National Institute of Arthritis and Musculoskeletal and Skin Diseases has awarded David Goldhamer, Professor of Cell and Developmental Biology a $2.2 million, 5-year award to study Satellite cells. Satellite cells are responsible for the marked regenerative capacity of skeletal muscle. Although these stem cells were discovered more than 50 years ago, the molecular mechanisms that program satellite cells for muscle differentiation are incompletely understood. Using unique mouse lines and strategies, the proposed studies will determine the functions of two key myogenic regulatory proteins (MyoD and Myf5) in satellite cell development, myogenic programming and differentiation.