title: Gliotactin, a novel transmembrane protein on peripheral glia, is required to form the blood-nerve barrier in Drosophila.
abstract: Peripheral glia help ensure that motor and sensory axons are bathed in the appropriate ionic and biochemical environment. In Drosophila, peripheral glia help shield these axons against the high K+ concentration of the hemolymph, which would largely abolish their excitability. Here, we describe the molecular genetic analysis of gliotactin, a novel transmembrane protein that is transiently expressed on peripheral glia and that is required for the formation of the peripheral blood-nerve barrier. In gliotactin mutant embryos, the peripheral glia develop normally in many respects, except that ultrastructurally and physiologically they do not form a complete blood-nerve barrier. As a result, peripheral motor axons are exposed to the high K+ hemolymph, action potentials fail to propagate, and the embryos are nearly paralyzed.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
authors.forename: V J
authors.initials: VJ
authors.lastname: Auld
authors.forename: R D
authors.initials: RD
authors.lastname: Fetter
authors.forename: K
authors.initials: K
authors.lastname: Broadie
authors.forename: C S
authors.initials: CS
authors.lastname: Goodman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000502:physiology*; D004594:Electrophysiology / Q000379:methods; D004950:Esterases / Q000235:genetics / Q000502:physiology; D017344:Genes, Insect / Q000235:genetics; D006458:Hemolymph / Q000502:physiology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008564:Membrane Potentials / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D009420:Nervous System / Q000737:chemistry / Q000648:ultrastructure; D009424:Nervous System Physiological Phenomena; D009457:Neuroglia / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D011188:Potassium / Q000378:metabolism; D012430:Ruthenium Red / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D009435:Synaptic Transmission / Q000502:physiology*; D014018:Tissue Distribution
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C094064:gliotactin; D012430:Ruthenium Red; D004950:Esterases; C022635:serine esterase; D011188:Potassium