Fig. 4

Gli1 cell distribution becomes restricted over postnatal development. A-E tdTom (red) expression in Gli1^CreER/+;Ai14 tissues that received tamoxifen at P0 (A), P3 (B), P7 (C), P14 (D), P28 (E) and as adults (F) and analyzed at ages shown. Adult mice were analyzed two weeks after tamoxifen. Counterstaining with DAPI (blue). Scale bar, 100 μm. G The fraction of marked cells in each layer in mice that received tamoxifen at P0 or in adulthood. H The fraction of all astrocytes across all layers that are marked at various ages. Bars represent mean ± SEM, data points represent individual animals (n = 3 animals per age). Statistical analysis performed by one-way ANOVA with Tukey’s post-hoc test for multiple comparisons. ** p < 0.005, ** p < 0.0005 compared to P0. I-L Single channel, confocal images of tdTom (I, red) and BrdU (J, green) identifying marked cells that are proliferating. Counterstained with DAPI (K, blue). Merged image shown in L. Scale bar, 25 μm. M The fraction of marked cells colabeled with BrdU at P14 in tissues marked at P0, P3 and P7 (n = 919 cells, n = 720 cells, n = 566 cells, respectively, from 2 to 4 animals). Bars represent mean ± SEM, data points represent individual animals. Statistical analysis performed by one-way ANOVA with Tukey’s post-hoc test for multiple comparisons. N-O Brightfield immunostaining for βGal in Gli1^nlacZ/+ tissues from mice at (N) P3 and (O) P14. Scale bar, 50 μm. P Estimated total number of Gli1-expressing cells derived from stereological quantification of βGal labeled cells in the cortex of Gli1^nlacZ/+ mice at various ages. Bars represent mean ± SEM, data points represent individual animals (n = 3–8 animals per age). Statistical analysis performed by one-way ANOVA with Tukey’s post-hoc test for multiple comparisons