title: Serotonergic neurons respond to nutrients and regulate the timing of steroid hormone biosynthesis in Drosophila.
abstract: The temporal transition of development is flexibly coordinated in the context of the nutrient environment, and this coordination is essential for organisms to increase their survival fitness and reproductive success. Steroid hormone, a key player of the juvenile-to-adult transition, is biosynthesized in a nutrient-dependent manner; however, the underlying genetic mechanism remains unclear. Here we report that the biosynthesis of insect steroid hormone, ecdysteroid, is regulated by a subset of serotonergic neurons in Drosophila melanogaster. These neurons directly innervate the prothoracic gland (PG), an ecdysteroid-producing organ and share tracts with the stomatogastric nervous system. Interestingly, the projecting neurites morphologically respond to nutrient conditions. Moreover, reduced activity of the PG-innervating neurons or of serotonin signalling in the PG strongly correlates with a delayed developmental transition. Our results suggest that serotonergic neurons form a link between the external environment and the internal endocrine system by adaptively tuning the timing of steroid hormone biosynthesis.
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba 305-8572, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimada-Niwa
authors.affiliation: 1] Faculty of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba 305-8572, Japan [2] PRESTO, JST, 4-1-8 Honcho, Kawaguchi 332-0012, Japan.
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Niwa
mesh_terms: D000818:Animals; D004032:Diet; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D026461:Ecdysteroids / Q000096:biosynthesis* / Q000235:genetics; D005088:Exocrine Glands / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D009420:Nervous System / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D016501:Neurites / Q000378:metabolism / Q000648:ultrastructure; D011985:Receptors, Serotonin / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D059326:Serotonergic Neurons / Q000378:metabolism* / Q000648:ultrastructure; D012701:Serotonin / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D029721:Drosophila Proteins; D026461:Ecdysteroids; D011985:Receptors, Serotonin; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D012701:Serotonin