Cloning and sequencing of Sag3 gene fragment of Toxoplasma gondii

Aim To clone and sequence the SAG3 gene fragment of RH,ZS2 strains of Toxoplasma gondii Methods The SAG3 gene fragments of RH,ZS2 and ZS1 strains of Toxoplasma gondii were amplified by PCR After purified,and digested with EcoRⅠ+ BamHⅠ,the gene fragment was cloned as a plasmid pGEX 4T 2 The recombinant plasmid pGEX 4T 2 SAG3,was transformed into E coli JM109 Positive clones were screened and identified by PCR technique and digestion with restriction enzyme The sequence of inserted SAG3 gene fragment was also determined Results The SAG3 gene fragment was specifically amplified by PCR technique The recombinant plasmid pGEX SAG3 was constructed and digested by EcoRⅠ+ BamHⅠ,the size of gene fragment was 1176 bp and in accordance with the expected one Sequence determination analysis showed that the gene was gene fragment coding SAG3 antigen Conclusion The recombinant plasmid containing SAG3 gene from Toxoplasma gondii has been constructed successfully That can make it convenient for SAG3 antigen express and dignosis