Fig. 3.

Prdx6^−/−-deficient cells, which are highly vulnerable to UV-B radiation exposure, undergo apoptosis. Cells were cultured in DMEM + 10% fetal bovine serum (FBS) in 60-mm petri dishes. The day after culturing, cells were exposed to UV-B radiation (800 J/m²). After a 24-h recovery period, cells were stained with either TdT-mediated dUTP-biotin nick end-labeling (TUNEL; A, top) or Hoechst (A, bottom) and photomicrographed. A significant number of apoptotic cell deaths were seen in Prdx6^−/− cells (A, b and d). B: % of apoptotic cells/100 Hoechst-stained nuclei. *P < 0.04, **P < 0.001.