Functional analysis in vivo of the double mutant mouse deficient in both proteolipid protein (PLP) and myelin basic protein (MBP) in the central nervous system

Myelination is an important developmental process of the central (CNS) and peripheral nervous system (PNS). To unravel the functions of the two dominant myelin proteins in the CNS, proteolipid protein (PLP) and myelin basic protein (MBP), we generated and characterized the homozygous double mutant mouse line (plp(-/-), mbp(-/-)), which is viable and fertile. Plasma membrane processes of oligodendrocytes deficient in PLP and MBP, but not in myelin-associated glycoprotein (MAG), spirally wrap large diameter axons, tightly adhering at their extracytosolic surfaces and forming a pseudo-compacted myelin. Neuromotor activity and coordination are considerably improved compared to the shiverer trait.