Apc deletion reduces OPC proliferation. Tamoxifen was injected in pups at P6 and P7 and CNS tissues were analyzed as indicated. A1–A5, Confocal images of PH3/Ki67 and PH3/SOX10/NG2 immunostaining and quantifications of cells positive for these markers in Apcfl/fl WT and OCE/Apcfl/fl KO (n = 3 WT, 3 KO at P8; n = 10 WT, 7 KO at P14). B1, B2, Representative confocal images of EdU (2 h labeling). C, The number of Sox10+/NG2+ OPCs in the spinal WM and GM of P14 Apcfl/fl WT (n = 10) and OCE/Apcfl/fl KO mice (n = 7). D, Western blot of cyclin D1 in P14 spinal cord. E, Quantification of cyclin D1 protein (left) and mRNA (right) levels in P14 Apcfl/fl WT (n = 4) and OCE/Apcfl/fl KO (n = 4) mice. Scale bars: A1–A4, 10 μm; B1, B2, 50 μm.