Context-dependent regulation of fate decisions in multipotent progenitor cells of the peripheral nervous system

A challenging problem in neural crest development is to understand how a mi gratory population of multipotent stem cells gives rise to a diverse array of differentiated cell types in the correct spatiotemporal manner. There is now ample evidence that this process involves the generation of postmigrat ory progenitor cells present in a variety of neural crest targets. When ind ividual progenitors are challenged by instructive growth factors they are a ble to produce neural and non-neural cells, raising the question of how fat e restrictions appropriate to a given embryonic location are regulated in m ultipotent postmigratory progenitor cells. Although some of the extracellul ar cues involved have been identified, it is likely that fate decisions in progenitor cells are controlled by the combinatorial action of multiple env ironmental signals. Moreover, cell type specificity is thought to be regula ted by an interplay between extracellular and intracellular cues. We are ju st beginning to unravel some of the mechanisms that allow the context-depen dent integration of cell-extrinsic and cell-intrinsic signals in multipoten t progenitor cells.