Fig. 4: Med23 deletion impairs OL maturation.

a In situ hybridization for Pdgfra in spinal cord sections of Ctrl and Med23cKO mice at P1. Scale bars: 100 μm. b Quantification of Pdgfra⁺ cells per area of the spinal cord in Ctrl and Med23cKO mice at P1. c Co-immunolabeling of CC1 and Olig2 in the corpus callosum (CC), white matter (SC-WM), and gray matter (SC-WM) of the spinal cord of Ctrl and Med23cKO mice at P14. Scale bars: 100 μm. d Quantification of CC1⁺ OLs per area in the corpus callosum, white matter, and gray matter of the spinal cord of Ctrl and Med23cKO mice at P14. e Western blot analysis of myelin protein and GFAP levels in the cortex (CTX), hippocampus (HP), pons (PON), and cerebellum (CB) of Ctrl and Med23cKO mice at P14. β-Actin was used as the internal control. f Representative images showing cell morphological differences between Ctrl and Med23^–/– cells at the indicated differentiation stages as revealed by static staining. Scale bars: 50 μm. g Immunostaining for NG2 and CNP in Ctrl and Med23^–/– OPCs cultured in differentiation medium for 1 day and 3 days. White arrows indicate the CNP⁺NG2^– cells. Scale bars, 50 μm. h Quantification of CNP⁺NG2^– OLs as a percentage of total DAPI⁺ cells in the Ctrl and Med23^–/– OPC population that were cultured in differentiation medium in vitro for 1 day and 3 days. i Immunostaining for MBP, CC1, and Olig2 in Ctrl and Med23^–/– OPCs cultured in differentiation medium for 3 days. Scale bars: 50 μm. j, k The proportions of MBP⁺ (j) or CC1⁺ (k) OL differentiated from Ctrl and Med23^–/– OPCs cultured in differentiation medium for 3 days. The data are presented as the mean ± SEM; n = 3 animals/genotype or n = 3 independent experiments. Two-tailed unpaired Student’s t-test, *P < 0.05, **P < 0.01, and ***P < 0.001.