Common precursors for neural and mesectodermal derivatives in the cephalic neural crest.

The cephalic neural crest (NC) of vertebrate embryos yields a variety of cell types belonging to the neuronal, glial, melanocytic and mesectodermal lineages. Using clonal cultures of quail migrating cephalic NC cells, we demonstrated that neurons and glial cells of the peripheral nervous system can originate from the same progenitors as cartilage, one of the mesectodermal derivatives of the NC. Moreover, we obtained evidence that the migrating cephalic NC contains a few highly multipotent precursors that are common to neurons, glia, cartilage and pigment cells and which we interprete as representative of a stem cell population. In contrast, other NC cells, although provided with identical culture conditions, give rise to clones composed of only one or some of these cell types. These cells thus appear restricted in their developmental potentialities compared to multipotent cells. It is therefore proposed that, in vivo, the active proliferation of pluripotent NC cells during the migration process generates distinct subpopulations of cells that become progressively committed to different developmental fates.