While Zfhx1b in the MGE SVZ regulates the switch between cortical and striatal interneurons, Zfhx1b is also expressed in the VZ of the MGE (Figure 1A). Two genes related to Notch signaling were up-regulated in the mutant MGE VZ, including the secreted delta-like ligand Dlk1 (Ferrón et al., 2011; Moon et al., 2002) and the HLH transcription factor ID4 (Yun et al., 2004) (Figure S6J-S6O’). Dlk1 up-regulation in the VZ and SVZ could alter the balance of cell fate decisions.
