Skeletal Muscle Satellite Cells (SMSC)

Satellite cells constitute a class of myogenic cells that differ distinctly from other embryonic myoblasts. Satellite cells arise from somites and first appear as a distinct myoblast type well before birth. Satellite cells from different muscles cannot be functionally distinguished from one another and are able to provide nuclei to all fibers without regard to phenotype.

Skeletal muscle contains both differentiated myofibers and stem cells, known as satellite cells. The skeletal muscle satellite cells (SMSC) are situated between the plasma membrane of the multinucleated muscle cells and the basal lamina that surrounds each myofiber.Within a muscle, satellite cells exhibit marked heterogeneity with respect to their proliferative behavior. The SMSC population on a fiber can be partitioned into those that function as stem cells and those which are readily available for fusion.When quiescent satellite cells are activated, they co-express the transcription factors Pax7 and myoD.