Chromatin interaction analyses elucidate the roles of PRC2-bound silencers in mouse development

Nat Genet. 2020 Mar;52(3):264-272. doi: 10.1038/s41588-020-0581-x. Epub 2020 Feb 24.

Abstract

Lineage-specific gene expression is modulated by a balance between transcriptional activation and repression during animal development. Knowledge about enhancer-centered transcriptional activation has advanced considerably, but silencers and their roles in normal development remain poorly understood. Here, we performed chromatin interaction analyses of Polycomb repressive complex 2 (PRC2), a key inducer of transcriptional gene silencing, to uncover silencers, their molecular identity and associated chromatin connectivity. Systematic analysis of cis-regulatory silencer elements reveals their chromatin features and gene-targeting specificity. Deletion of certain PRC2-bound silencers in mice results in transcriptional derepression of their interacting genes and pleiotropic developmental phenotypes, including embryonic lethality. While some PRC2-bound elements function as silencers in pluripotent cells, they can transition into active tissue-specific enhancers during development, highlighting their regulatory versatility. Our study characterizes the molecular profile of silencers and their associated chromatin architectures, and suggests the possibility of targeted reactivation of epigenetically silenced genes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Chromatin / genetics*
  • Enhancer Elements, Genetic / genetics*
  • Female
  • Gene Silencing*
  • Male
  • Mice
  • Mice, Knockout
  • Mouse Embryonic Stem Cells
  • Organ Specificity
  • Phenotype
  • Polycomb Repressive Complex 2 / genetics
  • Polycomb Repressive Complex 2 / metabolism*
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Silencer Elements, Transcriptional / genetics*
  • Transcriptional Activation

Substances

  • Chromatin
  • Repressor Proteins
  • Polycomb Repressive Complex 2