Figure 3. Levels of DNA damage and cell proliferation in spleen, thymus, liver, lung and kidney tissues of 7, 14, 24, 30 and 45 days old sham-irradiated and 1 Gy-irradiated male and female mice. Data are presented as a percentage of cells with more than 4 γH2AX foci per cell. Red bars represent the percentage of PCNA-positive cells that harbor more than 4 γH2AX foci per cell. CT-control, AC- acute effect, 30 minutes after exposure; DEL-delayed effect, 24 hours after exposure.