The Ionotropic Receptors IR21a and IR25a mediate cool sensing in Drosophila
Lina Ni,
Mason Klein,
Kathryn V Svec,
Gonzalo Budelli,
Elaine C Chang,
Anggie J Ferrer,
Richard Benton,
Aravinthan DT Samuel,
Paul A Garrity
Affiliations
Lina Ni
National Center for Behavioral Genomics, Brandeis University, Waltham, United States; Volen Center for Complex Systems, Brandeis University, Waltham, United States; Department of Biology, Brandeis University, Waltham, United States
Mason Klein
Department of Physics, Harvard University, Cambridge, United States; Department of Physics, University of Miami, Coral Gables, United States; Center for Brain Science, Harvard University, Cambridge, United States
Kathryn V Svec
National Center for Behavioral Genomics, Brandeis University, Waltham, United States; Volen Center for Complex Systems, Brandeis University, Waltham, United States; Department of Biology, Brandeis University, Waltham, United States
Gonzalo Budelli
National Center for Behavioral Genomics, Brandeis University, Waltham, United States; Volen Center for Complex Systems, Brandeis University, Waltham, United States; Department of Biology, Brandeis University, Waltham, United States
Elaine C Chang
National Center for Behavioral Genomics, Brandeis University, Waltham, United States; Volen Center for Complex Systems, Brandeis University, Waltham, United States; Department of Biology, Brandeis University, Waltham, United States
Anggie J Ferrer
Department of Physics, University of Miami, Coral Gables, United States
Richard Benton
Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
Aravinthan DT Samuel
Department of Physics, Harvard University, Cambridge, United States; Center for Brain Science, Harvard University, Cambridge, United States
National Center for Behavioral Genomics, Brandeis University, Waltham, United States; Volen Center for Complex Systems, Brandeis University, Waltham, United States; Department of Biology, Brandeis University, Waltham, United States
Animals rely on highly sensitive thermoreceptors to seek out optimal temperatures, but the molecular mechanisms of thermosensing are not well understood. The Dorsal Organ Cool Cells (DOCCs) of the Drosophila larva are a set of exceptionally thermosensitive neurons critical for larval cool avoidance. Here, we show that DOCC cool-sensing is mediated by Ionotropic Receptors (IRs), a family of sensory receptors widely studied in invertebrate chemical sensing. We find that two IRs, IR21a and IR25a, are required to mediate DOCC responses to cooling and are required for cool avoidance behavior. Furthermore, we find that ectopic expression of IR21a can confer cool-responsiveness in an Ir25a-dependent manner, suggesting an instructive role for IR21a in thermosensing. Together, these data show that IR family receptors can function together to mediate thermosensation of exquisite sensitivity.
