A view of nuclear Polycomb bodies

Curr Opin Genet Dev. 2012 Apr;22(2):101-9. doi: 10.1016/j.gde.2011.11.004. Epub 2011 Dec 16.


Polycomb group (PcG) proteins are concentrated in nuclear foci called PcG bodies. Although some of these foci are due to the tendency of PcG binding sites in the genome to occur in linear clusters, distant PcG sites can contact one another and in some cases congregate in the same PcG body when they are repressed. Experiments using transgenes containing PcG binding sites reveal that co-localization depends on the presence of insulator elements rather than of Polycomb Response Elements (PREs) and that it can occur also when the transgenes are in the active state. A model is proposed according to which insulator proteins mediate shuttling of PcG target genes between PcG bodies when repressed to transcription factories when transcriptionally active.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cell Nucleus / metabolism*
  • Genome
  • Humans
  • Polycomb-Group Proteins
  • Protein Binding
  • Protein Biosynthesis
  • RNA Interference
  • Repressor Proteins / metabolism*


  • Polycomb-Group Proteins
  • Repressor Proteins