Dietary and Plasmodium challenge effects on cuticular hydrocarbons in Anopheles albimanus

Abstract

The cuticular hydrocarbon (CHC) profile reflects the insect’s physiological states. These states include age, sex, reproductive stage, or gravidity. Environmental factors such as diet, relative humidity, or exposure to insecticides also affect the CHCs composition in mosquitoes. In this work, the CHC profile was analyzed in two Anopheles albimanus phenotypes with different degrees of susceptibility to Plasmodium: the susceptible-White and resistant-Brown phenotypes. The effects of the CHC profile were considered under a carbon-rich diet (sugar), a protein-rich diet (blood), and an infectious challenge (blood containing Plasmodium berghei ookinetes). The CHCs were analyzed by gas chromatography coupled with either mass spectrometry or flame ionization detection, identifying 19 CHCs with chain lengths ranging from 20 to 37 carbons. The qualitative and quantitative changes observed in the CHCs composition were dependent on the diet and parasite challenge, and independent of the phenotype. The exception was the challenged condition, where significant differences between the phenotypes were observed in Z-12 pentacosane, hexacosane 9-octyl, methyl-nonacosane, and methyl-hentriacontane. Since the lipid metabolism in Anopheles mosquitoes has been shown crucial for Plasmodium development, the changes in the CHC profiles associated with infection could have multiple effects on mosquito fitness and impacts on disease transmission.