The transcription factor Pou3f1 promotes neural fate commitment via activation of neural lineage genes and inhibition of external signaling pathways

The neural fate commitment of pluripotent stem cells requires repression of extrinsic inhibitory signals and activation of intrinsic positive transcription factors. However, it remains elusive how these two events are integrated to ensure appropriate neural conversion. Here, we show that Oct6 functions as an essential positive factor for neural differentiation of mouse embryonic stem cells (ESCs), specifically during the transition from epiblast stem cells (EpiSCs) to neural progenitor cells (NPCs). Chimera analysis showed that Oct6 knockdown leads to markedly decreased incorporation of ESC in neuroectoderm. By contrast, Oct6-overexpressing ESC derivatives preferentially contribute to neuroectoderm. Genome-wide ChIP-seq and RNA-seq analyses indicate that Oct6 is an upstream activator of neural lineage genes, and also a repressor of BMP and Wnt signalings. Our results establish Oct6 as a critical regulator that promotes neural commitment of pluripotent stem cells through a dual role: activating internal neural induction programs and antagonizing extrinsic neural inhibitory signals. Overall design: RNA-seq was performed to examine Oct6 function in ESC neural differentiation at Day2, Day4 and Day6 after dox induction. On Day4 EB, ChIP-seq assay was ultilized to characterize the targets of Oct6.