Fig. 7. Increased apoptosis in the Fz5^-/- retina at E10.5. (A,B) Whole-mount mouse embryos immunostained for cleaved caspase 3 showing increased apoptosis in the ventral Fz5^-/- optic cup (arrowhead). The intact optic cup is seen from the cornea. Dorsal is upward, as indicated in A. (C-F) Horizontal sections from littermate embryos harvested 1 hour after injection with BrdU. Sections were stained with DAPI (C,D) or immunostained for BrdU and activated caspase 3 (E,F). The boxed regions in C,D show the locations of E,F. In the Fz5^-/- optic cup, many more cells and cell fragments in both the inner (future retina) and outer (future retinal pigment epithelium) layers contain activated caspase 3. Proliferation appears to be grossly normal in the Fz5^-/- optic cup.