Fig. 3.

DDR-dependent mitochondrial biogenesis is decreased in old ISCs. Immunohistochemical analyses of PGC-1α were performed in young and old jejunum with (IR) or without 10 Gy X-ray irradiation (non-IR). Representative images stained with an anti-PGC-1α antibody, together with a graph of the percentage of positive cells, are shown. Arrows and arrowheads indicate GFP and PGC-1α double-positive and GFP single-positive cells, respectively. Data are mean ± s.e.m. (n = 3 and > 100 GFP+ cells). *p < 0.05. Scale bar, 50 μm