DNA damage foci: Meaning and significance

Environ Mol Mutagen. 2015 Jul;56(6):491-504. doi: 10.1002/em.21944. Epub 2015 Mar 12.


The discovery of DNA damage response proteins such as γH2AX, ATM, 53BP1, RAD51, and the MRE11/RAD50/NBS1 complex, that accumulate and/or are modified in the vicinity of a chromosomal DNA double-strand break to form microscopically visible, subnuclear foci, has revolutionized the detection of these lesions and has enabled studies of the cellular machinery that contributes to their repair. Double-strand breaks are induced directly by a number of physical and chemical agents, including ionizing radiation and radiomimetic drugs, but can also arise as secondary lesions during replication and DNA repair following exposure to a wide range of genotoxins. Here we aim to review the biological meaning and significance of DNA damage foci, looking specifically at a range of different settings in which such markers of DNA damage and repair are being studied and interpreted.

Keywords: 53BP1; DNA double-strand break; genotoxicity; ionizing radiation; γH2AX.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Biomarkers / metabolism
  • DNA Breaks, Double-Stranded*
  • DNA Damage / physiology*
  • DNA Damage / radiation effects
  • DNA Repair
  • Histones / metabolism
  • Humans
  • Mutagenicity Tests / methods*
  • Radiation Monitoring / methods
  • Radiation, Ionizing


  • Biomarkers
  • H2AX protein, human
  • Histones