Pax6 controls progenitor cell identity and neuronal fate in response to graded Shh signaling

The role of the Sonic hedgehog or Shh proteins such as Pax6 and Nkx2.2 in the regulation of neuronal identity was analyzed in ventral progenitor cell populations. In vitro assays of of the progenitor cells indicated the prensence of Pax6 expression that was characterized by a ventral to dorsal gradient. Furthermore, Pax6 acted as an essential intermediary in graded Shh signaling in the caudal neural tube which modulated ventral progenitor cell identity.