Table 1.

Summary of differing populations of skeletal muscle-resident progenitors. FAPs, fibro-adipogenic progenitors; MSCs, mesenchymal stem/progenitor cells; PICs, PW1⁺/Pax7⁻ interstitial cells; AP, alkaline phosphatise; NG2, neuro-glial 2 proteoglycan; PDGFRα/β, platelet-derived growth factor receptor α/β; Tcf4, transcription factor 7-like 2 (Tcf7L2). For most of these cell types, potentials other than myogenic have not been investigated thoroughly in vivo.

Described developmental potential in regenerating skeletal muscle
Population	Cellular markers	In vitro	In vivo	References
Satellite cells	Pax7, CD34, Myf5, caveolin-1 and Vcam-1	Myogenic and fibrogenic (?)	Myogenic	[5–9,40,48,49]
FAPs/MSCs	Sca-1, CD34, PDGFRα, Adam12 and Tcf4 (?)	Adipogenic, fibrogenic, osteogenic and chondrogenic	Adipogenic, fibrogenic, osteogenic and chondrogenic	[28–33]
PICs	PW1, Sca-1 and CD34	Myogenic (smooth muscle)	Myogenic	[21]
Pericytes	AP, PDGFRβ and NG2	Myogenic, adipogenic (smooth muscle) and osteogenic	Myogenic	[26,27]
Side population cells	Hoechst-negative	Myogenic, adipogenic, fibrogenic, osteogenic and haematopoietic	Myogenic	[13,15,20]