title: Behavioral Analysis of Bitter Taste Perception in Drosophila Larvae.
abstract: Insect larvae, which recognize food sources through chemosensory cues, are a major source of global agricultural loss. Gustation is an important factor that determines feeding behavior, and the gustatory receptors (Grs) act as molecular receptors that recognize diverse chemicals in gustatory receptor neurons (GRNs). The behavior of Drosophila larvae is relatively simpler than the adult fly, and a gustatory receptor-to-neuron map was established in a previous study of the major external larval head sensory organs. Here, we extensively study the bitter taste responses of larvae using 2-choice behavioral assays. First, we tested a panel of 23 candidate bitter compounds to compare the behavioral responses of larvae and adults. We define 9 bitter compounds which elicit aversive behavior in a dose-dependent manner. A functional map of the larval GRNs was constructed with the use of Gr-GAL4 lines that drive expression of UAS-tetanus toxin and UAS-VR1 in specific gustatory neurons to identify bitter tastants-GRN combinations by suppressing and activating discrete subsets of taste neurons, respectively. Our results suggest that many gustatory neurons act cooperatively in larval bitter sensing, and that these neurons have different degrees of responsiveness to different bitter compounds.
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea and.
authors.forename: Haein
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea and.
authors.forename: Min Sung
authors.initials: MS
authors.lastname: Choi
authors.affiliation: Samsung Biomedical Research Institute, Department of Anatomy and Cell Biology, School of Medicine, Sungkyunkwan University, Suwon 16419, Republic of Korea.
authors.forename: KyeongJin
authors.initials: K
authors.lastname: Kang
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea and jykwon@skku.edu.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Kwon
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D004331:Drosophila melanogaster / Q000254:growth & development / Q000502:physiology*; D007814:Larva / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000502:physiology; D013649:Taste / Q000502:physiology; D055697:Taste Perception / Q000502:physiology*
keywords: Drosophila; bitter; gustatory receptor neurons; gustatory receptors; larva; taste