Fig. 1

Derivation and characterization of Pax3-induced satellite cells. a (I) FACS purification of satellite cells based on ZsGreen expression (Pax7), (II) transduction of Pax7⁺ cells with an inducible expression system encoding Pax3, (III) in vitro expansion of Pax3-induced cells and control empty vector counterparts, and (IV) transplantation of iPax3 and control cells into NSG-mdx ^4Cv. b Representative FACS profile for ZsGreen (Pax7) expression in digested muscles isolated from Pax7-ZsGreen reporter mice. Sorting gate for ZsGreen⁺ (Pax7⁺) satellite cells is shown. c Phase-contrast image of sorted ZsGreen⁺ (Pax7⁺) satellite cells. d Cell growth curve of Pax3-induced cells and control counterparts at several passages (P1–P4) (n = 2, mean ± SD). e, f In vitro characterization of ex vivo expanded satellite cells grown under proliferation and differentiation culture conditions. Phase-contrast images of control empty vector (e) and Pax3-induced (f) monolayers. Representative immunofluorescence staining for Pax3 (red, upper panels) and MHC (red, lower panels) in control empty vector SCs (e) and Pax3-induced SCs (f). Cells are co-stained with DAPI (blue). Scale bar 200 μm. g Fusion index calculation. Error bars represent s.e.m. (n = 3). **P < 0.01