Figure 2.

Genetic programs controlling cortical interneuron development. (a) Progressive stages of cortical interneuron development. (b) Cortical interneuron development from the three major telencephalic sources: the MGE, the dCGE and the POA. Transcription factors involved at different stages of cortical interneuron development are shown. Some of these factors participate broadly in interneuron development (e.g. members of the DLX and NR2F families and ARX). ZEB2 has been described in the MGE lineage but may also be expressed in other interneuron populations. Other transcription factors are unique to specific domains and/or stages of differentiation: NKX2-1 defines the MGE neuroepithelium and activates a cascade of genes downstream including Lhx6, Sox6 and Satb1; NKX6-2 and GLI1 are enriched in the neuroepithelium of the dMGE (although not restricted to that region) and provide this domain with its unique identity and differentiation potential; DBX1 and HMX3 have been used to fate-map the POA because of their restricted expression in this domain; PROX1 and SP8 have been identified as being expressed in CGE-derived cortical interneurons at all stages of their development. Although depicted as having common precursors, interneurons that originate from the same neuroepithelial domain may arise from lineages that split early during development. Note that the VZ of the dMGE expresses MGE transcription factors in addition to the dMGE-specific genes indicated. ? indicates that expression is unclear or unknown. * indicates expression in some but not all cells. Expression of Zeb2, Sox6 and Satb1 has not been examined in POA-derived cortical interneurons.