Figure 3. In situ hybridization of the human Hes 1 gene. In both the central corneal epithelium (A) and the limbal epithelium (B), expression of Hes1 is seen predominantly in the basal layer with some extension into the suprabasal layers. The intensity of the staining was slightly lower in the limbus. The areas with darker staining observed in the limbal basal epithelium (arrows) actually represent underlying pigmentation of the tissue. The pigmented cells in the limbus are seen more clearly in C, which represents the same section in B without the purple staining. Minimal non-specific staining is observed in the sense control in the central cornea (D). Bar=30 μm.