Origins of the Neural Crest

The neural crest originates from cells located along the lateral margins of the neural plate. Neural crest cells are specified as the result of an inductive action by the nonneural ectoderm (possibly mediated by bone morphogenetic protein-4 [BMP-4] and BMP-7) on the lateral cells of the neural plate. (Hall, 21)

Neural Crest Cells Expression

The induced neural crest cells express slug, a
transcription factor of the zinc finger family, which characterizes cells that break away from an embryonic epithelial layer and subsequently migrate as mesenchymal cells. (Carlson, 249) Slug is also expressed during gastrulation by cells of the epiblast after they have entered the walls of the primitive streak and are about to leave as mesenchymal cells of the mesodermal germ layer.

Changes in Cell Adhesion Molecules

Neural crest cells break away from the neural plate or neural tube by changing their shape and properties from those of typical neuroepithelial cells to those of mesenchymal cells. Accompanying this transformation of the neural crest cells is a loss of cell-to-cell adhesiveness. This is accompanied by the loss of cell adhesion molecules (CAMs) characteristic of the neural tube (e.g., N-CAM and N-cadherin) on the neural crest cells during their migratory phase. After neural crest cells have completed their migrations and differentiated into certain structures (such as spinal ganglia), Cams are often reexpressed. (Maderson, 21)

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