Abstract:

Vector population genetic structure is rarely analyzed yet it is important in the understanding
of the epidemiology of vector home diseases and their control. In this study, patterns of genetic
variation in the tsetse fly Glossina fuscipes fuscipes, the main vector of Human African
Trypanosomosis (HAT) and Animal African Trypanosomosis (AAT) were assessed at five
microsatellite loci. A total of 286 individuals were sampled from seven putative subpopulations
in Uganda. Six of the subpopulations (Lumino, Kwapa, Osukuru, Namungalwe, Kaliro, and
Serere) are sleeping sickness foci where the disease is endemic and the numbers of cases
sometimes escalate. In one subpopulation (Ogur), G.f fuscipes exists but active transmission is
rarely observed. The mean number of alleles per locus for each of the subpopulations was
relatively moderate ranging from 2 to 7 with generally low gene diversity (//e ranging from
0.2455 to 0.4376). Analysis of population structure with 21 possible pair wise comparisons
revealed 12 significantly divergent pairs of which, Kaliro and Lumino populations had the least
divergence (Fst =0.0443, P>0.05) while Kaliro and Serere represented the highest divergence
(Fst =0.2288, P<0.0000). Analysis of molecular variance (AMOVA) indicated significant
differentiation at all hierarchical levels between populations (Tst = 0.1474, P<0.001), among
populations within each group (Fsc = 0.0313, P<0.001) and between the two groups (Fct =
0.1199, PcO.001). These data show that G. f. fuscipes populations are highly structured, with
clearly defined northern and southern cluster that are separated by Lake Kyoga. These results
area-wide integrated tsetse and
trypanosomosis control/elimination strategy.
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are interpreted in terms of their implications for an