中文摘要：

目的构建可快速标记蓝氏贾第鞭毛虫（简称贾第虫）基因的重组载体。方法采用重叠PCR法将新霉素（Neo）基因置于gdh启动子调控下,并插入pGEM-5zf载体,获得带有Neo筛选标记的重组载体pGL gdh-Neo;并将基因合成所得3′末端带有3×HA标签的多克隆位点区克隆至重组载体pGL gdh-Neo,构建可快速标记贾第虫基因的重组载体pGLMCS-3HA-gdh-Neo。以该载体标记贾第虫H2A基因验证其可用性。PCR扩增组蛋白H2A基因序列,用EcoRⅠ和SpeⅠ双酶切后克隆至重组载体pGL MCS-3HA-gdh-Neo多克隆位点区。重组质粒线性化后转染虫体,并对G418筛选所获得的H2A贾第虫重组株进行基因组PCR、蛋白质印迹（Western blotting）和免疫荧光分析。结果构建了带有多克隆位点区和3×HA标签的可快速标记贾第虫基因的重组载体pGL MCS-3HA-gdh-Neo,其长度为4 260 bp;H2A重组质粒稳定转染至贾第虫滋养体并正确整合至其基因组,可表达相对分子质量（Mr）为16 900的H2A（含3×HA标签）。结论构建了可快速标记贾第虫基因的重组载体pGL MCS-3HA-gdh-Neo。

英文摘要：

Objective To construct a recombinant vector for rapid gene tagging in Giardia lamblia. Methods To obtain the recombinant vector pGL gdh-Neo with the Neo selection marker, the Neo gene was put under the control of gdh promoter by overlap PCR and inserted into pGEM-5zf. A DNA fragment containing multiple cloning sites （MCS） followed by triple hemagglutinin（3HA） coding sequences was synthesized and cloned into the pGL gdh-Neo to construct a recombinant vector pGL MCS-3HA-gdh-Neo. Giardia H2A gene was selected as a tagging gene to validate the effectivity of the recombinant vector pGL MCS-3HA-gdh-Neo. The histone H2A coding sequence was amplified by PCR, digested with EcoR I and Spe I , and inserted into MCS of pGL MCS-3HA-gdh-Neo. The resulting plasmid was then linearized and transfected into Giardia trophozoites. The H2A recombinant strain selected by G418 was analyzed by PCR,Western blotting and immunofluorescence. Results A rapid tagging recombinant vector with multiple cloning sites and triple hemagglutinin （3HA） was constructed with a length of 4 260 bp. The H2A recombinant vector was transfected into Giardia trophozoites and integrate into the Giardia genome at the correct locus. The HA-tagged H2A protein was expressed with a molecular weight （Mr） of 16 900. Conclusion A rapid tagging recombinant vector of genes in Giardia lamblia, pGL MCS-3HA-gdh-Neo, has been constructed.