Data from: Spatio-temporal genetic structure of Anopheles gambiae in the Northwestern Lake Victoria Basin, Uganda: implications for genetic control trials in malaria endemic regions

Background: Understanding population genetic structure in the malaria
vector Anopheles gambiae (s.s.) is crucial to inform genetic control and
manage insecticide resistance. Unfortunately, species characteristics such
as high nucleotide diversity, large effective population size, recent
range expansion, and high dispersal ability complicate the inference of
genetic structure across its range in sub-Saharan Africa. The ocean, along
with the Great Rift Valley, is one of the few recognized barriers to gene
flow in this species, but the effect of inland lakes, which could be
useful sites for initial testing of genetic control strategies, is
relatively understudied. Here we examine Lake Victoria as a barrier
between the Ugandan mainland and the Ssese Islands, which lie up to 60 km
offshore. We use mitochondrial DNA (mtDNA) from populations sampled in
2002, 2012 and 2015, and perform Bayesian cluster analysis on mtDNA
combined with microsatellite data previously generated from the same 2002
mosquito DNA samples. Results: Hierarchical analysis of molecular variance
and Bayesian clustering support significant differentiation between the
mainland and lacustrine islands. In an mtDNA haplotype network constructed
from this and previous data, haplotypes are shared even between localities
separated by the Rift Valley, a result that more likely reflects retention
of shared ancestral polymorphism than contemporary gene flow. Conclusions:
The relative genetic isolation of An. gambiae on the Ssese Islands, their
small size, level terrain and ease of access from the mainland, the
relative simplicity of the vectorial system, and the prevalence of
malaria, are all attributes that recommend these islands as possible sites
for the testing of genetic control strategies.