Neural crest cells: a model for invasive behavior.

Neural crest cells are the embryonic precursors of the neurons and glia of the peripheral nervous system, pigment cells, and connective tissue in the face, neck and heart. They are induced near the junction of the neural plate and embryonic ectoderm and undergo an epithelial to mesenchymal transition (EMT). Neural crest cells then display invasive behavior and migrate into the surrounding tissues along specific pathways. Neural crest cells are amenable to study in tissue culture, and the molecules that regulate their development can be studied in vivo with antisense techniques as well as with the expression of gain and loss-of-function constructs. Mutations in factors that regulate neural crest cell survival or differentiation can lead to cell death or the premature cessation of their migration, resulting in craniofacial abnormalities, pigmentation defects and the absence of enteric neurons. This paper reviews recent advances in our understanding of neural crest cell induction and migration, emphasizing both avian and amphibian models. Cell facts: The embryonic progenitors of pigment cells, the neurons and glia of the peripheral nervous system, as well as connective tissue in the face, neck and heart. Induced to form at the boundary of the neuroepithelium and embryonic ectoderm. Expression of the transcription factors Snail, Slug and FoxD3 leads to delamination from the neural tube. Invasive motility not unlike that of tumor cells can be studied in vitro. Express proteases, distinctive cell surface receptors and glycoproteins to acquire an invasive phenotype. Mutations of transcription factors expressed by the neural crest or in other factors that inhibit their premature differentiation can lead to survival and migration-associated birth defects.