Neural Crest

Introduction: A distinctive feature of vertebrate development is the transient formation of neural crest. Neural crest originates from the neural plate border, which separates the neural plate from non-neural ectoderm prior to neural tube closure. Upon neural tube closure, neural crest cells (NCCs) undergo epithelial-to-mesenchymal transition and migrate away from the neural tube. These migratory NCCs are multipotent stem cells that invade and colonize specific regions along the embryonic anterior-posterior (A-P) axis and develop into a variety of cell types, ranging from craniofacial cartilage and pigment cells to neurons and glia.1 Migrating NCCs are guided by extrinsic and intrinsic signals that lead to proper neural crest patterning. Many of these signals are involved in transcriptional regulation, including those of the homeobox (Hox) gene family, which encodes conserved transcriptional factors important in A-P patterning. A number of expression studies have identified Hox factors as potential regulators in the patterning of specific regions of neural crest. Hoxb5, a posterior Hox factor expressed in the mouse hindbrain and gut at the neural crest migration front, has been shown to play a role in the migration and survival of enteric NCCs,

ibly through the positive regulation of transcription factor Foxd3.2,3 Preliminary data support this finding, but they also reveal a more global effect on neural crest along the A-P axis resulting from aberrant expression of hoxb5b, a zebrafish