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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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Base Sequence
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Biological Transport
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Cells, Cultured
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Cloning, Molecular
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Drosophila / embryology
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Drosophila / genetics
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Drosophila / physiology*
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Electrophysiology / methods
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Esterases / genetics
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Esterases / physiology
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Genes, Insect / genetics
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Hemolymph / physiology
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Immunohistochemistry
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In Situ Hybridization
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Membrane Potentials / physiology
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Membrane Proteins / genetics
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Membrane Proteins / physiology*
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Microscopy, Electron
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Molecular Sequence Data
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Mutagenesis
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / physiology*
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Nervous System / chemistry
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Nervous System / ultrastructure
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Nervous System Physiological Phenomena*
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Neuroglia / chemistry
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Neuroglia / physiology*
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Neuroglia / ultrastructure
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Potassium / metabolism
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Ruthenium Red / metabolism
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Sequence Homology, Amino Acid
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Synaptic Transmission / physiology*
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Tissue Distribution
Substances
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Membrane Proteins
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Nerve Tissue Proteins
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gliotactin
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Ruthenium Red
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Esterases
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serine esterase
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Potassium