title: Plasmodium vivax Duffy binding protein: a modular evolutionary proposal.
abstract: The population of malaria-causing parasites is characterized by great genetic diversity. Knowledge of the polymorphism generation mechanism is a central issue for developing effective vaccines against malaria and understanding the parasite population structure. Plasmodium vivax genetic diversity has been explained in terms of two major factors: natural selection and intragenic recombination. A modular organization was found within P. vivax Duffy binding protein in the present work. Four Colombian isolates have identical sequences to Salvador-1 strain amongst dpb regions III-VI analysed, suggesting a high identity between Central and South American isolates. Geographically clustered sectors, corresponding to cysteine-rich regions (II and VI), show a high sequence diversity that could reflect a possible immune response evasion mechanism; both positive and negative selection were detected in these regions. In contrast, other dbp gene regions display a non-geographical clustering pattern, lower sequence diversity and predominant negative selective pressure. Recombination was homogeneously detected all along the molecule. These findings suggest that diversification vs. homogenizing forces, drive dbp gene evolution and determine its mosaic region organization.
authors.affiliation: Molecular Biology Department, Fundacion Instituto de Inmunologia de Colombia, Carrea 50#26-00, Bogota, Colombia.
authors.forename: P
authors.initials: P
authors.lastname: Martinez
authors.forename: C F
authors.initials: CF
authors.lastname: Suarez
authors.forename: P P
authors.initials: PP
authors.lastname: Cardenas
authors.forename: M A
authors.initials: MA
authors.lastname: Patarroyo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D016780:Malaria, Vivax / Q000469:parasitology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010966:Plasmodium vivax / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics*; D012641:Selection, Genetic; D016415:Sequence Alignment; D013499:Surface Properties
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; C066001:Duffy antigen binding protein, Plasmodium; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface