Fig. 1. Bmp7-null embryos with a microphthalmic phenotype lack a morphologically visible RF. (A-C) Lateral view of intact embryos and Cresyl Violet stained frontal (D-F) or parasagittal (G-I) sections from E12.5 (A-F) or E11.5 (G-I) wild-type (A,D,G) and Bmp7^-/- mouse embryos affected by an anophthalmic (B,E,H) or microphthalmic (C,F,I) phenotype. The anophthalmic eye is rudimentary, consisting of a small heavily pigmented neuroepithelium with no evidence of the RF (arrowheads in E,H). Embryos with a microphthalmic phenotype show a well-developed optic cup but a complete absence of the RF (arrowheads in F,I) when compared with wild-type embryos (arrows in D,G). The optic stalk is composed of two juxtaposed neuroepithelial layers (arrow in F). Scale bar: 300 µm in A-C; 100 µm in D,F; 50 µm in E,G-I.