Endogenous patterns of BMP signaling during early chick development.
Bone morphogenetic proteins (BMPs) are members of the transforming growth factor beta superfamily signaling molecules that play important roles in a wide variety of developmental processes. In this study, we have used an antibody specific for the phosphorylated and activated form of Smad1 to examine endogenous patterns of BMP signaling in chick embryos during early development. We find complex spatial and temporal distributions of BMP signaling that elucidate how BMPs may function in multiple patterning events in the early chick embryo. In the pregastrula embryo, we find that BMP signaling is initially ubiquitous and is extinguished in the epiblast at the onset of primitive streak formation. At the head process stage, BMP signaling is inactivated in prospective neural plate, while it is strongly activated at the neural plate border, a region which is populated by cells that will give rise to neural crest. During later development, we find a dynamic spatiotemporal activation of BMP signaling along the rostrocaudal axis, in the dorsal neural tube, in the notochord, and in the somites during their maturation process. We discuss the implication of our results for endogenous functions of BMP signaling during chick development.
Faure
Sandrine
S
Department of Cell Biology, Massachusetts General Hospital, Boston, Massachusetts 02115, USA.
de Santa Barbara
Pascal
P
Roberts
Drucilla J
DJ
Whitman
Malcolm
M
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D019521:Body Patterning / Q000502:physiology*; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000502:physiology*; D002642:Chick Embryo / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005775:Gastrula / Q000502:physiology; D009024:Morphogenesis / Q000502:physiology*; D009420:Nervous System / Q000196:embryology*; D010766:Phosphorylation; D015398:Signal Transduction; D051785:Smad Proteins; D015534:Trans-Activators / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000502:physiology
D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; D051785:Smad Proteins; D015534:Trans-Activators; D016212:Transforming Growth Factor beta