The majority of these Hox
spatial network members make contacts with ‘poised’ enhancers which harbour both H3K27me3 and H3K4me1. Induced PRC1 knockout leads to complete disruption of the promoter-promoter contacts comprising the Hox
spatial network (Figure 3).
In contrast, promoter-poised enhancer contacts are maintained and this is accompanied by widespread acquisition of active chromatin signatures at these enhancers, as well as pronounced transcriptional up-regulation of genes in the network.
Our results show that PRC1 physically constrains promoters and regulatory elements of key transcription factor genes in a silenced but poised spatial network. We propose that selective release of genes from the Hox
network drives lineage specification during early development (Figure 4).
Check out our paper in Nature Genetics.