Fig. 2.

Populations of satellite cells, their myogenic derivatives and FAPs during skeletal muscle regeneration. In response to injury, quiescent satellite cells and FAPs are activated and these activated cells are distinct from their quiescent counterparts (e.g. McKellar et al., 2020 preprint). Activated satellite cells differentiate into myoblasts and then myocytes, which fuse to form regenerated myofibers with characteristic centralized nuclei. Activated FAPs differentiate into fibrogenic or adipogenic FAPs and presumably transition to a quiescent FAP phenotype when regeneration is largely complete at 28 dpi (e.g. McKellar et al., 2020 preprint). ECM, extracellular matrix; MTJ, myotendinous junctions.