Polycomb repressive complexes 1 and 2 have been historically described as transcriptional repressors, but recent reports suggest that PRC1 might also support activation, although the underlying mechanisms remain elusive. Here, we show that stage-specific PRC1 binding at a subset of active promoters and enhancers during Drosophila development coincides with the formation of three-dimensional (3D) loops, an increase in expression during development and repression in PRC1 mutants. Dissection of the dachshund locus indicates that PRC1-anchored loops are versatile architectural platforms that persist when surrounding genes are transcriptionally active and fine-tune their expression. The analysis of RING1B binding profiles and 3D contacts during neural differentiation in mice suggests that this role is conserved in mammals.

中文翻译：

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以PRC1依赖性染色质环化为特征的发育基因表达的广泛激活。

聚梳阻抑复合物1和2在历史上曾被描述为转录阻遏物，但最近的报道表明PRC1也可能支持激活，尽管其潜在机制尚不清楚。在这里，我们显示在果蝇发育过程中，在活性启动子和增强子的一个阶段特异性PRC1结合与三维（3D）环的形成相吻合，在PRC1突变体的发育和抑制过程中表达增加。腊肠犬的解剖表明，PRC1锚定的环是通用的架构平台，当周围的基因具有转录活性并对其表达进行微调时，该平台将持续存在。对小鼠神经分化过程中RING1B结合概况和3D接触的分析表明，这种作用在哺乳动物中是保守的。