Figure 5. The relationships between markers of satellite cell differentiation, the p53/p21 axis of autophagy and the PERK arm of the UPR. The fold change from baseline to 18h post-exercise in gene transcripts representing satellite cell differentiation in young and older adults (A). Correlations demonstrate significant positive (dark red) and negative (dark blue) relationships between the fold-change from baseline to 18h post-exercise for the individual gene transcripts associated with the satellite cells differentiation markers (Pax3, Pax7, MyoD, MyoG), the p53/p21 axis, and the PERK arm of the UPR pathway in young and older adults (B). Data bars are presented as mean ± SEM. *Significant correlation (p ≤ 0.05). † Significantly different (p ≤ 0.05) between young and older adults.