An in vitro model for characterizing the post-migratory cranial neural crest cells of the first branchial arch.

The cranial neural crest (CNC) is a transient cell population that originates at the crest of the neural fold and gives rise to multiple cell types during craniofacial development. Traditionally, researchers have used tissue explants, such as the neural tube, to obtain primary neural crest cells for their studies. However, this approach has inevitably resulted in simultaneous isolation of neural and non-neural crest cells as both of these cells migrate away from tissue explants. Using the Wnt1-Cre/R26R mouse model, we have obtained a pure population of neural crest cells and established a primary CNC cell culture system in which the cell culture medium best supports the proliferation of E10.5 first branchial arch CNC cells and maintains these cells in their undifferentiated state. Differentiation of CNC cells can be initiated by switching to a differentiation medium. In this model, cultured CNC cells can give rise to neurons, glial cells, osteoblasts, and other cell types, faithfully mimicking the differentiation process of the post-migratory CNC cells in vivo. Taken together, our study shows that the Wnt1-Cre/R26R mouse first branchial arch provides an excellent model for obtaining post-migratory neural crest cells free of any mesodermal contaminants. The cultured neural crest cells are under sustained proliferative, undifferentiated, or lineage-enhanced conditions, hence, serving as a tool for the investigation of the regulatory mechanism of CNC cell fate determination in normal and abnormal craniofacial development.