title: Genetic polymorphism of the serine rich antigen N-terminal region in Plasmodium falciparum field isolates from Brazil.
abstract: In this work we investigated the frequency of polymorphism in exon II of the gene encoding most of the amino-terminal region of the serine rich antigen (SERA) in Plasmodium falciparum field samples. The blood samples were collected from P. falciparum infected individuals in three areas of the Brazilian Amazon. Two fragments have been characterized by polymerase chain reaction: one of 175 bp corresponding to the repeat region with 5 octamer units and one other of 199 bp related to the 6 repeat octamer units of SERA protein. The 199 bp fragment was the predominant one in all the studied areas. The higher frequency of this fragment has not been described before and could be explained by an immunological selection of the plasmodial population in the infected individuals under study. Since repeat motifs in the amino-terminal region of SERA contain epitopes recognized by parasite-inhibitor antibodies, data reported here suggest that the analysis of the polymorphism of P. falciparum isolates in different geographical areas is a preliminary stage before the final drawing of an universal vaccine against malaria can be reached.
authors.affiliation: Laboratório de Pesquisas em Malária, Departamento de Imunologia, Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brazil.
authors.forename: Evelyn Kety Pratt
authors.initials: EK
authors.lastname: Riccio
authors.forename: Mariano Gustavo
authors.initials: MG
authors.lastname: Zalis
authors.forename: Helena Cristina Balthazar
authors.initials: HC
authors.lastname: Guedes
authors.forename: Dalma Maria
authors.initials: DM
authors.lastname: Banic
authors.forename: José Maria de
authors.initials: JM
authors.lastname: Souza
authors.forename: Wilson
authors.initials: W
authors.lastname: Alecrim
authors.forename: Daniel
authors.initials: D
authors.lastname: Camus
authors.forename: Cláudio Tadeu
authors.initials: CT
authors.lastname: Daniel-Ribeiro
authors.forename: Maria de Fátima
authors.initials: Mde F
authors.lastname: Ferreira-da-Cruz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D001938:Brazil; D016054:DNA, Protozoan / Q000032:analysis; D005091:Exons; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; C057495:serine repeat antigen, Plasmodium