C2株蓝氏贾第鞭毛虫组蛋白H2B基因的克隆与同源性分析

目的 获取C2株蓝氏贾第鞭毛虫H2B组蛋白基因序列,与WB株蓝氏贾第鞭毛虫及其他物种进行同源分析。方法 PCR扩增获取H2B组蛋白基因,连接pGM-T载体,转化E. coli DH5α感受态宿主细胞,挑选阳性克隆并进行序列分析,与美国WB株蓝氏贾第鞭毛虫及模式生物H2B组蛋白基因和蛋白序列进行同源分析。结果 测序C2株蓝氏贾第鞭毛虫H2B组蛋白基因序列,同源比对结果显示其基因序列与美国WB株完全一致,进化树分析表明贾第虫H2B组蛋白基因在进化过程中与其他物种分化较早。结论 蓝氏贾第鞭毛虫H2B组蛋白基因同源分析结果显示贾第虫与其他现存真核生物亲缘关系较为疏远,为进一步研究蓝氏贾第鞭毛虫的生物进化地位提供有价值的资料。

Cloning and homologous alignment of H2B histone gene in C2 Giardia lamblia

The aim of this study is to obtain histone H2B gene sequence from C2 Giardia lamblia genome DNA and process homology analysis with WB Giardia lamblia and other species. The histone H2B gene sequence of Giardia lamblia was amplified by PCR and restructured into pGM-T vector. E. coli DHS~ competent bacteria cells were transformed with re- combinant plasmid DNA. Positive cloning was chosen and the sequence was analysed. The coding sequence of H2B was aligned with WB Giardia lamblia histone H2B gene sequence and other model organisms. Homology alignment results showed that histone H2B gene sequence of C2 Giardia lamblia was the same with histone H2B gene sequence of WB Giardia lamblia. The phylogenetic tree analysis results showed that histone H2B gene of C2 Giardia lamblia was differentiated early in biological e- volution, which implied that the genetic relationship was distant between Giardia lamblia and other existing eukaryotes. Our results provided valuable experimental data for further understanding the biological evolution orientation of Giardia larnblia.