Development and evolution of the migratory neural crest: a gene regulatory perspective

The neural crest, a uniquely vertebrate characteristic, gives rise to pigment cells, much of the peripheral nervous system, the craniofacial skeleton, and a plethora of other cell types. Classical embryological studies have revealed important details about the migratory pathways followed by these cells, and their subsequent differentiation into diverse derivatives. More recently, many aspects of the molecular cascade of events involved in neural crest induction and generation of these migratory cells have been revealed. Formation of the neural crest appears to involve a network of interactions whereby signaling molecules initiate the induction and, subsequently, the establishment of the neural plate border, which is marked by expression of a characteristic set of transcription factors designated as neural plate border-specifiers. These in turn regulate other transcription factors termed neural crest-specifiers, which control genes involved in neural crest delamination, the generation of migratory cells and ultimately the acquisition of appropriate fates.