[Construction and sequencing of recombinant plasmid pcDNA3/GRA1 from Toxoplasma gondii].

Objective: To construct a mammalian expression plasmid pcDNA3/GRA1 to express dense granules antigen-1 (GRA1) of Toxoplasma gondii, and to lay a foundation for further studying the protective immunity of pcDNA3/GRA1 as a DNA vaccine.

Methods: The GRA1 opening reading frame (ORF) was amplified with two specific primers. The ORF and plasmid pcDNA3 were digested with EcoR I and Xho I respectively and the ORF was ligated into the pcDNA3 at polylinker. The recombinant vector pcDNA3/GRA1 was characterized by PCR, restriction enzyme digestion, and sequencing analysis.

Results: The expected ORF, 573 bp long, was amplified by PCR, and inserted into plasmid pcDNA3. PCR, restriction enzyme digestion and sequencing analysis showed that pcDNA3/GRA1 contained GRA1 ORF with the right orientation.

Conclusion: The mammalian expression vector pcDNA3/GRA1 is successfully constructed.