Compact myelin exists in the absence of basic protein in the shiverer mutant mouse.

摘要: The myelin sheath is a multilamellar membrane system which surrounds axons in vertebrates and provides the electrical insulation necessary for saltatory nerve impulse conduction. Myelin forms from its cell of origin as flattened, membrane-bound cytoplasmic process wraps spirally around axon; periodic compact array pairs produced wrappings contents are extruded, external surfaces membranes become apposed1,2. Neurological mutant mice show abnormalities useful models examining formation, stability breakdown myelin. For example, shiverer mouse carries an autosomal recessive mutation3 (shi)4 that results severe deficiency central nervous (CNS)5,6, apparently due to defect formation5,6. small amount does form CNS generally not compacted at surfaces6, possibly low level basic protein tissue7. In peripheral (PNS), contrast, amounts seem be normal6. coarse tremor convulsions begin about 2 weeks age presumably myelin, similar neurological signs shown by other mutants with reduced myelin8. Most studies on such have concentrated those regions grossly deficient myelin5–10. seems light microscopy normal. At ultrastructural molecular level, however, this sometimes shows abnormalities11–14, has prompted us examine intensively several mutants. we used X-ray diffraction, electron SDS-polyacrylamide gel electrophoresis (SDS-PAGE). We report here that, examined so far, unique showing striking alteration composition significantly affect gross morphology lamellar organisation sheath. Our thus question proposed role proteins15–19 ‘structural cement’.