Carboxylic acids that drive mosquito attraction to humans activate ionotropic receptors

• Published in: PLoS neglected tropical diseases 2023-06, Vol.17 (6), p.e0011402-e0011402
• Main Authors: Ray, Garrett, Huff, Robert M, Castillo, John S, Bellantuono, Anthony J, DeGennaro, Matthew, Pitts, R Jason
• Format: Article
• Language: English
• Subjects: Acids; Amino acids; Analysis; Annotations; Aquatic insects; Attraction; Behavior; Behavioural responses; Biology and Life Sciences; Carboxylic acids; Cloning; Culicidae; Disease transmission; Environmental DNA; Genomes; Glutamic acid receptors (ionotropic); Homology; Host preferences; Human populations; Insects; Ion channels (ligand-gated); Major constituents; Medicine and Health Sciences; Molecular modelling; Mosquitoes; Nucleotide sequence; Odor; Odors; Odour; Physical Sciences; Plumes; Prevention; Properties; Receptors; Repellents; Sensory evaluation; Sensory neurons; Software; Transmission; Tropical diseases; Vector-borne diseases; VOCs; Volatile compounds; Volatile organic compounds; Volatiles
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0011402

The mosquito, Aedes aegypti, is highly anthropophilic and transmits debilitating arboviruses within human populations and between humans and non-human primates. Female mosquitoes are attracted to sources of blood by responding to odor plumes that are emitted by their preferred hosts. Acidic volatile compounds, including carboxylic acids, represent particularly salient odors driving this attraction. Importantly, carboxylic acids are major constituents of human sweat and volatiles generated by skin microbes. As such, they are likely to impact human host preference, a dominant factor in disease transmission cycles. A more complete understanding of mosquito host attraction will necessitate the elucidation of molecular mechanisms of volatile odor detection that function in peripheral sensory neurons. Recent studies have shown that members of the variant ionotropic glutamate receptor gene family are necessary for physiological and behavioral responses to acidic volatiles in Aedes. In this study, we have identified a subfamily of variant ionotropic receptors that share sequence homology across several important vector species and are likely to be activated by carboxylic acids. Moreover, we demonstrate that selected members of this subfamily are activated by short-chain carboxylic acids in a heterologous cell expression system. Our results are consistent with the hypothesis that members of this receptor class underlie acidic volatile sensitivity in vector mosquitoes and provide a frame of reference for future development of novel mosquito attractant and repellent technologies.