Polymorphism of Merozoite Surface Protein-3α Gene of Plasmo- dium vivax in Isolates of Iran

Background: The worldwide distribution of P. vivax has expanded significantly and the number of reported cases has been on the rise. Approximately 88% of malaria cases in Iran are caused by Plasmodium vivax, and in order to management of the disease, understanding the population genetic structure of the parasite is necessary for designing and applying drugs and vaccines. Among many potential candidates, merozoite surface protein-3α gene (PvMSP-3α) is promising target to develop an effective vaccine. This study was carried out to determine the variation of this gene, as a genetic marker, in Plasmodium vivax isolates in malarious areas of Iran. Methods: Diversity in PvMSP-3α gene was assessed in 85 Plasmodium vivax isolated from four southern and east-southern provinces of the country by PCR/RFLP method. Amplification was performed with two primer pair sets in a nested PCR format and the products were digested by the enzyme HhaI in RFLP method. Results: Based on the size of the PCR products, we observed three biotypes A (about 1900bp), B (about 1400bp) and C (about 1100bp) of PvMSP-3α gene. Biotype A was predominant. According to RFLP patterns, 10 allelic groups of the gene were observed, that, 7, 2 and 1 groups correspond to the biotype A, B and C, respectively. Mixed genotype and multiple infections were not seen. Conclusion: RFLP method with HhaI enzyme is a useful method for determining the polymorphism of biotype A of PvMSP-3α gene.