Heterogeneous genetic diversity pattern in Plasmodium vivax genes encoding merozoite surface proteins (MSP) -7E, -7F and -7L Academic Article

abstract

  • © 2014 Garzón-Ospina et al.Background: The msp-7 gene has become differentially expanded in the Plasmodium genus; Plasmodium vivax has the highest copy number of this gene, several of which encode antigenic proteins in merozoites. Methods: DNA sequences from thirty-six Colombian clinical isolates from P. vivax (pv) msp-7E, -7F and -7L genes were analysed for characterizing and studying the genetic diversity of these pvmsp-7 members which are expressed during the intra-erythrocyte stage; natural selection signals producing the variation pattern so observed were evaluated. Results: The pvmsp-7E gene was highly polymorphic compared to pvmsp-7F and pvmsp-7L which were seen to have limited genetic diversity; pvmsp-7E polymorphism was seen to have been maintained by different types of positive selection. Even though these copies seemed to be species-specific duplications, a search in the Plasmodium cynomolgi genome (P. vivax sister taxon) showed that both species shared the whole msp-7 repertoire. This led to exploring the long-term effect of natural selection by comparing the orthologous sequences which led to finding signatures for lineage-specific positive selection. Conclusions: The results confirmed that the P. vivax msp-7 family has a heterogeneous genetic diversity pattern; some members are highly conserved whilst others are highly diverse. The results suggested that the 3′-end of these genes encode MSP-7 proteins' functional region whilst the central region of pvmsp-7E has evolved rapidly. The lineage-specific positive selection signals found suggested that mutations occurring in msp-7s genes during host switch may have succeeded in adapting the ancestral P. vivax parasite population to humans.

publication date

  • 2014/1/1

keywords

  • Erythrocytes
  • Gene Dosage
  • Genes
  • Genetic Selection
  • Genome
  • Membrane Proteins
  • Merozoites
  • Mutation
  • Parasites
  • Plasmodium
  • Plasmodium cynomolgi
  • Plasmodium vivax
  • Population
  • Proteins

International Standard Serial Number (ISSN)

  • 1475-2875

start page

  • 1

end page

  • 28