青岛文昌鱼zglp-1基因的进化与表达研究

Evolution and Expression of zglp-1 Gene in Qingdao Amphioxus

为了在头索动物文昌鱼中对zglp-1(Zinc finger, GATA-like protein 1)基因进行鉴定,并检测其在青岛文昌鱼(Branchiostomajaponicum)中的组织定位,本文对文昌鱼zglp-1基因的进化及表达进行了研究。同线性分析表明,文昌鱼zglp-1基因是斑马鱼zglp-1和人ZGLP-1基因的同源基因。文昌鱼Zglp-1蛋白的锌指结构域在进化上保守性较高,其三维结构与脊椎动物Zglp-1蛋白的三维结构也高度相似。系统进化分析显示,文昌鱼Zglp-1处于脊椎动物Zglp-1进化的基部,可能代表了脊椎动物Zglp-1进化的原始形式。利用RACE技术克隆得到青岛文昌鱼zglp-1基因完整的ORF序列,其编码389个氨基酸。实时定量PCR技术显示zglp-1基因在文昌鱼性腺中特异高表达,其中在卵巢表达最高;再利用切片原位杂交技术发现zglp-1基因在卵巢、精巢、肝盲囊和鳃等组织中有阳性信号,其中在卵巢中信号最强,与实时定量PCR检测结果基本一致。综上,本研究表明文昌鱼zglp-1为脊椎动物Zglp-1的同源基因,其在文昌鱼性腺高表达,这与该基因在脊椎动物性腺中的表达模式相类似。

In order to identify the zglp-1(zinc finger,GATA-like protein 1)gene in amphioxus and detect its tissue localization in Qingdao amphioxus(Branchiostoma japonicum),the evolution and expression of zglp-1 gene in amphioxus are studied.Analysis of the synteny of genes on chromosomes shows that zglp-1 gene of amphioxus is the homologous gene of zebrafish and human Zglp-1 genes.The zinc finger domain of amphioxus Zglp-1 protein is highly conserved during evolution,and its three-dimensional structure is highly similar to that of vertebrate Zglp-1 protein.Phylogenetic analysis shows that amphioxus Zglp-1 locates at the base of vertebrate Zglp-1 proteins,which may represent the primitive form of vertebrate Zglp-1.The complete ORF sequence of zglp-1 gene in Qingdao amphioxus is cloned by RACE technology,which encodes 391 amino acids.Real-time PCR shows that zglp-1 gene is specifically highly expressed in the gonad of amphioxus,with the highest expression in the ovary.Section in situ hybridization shows that zglp-1 gene has positive signals in ovaries,testis,hepatic caecum,gill and other tissues,among which the signal is the strongest in ovaries,which is basically consistent with the results of real-time PCR.In conclusion,this study shows that zglp-1 gene of amphioxus is the homologous gene of vertebrate Zglp-1 genes.The zglp-1 gene is highly expressed in amphioxus gonad,which is similar to the expression pattern of Zglp-1 genes in vertebrate gonad.