Myelin messenger ribonucleic acids : their association with the cytoskeleton and their subcellular distribution

Abstract

This work presents an examination of the subcellular localization of the major myelin proteins of oligodendrocytes, and the messages that encode these proteins. The association of these messages with the cytoskeleton is also examined. All messages investigated show some degree of association with the cytoskeleton; Indeed messages encoding actin and tubulin are found exclusively bound to the cytoskeleton. In general a specific myelin message and its protein counterpart are found in the same area of the cell. This suggests that these messages are translated close to their targetted site. In most Instances the messages being probed by in situ hybridization are being sought for the first time in cells grown in tissue culture, and in some instances messages are being probed for the first time ever. In addition, the messages encoding DM-20 and PLP are found in different areas of the cell. As these are the products of a single gene, this suggests that there is a significant role to be played by differential splicing in individual cells. The role of cytoske1eton-mRNA association in the targetting and assembly of myelin proteins is discussed.