Extracellular signals, cell interactions and transcription factors involved in the induction of the neural crest cells.
The neural crest is induced at the border between the neural plate and the epidermis. A complex set of signals is required for the specification of the crest cells between the epidermis and the neural plate. Here we discuss evidence supporting a model for neural crest induction in which different signals contribute in a sequential order. First, a gradient of bone morphogenic proteins (BMPs) is established in the ectoderm that results in segregation into neural plate, neural folds and epidermis at increasing levels of BMP activity. Thus, the neural folds are induced at a precise threshold concentration of BMP, but this neural fold has an anterior character. In a second step, these anterior neural folds are transformed into prospective neural crest by posteriorizing signals due to fibroblast growth factor, Wnts and retinoic acid. Finally, the induced cells interact to complete neural crest induction by a process that requires Notch/Delta signaling. Once neural crest formation has been induced by this combination of extracellular and intracellular signals, a cascade of transcription factors is activated in these cells that culminates in the ultimate steps of neural crest differentiation.
Aybar
Manuel J
MJ
Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile.
Glavic
Alvaro
A
Mayor
Roberto
R
D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology*; D002645:Chickens; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000378:metabolism; D009432:Neural Crest / Q000166:cytology / Q000196:embryology*; D051880:Receptors, Notch; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014981:Xenopus; D015027:Zebrafish
D019485:Bone Morphogenetic Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051880:Receptors, Notch; D015534:Trans-Activators; D014157:Transcription Factors; C064045:delta protein