Segregation of cell lineage in the neural crest.

Following neurulation, neural crest cells emerge from the neural tube and undergo extensive migrations. At the onset of migration, multipotent stem cells exist within the neural crest population. Eventually, these assume one of a number of possible fates, ranging from neurons and glia of the peripheral nervous system to pigment cells and cells of the facial skeleton. Neural crest cells follow migratory pathways and differentiate into derivatives that often are characteristic of their axial level of origin. Based on their stereotyped patterns of migration, limited intermixing and distinct homeobox-gene codes, some populations of neural crest cells may have a rostrocaudal regional identity imprinted prior to their emigration.