Bmp signaling at the tips of skeletal muscles regulates the number of fetal muscle progenitors and satellite cells during development.
Muscle progenitors, labeled by the transcription factor Pax7, are responsible for muscle growth during development. The signals that regulate the muscle progenitor number during myogenesis are unknown. We show, through in vivo analysis, that Bmp signaling is involved in regulating fetal skeletal muscle growth. Ectopic activation of Bmp signaling in chick limbs increases the number of fetal muscle progenitors and fibers, while blocking Bmp signaling reduces their numbers, ultimately leading to small muscles. The Bmp effect that we observed during fetal myogenesis is diametrically opposed to that previously observed during embryonic myogenesis and that deduced from in vitro work. We also show that Bmp signaling regulates the number of satellite cells during development. Finally, we demonstrate that Bmp signaling is active in a subpopulation of fetal progenitors and satellite cells at the extremities of muscles. Overall, our results show that Bmp signaling plays differential roles in embryonic and fetal myogenesis.
Wang
Hui
H
CNRS, UMR7622, Université Pierre et Marie Curie, 9 Quai St Bernard, Bat. C, 6E, Case 24, 75252 Paris Cedex 05, France.
Noulet
Fanny
F
Edom-Vovard
Frédérique
F
Tozer
Samuel
S
Le Grand
Fabien
F
Duprez
Delphine
D
D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D002454:Cell Differentiation; D002642:Chick Embryo; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D051379:Mice; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000378:metabolism; D009132:Muscles / Q000196:embryology*; D051763:PAX7 Transcription Factor / Q000378:metabolism; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology*; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology*; D013710:Tendons / Q000473:pathology
D019485:Bone Morphogenetic Proteins; D051763:PAX7 Transcription Factor; C497322:Pax7 protein, mouse