title: Neurotrophic and gliatrophic contexts in Drosophila.
abstract: Trophic interactions in the vertebrate nervous system enable the adjustment of cell number and axon guidance, targeting and connectivity. Computational analysis of the sequenced Drosophila genome failed to identify some of the main trophic factors, the neuregulins and neurotrophins, as well as many other genes. This provoked speculations that the Drosophila nervous system might not require such regulative interactions. Here we review abundant cellular, genetic and functional data that demonstrate the existence of both neurotrophic and gliatrophic interactions in the Drosophila nervous system. Glial survival is maintained by the epidermal growth factor receptor (EGFR) signaling pathway in response to the ligands Spitz, a transforming growth factor-alpha (TGF-alpha) signaling molecule, and Vein, a neuregulin homologue. Cellular and genetic evidence predicts the existence of neuronal trophic factors operating at least in the Drosophila embryo during axon guidance and, in the visual system, during the targeting of retinal axons in the brain.
authors.affiliation: Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, UK. a.hidalgo@bham.ac.uk
authors.forename: Alicia
authors.initials: A
authors.lastname: Hidalgo
authors.forename: Anabel R
authors.initials: AR
authors.lastname: Learte
authors.forename: Peter
authors.initials: P
authors.lastname: McQuilton
authors.forename: Jenny
authors.initials: J
authors.lastname: Pennack
authors.forename: Bangfu
authors.initials: B
authors.lastname: Zhu
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D004330:Drosophila / Q000254:growth & development / Q000502:physiology*; D029721:Drosophila Proteins / Q000502:physiology*; D009414:Nerve Growth Factors / Q000502:physiology*; D009420:Nervous System / Q000254:growth & development / Q000378:metabolism; D020880:Neuregulins / Q000502:physiology; D009457:Neuroglia / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins; D009414:Nerve Growth Factors; D020880:Neuregulins; C086179:spz protein, Drosophila; C102104:vn protein, Drosophila