Federica VerraWatcharee ChokejindachaiGareth D. WeedallSpencer D. PolleyTabitha W. MwangiKevin MarshDavid J. ConwayLondon School of Hygiene & Tropical MedicineMahidol UniversityCentre for Geographic Medicine ResearchMedical Research Council Laboratories Gambia2018-08-202018-08-202006-10-01Molecular and Biochemical Parasitology. Vol.149, No.2 (2006), 182-190016668512-s2.0-33748028816https://repository.li.mahidol.ac.th/handle/20.500.14594/22972Erythrocyte binding antigens of Plasmodium falciparum are involved in erythrocyte invasion, and may be targets of acquired immunity. Of the five eba genes, protein products have been detected for eba-175, eba-181 and eba-140, but not for ψeba-165 or ebl-1, providing opportunity for comparative analysis of genetic variation to identify selection. Region II of each of these genes was sequenced from a cross-sectional sample of parasites in an endemic Kenyan population, and the frequency distributions of polymorphisms analysed. A positive value of Tajima's D was observed for eba-175 (D = 1.13) indicating an excess of intermediate frequency polymorphisms, while all other genes had negative values, the most negative being ebl-1 (D = -2.35) followed by ψeba-165 (D = -1.79). The eba-175 and ebl-1 genes were then studied in a sample of parasites from Thailand, for which a positive Tajima's D value was again observed for eba-175 (D = 1.79), and a negative value for ebl-1 (D = -1.85). This indicates that eba-175 is under balancing selection in each population, in strong contrast to the other members of the gene family, particularly ebl-1 and ψeba-165 that may have been under recent directional selection. Population expansion simulations were performed under a neutral model, further supporting the departures from neutrality of these genes. © 2006 Elsevier B.V. All rights reserved.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyImmunology and MicrobiologyArticleSCOPUS10.1016/j.molbiopara.2006.05.010