Event Details:
Wu Tsai Neurosciences Institute Seminar Series Presents
Leslie B. Vosshall, PhD
Robin Chemers Neustein Professor
HHMI – Rockefeller University
Director, Kavli Neural Systems Institute
Host: Kang Shen
Abstract
Current dogma in the field of olfaction, dating from the cloning of odorant receptors by Buck and Axel in 1991, is that each olfactory sensory neuron expresses a unique odorant receptor that specifies its functional properties. All neurons expressing a given receptor project axons to a single olfactory glomerulus in the first sensory processing center in the brain, the olfactory bulb in vertebrates and antennal lobe in insects. Such an organization permits the brain to monitor activity individual glomeruli to understand what smell has been encountered. We have discovered that the Zika and dengue mosquito (Aedes aegypti) discards all of these rules. Insects have three separate super families of chemosensory receptors (ORs, IRs, and GRs). All mosquito sensory neurons profiled express multiple members of at least 2 of these receptor families. This unexpected co-expression is functional, as assessed by GCaMP imaging in the antennal lobe. A given glomerulus is activated by multiple ligands specific to different gene families. Finally, we demonstrate that this dogma-disrupting co-expression has direct functional consequences for mosquito host-seeking behavior. We speculate that this overlapping gene expression affords the female mosquito redundant and ‘unbreakable’ attraction to humans. This behavior is essential because without blood obtained from hosts, mosquitoes are unable to reproduce.