Fig. 1

Histological analysis of the TA muscles isolated from mdx mice that had been treated with rGDF11 or vehicle. a Representative images of the TA muscles stained with H&E from mice treated with rGDF11 or vehicle (upper panels). Another cohort of mice treated with rGDF11 or vehicle was injured with cardiotoxin at day 30 and analyzed 10 days later (lower panels). b The percentage of centrally nucleated fibers was not altered upon rGDF11 treatment in mice with or without cardiotoxin injury. As expected, the cardiotoxin injury increased the percentage of centrally nucleated fibers. Treatment with GDF11 resulted in increased numbers of myofibers when compared to vehicle-treated mice (c) but did not affect the cross-sectional area frequency distribution (d). Quantification was performed in the entire cross sections of the tibialis anterior muscles. Both rGDF11- and vehicle-treated mice show leftward shift in frequency distribution. ≤200 μm² myofibers were the largest group, and CTX injury increased the frequency of this group, irrespective of GDF11. Fiji ImageJ software was used to determine number and size of myofibers. Scale bar = 100 μm. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001