我国细粒棘球蚴新疆分离株AgB亚基基因克隆及序列分析

Cloning and sequence analysis .of the antigen B sub-units from Echinococcus granulosus isolate from Xinjiang, China

目的对我国细粒棘球蚴新疆分离株AgB亚基基因进行克隆、测序，对序列进行遗传变异性分析。方法根据参考文献设计特异性引物，从新疆源细粒棘球蚴（Echinococcus granulosus，Eg）原头节中提取总RNA，通过RT—PCR扩增目的基因片段并克隆人TA载体中测序。用Bioedit分析软件和Blastn和clusterW2等在线分析系统对序列进行分析。结果从细粒棘球蚴中克隆获得AgB抗原的3个亚单位基因，经测序确定为正确的目的序列；序列比对分析表明，3个亚单位基因的核苷酸序列一致性为43％～60％，氨基酸序列一致性为30％～42％。结论EgAgB的亚单位基因变异性较大。

Objective To clone the subunits of AgB antigen gene family of Echinococcus granulosus （ Eg）, analyze genetic variability of the gene sequences. Methods Specific primers were designed based on the published references. Total RNA was extracted from E. granulosus protoscoleces collected from a sheep hydatid cyst from Xinjiang, the fragments of three AgB subunits gene were obtained by RT-PCR using the extracted RNA and cloned into TA vector for sequencing. The online sequence analysis systems such as Bioedit software, Blastn and clusterW2 were used for the analysis. Results Three AgB gene subunits were cloned from E. granulosus, respectively, and identified by sequencing. Sequence homology analysis indicated that the EgAgB subunits were variable. Sequence alignment of the nucleic acid sequences of three AgB subunits gene showed that the identity ranged from 43% to 60% , alignment of the putative amino acid sequences of three AgB subunits gene ranged from 30% to 42%. Conclusion The EgAgB subunits showed a high degree of genetic variability.