Figure 1

The satellite cell niche. Adult stem cells, such as skeletal muscle satellite cells, engage in bidirectional communication with the surrounding niche to maintain tissue homeostasis. Pax7 (green) expressing satellite cells receive direct biophysical and biochemical cues from the multinucleated (blue) skeletal muscle fibers (black) they sit on top of and the laminin (red) containing basement membrane with associated growth factors and cytokines surrounding each fiber and encasing the stem cell. This confocal image of a muscle cross-section further illustrates the architecture of the resting niche, which poses an additional level of regulation on stem cells.