Loss of Pten alters proliferation and retinal cell number. A–C, Immunolabeling of wild-type and Pten cKO retinas at E15.5 (A, A′) and P4 (B, B′) for BrdU (red). Blue is a DAPI counterstain. The graph (C) shows the number of BrdU+ cells in wild-type and Pten cKO retinas at E12.5, E15.5, E18.5, and P4. D–F, Immunolabeling of wild-type and Pten cKO retinas at E15.5 (D, D′) and P4 (E, E′) for pHH3 (red). The graph (F) shows the number of pHH3+ cells in wild-type and Pten cKOs at E12.5, E15.5, E18.5, and P4. G–L, DAPI staining of wild-type and Pten cKO retinas at E15.5 (G, G′), E18.5 (I, I′), and P7 (K, K′). The total number of cells in wild-type and Pten cKO retinas at three different stages are shown in the graphs (H, J, L). M–R, Immunolabeling of P7 wild-type and Pten cKO retinas for BrdU after administering at E12.5 (M, M′), E14.5 (O, O′), and E18.5 (Q, Q′). The graphs show the percentages of BrdU+ cells in each retinal layer (left) and the total number of BrdU+ cells (right; N, P, R). *p < 0.05; **p < 0.01; ***p < 0.001.