Mutações sinônimas e não sinônimas como um dos mecanismos de geração de polimorfismo do antígeno msp1 de plasmodium vivax

Abstract

subtropical regions of the planet. In North America, Plasmodium vivax is responsible for the most part of the infections. In 2011, 250,498 cases of malaria fever were studied; 80% of these cases were caused by Plasmodium vivax. The purpose of this study was to investigate the diversity generation of the gene MSP1 from Plasmodium vivax through the analisys of a specific mutation in the region from the block 2 genetic precombination events. In order to identify the existing mutations in multiclonal infections and generation of diversity in PvMSP1 a series of experiments were done, respectively, the extraction of genomic DNA of the parasite, PCR (polymerase chain reaction) using specific primers for the block 2, ligation of the fragment to cloning vector (top), processing using Escherichia coli competent cells, selection of colonies belonging to the same sample, DNA sequencing and analysis of synonymous and nonsynonymous mutations as their location in the prediction of B and T cell epitopes (not synonymous). The calculation of genetic distance between recombinant clones of the same sample by the MEGA 4.0 program confirmed the multiclonality of samples. The alignment of amino acid sequences showed the presence of genetic recombination events using DNASP program. DNA sequences obtained showed another interesting result: several synonymous and non-synonymous mutations in a relatively small stretch of DNA. Genetic diversity showed most mutations are not synonymous, and that most of them were located in regions referred to as B and T cell epitopes by BcPred and ProPred. So, as expected, the genetic diversity based on synonymous mutations and not synonymous possible sustains the phenomenon of escape on the immunity of the host. The characterization of these polymorphisms may contribute to immunological studies aiming at the development of a vaccine against malaria on stages caused by p. vivax.