Matthieu J M
Bull Schweiz Akad Med Wiss. 1981:101-8.
A purified myelin fraction was prepared from myelin deficient (mld) mutant mice and normal littermates (20 to 25 days old). Mld brains contained only 5% of the amount of myelin present in controls. Myelin isolated from mld brains had a normal lipid and protein content. The lipid composition of mld myelin was also normal. Myelin basic protein (MBP) was nearly missing in mld myelin. At the electron microscope, in mld myelin, the major dense line was often missing and the myelin lamellae were uncompacted. The high specific radioactivity of the myelin associated glycoprotein and sulfatides, two myelin constituents which are not affected by the mutation, indicate a high turnover rate of myelin membranes in the mld mutant. Furthermore, the presence of increased amounts of cholesterol esters in mld brains suggests that myelin in mld mutants is unstable. We propose that MBP, which is responsible in the central nervous system for myelin compaction, is responsible for the stability of this membrane.
从髓鞘缺陷（mld）突变小鼠和正常同窝仔鼠（20至25日龄）制备纯化的髓鞘组分。mld小鼠脑内的髓鞘含量仅为对照的5%。从mld小鼠脑内分离出的髓鞘具有正常的脂质和蛋白质含量。mld髓鞘的脂质组成也正常。髓鞘碱性蛋白（MBP）在mld髓鞘中几乎缺失。在电子显微镜下，mld髓鞘中的主致密线常常缺失，髓鞘板层疏松。髓鞘相关糖蛋白和硫脂这两种不受该突变影响的髓鞘成分具有高比放射性，表明mld突变体中髓鞘膜的更新率很高。此外，mld小鼠脑中胆固醇酯含量增加表明mld突变体中的髓鞘不稳定。我们认为，在中枢神经系统中负责髓鞘压实的MBP对该膜的稳定性起作用。
