Fine structure analysis of lens fiber cell abnormalities in the dnBrg1 transgenic lens. Semithin sections (A, B, and E) and transmission electron microscopy (C, D, and F) of dnBrg1 transgenic lenses (A-D) and that of wild-type littermates (E and F). (A) In lenses of dnBrg1 transgenic animals, the fibers in the core of the lens are completely disrupted and replaced by amorphous material (asterisk). At the posterior pole of the lens, fibers do not contact each other (black arrows). The boxed area is shown at higher magnification in (B). (B) Lens fibers next to the central amorphous zone contain intensely labeled granular material close to their cell border, as well as some nuclei (black arrows). Nuclei are more frequent in more peripheral lens fibers (white arrows). (C) Nuclei (white arrow) of peripheral lens fibers show a homogeneous structure containing nucleoli. (D) Lens fibers that are localized more closely to the core contain numerous electron-dense granules with an average diameter of about 500 nm. Nuclei (white arrow) contain electron-dense granules of a size comparable to those seen in the peripheral cytoplasm, as well as numerous fine electron-dense particles that are considerably smaller. (E and F) Fibers of wild-type lenses show an overall ordered organization. Note that nuclei are only present in and next to the bow region. Scale bars, 100 μm (A and E); 10 μm (B); 5 μm (C, D and F).