Résumé :
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Skeletal muscle development, growth and regeneration rely on muscle stem cells. An important goal is to understand the source and the nature of the signals regulating these muscle stem cells during myogenesis. Intrinsic and extrinsic regulatory pathways control the pool of muscle progenitors at different developmental times and places, during embryonic, foetal and peri-natal myogenesis. As an intrinsic signal, we have identified the bHLH-PAS, Sim2 (Single minded-2) gene as a regulator of embryonic muscle progenitors. As an extrinsic signal, we have identified the Bmp (Bone morphogenetic protein) signalling pathway as a positive regulator of foetal muscle progenitors. In addition, this Bmp regulation is regionalised at the tips of muscles, close to the tendons. Lastly, we have identified components of the Fgf (Fibroblast growth factor) signalling pathway localized at muscle tips as Bmp signalling and involved in foetal muscle progenitor regulation.
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