Genetic Variation and Selection of Domain I of the Plasmodium vivax Apical Membrane Antigen-1(AMA-1) Gene in Clinical Isolates from Iran

BACKGROUND: Apical Membrane antigen 1 (AMA-1) is positioned on the surface of merozoite and it may play a role in attack to red blood cells. The main aim of present study was to determine the genetic variation, as well as, to detect of selection at domain I of AMA-1 gene Plasmodium vivax isolates in Iran. METHODS: Blood samples were collected from 58 patients positive for P. vivax, mono infection and the domain I of AMA-1 gene was amplified by nested PCR and then sequenced. RESULTS: A total 33 different haplotypes were identified among 58 Iranian sequences. The 23 new haplotypes were determined in this study that was not reported previously in other regions of the world. There were totally observed 36 point mutations at the nucleotide level in the analyzed sequences. Sequences analyses indicated 25 amino acid changes at 20 positions in which 5 sites demonstrated thrimorphic polymorphism and the others were dimorphic in the domain I of the Iranian PvAMA-1 isolates. CONCLUSION: Our findings indicated relatively high level of allelic diversity at the domain I of PvAMA-1 among P.vivax isolates of Iran. Since, PvAMA-1 is considering as vaccine candidate antigen, these data provide valuable information for the development of a PvAMA-1 based malaria vaccine.