Figure 1.
Heterozygote, 4-mo-old mouse CNS, expressing wild-type and null alleles of the Plp gene, immunostained for PLP/DM20. (A) Ventral column of spinal cord to show mosaic of wild-type myelin (positively stained) and myelin formed by oligodendrocytes expressing a null allele (no staining); the former predominate. (B) Optic nerve to show mosaic of positive and negative sheaths in conjunction with patches predominantly of one immunotype. Bars: (A) 20 μm; (B) 50 μm.