Fluorescent in situ hybridization staining for Fgf15 (A, B), Tbx3 (C, D) and Gdf6 (E, F) in E10.5 eyes from wild type and Bmp4CKO embryos. In all cases staining was greatly decreased or undetectable in the prospective retina (distal optic vesicle) of Bmp4CKO embryos. Cells in the dorsal half of the wild type lens vesicle also expressed Gdf6, which was greatly decreased in the surface ectoderm of Bmp4CKO embryos. For all sections, dorsal is to the left. R, retina; PR, prospective retina.