Expression of retinal epithelium and RPE markers in β-catenin gain-of-function embryos. Immunolabeling for Chx10 (red; A-H) and Mitf (red; I-P) on cryosections from control (A, C, E, G, I, K, M, O) and Lens-cre; Catnblox(ex3) mutant (B, D, F, H, J, L, N, P) embryos at the ages indicated. Immunofluorescence for F-actin is also shown (green) with Hoechst 33258 nuclear labeling (blue). White arrowheads in (D, F) indicate area of expanded Chx10 expression. (L, N) White arrows indicate areas with diminished Mitf activity. Labeling abbreviations as in Fig. 1.