(A) Experimental scheme for analyzing new MuSC-derived myonuclei in plantaris muscle of control (Cont), Hey1-KO (1KO), or HeyL-KO (LKO) mice at 4 or 7 days after tenotomy. Arrowheads indicate the day of EdU injection. (B) Arrows indicate new myonuclei supplied by MuSCs in overloaded muscle of Cont, 1KO, or LKO mice. MuSC-derived myonuclei were labeled with EdU (white) and located inside the staining for dystrophin (Dys; green). Nuclei were counterstained with DAPI. Scale bar: 50 μm. (C) Number of EdU+ myonuclei in muscle: sham (open circle) versus tenotomy (closed circle). Left graph: results at 4 days after tenotomy (Ope-4d) (Cont: light gray, n = 4; LKO: blue, n = 4). Right graph: results at 7 days after tenotomy (Cont: light gray, n = 8; 1KO: black, n = 6; LKO: blue, n = 7). **p<0.01. N.S.: not significant. (D) Ratio of overloaded muscle weight to sham muscle weight in Cont (light gray, n = 8), 1KO (black, n = 6), or LKO (blue, n = 8) mice at 7 days after tenotomy. N.S.: not significant. Data represent the mean ± standard deviation. One-way ANOVA, followed by the Tukey–Kramer or Bonferroni test, was used for statistical analyses.
Figure 5—source data 1. Numerical data for making the graphs in Figure 5.Experiment number corresponds to all results.