Fig. 3. Abrogation of Vax1 and Vax2 function disrupts eye development. Stages indicated bottom left. The morpholino oligonucleotides (MOs) injected are indicated top right. (A-H) Lateral views of left eyes of living embryos with anterior to the left. Bars indicate the choroid fissure, which fails to close in the MO-injected embryos. (I-T) Toluidine blue-stained transverse sections at the level of the choroid fissure or optic nerve head. S and T show higher magnifications of K and R, respectively. Arrows indicate disorganization of cells at the choroid fissure (O,S) and the arrowhead indicates reduced retinal pigment epithelium in the ventral retina (N). (U-X) Dorsal views of Vax (U,V) and rx1 (W,X) expression with anterior to the left (compare U and V with Fig. 2G,J). Arrowheads indicate that the retinal marker rx1 is extended into the optic stalk region in the MO-injected embryos. (Y,Z) Confocal projection of DiI-labeled optic nerve with Z' showing a higher magnification of the midline of Z. Abbreviations: cf, choroid fissure; 1, lens; nr, neural retina; oc, optic chiasm; on, optic nerve; ot, optic tectum; pr, photoreceptor layer; rg, retinal ganglion cells; rpe, retinal pigment epithelium.