Fig 1: Assessing 53BP1 foci and cell death in intestinal sections after ? and 56Fe radiation exposure.A) Intestinal sections from 6 to 8 week control, 1-year post-exposure control, 2 Gy ?, and 1.6 Gy 56Fe 1-year post-exposure mice were immunofluorescently stained for 53BP1. B) Quantification of 53BP1 foci in intestinal cell nuclei counterstained with DAPI. C) Quantification of TUNEL staining of intestinal sections after exposure to ? and 56Fe radiation. *significant compared to 6–8 wks unirradiated control; **significant compared to 1-year post-exposure unirradiated control; ***significant compared to ? radiation.