Fig. 1.

Cellular localization of p27 in the mouse retina during postnatal development. a Immunofluorescence for p27 in the wild-type (WT) and p27 knockout (KO) retinas at P0, P6 and P21. At P0, the ganglion cell layer (*), amacrine cell layer (**), and photoreceptor layer (***) are intensely immunoreactive. p27 is detected in all nuclear layers at P6 and P21. Arrowheads indicate Müller glia with intense immunoreactivity. No staining is observed in the KO retinas showing antibody specificity. b p27 expression in cones and horizontal cells in the P0 retinas. Double immunofluorescence for p27 in combination with the cone markers S-opsin and RXRγ and horizontal cell marker calbindin (Calb) showing colocalization (arrows). c P21 mouse retinas showing expression of p27 in Brn3+ ganglion cells, syntaxin (Syn) + amacrine cells, Sox9+ Müller glia, Chx10+ bipolar cells, calbindin (Calb) + horizontal cells, and RXRγ + cones. Arrows indicate colocalization. NBL, neuroblastic layer; GCL, ganglion cell layer; ONL, outer nuclear layer; INL, inner nuclear layer. Scale bars = 20 μm