title: Wide distribution of the variant form of the human malaria parasite Plasmodium vivax.
abstract: We have found polymorphism in the repetitive and nonrepetitive regions of the sporozoite vaccine antigen, the circumsporozoite (CS) protein, in Plasmodium vivax malaria parasites from two geographically distant malaria endemic regions of the world. Like the recently described variant repeat sequence of P. vivax from Thailand, the CS protein repeat sequence of the variant P. vivax parasites from Papua New Guinea and Brazil is ANGA(G/D)(N/D)QPG, which differs from the previously identified CS repeat sequence, GDRA(D/A)GQPA, of P. vivax parasites from South America, Central America, and North Korea. Comparison of the P. vivax CS protein outside the repeat region revealed restricted polymorphism in regions that have exhibited T-cell immune function and sequence heterogeneity in the CS protein of Plasmodium falciparum. Our results show that P. vivax malaria parasites with the variant CS repeat sequences are widespread in nature and that the polymorphism in the CS protein of P. vivax is also present in the nonrepeat region.
authors.affiliation: Malaria Branch, Centers for Disease Control, Atlanta, Georgia 30333.
authors.forename: S H
authors.initials: SH
authors.lastname: Qari
authors.forename: I F
authors.initials: IF
authors.lastname: Goldman
authors.forename: M M
authors.initials: MM
authors.lastname: Povoa
authors.forename: S
authors.initials: S
authors.lastname: Oliveira
authors.forename: M P
authors.initials: MP
authors.lastname: Alpers
authors.forename: A A
authors.initials: AA
authors.lastname: Lal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D001483:Base Sequence; D016054:DNA, Protozoan; D008969:Molecular Sequence Data; D010966:Plasmodium vivax / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan