title: The molecular basis for attractive salt-taste coding in Drosophila.
abstract: Below a certain level, table salt (NaCl) is beneficial for animals, whereas excessive salt is harmful. However, it remains unclear how low- and high-salt taste perceptions are differentially encoded. We identified a salt-taste coding mechanism in Drosophila melanogaster. Flies use distinct types of gustatory receptor neurons (GRNs) to respond to different concentrations of salt. We demonstrated that a member of the newly discovered ionotropic glutamate receptor (IR) family, IR76b, functioned in the detection of low salt and was a Na(+) channel. The loss of IR76b selectively impaired the attractive pathway, leaving salt-aversive GRNs unaffected. Consequently, low salt became aversive. Our work demonstrated that the opposing behavioral responses to low and high salt were determined largely by an elegant bimodal switch system operating in GRNs.
authors.affiliation: Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Yali V
authors.initials: YV
authors.lastname: Zhang
authors.forename: Jinfei
authors.initials: J
authors.lastname: Ni
authors.forename: Craig
authors.initials: C
authors.lastname: Montell
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D002628:Chemoreceptor Cells / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D004331:Drosophila melanogaster / Q000502:physiology*; D017353:Gene Deletion; D017470:Receptors, Glutamate; D058468:Receptors, Ionotropic Glutamate / Q000235:genetics / Q000502:physiology*; D058618:Sensilla / Q000502:physiology; D015222:Sodium Channels / Q000235:genetics / Q000502:physiology*; D012965:Sodium Chloride; D055697:Taste Perception / Q000235:genetics / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins; C581929:IR76b protein, Drosophila; D017470:Receptors, Glutamate; D058468:Receptors, Ionotropic Glutamate; D015222:Sodium Channels; D012965:Sodium Chloride