title: The transmembrane protein Golden goal regulates R8 photoreceptor axon-axon and axon-target interactions.
abstract: During Drosophila visual system development, photoreceptor (R) axons choose their correct paths and targets in a step-wise fashion. R axons with different identities make specific pathfinding decisions at different stages during development. We show here that the transmembrane protein Golden goal (Gogo), which is dynamically expressed in all R neurons and localizes predominantly to growth cones, is required in two distinct steps of R8 photoreceptor axon pathfinding: Gogo regulates axon-axon interactions and axon-target interactions in R8 photoreceptor axons. gogo loss-of-function and gain-of-function phenotypes suggest that Gogo mediates repulsive axon-axon interaction between R8 axons to maintain their proper spacing, and it promotes axon-target recognition at the temporary layer to enable R8 axons to enter their correct target columns in the medulla. From detailed structure-function experiments, we propose that Gogo functions as a receptor that binds an unidentified ligand through its conserved extracellular domain.
authors.affiliation: Max Planck Institute of Neurobiology, Am Klopferspitz 18, D-82152 Martinsried, Germany.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Tomasi
authors.forename: Satoko
authors.initials: S
authors.lastname: Hakeda-Suzuki
authors.forename: Stephan
authors.initials: S
authors.lastname: Ohler
authors.forename: Alexander
authors.initials: A
authors.lastname: Schleiffer
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D002450:Cell Communication / Q000502:physiology*; D002460:Cell Line; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D017956:Photoreceptor Cells, Invertebrate / Q000254:growth & development* / Q000378:metabolism*; D014795:Visual Pathways / Q000254:growth & development / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D008565:Membrane Proteins