Fig. 1

Pdgfrb-Cre effectively targets recombination in quiescent PDGFRβ⁺ cells and activated myofibroblasts. a Immunofluorescence micrographs of skeletal muscle from mTmG;Pdgfrb-Cre mice co-stained with anti-PDGFRβ antibody. Scale bar 10 μm. b, c Quantification of GFP reporting and PDGFRβ antibody colocalisation in skeletal muscle (n = 7). d Flow cytometric analysis of PDGFRβ expression in GFP⁺ cells sorted from mTmG:Pdgfrb-Cre mouse skeletal muscle (n = 3). e Immunofluorescence micrographs of skeletal muscle sections harvested from mTmG;PDGFR β-Cre reporter mice 4, 8 and 21 days after control (PBS) or CTX intramuscular injection. Scale bars 30 μm. f Percentage field coverage of GFP⁺ cells at 4, 8, 21 and 60 days after control (PBS) or CTX intramuscular injection (n = 4). g Quantitation of GFP⁺ nuclei at 4, 8, 21 and 60 days after control (PBS) or CTX intramuscular injection (n = 4). h Gene expression profile of freshly sorted GFP⁺ cells from skeletal muscle at day 10 following control (PBS) or CTX intramuscular injection (n = 4). i Immunofluorescence staining of a typical GFP⁺ cell sorted from uninjured skeletal muscle of mTmG;Pdgfrb-Cre reporter mice and plated on tissue culture plastic for 5 days. Scale bar 50 μm. j qPCR analysis of the genes encoding PDGFRβ, αSMA, Col1A1 and TIMP1 in freshly sorted GFP⁺ cells from mTmG;Pdgfrb-Cre reporter mice and from GFP⁺ cells cultured for 7 and 14 days (n = 4). Data are mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 (Student’s t-test)