Figure 1. Caveolin-1, integrin α7 and CTR are expressed by Pax7+ve quiescent satellite cells in their niche on the myofibre.

Satellite cells in their niche on the surface of freshly isolated EDL myofibres were co-immunostained for Pax7 (green) and either caveolin-1 (a - red), integrin α7 (b - red) or CTR (c - red). All three proteins were expressed in the plasma membrane of Pax7+ve satellite cells (arrowed), clearly revealing their bi-polar morphology. Myofibres were also examined from the masseter of the jaw, and again Pax7+ve satellite cells expressed all three markers (caveolin-1 shown as an example in d). All nuclei were counterstained with DAPI (blue), revealing the presence of the myonuclei of the myofibres on which the satellite cells were located. Scale bar represents 20 µm.