Immunohistochemical analysis of collagen type I expression (FITC). Wild-type (A), Smad3-/- (B), TGF-β1/Smad3+/+ (C, E), and TGF-β1/Smad3-/- (D, F) lenses are shown. Arrows: subcapsular plaques. Expression of collagen type I was detected in the subcapsular plaques of the TGF-β1/Smad3+/+ and TGF-β1/Smad3-/- lenses. There was no observable difference in collagen I expression between the TGF-β1/Smad3-/- and TGF-β1/Smad3+/+ lenses. Both the wild-type and Smad3-/- lenses show no expression of collagen type I in the lens. Scale bars: (A-D) 100 μm; (E, F) 50 μm.