FIGURE 1:

IR triggers mitochondrial fission. After x-irradiation at 10 Gy, WT MEFs were incubated for 12 h. Mitochondria were stained with 300 nM MitoTracker Green FM and analyzed by confocal laser scanning microscopy. (A) Representative confocal image of mitochondria in nonirradiated cells. (B) Magnified image of the boxed region in A. (C) Representative confocal image of mitochondria in irradiated cells. (D) Magnified image of the boxed region in C. (E, F) Quantitative analysis of mitochondrial morphologies. Microscopic analyses were conducted at the indicated times after x-irradiation at 10 Gy (E) or at 12 h after x-irradiation at the indicated doses (F). Quantitative image analysis of mitochondrial morphologies was performed as described in Materials and Methods. Data are expressed as means ± SD of three experiments.