title: CNS-derived glia ensheath peripheral nerves and mediate motor root development.
abstract: Motor function requires that motor axons extend from the spinal cord at regular intervals and that they are myelinated by Schwann cells. Little attention has been given to another cellular structure, the perineurium, which ensheaths the motor nerve, forming a flexible, protective barrier. Consequently, the origin of perineurial cells and their roles in motor nerve formation are poorly understood. Using time-lapse imaging in zebrafish, we show that perineurial cells are born in the CNS, arising as ventral spinal-cord glia before migrating into the periphery. In embryos lacking perineurial glia, motor neurons inappropriately migrated outside of the spinal cord and had aberrant axonal projections, indicating that perineurial glia carry out barrier and guidance functions at motor axon exit points. Additionally, reciprocal signaling between perineurial glia and Schwann cells was necessary for motor nerve ensheathment by both cell types. These insights reveal a new class of CNS-born glia that critically contributes to motor nerve development.
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Kucenas
authors.forename: Norio
authors.initials: N
authors.lastname: Takada
authors.forename: Hae-Chul
authors.initials: HC
authors.lastname: Park
authors.forename: Elvin
authors.initials: E
authors.lastname: Woodruff
authors.forename: Kendal
authors.initials: K
authors.lastname: Broadie
authors.forename: Bruce
authors.initials: B
authors.lastname: Appel
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000502:physiology*; D002454:Cell Differentiation; D002490:Central Nervous System / Q000166:cytology*; D004625:Embryo, Nonmammalian; D005399:Fishes; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D009025:Morpholines / Q000494:pharmacology; D009046:Motor Neurons / Q000502:physiology*; D009186:Myelin Sheath / Q000502:physiology* / Q000648:ultrastructure; D009457:Neuroglia / Q000502:physiology* / Q000648:ultrastructure; D010525:Peripheral Nerves / Q000166:cytology / Q000502:physiology*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D012583:Schwann Cells / Q000502:physiology / Q000648:ultrastructure; D013116:Spinal Cord / Q000166:cytology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014704:Veratrum Alkaloids / Q000494:pharmacology; D029961:Zebrafish Proteins / Q000235:genetics; D062826:Zonula Occludens-1 Protein
chemical_list: D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; D008565:Membrane Proteins; D009025:Morpholines; D010750:Phosphoproteins; D014157:Transcription Factors; D014704:Veratrum Alkaloids; D029961:Zebrafish Proteins; D062826:Zonula Occludens-1 Protein; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C037574:morpholine; C000541:cyclopamine