Figure 1.

Methylation of genomic DNA isolated from hearts of male C57Bl/6 mice at 7 d and 90 d after exposure to protons (150 MeV, 0.1 Gy) or iron ions (600 MeV/n, 0.5 Gy). DNA methylation of the open reading frame 1 of long interspersed nuclear element-1, a transposable element that comprises about 20% of the mouse genome, as assessed by pyrosequencing and indicated as fold change compared to sham-irradiated controls. Each group contained 4-5 animals. Horizontal lines indicate average ± standard error of the mean. ^aP < 0.05 vs the sham-irradiated control group.