Fig. 4

Daily RAPA reduces central nucleation and alters fiber size of Myf5/Fktn KO iliopsoas. a Images from iliopsoas muscles of VEH- or RAPA-treated LC and KO mice. H&E, functionally glycosylated αDG, and core αDG/embryonic myosin heavy chain (eMHC) are shown. Nuclear DAPI counterstain is shown in blue. Scale bar = 100 μm. Asterisks denote identical tissue locations across images. Muscle fiber regeneration as measured historically by (b, left) central nucleation (CN) or acutely by (b, right) eMHC. Data are plotted as ((#positive fibers/total fibers)*100). Two-way ANOVA; *p < 0.05; ***p < 0.001. n = 10 VEH LC, n = 9 RAPA LC, n = 12 VEH KO, n = 12 RAPA KO. c Distribution of muscle fiber minimum diameter from iliopsoas of VEH- and RAPA-treated LC and KO mice. Fibers are grouped into bins of 2.5 μm. Two-way ANOVA performed for each bin. *, Drug*Genotype p < 0.05; †, Genotype p < 0.05. n = 5 VEH LC (tissue artifact), n = 5 RAPA LC (tissue artifact), n = 7 VEH KO, n = 7 RAPA KO