Axonal swellings and degeneration in mice lacking the major proteolipid of myelin.
Glial cells produce myelin and contribute to axonal morphology in the nervous system. Two myelin membrane proteolipids, PLP and DM20, were shown to be essential for the integrity of myelinated axons. In the absence of PLP-DM20, mice assembled compact myelin sheaths but subsequently developed widespread axonal swellings and degeneration, associated predominantly with small-caliber nerve fibers. Similar swellings were absent in dysmyelinated shiverer mice, which lack myelin basic protein (MBP), but recurred in MBP*PLP double mutants. Thus, fiber degeneration, which was probably secondary to impaired axonal transport, could indicate that myelinated axons require local oligodendroglial support.
Griffiths
I
I
Applied Neurobiology Group, Department of Veterinary Clinical Studies, University of Glasgow, Glasgow G61 1QH, Scotland, UK.
Klugmann
M
M
Anderson
T
T
Yool
D
D
Thomson
C
C
Schwab
M H
MH
Schneider
A
A
Zimmermann
F
F
McCulloch
M
M
Nadon
N
N
Nave
K A
KA
D000818:Animals; D001370:Axonal Transport; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure*; D002450:Cell Communication; D002490:Central Nervous System / Q000648:ultrastructure*; D005260:Female; D051379:Mice; D008818:Mice, Neurologic Mutants; D008959:Models, Neurological; D009043:Motor Activity; D018991:Myelin Proteolipid Protein / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D009186:Myelin Sheath / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D009410:Nerve Degeneration / Q000473:pathology*; D009419:Nerve Tissue Proteins; D009836:Oligodendroglia / Q000502:physiology; D009900:Optic Nerve / Q000648:ultrastructure; D015388:Organelles / Q000648:ultrastructure; D013116:Spinal Cord / Q000648:ultrastructure; D019076:Transgenes
D018991:Myelin Proteolipid Protein; D009419:Nerve Tissue Proteins; C047516:Plp1 protein, mouse