Supplementary Figure 4: MF-specific Mib1 ablation affects precocious depletion of SCs in hindlimb muscles and defective muscle regeneration.

(a) IHC staining for Pax7 and Ki67 in TA muscles from Mib1^WT and Mib1^ΔMF mice at the indicated ages. Arrows and arrowheads indicate Ki67⁺Pax7⁺ and Ki67⁻Pax7⁺ cells, respectively; scale bar, 50 μm. (b) p21, p27 and Spry1 levels in the MCs from Mib1^WT and Mib1^ΔMF hindlimb muscles. n = 5 animals for each group; data are mean ± s.d.; two-sample t-test; ^∗P < 0.05. (c,d) Optic (c; scale bar, 0.2 cm) and hematoxylin and eosin-stained (d; scale bar, 25 μm) images of BaCl₂-injured TA muscles in 8-week-old mice. (e) IHC stained images for Laminin in TA muscles 5 or 10 days after BaCl₂ injury. Scale bar, 25 μm. (f) Flow cytometric analysis of SC populations in 8-week-old Cont^WT (Mib1^WT and N1^WT), Mib1^ΔMF, and N1^ΔSC mice. n = 5 animals for each group; data are mean ± s.d.; Tukey’s pairwise comparison test; ^∗∗P < 0.01. Controls are designated as the WT of comparing mutant mice. Statistical source data for f is provided in Supplementary Table 2.