LAUSR

Cell differentiation involves activation of mutually exclusive genetic programs The shape of our nose, the color of our skin, the movement of our gut, all depend on an extraordinary cell type called neural crest cells, which originate during embryogenesis. Since their discovery in 1868 (1), neural crest cells, which are present in all vertebrates, have fascinated developmental biologists (2). One of the amazing features of neural crest cells is their extraordinary multipotency: They form cartilage, muscle, neurons, glia, pigment cells, adrenal cells, and so on. (3). No other embryonic cell type can differentiate into so many different kinds of cells. However, how this multipotency is achieved is not understood. On page 971 of this issue, Soldatov et al. (4) clarify some of the mechanisms that explain how the multiplicity of cell types is generated by neural crest cells.