Neural crest cells migrate from the dorsal aspect of the neural tube and differentiate into a variety of cell types in different locations. These cell types include peripheral neurons and glia (Schwann cells), melanocytes, endocrine cells, smooth muscle, skeletal muscle and bone (1 ). In vivo lineage tracing and in vitro clonal analyses in avian embryos have indicated that many neural crest cells are multipotent (2 ,3 ) and transplantation and culture studies suggest that the fate of multipotent neural crest cells can be determined by the environment (4 –6 ).
