Distinct Olfactory Signaling Mechanisms in the Malaria Vector Mosquito Anopheles gambiae

• Published in: PLoS biology Vol. 8; no. 8; p. e1000467
• Main Authors: Liu, Chao, Pitts, R. Jason, Bohbot, Jonathan D, Jones, Patrick L, Wang, Guirong, Zwiebel, Laurence J, Amrein, Hubert
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01-08-2010; Public Library of Science (PLoS)
• Subjects: adults; Animals; Anopheles; Anopheles - physiology; Anopheles gambiae; Behavior; Behavior, Animal - drug effects; Control; deet; DEET - pharmacology; Gene expression; Gene Silencing; genes; Genetic aspects; Genetics and Genomics/Functional Genomics; host preferences; humans; Infectious Diseases/Protozoal Infections; Infectious Diseases/Tropical and Travel-Associated Diseases; Insect Repellents - pharmacology; insect vectors; Insect Vectors - physiology; Larva - physiology; larvae; Malaria; Malaria - parasitology; Malaria - transmission; mosquito-borne diseases; Mosquitoes; Neuroscience/Sensory Systems; odor compounds; olfaction; Olfactory Pathways - physiology; Peptides; receptors; Receptors, Odorant - genetics; Receptors, Odorant - metabolism; Rhinencephalon; RNA Interference; Signal Transduction; smell; Smell - physiology; vector control; United States; Receptors, Odorant; Insect Vectors; Malaria; Signal Transduction; Gene Silencing; Olfactory Pathways; DEET; Smell; Behavior, Animal; Animals; Insect Repellents; Anopheles gambiae; Larva; RNA Interference
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.1000467

Anopheles gambiae is the principal Afrotropical vector for human malaria, in which olfaction mediates a wide range of both adult and larval behaviors. Indeed, mosquitoes depend on the ability to respond to chemical cues for feeding, host preference, and mate location/selection. Building upon previous work that has characterized a large family of An. gambiae odorant receptors (AgORs), we now use behavioral analyses and gene silencing to examine directly the role of AgORs, as well as a newly identified family of candidate chemosensory genes, the An. gambiae variant ionotropic receptors (AgIRs), in the larval olfactory system. Our results validate previous studies that directly implicate specific AgORs in behavioral responses to DEET as well as other odorants and reveal the existence of at least two distinct olfactory signaling pathways that are active in An. gambiae . One system depends directly on AgORs; the other is AgOR-independent and requires the expression and activity of AgIRs. In addition to clarifying the mechanistic basis for olfaction in this system, these advances may ultimately enhance the development of vector control strategies, targeting olfactory pathways in mosquitoes to reduce the catastrophic effects of malaria and other mosquito-borne diseases.