Fig. 5: Serum from exercised mice induce proliferation of Calcr-cKO MuSCs in systemic muscle.

A Experimental scheme for analyses of MuSC behaviors by isolated single myofiber (SMF; B, C) of EDL or immunohistochemistry (IHC; D-G) of TA, GM, Tri, GC, and Qu from C-cKO (Pax7^CreERT2:: Calcr^flox/flox::Rosa^yfp/yfp) mice transferred with exercised serum (+Ex-serum, n = 7) or non-exercised serum (−Ex-serum, n = 4). B Detection of YFP⁺Pax7⁺ MuSCs on freshly isolated myofibers from C-cKO mice with +Ex-serum or −Ex-serum. Arrowheads indicate YFP⁺Pax7⁺ cells. Scale bar, 50 µm. C Number of MuSCs per single myofiber from EDL of C-cKO mice with −Ex- (n = 4) or +Ex-serum (n = 7). D Detection of EdU⁺ myonuclei in GM and Tri of C-cKO mice transferred with +Ex-serum. Arrowheads indicated EdU⁺ nuclei (white) beneath dystrophin (green). Scale bar, 20 µm. E Number of EdU⁺ myonuclei in TA, GM, Tri, GC, and Qu in C-cKO mice transferred with −Ex- (n = 4) or +Ex-serum (n = 7). F Immunostaining for LNα2 (green), M-cadherin (red), and EdU (white) of GM and Tri muscles from C-cKO mice transferred with +Ex-serum. Arrowheads indicate EdU⁺M-cadherin⁺ cells. Scale bar, 20 µm. G Number of EdU⁺M-cadherin⁺ cells in TA, GM, Tri, GC, and Qu in C-cKO mice transferred with −Ex- (n = 4) or +Ex-serum (n = 7). The graphs show individual data with mean ± s.d.; unpaired two-tailed Student’s t test (C, E, G). The reproducibility of the data was confirmed using more than four biological replicates (B, D, F).