Chromodomain protein CDYL confers forebrain identity to human cortical organoids by inhibiting neuronatin [RNA-seq]

Epigenetic regulation is essential for the normal development of human cerebral cortex, and its disruptions would lead to diverse neurodevelopmental disorders. The epigenetic co-repressor CDYL exhibits widespread expression across various cell clusters within the human embryonic cortex, yet its roles in this intricate process have remained elusive. Here, we show that CDYL is critical for cortical neurogenesis, and CDYL deficiency led to an augmentation in the generation of GABAergic neurons instead of cortical progenitors and neurons in the cortical organoid model. Combining analysis of bulk RNA-seq and ChIP seq, we identified NNAT as a significant CDYL target by H3K27me3 modification, crucial for the fate determination of neural stem cells within human cortical organoids, distinctly diverging from the murine cortex at a similar developmental stage. Collectively, our study sheds light on the critical function of CDYL in the maintenance of cortical neural stem cell fate commitment during human corticogenesis through the inhibition of NNAT expression.