Taste cells expressing Ionotropic Receptor 94e reciprocally impact feeding and egg laying in Drosophila
Jacqueline Guillemin,
Jinfang Li,
Viktoriya Li,
Sasha A.T. McDowell,
Kayla Audette,
Grace Davis,
Meghan Jelen,
Samy Slamani,
Liam Kelliher,
Michael D. Gordon,
Molly Stanley
Affiliations
Jacqueline Guillemin
Department of Biology, The University of Vermont, Burlington, VT 05405, USA
Jinfang Li
Department of Zoology, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
Viktoriya Li
Department of Zoology, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
Sasha A.T. McDowell
Department of Zoology, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
Kayla Audette
Department of Biology, The University of Vermont, Burlington, VT 05405, USA
Grace Davis
Department of Biology, The University of Vermont, Burlington, VT 05405, USA
Meghan Jelen
Department of Zoology, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
Samy Slamani
Department of Biology, The University of Vermont, Burlington, VT 05405, USA
Liam Kelliher
Department of Biology, The University of Vermont, Burlington, VT 05405, USA
Michael D. Gordon
Department of Zoology, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Corresponding author
Molly Stanley
Department of Biology, The University of Vermont, Burlington, VT 05405, USA; Corresponding author
Summary: Chemosensory cells across the body of Drosophila melanogaster evaluate the environment to prioritize certain behaviors. Previous mapping of gustatory receptor neurons (GRNs) on the fly labellum identified a set of neurons in L-type sensilla that express Ionotropic Receptor 94e (IR94e), but the impact of IR94e GRNs on behavior remains unclear. We used optogenetics and chemogenetics to activate IR94e neurons and found that they drive mild feeding suppression but enhance egg laying. In vivo calcium imaging revealed that IR94e GRNs respond strongly to certain amino acids, including glutamate, and that IR94e plus co-receptors IR25a and IR76b are required for amino acid detection. Furthermore, IR94e mutants show behavioral changes to solutions containing amino acids, including increased consumption and decreased egg laying. Overall, our results suggest that IR94e GRNs on the fly labellum discourage feeding and encourage egg laying as part of an important behavioral switch in response to certain chemical cues.
