蛔虫抗原基因ALAg克隆及序列分析

Cloning and sequence analysis of ALAg antigen gene from Ascaris lumbricoides

为了确定蛔虫基因工程疫苗的候选基因,试验以蛔虫幼虫的RNA为模板,利用RT-PCR方法扩增出ALAg基因,扩增产物克隆到pMD18-T载体,筛选阳性克隆测序并进行Blast分析。结果表明:该基因与GenBank公布的猪蛔虫As37抗原基因(AB078971)的同源性为95%,与西式贝蛔虫Ag3抗原基因(EU927450)的同源性为92%。说明ALAg基因是线虫特有的抗原基因。

To determine the candidate genes of gene engineering vaccine for Ascaris lumbricoides,this experiment selected the RNA as a template from larva of Ascaris lumbricoides.The ALAg gene from Ascaris lumbricoides was amplified by RT-PCR.The amplification product was cloned into pMD18-T vector,then the positive clones were sequenced and analyzed.A search of the public databases revealed that ALAg shared 95% similarity with the nucleotide sequence of the As37（AB078971） antigen gene from Ascaris suum,and 92% similarity with the nucleotide sequence of Ag3 from Baylisascaris schroederi（EU927450）.It suggests that the ALAg predicted by the cDNA sequence is a nematode-specific antigen gene.