Immunocytochemical investigations of murine leukodystrophies. A study of the mutants 'jimpy' (jp) and 'myelin deficient' (mld).

Sections of the central nervous system of the leukodystrophic mouse mutants 'jimpy' (jp) and 'myelin deficient' (mld), as well as of healthy littermates, were immunostained for glial fibrillary acidic protein (GFA), myelin basic protein (MBP) and myelin-associated glycoprotein (MAG). Adjacent sections were stained conventionally for myelin. In jp, GFA-stained astrocytes were abnormally prominent already at the age of 12 days. A considerable amount of MBP and MAG was present in the vicinity of axons, although no myelin was visible in the conventional stains for myelin. In mld, GFA-staining astrocytes were present in normal numbers. MAG could be demonstrated in its normal localization along axons, but MBP was visible only in the comparatively old animal (85 days). Here, it was demonstrated in an abnormal site--the perikarya and the proximal parts of the processes of oligodendrocytes. Thin myelin sheaths present in this animal could not be stained for MBP.