The DLX/Notch axis is necessary for spatiotemporal regulation of neural cell fate

The neuronal-glial cell fate switch in the developing ventral telencephalon is a tightly regulated process. DLX2 is well established as important in promoting interneuron differentiation and migration but the mechanisms for repression of glial fate remain elusive. Here, the DLX2 regulatory network dynamic in the developing telencephalon was fully characterised using a multiomic approach at single-cell resolution. Using coupled snRNAseq and snATACseq, and single-cell spatial transcriptomics we identified spatiotemporal-context dependent effects of Notch repression by DLX2 in maintaining progenitor populations and facilitating neuronal differentiation. Furthermore, we showed that DLX2 directly represses Notch signalling genes and glial fate promoting transcription factors, thereby repressing early adoption of oligodendrocyte fate during neurogenesis. Thus, this demonstrates that the temporal cell fate switch is mediated by DLX2 via a multilayer gene regulatory network and redefines the complex neuronal-glial cell specification mechanisms in the developing telencephalon.