Fig. 7. Schematic representation of the interaction between Ring1A/B and the core transcriptional regulatory circuitry in mouse ES cells. Ring1A/B-mediated PcG silencing functions downstream of the core transcriptional regulatory circuitry including Oct3/4. Developmental cues, such as Gata6 activation, downregulate the activity of the core transcriptional regulatory circuitry, which accompanies a global decrease in PcG silencing.