly up-regulated in most tissues following challenge with grass carp reovirus（GCRV）.The expression of C1qC expression differed during the various stages of embryonic development.Our results suggest that C1qC plays an important role in early embryonic development and in the response to GCRV-related diseases in grass carp.Our result provide a basis for further evaluation of the role of grass carp C1qC in immune function.