title: Glial cells mediate target layer selection of retinal axons in the developing visual system of Drosophila.
abstract: In the fly visual system, each class of photoreceptor neurons (R cells) projects to a different synaptic layer in the brain. R1-R6 axons terminate in the lamina, while R7 and R8 axons pass through the lamina and stop in the medulla. As R cell axons enter the lamina, they encounter both glial cells and neurons. The cellular requirement for R1-R6 targeting was determined using loss-of-function mutations affecting different cell types in the lamina. nonstop (encoding a ubiquitin-specific protease) is required for glial cell development and hedgehog for neuronal development. Removal of glial cells but not neurons disrupts R1-R6 targeting. We propose that glial cells provide the initial stop signal promoting growth cone termination in the lamina. These findings uncover a novel function for neuron-glial interactions in regulating target specificity.
authors.affiliation: Lehrstuhl für Entwicklungsbiologie, Institut für Zoologie, Universität Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Poeck
authors.forename: S
authors.initials: S
authors.lastname: Fischer
authors.forename: D
authors.initials: D
authors.lastname: Gunning
authors.forename: S L
authors.initials: SL
authors.lastname: Zipursky
authors.forename: I
authors.initials: I
authors.lastname: Salecker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001369:Axons / Q000378:metabolism*; D002465:Cell Movement / Q000235:genetics; D004330:Drosophila; D029721:Drosophila Proteins; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D005123:Eye / Q000166:cytology / Q000254:growth & development*; D020439:Growth Cones; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology; D012160:Retina / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D014452:Ubiquitins / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D019476:Insect Proteins; D014452:Ubiquitins; D010450:Endopeptidases; C421164:not protein, Drosophila