Genomic evidence for local adaptation in Aedes aegypti in response to environmental heterogeneity across Panama

Local adaptation is important when predicting arthropod-borne disease risk because it impacts on vector population fitness and persistence. However, the extent that vector populations are adapted to the environment generally remains unknown. Despite low population structure and high gene flow in Ae. aegypti across Panama, excepting the province of Bocas del Toro, we identify 128 candidate SNPs, clustered within 17 genes, which show a strong genetic signal of local adaptation. This putatively adaptive variation occurs across fine geographic scales with the composition and frequency of candidate adaptive loci differing between populations in wet tropical environments along the Caribbean coast and dry tropical conditions typical of the Pacific coast. Temperature and vegetation were important predictors of adaptive genomic variation in Ae. aegypti with several potential areas of local adaptation identified. Our study lays the foundations of future work to understand whether environmental adaptation in Ae. aegypti impacts on the arboviral disease landscape and whether this could either aid or hinder efforts of population control.