FIG. 3.

In situ detection of apoptosis in lenses from neonatal E7 transgenic mice on E2F-1-sufficient or -deficient backgrounds by using TUNEL analysis. Paraffin sections (5-μm thickness) of neonatal eyes from nontransgenic (A), E7/E2F-1^+/− (B), and E7/E2F-1^−/− (C) mice were subjected to a fluorescein-TUNEL assay and counterstained with propidium iodide. Representative sections are shown. No detectable signal was observed in control sections from which terminal deoxytransferase was omitted (data not shown). The arrowhead indicates TUNEL-positive nuclei, which are green or yellow, whereas the arrow points to TUNEL-negative nuclei, which are red. Bar, 100 μm. In all panels the anterior of the lens is oriented at the top.