Genetic differentiation of Glossina morsitans centralis populations

Variation at mitochondrial and microsatellite loci was used to study the br eeding and dispersal structure of Glossina morsitans centralis, in six natu ral populations from Botswana, the Caprivi Strip (Namibia), Zambia, and in a laboratory culture derived from Singida, Tanzania. Only seven mitochondri al haplotypes were found. Mean diversity averaged over the six natural popu lations was 0.216 +/- 0.085. The fixation index F-ST = 0.866 indicated a hi gh degree of genetic differentiation among populations. Fifty-three alleles ; were detected among six microsatellite loci and six natural populations. Mean microsatellite diversity was 0.702 +/- 0.091. Depending on the estimat ing model used, fixation indices varied from 0.15 to 0.225 confirming that G. m. centralis populations are strongly subdivided. For all F-ST estimates , positive correlations were detected between pair-wise genetic distance me asures and geographical distances. The difference in fixation indices estim ated from mitochondrial or nuclear loci was explained by the greater sensit ivity of mitochondrial genomes to genetic drift. Population differentiation can be explained by genetic drift and the subsequent recovery of extant po pulations from small, discontinuous populations. These data confirm genetic ally the collapse and retreat of G. m. centralis populations caused by the rinderpest epizootic of the late 19th and early 20th centuries.