细粒棘球绦虫EG95基因的克隆和序列分析

Cloning and sequence analyzing of the EG95 gene from Echinococcus granulosus

目的 获得细粒棘球蚴EG95基因序列资料 ,进行序列分析 ,为研究包虫病疫苗候选抗原基因奠定基础。方法 从包囊内获取细粒棘球蚴原头蚴 (protoscoleces) ,提取RNA和DNA ,用特异引物分别以基因组DNA和cDNA为模板扩增EG95基因 ;并将其克隆到T载体后进行序列测定和分析。结果 以基因组为模板获得一个基因 ,长度为 12 5 3bp ,以cDNA为模板获得两个基因 ,长度分别为 112 1bp和 833bp ;同源性比较结果表明 :来自新疆羊源EG95基因序列和澳大利亚羊源EG95 2基因同源性为 98% ,有 13个碱基变异 ;从cDNA获得的EG95基因 (EG95 -like)和DNA来源的EG95相同 ,只是EG95序列的一部分 ;从cDNA获得的另一个EG95基因 (mEG95 )和澳大利亚源EG95 2同源性为 99% ,有 2个碱基不同。分析表明EG95是一个基因家族 ,可能是虫体发育到六沟蚴阶段特定表达的基因。结论 EG95是一个基因家族 ,进一步研究该基因家族的结构和功能对包虫病的免疫预防具有重要意义。

Aim To obtain and analyze sequence EG95 genes,and lay bases for screening candidate antigen gene of Echinococcus granulosus.Method RNA and DNA were isolated from protoscoleces of Echinococcus granulosus,and EG95 gene were amplified using genomic DNA and cDNA as templates respectively,with specific primer,and were submitted for DAN sequencing after cloned into T vector.Results One gene of 1253bp was obtained from the template of genome DNA,and two gene with length of 1121bp and 833bp were obtained from the template of cDNA.BLAST analysis show that Xinjiang sheep genous EG95 gene were 98% homologous to Austrlia sheep genous EG95-2,with mutation of 13bp.One of the EG95 (EG95-like) gene get from the template of cDNA were identical to EG95 from genomic DNA,indicate it is just part of EG95.and another one (mEG9) was 99% homologous to EG95-2,with 2bp mutation.Analysis indicate EG95 were a family of gene,which may specifically expresses at the oncosphere life-cycle stage.Conclusion EG95 is a gene family and further reseach on the structure and function of EG95 family have great significance for the immunoprovention of Echinococcus granulosus.