Use of short tandem repeats to describe genetic variability in Anopheles Gambiae from three countries in Africa.
Abstract
Macrogeographic variation in An. gambiae was measured by
analysing four polymorphic STR loci in four populations by
electrophoresis on horizontal slab polyacrylamide gels. Mosquitoes
were sampled from inland (Asembo) and coastal (Kilifi) Kenya in
East Africa, Ghana (Navrongo province) in West Africa and Malawi
(Mangochi district) in Central Africa. On average 3 to 12 alleles
were detected per locus per population. The mean unbiased
heterozygosity (HE) was 0.598 (Asembo), 0.591 (Ghana), 0.516
(Kilifi) and 0.432 (Malawi}. Departures from Hardy-Weinberg
equilibrium were not significant in Asembo and Ghana populations
but allele frequency data revealed heterozygote deficiency in
Kilifi and Malawi. Mean pairwise FST was 0.1290 (Asembo Vs Kilifi),
0.0085 (Asembo Vs Ghana) and 0.1596 (Kilifi Vs Ghana). Apparently
no barriers to gene flow occur between Asembo and Ghana. Estimates
of genetic differentiation in Asembo Vs Kilifi and Kilifi Vs Ghana
matched low effective migra~ion indices (Nm) suggesting restricted
gene flow between. the regions. The Rift Valley, in East Africa,
might be a barrier-to gene flow in natural An. gambiae populations.
However should the resulf6f limited genetic differentiation across
large distances (Asembo Vs Ghana) be confimed, An. gambiae may be
a good candidate for genetic modification.
Citation
MSc.Publisher
Department of Zoology, University of Nairobi
Description
Master of Science in zoology (Medical Parasitology)