TY - JOUR
T1 - Polymorphism in the gene encoding the apical membrane antigen-1 (AMA-1) of Plasmodium falciparum. X. Asembo Bay Cohort Project
AU - Escalante, Ananias A.
AU - Grebert, Heather M.
AU - Chaiyaroj, Sansanee C.
AU - Magris, Magda
AU - Biswas, Sukla
AU - Nahlen, Bernard L.
AU - Lal, Altaf A.
N1 - Funding Information:
This research is supported by grants from the ‘Consejo Venezolano de Investigaciones Cientı́ficas’, (G97000634) and The National Institutes of Health (R01 GM60740-01) to A.A.E. This work was supported in part by the US Agency for International Development grant HRN-60010-A-00-4010-00 to A.A.L. We thank Oralee Branch, Shannon L. Takala, and Lauren M. Singer for helpful comments on the manuscript.
PY - 2001/4/6
Y1 - 2001/4/6
N2 - We have investigated the genetic diversity of the gene encoding the apical membrane antigen-1 (AMA-1) in natural populations of Plasmodium falciparum from western Kenya and compared it with parasite populations from other geographic regions. A total of 28 complete sequences from Kenya, Thailand, India, and Venezuela field isolates were obtained. The genetic polymorphism is not evenly distributed across the gene, which is in agreement with the pattern reported in earlier studies. The alleles from Kenya exhibit 20 and 30% more polymorphism than that found in Southeast Asia and Venezuelan alleles, respectively. Based on the gene genealogies derived from sequencing data, no evidence for allele families was found. We have found evidence supporting limited gene flow between the parasite populations, specifically, between the Southeast Asian and Venezuelan isolates; however, no alleles could be linked to a specific geographic region. This study reveals that positive natural selection is an important factor in the maintenance of genetic diversity for AMA-1. We did not find conclusive evidence indicating intragenic recombination is important in the generation of the AMA-1 allelic diversity. The study provides information on the genetic diversity of the AMA-1 gene that would be useful in vaccine development and testing, as well as in assessing factors that are involved in the generation and maintenance of the genetic diversity in P. falciparum.
AB - We have investigated the genetic diversity of the gene encoding the apical membrane antigen-1 (AMA-1) in natural populations of Plasmodium falciparum from western Kenya and compared it with parasite populations from other geographic regions. A total of 28 complete sequences from Kenya, Thailand, India, and Venezuela field isolates were obtained. The genetic polymorphism is not evenly distributed across the gene, which is in agreement with the pattern reported in earlier studies. The alleles from Kenya exhibit 20 and 30% more polymorphism than that found in Southeast Asia and Venezuelan alleles, respectively. Based on the gene genealogies derived from sequencing data, no evidence for allele families was found. We have found evidence supporting limited gene flow between the parasite populations, specifically, between the Southeast Asian and Venezuelan isolates; however, no alleles could be linked to a specific geographic region. This study reveals that positive natural selection is an important factor in the maintenance of genetic diversity for AMA-1. We did not find conclusive evidence indicating intragenic recombination is important in the generation of the AMA-1 allelic diversity. The study provides information on the genetic diversity of the AMA-1 gene that would be useful in vaccine development and testing, as well as in assessing factors that are involved in the generation and maintenance of the genetic diversity in P. falciparum.
KW - Genetic diversity
KW - Geographic variation
KW - Malaria
KW - Merozoite
KW - Plasmodium
KW - Vaccine
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U2 - 10.1016/S0166-6851(01)00229-8
DO - 10.1016/S0166-6851(01)00229-8
M3 - Article
C2 - 11295182
AN - SCOPUS:0035815317
SN - 0166-6851
VL - 113
SP - 279
EP - 287
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
IS - 2
ER -