MYELINATION - COORDINATED REGULATION OF MANY MOLECULAR-ELEMENTS

The formation of the myelin sheath requires the coordinated regulation of a number of gene products, both glial and axonal. These include th e myelin structural genes, enzymes involved in lipid biosynthetic path ways, transcriptional regulators, trophic and recognition factors. Alt erations in gene dosage or gene expression timing can have profoundly deleterious effects on either the establishment or maintenance of the myelin sheath. In this review, the major structural genes are describe d, as are the consequences of changes in gene dosage which occur as a result of either natural mutations or experimentally mediated events. While it is clear that our knowledge has expanded greatly with regard to these events, there continue to be large gaps, especially within th e genetics of gene regulation and the mechanisms of glial axon interac tions. (C) 1998 Wiley-Liss, Inc.