Our group studies development, regeneration and disease in mammalian skeletal muscle, with a focus on extracellular signaling pathways that modify muscle stem cell (satellite cell) activity. The signaling molecules controlling satellite cell activation, proliferation, migration, differentiation, and self-renewal are produced by muscle fibers, muscle fibroblasts, inflammatory immune cells, and the satellite cells themselves, and are dynamically expressed in space and time. Our “big picture question” is how satellite cells integrate and respond to extracellular signals in order to rapidly, efficiently, and repeatedly respond to muscle damage or disease. We study satellite cells from wildtype and disease models of mouse, dog, and human in vitro and in vivo using timelapse microscopy, immunohistochemistry, gene expression assays, flow cytometry and molecular tools.