人源蓝氏贾第鞭毛虫表面变异抗原部分基因的克隆及序列分析

目的获取蓝氏贾第鞭毛虫(简称贾第虫)表面变异抗原基因的部分核苷酸序列,并对其进行序列分析。方法根据贾第虫VSP已知基因序列的特点设计引物,利用PCR技术扩增VSP基因的部分核苷酸序列,将PCR产物纯化后连接到pMD19-TSimple Vector,转化至感受态细胞JM109,扩增目的片段。扩增的片段测序后进行生物信息学分析。结果成功克隆了编码贾第虫VSP的一分子质量为1486bp的基因片段。该片段富含半胱氨酸(12.8%),且含有26个-CXXC-模体,所得序列与GenBank中Gillin(1990)公布的TSA417基因序列同源性为99%。结论我国人源贾第虫北京株(BEIJ88/BTMR1/1)中表面变异抗原部分基因已测序完成。

Cloning and sequence analysis of the partial gene encoding variant-specific surface antigen of Giardia lamblia isolated from human in China

Objective To obtain and analysis the partial sequence of Giardia lamblia BEIJ88/BTMR1/1 surface antigen gene.Methods Primers were designed according to the published G.lamblia VSP gene sequence.Partial VSP gene was amplified from G.lamblia BEIJ88/BTMR1/1 genomic DNA by PCR.PCR product was inserted into pMD19-T Simple Vector and then transformed into E.coli JM109.Positive clone was sequcenced and analyzed.Results A 1 486 bp DNA fragment of VSP gene was obtained.The deduced polypeptide sequence is rich in cysteine,most of which occur with in 26 copies of the 4-amino acid-CXXC-motif.The DNA sequence of the cloned fragment was nearly identical to that of TSA 417's G.lamblia.Conclusion The partial gene of the G.lamblia BEIJ88/BTMR1/1 encoding surface antigen had been sequenced.