Razi Journal of Medical Sciences

    Background & Aim: Toxoplasmosis is caused by a protozoan parasite called toxoplasma gondii. SAG1 is an antigen which only exists in tachyzoite stage. This antigen which has two glycoforms is a conformational antigen. The aim of this research is to study cloning of SAG1 gene in PTZ57R and transformation of recombinant plasmid in E.coli(TG1 & DH5a). Material & Method: Tachyzoites of T.gondii are able to multiplicate in mouse macrophages. SAG1(30 KDa) is one of the three surface antigens and a main candidate for DNA vaccine. Also, SAG1 is the most immunogenic antigen of toxoplasmosis and a major surface antigen of the proliferative tachyzoite form of T.gondii. SAG1 genome with a 960 bp band is single copy. In this study, the DNA of toxoplasma gondii was extracted and SAG1 genome was amplified. Then PCR(Polymrase Chain Reaction) product was purified and cloned in PTZ57R and finally transformed into two strains of E.coli(TG1 & DH5α). Results: The DNA of toxoplasma gondii was extracted and SAG1 gene was amplified. The PCR product was seen as a 960 bp band in 1% agarose gel. After cloning and transformation, to recognize the E.coli recombinant plasmid, the bacteria were cultured in LB with ampicilin, X-Gal and IPTG. The mean and standard deviation of colonies that grew in LB were measured. To confirm the data, the plasmids were extracted and the DNA of SAG1 was amplified and digested by BamH I enzyme. The recombinant plasmid was restricted by enzyme and two 2982 and 864 bp bands were obtained. Conclusion: It was noticed that as for transformation of plasmid with the DNA of SAG1, TG1 is more suitable than DH5α. This method is useful for cloning and storing the important genome of toxoplasma gondii, SAG1.