Extended Data Fig. 6: Actc1 is increased on regenerating mouse myofibers and marks ACTC1 human-only myofibers in Pax7-DTX mdx-NSG mice.
From: Regenerating human skeletal muscle forms an emerging niche in vivo to support PAX7 cells
Related to Fig. 5a. a. Actc1+ mouse myofibers (green) are markedly increased 8 days post injury (dpi). Actc1 is expressed by Type IIB mouse myofibers as shown by Myh4 (red) co-staining. Mouse Pax7 SC numbers (boxes) increase near regenerative Actc1+ myofibers. Inset highlights Pax7 cells in niches of non-regenerating and small regenerating mouse myofibers. b. hPSC SMPCs engraft to predominantly form ACTC1+ myofibers. LaminAC/Spectrin (red), ACTC1 (green), DAPI (blue). c. Engrafted human adult SCs form ACTC1+ myofibers (green) in Pax7 DTX mice but lack expression of Myh4 (red) suggesting these are human-only myofibers, 30 days post engraftment.
