Fig. 7.

Rack1 deficiency reduces apoptotic activity as measured by DNA fragmentation following radiation injury. Mice received whole body X-ray radiation, as indicated (IR), and were euthanized 72 h later. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays for DNA fragmentation were performed as described in materials and methods. Fluorescent staining for Rack1 (green, panels at left) and DNA fragments (red, panels at right) from a litter containing a nonirradiated Rack1^fl/fl control (A, panels at top), an irradiated Rack1^+/+ control (A, panels at middle), and an irradiated Rack1^−i/−i mouse (A, panels at bottom) or from another litter containing an irradiated Rack1^+/−i control (B, panels at top) and an irradiated Rack1^−i/−i mouse (B, panels at bottom). Scale bar: 100 μm. Data are representative of up to 50 fields examined from 4 mice.