ABSTRACT

Although it is largely a postmitotic tissue, skeletal muscle has a remarkable capacity for regeneration, mediated by satellite cells. Here, we discuss the development of skeletal muscle, including the genetic controls of embryonic myogenesis and specifi cation of satellite cells. Several recently-developed markers have facilitated studies showing that satellite cells within postnatal muscles are heterogeneous, some able to contribute more effi ciently to muscle regeneration and to self-renew than others. The environment-both within the satellite cell niche and elsewhere-has a profound effect on satellite cell quiescence, activation, migration, proliferation, differentiation and self-renewal, with growth and infl ammatory factors and Notch, Wnt and Sonic hedgehog signalling being especially implicated in determining satellite cell function within adult muscle. A major drawback of satellite cells, or their progeny myoblasts, as a therapy for muscular dystrophies (e.g., Duchenne muscular dystrophy) is that they seem not to be systemicallydeliverable. Attention has therefore turned to other stem cells that can be delivered intra-arterially to downstream muscles, where they contribute

Dubowitz Neuromuscular Centre, UCL Institute of Child Health, 30 Guilford Street, London WC1N1EH, UK. *Corresponding author: jennifer.morgan@ucl.ac.uk

List of abbreviations after the text.