Population genetic structure of Central African Trypanosoma brucei gambiense isolates using microsatellite DNA markers.

Genetic variation of microsatellite loci is a widely used method for the analysis of population genetic structure of microorganisms. Seven microsatellite markers were used here to characterize Trypanosoma brucei gambiense isolates from Central Africa sub-region in order to improve knowledge on the population genetic structure of this subspecies. These markers confirmed the low genetic polymorphism within Central African T. b. gambiense isolates from the same focus and strong differentiation between different foci. The presence of many multilocus genotypes of T. b. gambiense and the excess of heterozygotes found in this study play in favour of a clonal reproduction of this parasite. But some data may be indicative of a unique recombination event in one subsample. The high F(ST) value indicates low migration rates between T. b. gambiense subpopulations (foci). Very negative F(IS) suggests fairly small clonal population sizes of this pathogen in the different human trypanosomosis foci of Central Africa.