Molecular Basis of Insect Olfaction

Insects such as mosquitoes use volatile odors to localize humans for blood-meals, incidentally spreading potentially lethal diseases to hundreds of millions of people worldwide each year. To better manipulate insect behavior with repellents and traps, we must understand how the insect olfactory system works at the level of genes, molecular signaling networks, olfactory neurons, and anatomical sensory units known as sensilla. This proposal focuses on the molecular and cellular mechanisms that allow olfactory neurons to robustly signal environmental odors, with a particular interest in evolutionarily conserved mechanisms. Given our focus on critical, yet previously unstudied genes, we employ Drosophila as a model system due to the ease of generating new genetic mutants and transgenic tools. We also utilize existing tools to perform targeted manipulations of specific populations of antennal cells including olfactory neurons and their support cells. A further advantage of Drosophila is that we can repeatedly target the same olfactory neuron populations for functional assays based on foundational knowledge of their antennal localizations and odor response profiles. Using genomic, molecular, histological, electrophysiological, and behavioral approaches, our recent research has led to the discovery of several conserved signaling molecules that play critical roles in insect olfaction. This proposal builds upon our prior research to more deeply understand the mechanisms by which these molecules and others affect olfactory neuron responses to odors. Particular attention will be paid to the poorly understood intercellular connections within sensilla, such as interactions between olfactory neurons and the three types of non-neuronal support cells. Together this research will make powerful molecular inroads into the signaling networks and intercellular interactions supporting insect olfactory behavior, some of which may be shared with other sensory systems.