Natural selection maintains a stable polymorphism at the circumsporozoite protein locus of Plasmodium falciparum in a low endemic area.

ABSTRACT: Circumsporozoite protein gene sequences of Plasmodium falciparum were collected in 1996-1997 and in 2006-2007 from a single endemic area in Thailand. Repeat units were more similar within the same haplotype than between haplotypes, supporting the hypothesis that repeat arrays evolve by a process of concerted evolution. There was evidence that natural selection has favored amino acid changes in the Th2R and Th3R T-cell epitope regions. One haplotype in these epitopes, designated *5/*1, occurred in approximately 70% of sequences in both collection periods. The most common other haplotypes differed from *5/*1 by at least two amino acid replacements; and divergence in the epitopes was correlated with divergence in the repeats. These patterns are most consistent with balancing selection driven

SUBMITTER: Putaporntip C 

PROVIDER: S-EPMC4009382 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature