Influence of a Major Mountainous Landscape Barrier (Mount Cameroon) on the Spread of Metabolic () and Target-Site () Resistance Alleles in the African Malaria Vector .

Increased levels of insecticide resistance in major malaria vectors such as threaten the effectiveness of insecticide-based control programmes. Understanding the landscape features impacting the spread of resistance makers is necessary to design suitable resistance management strategies. Here, we examined the influence of the highest mountain in West Africa (Mount Cameroon; 4095 m elevation) on the spread of metabolic and target-site resistance alleles in . populations. Vector composition varied across the four localities surveyed along the altitudinal cline with major vectors exhibiting high parity rate (80.5%). infection rates ranged from 0.79% () to 4.67% (). High frequencies of (67-81%) and (49-90%) resistance alleles were observed in throughout the study area, with frequency increasing with altitude, whereas the opposite is observed for . Patterns of genetic diversity and population structure analyses revealed high levels of polymorphisms with 12 and 16 haplotypes respectively for and . However, the reduced diversity patterns of resistance allele carriers revealed signatures of positive selection on the two genes across the study area irrespective of the altitude. Despite slight variations associated with the altitude, the spread of resistance alleles suggest that control strategies could be implemented against malaria vectors across mountainous landscapes.