title: Identification of a novel gene, anorexia, regulating feeding activity via insulin signaling in Drosophila melanogaster.
abstract: Feeding activities of animals, including insects, are influenced by various signals from the external environment, internal energy status, and physiological conditions. Full understanding of how such signals are integrated to regulate feeding activities has, however, been hampered by a lack of knowledge about the genes involved. Here, we identified an anorexic Drosophila melanogaster mutant (GS1189) in which the expression of a newly identified gene, Anorexia (Anox), is mutated. In Drosophila larvae, Anox encodes an acyl-CoA binding protein with an ankyrin repeat domain that is expressed in the cephalic chemosensory organs and various neurons in the central nervous system (CNS). Loss of its expression or disturbance of neural transmission in Anox-expressing cells decreased feeding activity. Conversely, overexpression of Anox in the CNS increased food intake. We further found that Anox regulates expression of the insulin receptor gene (dInR); overexpression and knockdown of Anox in the CNS, respectively, elevated and repressed dInR expression, which altered larval feeding activity in parallel with Anox expression levels. Anox mutant adults also showed significant repression of sugar-induced nerve responses and feeding potencies. Although Anox expression levels did not depend on the fasting and feeding states cycle, stressors such as high temperature and desiccation significantly repressed its expression levels. These results strongly suggest that Anox is essential for gustatory sensation and food intake of Drosophila through regulation of the insulin signaling activity that is directly regulated by internal nutrition status. Therefore, the mutant strain lacking Anox expression cannot enhance feeding potencies even under starvation.
authors.affiliation: Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan.
authors.forename: Masasuke
authors.initials: M
authors.lastname: Ryuda
authors.affiliation: Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Tsuzuki
authors.affiliation: Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Oda
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 812-8581, Japan.
authors.forename: Teiichi
authors.initials: T
authors.lastname: Tanimura
authors.affiliation: Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan. Electronic address: hayakayo@cc.saga-u.ac.jp.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hayakawa
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D002490:Central Nervous System / Q000196:embryology; D026261:Diazepam Binding Inhibitor / Q000737:chemistry; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000737:chemistry* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000378:metabolism*; D004594:Electrophysiology / Q000379:methods; D005247:Feeding Behavior; D018507:Gene Expression Regulation, Developmental; D015151:Immunoblotting; D007328:Insulin / Q000378:metabolism; D010641:Phenotype; D017434:Protein Structure, Tertiary; D015398:Signal Transduction
chemical_list: C569110:Anox protein, Drosophila; D002352:Carrier Proteins; D026261:Diazepam Binding Inhibitor; D029721:Drosophila Proteins; D007328:Insulin