Figure 6.

Canonical Wnt-Fz/β-catenin signaling is not a feature of FGF-induced fiber differentiation. Lens epithelial explants prepared from the TCF/Lef reporter mouse line were cultured for 4 days with no added factors (A, C) or 200 ng/mL FGF-2 (B, D). Low-power images stained for β-galactosidase to detect TCF/Lef reporter activity show that it is not detectable in lens cells of control or FGF-treated explants. Note that remnants of ciliary body associated with the peripheral capsule in the explants show strong blue coloration and act as a positive control for Wnt-Fz/β-catenin signaling (A, B). Higher power images show that control (C) explants retain the characteristic lens epithelial cobblestone packing arrangement whereas FGF-treated (D) show early fiber elongation changes. A sagittal section of a TCF/Lef mouse eye stained for β-galactosidase (E) shows prominent blue staining in the ciliary body (cb) but no blue staining in the lens fibers.