Figure 11. Combinatorial Wnt, RA, and FGF Signals Specify Progenitor Cell Identity That Prefigure MN Subtype in the Developing Hindbrain and Spinal Cord.

Combinatorial actions of Wnt, FGF, and RA signals specify neural progenitor cells expressing Hox gene profiles characteristic of the cHB, rSC, and cSC that generate patterns of differentiated MNs, with dMN or vMN exit points, characteristic of hindbrain and spinal cord, in response to Shh signaling.