An interdisciplinary team of researchers at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at UCLAhas developed a first-of-its-kind roadmap of how human skeletal muscle develops, including the formation of muscle stem cells. The study, published May 11 in the peer-reviewed journal Cell Stem Cell, identified various cell types present in skeletal muscle tissues, from early embryonic development all the way to adulthood. Focusing on muscle progenitor cells, which contribute to muscle formation before birth, and muscle stem cells, which contribute to muscle formation after birth and to regeneration from injury throughout life, the group mapped out how the cells gene networks which genes are active and inactive change as the cells mature