Figure 4.
Inhibition of oligodendrocyte differentiation and myelination persists in the adult CNS. Tamoxifen was injected in pups at P6 and P7 and CNS tissues were analyzed at P40. A, Representative confocal images showing Sox10 and CC1 double immunostaining in P40 spinal cord. B, Quantifications of Sox10+ oligodendroglial lineage cells (left) and CC1+ oligodendrocytes (right) in P40 Apcfl/fl WT (n = 6) and OCE/Apcfl/fl KO (n = 4) spinal cord. C, Plp and Cnp mRNA expression levels in P40 Apcfl/fl WT (n = 6) and OCE/Apcfl/fl KO (n = 4) spinal cord by qRT-PCR. D, Proportions of Sox10+/NG2+ OPCs and Sox10+/CC1+ OLs among total Sox10+ oligodendroglial lineage cells in P40 Apcfl/fl WT spinal cord (n = 6) (left bar) and proportions of EYFP+/Sox10+/NG2+ OPCs and EYFP+/Sox10+/CC1+ OLs among total EYFP+/Sox10+ in OCE/Apcfl/fl/Rosa-EYFP KO spinal cord (n = 4) (right bar) at P40. E, The single surviving P50 adult Cnp-Cre, Apcfl/fl mouse displayed hind-limb paralysis (left), whereas a Cnp-Cre/Apcfl/+ littermate did not (right). F, G, MBP and SMI312 double IHC revealed severe hypomyelination (SMI312+/MBP− naked axon fibers, green when overlaid) in the spinal cord dorsal horn (arrowheads) of the Cnp-Cre/Apcfl/fl mouse (G), compared with normal myelination in a Cnp-Cre/Apcfl/+ littermate (F, SMI312+/MBP+ axons, yellow when overlaid). Scale bars: 50 μm, applied to all.