Cloning and sequence of taxoplasma gondii major surface antigen (SAGI) gene

Genetic typing methods of T. gondii strains have been extensively perfected in recent years. From atechnical point of view, many tools usable for genetic studied on single-copy loci have been used: RFLP,PCR-RFLP, sequencing, RAPD-PCR and isoenzyme analysis. We described the cloning and sequenceanalysis of the gene which encodes the major surface antigen (SAG1 or P30) of T. gondii. SAG. is theimmunodominant antigen of Toxoplasma gondii tachyzoites being considered as the most promising molecule for a recombinant vaccine or such as DNA vaccine against toxoplasmosis. In the present work,first, genomic DNA of Toxoplasma gondii was extracted and used for amplifying of SAG. gene as atemplate. Then PCR product was cloned into pTZ.57R/T vector and plasmid containing SAG. gene (pTSAG.) was extracted from transformed bacteria and SAG. gene cloned into pTZ 57R/T was sequenced.Results showed that the P.. gene contains no introns and can extract it from genomic DNA of tachyzoitestage. Results showed also that SAG. gene is cloned in pTZ.`R/T plasmid, forming pT-SAG.recombinant plasmid and E. coli TG. strain is the best host for pT-SAG. transformation. Sequenceanalysis of SAG. gene cloned into pTZ 57R/T vector showed that SAG. gene sequence from a high virulent strain of T. gondii (Known as RH 98% with RH strain and ZS1strain.