Fig. 3.

Temporal sequence of the ocular phenotype in whole-mount Sox2^HYP embryos. (A and D) Lateral views of E10.5 whole mount Sox2^EGFP/+ (A) and Sox2^HYP (D) heads. In Sox2^EGFP/+ embryos, the ring of the distal optic cup (OC) can be seen ventral and posterior to the telencephalic vesicle (T), contacting the surface ectoderm. The SOX2-positive lens is visible in the center of the ring. In contrast, the ventral aspect of the distal OC is not visible in the Sox2^HYP embryo (red arrow, D). (B and E) Lateral views of E13.5 whole mount Sox2^EGFP/+ (B) and Sox2^HYP (E) eyes. In the Sox2^EGFP/+ embryo, the black retinal pigment epithelium surrounds the entire outer surface of the eye. In contrast, the ventral optic fissure of the Sox2^HYP eye has failed to close, a defect referred to as coloboma (red arrowhead, E). (C and F) E14.5 whole mount Sox2^CONT (C) and Sox2^HYP (F) embryos. A round, symmetric eye with a visible lens is present in the Sox2^CONT embryo, whereas only a remnant of the retinal pigmented epithelium can be seen in the Sox2^HYP embryo.