Spencer D. PolleyWatcharee ChokejindachaiDavid J. ConwayLondon School of Hygiene & Tropical MedicineMahidol University2018-07-242018-07-242003-10-01Genetics. Vol.165, No.2 (2003), 555-561001667312-s2.0-0242349712https://repository.li.mahidol.ac.th/handle/20.500.14594/20688The Plasmodium falciparum apical membrane antigen 1 (AMA1) is a leading candidate for a malaria vaccine. Here, within-population analyses of alleles from 50 Thai P. falciparum isolates yield significant evidence for balancing selection on polymorphisms within the disulfide-bonded domains I and III of the surface accessible ectodomain of AMA1, a result very similar to that seen previously in a Nigerian population. Studying the frequency of nucleotide polymorphisms in both populations shows that the between-population component of variance (FST) is significantly lower in domains I and III compared to the intervening domain II and compared to 11 unlinked microsatellite loci. A nucleotide site-by-site analysis shows that sites with exceptionally high or low FST values cluster significantly into serial runs, with four runs of low values in domain I and one in domain III. These runs may map the sequences that are consistently under the strongest balancing selection from naturally acquired immune responses.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS