Peripheral nervous system of shiverer mutant mice: developmental change of myelin components and immunohistochemical demonstration of the absence of MBP and presence of P2 protein

Abstract

Peripheral nerves of the shiverer mouse, which are characterized by the absence of major dense lines and myelin basic proteins in CNS myelin, were analyzed. From subcellular fractionation of sciatic nerves, it was found from the SDS-polyacrylamide gel electrophoresis that the Pl and Pr proteins equivalent to myelin basic protein of CNS and PM protein were missing in the shiverer in both P2A and P3A fractions in which PNS myelin is recovered. No extra bands were observed in any other fractions of the shiverer in place of the absence of the proteins. The activities of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) of P2A and P3A fractions were high, but that of the P3X fraction which floated over 0.32 M sucrose was the highest among the fractions examined in both the shiverer and the control. Developmental analysis of the protein profiles revealed that PO, Pl, Pr and PM proteins increased rapidly from the sixth day postnatally up to the twentieth day after birth in the control. No differences were observed between the shiverer and the control as for PO protein, but Pl, Pr and PM proteins were absent in the shiverer throughout the development. The CNPase activity of total homogenate of sciatic nerve fibers at birth in the control showed high activity comparable to that of the adult value, but there was no significant difference in activity between the control and the shiverer at any stage of development. Immunohistochemical reaction using peroxidase anti-peroxidase method showed that the myelin from the shiverer did not react with the MBP antiserum, while that of the control reacted positively. On the contrary, the myelin from both shiverer and the control reacted positively against P2 antibody.