title: A Molecular and Cellular Context-Dependent Role for Ir76b in Detection of Amino Acid Taste.
abstract: Amino acid taste is expected to be a universal property among animals. Although sweet, bitter, salt, and water tastes have been well characterized in insects, the mechanisms underlying amino acid taste remain elusive. From a Drosophila RNAi screen, we identify an ionotropic receptor, Ir76b, as necessary for yeast preference. Using calcium imaging, we identify Ir76b+amino acid taste neurons in legs, overlapping partially with sweet neurons but not those that sense other tastants. Ir76b mutants have reduced responses to amino acids, which are rescued by transgenic expression of Ir76b and a mosquito ortholog AgIr76b. Co-expression of Ir20a with Ir76b is sufficient for conferring amino acid responses in sweet-taste neurons. Notably, Ir20a also serves to block salt response of Ir76b. Our study establishes the role of a highly conserved receptor in amino acid taste and suggests a mechanism for mutually exclusive roles of Ir76b in salt- and amino-acid-sensing neurons.
authors.affiliation: Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA.
authors.forename: Anindya
authors.initials: A
authors.lastname: Ganguly
authors.affiliation: Department of Entomology, University of California, Riverside, CA 92521, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Pang
authors.affiliation: University Honors Program, University of California, Riverside, CA 92521, USA.
authors.forename: Vi-Khoi
authors.initials: VK
authors.lastname: Duong
authors.affiliation: Undergraduate Anthropology Major, University of California, Riverside, CA 92521, USA.
authors.forename: Angelina
authors.initials: A
authors.lastname: Lee
authors.affiliation: University Honors Program, University of California, Riverside, CA 92521, USA.
authors.forename: Hanni
authors.initials: H
authors.lastname: Schoniger
authors.affiliation: University Honors Program, University of California, Riverside, CA 92521, USA.
authors.forename: Erika
authors.initials: E
authors.lastname: Varady
authors.affiliation: Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA; Department of Entomology, University of California, Riverside, CA 92521, USA. Electronic address: anupama.dahanukar@ucr.edu.
authors.forename: Anupama
authors.initials: A
authors.lastname: Dahanukar
mesh_terms: D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D030801:Animals, Genetically Modified / Q000502:physiology; D001483:Base Sequence; D001522:Behavior, Animal / Q000187:drug effects; D064113:CRISPR-Cas Systems / Q000235:genetics; D002118:Calcium / Q000378:metabolism; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000187:drug effects / Q000502:physiology*; D005260:Female; D008297:Male; D018613:Microscopy, Confocal; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D034622:RNA Interference; D058468:Receptors, Ionotropic Glutamate / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015222:Sodium Channels / Q000235:genetics / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D000073893:Sugars / Q000494:pharmacology; D013649:Taste / Q000187:drug effects* / Q000502:physiology
chemical_list: D000596:Amino Acids; D029721:Drosophila Proteins; C581929:IR76b protein, Drosophila; D058468:Receptors, Ionotropic Glutamate; D015222:Sodium Channels; D000073893:Sugars; D012965:Sodium Chloride; D002118:Calcium
keywords: Drosophila; Ir76b; amino acid taste; feeding behavior; ionotropic receptors; post-mating behavior