Fig. 5

The fate of dividing cells in the p27 knockout retinas. a Experimental scheme of BrdU incorporation assays indicating the postnatal stages of BrdU injection and sacrifice. b Single staining for BrdU in the P21 retinas treated with BrdU at P6 and P9. Arrows indicate positive cells in the outer nuclear layer (ONL). c P21 retina (BrdU injected at P6) double-stained for BrdU and the rod marker NR2E3 showing colocalization (arrows). d P21 retina (BrdU injected at P6) double-stained for BrdU and the cone marker M-opsin. No colabeling is observed. e Triple immunofluorescence for BrdU, Chx10 and Sox9 in the P21 retinas injected with BrdU at P6. Arrows indicate BrdU+ Müller glia labeled weakly for Chx10 and intensely for Sox9. Arrowheads denote BrdU+ bipolar cells expressing Chx10 but not Sox9. f P21 retina (BrdU injected at P6) double-labeled for BrdU and the bipolar marker PKCα (PKC) showing colocalization (arrows). g P21 retina (BrdU injected at P6) double-labeled for BrdU and the Müller marker glutamine synthetase (GS) showing colocalization (arrows). h Quantification of the cell types which were in the last S-phase at the time of BrdU injection. Rods were identified by NR2E3 labeling, and bipolar and Müller cells were determined based on the expression of Chx10 and Sox9. Each bar represents the mean ± SEM (n = 3 per stage). GCL, ganglion cell layer; INL, inner nuclear layer. Scale bars = 20 μm