Distinct combinations of variant ionotropic glutamate receptors mediate thermosensation and hygrosensation in Drosophila
Zachary A Knecht,
Ana F Silbering,
Lina Ni,
Mason Klein,
Gonzalo Budelli,
Rati Bell,
Liliane Abuin,
Anggie J Ferrer,
Aravinthan DT Samuel,
Richard Benton,
Paul A Garrity
Affiliations
Zachary A Knecht
Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, United States
Ana F Silbering
Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
Lina Ni
Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, United States
Mason Klein
Department of Physics and Center for Brain Science, Harvard University, Cambridge, United States; Department of Physics, University of Miami, Coral Gables, United States
Gonzalo Budelli
Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, United States
Rati Bell
Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
Liliane Abuin
Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
Anggie J Ferrer
Department of Physics, University of Miami, Coral Gables, United States
Aravinthan DT Samuel
Department of Physics and Center for Brain Science, Harvard University, Cambridge, United States
Richard Benton
Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
Ionotropic Receptors (IRs) are a large subfamily of variant ionotropic glutamate receptors present across Protostomia. While these receptors are most extensively studied for their roles in chemosensory detection, recent work has implicated two family members, IR21a and IR25a, in thermosensation in Drosophila. Here we characterize one of the most evolutionarily deeply conserved receptors, IR93a, and show that it is co-expressed and functions with IR21a and IR25a to mediate physiological and behavioral responses to cool temperatures. IR93a is also co-expressed with IR25a and a distinct receptor, IR40a, in a discrete population of sensory neurons in the sacculus, a multi-chambered pocket within the antenna. We demonstrate that this combination of receptors is required for neuronal responses to dry air and behavioral discrimination of humidity differences. Our results identify IR93a as a common component of molecularly and cellularly distinct IR pathways important for thermosensation and hygrosensation in insects.
