Myelin Proteolipid Protein Expression in Normal and Jimpy Mice

Abstract

The myelin membrane is a highly specialized extension of the oligo-dendroglial plasma membrane, which surrounds axons and forms a tightly compacted multilamellar structure (Peters et al., 1970). Myelin integrity is essential for normal nervous system function, and understanding the mechanism of myelin formation is important because of the large number of clinical problems observed when normal myelin formation is altered (Adams and Victor, 1970). Oligodendrocyte differentiation and myelin formation have become important developmental problems to investigate at the molecular level for several reasons. Oligodendrocyte differentiation occurs over a narrow time period during brain development, indicating that it is tightly developmentally regulated. Since the myelin membrane has a somewhat simple protein composition, with the proteolipid protein (PLP) and myelin basic protein (MBP) comprising 70–80% of adult CNS myelin protein (Eng et al., 1968; Norton and Poduslo, 1973) a major portion of the oligodendrocyte differentiation program is dedicated to the synthesis of these two groups of proteins.