Fig. 3. Proliferation and cell death in Cited2^-/- lens. (A-C) Proliferation of the developing mouse lens at 10.5 dpc was examined by phosphorylated histone H3 immunostaining (green) and counterstained with DAPI (blue). No significant difference in proliferation was detected between Cited2^+/+ littermate controls (A) (n=3) and Cited2^-/- lens (B) (n=5); the data are summarized in C (P>0.05). (D-F) Cell death of the developing lens at 10.5 dpc was examined by the TUNEL assay. For counting cell number, sections were counterstained with DAPI to reveal nuclei (data not shown). Compared with Cited2^+/+ littermate controls (D) (n=3), increased cell death was observed in Cited2^-/- lens (E) (n=5); the data are summarized in F (P<0.01).