RRC ID 30246
Author Oike H, Nagai T, Furuyama A, Okada S, Aihara Y, Ishimaru Y, Marui T, Matsumoto I, Misaka T, Abe K.
Title Characterization of ligands for fish taste receptors.
Journal J. Neurosci.
Abstract Recent progress in the molecular biology of taste reception has revealed that in mammals, the heteromeric receptors T1R1/3 and T1R2/3 respond to amino acids and sweeteners, respectively, whereas T2Rs are receptors for bitter tastants. Similar taste receptors have also been characterized in fish, but their ligands have not been identified yet. In the present study, we conducted a series of experiments to identify the fish taste receptor ligands. Facial nerve recordings in zebrafish (Danio rerio) demonstrated that the fish perceived amino acids and even denatonium, which is a representative of aversive bitter compounds for mammals and Drosophila. Calcium imaging analysis of T1Rs in zebrafish and medaka fish (Oryzias latipes) using an HEK293T heterologous expression system revealed that both T1R1/3 and a series of T1R2/3 responded to amino acids but not to sugars. A triple-labeling, in situ hybridization analysis demonstrated that cells expressing T1R1/3 and T1R2/3s exist in PLCbeta2-expressing taste bud cells of medaka fish. Functional analysis using T2Rs showed that zfT2R5 and mfT2R1 responded to denatonium. Behavior observations confirmed that zebrafish prefer amino acids and avoid denatonium. These results suggest that, although there may be some fish-specific way of discriminating ligands, vertebrates could have a conserved gustatory mechanism by which T1Rs and T2Rs respond to attractive and aversive tastants, respectively.
Volume 27(21)
Pages 5584-92
Published 2007-5-23
DOI 10.1523/JNEUROSCI.0651-07.2007
PII 27/21/5584
PMID 17522303
MeSH Amino Acids / administration & dosage Amino Acids / metabolism Animals Cell Line Dose-Response Relationship, Drug Humans Ligands* Oryzias / physiology* Quaternary Ammonium Compounds / administration & dosage Quaternary Ammonium Compounds / metabolism Receptors, G-Protein-Coupled / metabolism* Receptors, G-Protein-Coupled / physiology Taste Buds / drug effects Taste Buds / metabolism* Taste Buds / physiology Zebrafish / physiology*
IF 5.971
Times Cited 55
Medaka cab
Zebrafish RIKEN WT