Lens differentiation is normal under Rap1 deficiency. To test whether Rap1 deficiency influences lens differentiation, E17.5 ocular specimens derived from Rap1 cKO mouse embryos along with their respective WT specimens were examined by immunofluorescence analysis for expression profile of lens fiber specific markers including aquaporin-0 (green) and γ-crystallin (red). As shown in the figure, the distribution profile of various fiber cell differentiation markers was found to be comparable between the Rap1 cKO and WT specimens, indicating that Rap1 deficiency does not impact normal lens differentiation. In some Rap1 cKO specimens, there was aquaporin-0 positive staining at the apical surface of lens epithelium as indicated by the arrows. Bar represents image magnification. LE: Lens epithelium, LF: Lens fibers.