(A–B) Representative images of the lesion site (delineated by white dashed lines) in the corpus callosum of control (A) and mutant (B) mice at eight dpi illustrating the enlargement of the lesion size in mutant mice compared to control mice. (C) Quantitative analysis of the lesion size at 4, 8 and 14 dpi (n = 8,9,4 control and n = 9,12,6 mutant mice respectively). (D–E) Oligodendroglia labeled by Olig2 staining within the demyelinated area at eight dpi (E) compared to control mice (D). (F) Olig2 mean cell density in healthy (CTL) or demyelinated control and mutant mice at 4, 8, 14 dpi. (G–H) Mature OLG co-labeled by Olig2/CC1 within the demyelinated lesion at eight dpi in control (G) and mutant (H) mice. (I) Quantification of mean cell density of Olig2+/CC1+ cells within the demyelination lesion in healthy (CTL) or demyelinated control and mutant mice at 4, 8, 14 dpi. (J–K) Ki67+ immunolabeling shows the proliferation status of cells within the lesion 8dpi in control (J) and mutant (K) mouse. (L) Graph represents the cell proliferation (Ki67+ cells) in mutant relative to control mice at 4 and 8 dpi (n = 9,12 control and n = 8,16 mutant mice respectively). (M–N) Co-immunolabelling of Olig2 and Ki67 showing OPC proliferation in control (M) and mutant (N) mouse 8dpi. (I) Quantification of proliferating OPC (Ki67+/olig2+ cells) in lesion sites at 4 and 8 dpi (n = 6,11 control and n = 7,13 mutant mice respectively). Error bars represent S.E.M. *p<0.05, ***p<0.001, non-parametric Mann-Whitney test (independent two group comparisons). Scale bars: 50 µm in A, B, D, E and 10 µm in, G, H, J, K, M and N. Source files of quantitative analyses are available in the Figure 4—source data 1.