Olfactory and thermosensory signaling in malaria vector mosquito Anopheles gambiae

Abstract

Human malaria is primarily transmitted by the anthropophilic mosquito, Anopheles gambiae. In order to seek for a blood meal to complete the gonotrophic cycle, female An. gambiae utilize a variety of sensory modalities in order to locate the human host. These include olfaction, which is highly sensitive towards human emanations and essential for long-range host seeking. In addition, An. gambiae is able to utilize heat as a short-range guidance cue for the final landing onto the skin surface. Therefore, the mission to eliminate malaria worldwide is profoundly dependent on the understanding of the molecular mechanisms underlying olfaction and thermosensation. I have focused on the larval-stage mosquitos to study the biological role of odorant receptors (ORs) and illustrate how the peripheral olfactory signaling directs downstream animal responses. Interdisciplinary approaches including molecular biology, immunohistochemistry and behavioral analysis are combined to characterize the roles of odorant receptor ion channels in not only peripheral olfaction, but also the reproductive processes of An. gambiae. Moreover, I have discovered the importance of a member of Transient Receptor Potential (TRP) channels, TRPA1, in conferring heat sensitivities towards the upper-range of ambient temperatures in An. gambiae larvae.