Polycomb silencing mechanisms and the management of genomic programmes

Nat Rev Genet. 2007 Jan;8(1):9-22. doi: 10.1038/nrg1981.


Polycomb group complexes, which are known to regulate homeotic genes, have now been found to control hundreds of other genes in mammals and insects. First believed to progressively assemble and package chromatin, they are now thought to be localized, but induce a methylation mark on histone H3 over a broad chromatin domain. Recent progress has changed our view of how these complexes are recruited, and how they affect chromatin and repress gene activity. Polycomb complexes function as global enforcers of epigenetically repressed states, balanced by an antagonistic state that is mediated by Trithorax. These epigenetic states must be reprogrammed when cells become committed to differentiation.

Publication types

  • Review

MeSH terms

  • Animals
  • Base Sequence
  • Chromatin Assembly and Disassembly / genetics
  • Chromosomal Proteins, Non-Histone / genetics
  • DNA / genetics
  • Drosophila / genetics
  • Drosophila Proteins / genetics
  • Drosophila melanogaster / genetics
  • Epigenesis, Genetic
  • Gene Silencing*
  • Genes, Homeobox
  • Genomics
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • Phylogeny
  • Plants / genetics
  • Polycomb Repressive Complex 1
  • Polycomb-Group Proteins
  • Repressor Proteins / genetics*
  • Sequence Homology, Nucleic Acid


  • Chromosomal Proteins, Non-Histone
  • Drosophila Proteins
  • Pc protein, Drosophila
  • Polycomb-Group Proteins
  • Repressor Proteins
  • trx protein, Drosophila
  • DNA
  • Polycomb Repressive Complex 1