Fig. 1.

Acute exercise causes transient mitochondrial stress and mitophagy during recovery. a Representative images of C57BL/6J mouse (10–12 weeks) FDB fibers transfected with pMitoTimer at time points following acute exercise. Images are merged red and green channels. Scale bar = 20 µm. See also Supplementary Fig. 1. b Quantification of MitoTimer red:green fluorescence intensity and c pure red puncta in n = 7–10 mice per time point. d Representative images of mouse FDB fibers co-transfected with pMitoTimer and pLamp1-YFP at 6 h post exercise illustrating that MitoTimer pure red puncta co-localized with Lamp1-YFP puncta. e Representative images of contralateral mouse FDB fibers transfected with pER-Timer at time points following acute exercise. Scale bar = 20 µm. See also Supplementary Fig. 1. f Quantification of ER-Timer red:green fluorescence intensity and g pure red puncta in n = 5–6 mice per time point. h Representative western blot for Lc3 in mitochondria enriched skeletal muscle fractions. Upper band corresponds to Lc3-I and lower band to Lc3-II, with Vdac as the loading control, at time points following acute exercise. i Quantification of Lc3-II and j Lc3-I protein abundance relative to Vdac, n = 5. See also Supplementary Fig. 5. Data presented as mean ± standard error of the mean. Results of one-way ANOVAs are *p < 0.05, **p < 0.01, and ***p < 0.001. F = 8.07 (b), F = 3.10 (c), F = 1.29 (f), F = 0.91 (g), F = 5.15 (i), F = 0.74 (j). DF = 5 MitoTimer and ER-Timer pure red puncta c, g were log transformed to account for unequal variance