A robust network of double-strand break repair pathways governs genome integrity during C. elegans development

Curr Biol. 2009 Aug 25;19(16):1384-8. doi: 10.1016/j.cub.2009.06.045. Epub 2009 Jul 30.


To preserve genomic integrity, various mechanisms have evolved to repair DNA double-strand breaks (DSBs). Depending on cell type or cell cycle phase, DSBs can be repaired error-free, by homologous recombination, or with concomitant loss of sequence information, via nonhomologous end-joining (NHEJ) or single-strand annealing (SSA). Here, we created a transgenic reporter system in C. elegans to investigate the relative contribution of these pathways in somatic cells during animal development. Although all three canonical pathways contribute to repair in the soma, in their combined absence, animals develop without growth delay and chromosomal breaks are still efficiently repaired. This residual repair, which we call alternative end-joining, dominates DSB repair only in the absence of NHEJ and resembles SSA, but acts independent of the SSA nuclease XPF and repair proteins from other pathways. The dynamic interplay between repair pathways might be developmentally regulated, because it was lost from terminally differentiated cells in adult animals. Our results demonstrate profound versatility in DSB repair pathways for somatic cells of C. elegans, which are thus extremely fit to deal with chromosomal breaks.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / growth & development
  • Caenorhabditis elegans Proteins / genetics
  • DNA Breaks, Double-Stranded*
  • DNA Repair / genetics
  • DNA Repair / physiology*
  • DNA, Helminth / genetics*
  • DNA, Helminth / metabolism
  • Genes, Reporter
  • Genome, Helminth
  • Larva
  • Models, Genetic
  • Polymerase Chain Reaction
  • Recombinant Fusion Proteins / physiology
  • Sequence Deletion
  • Transgenes / genetics


  • BRC-1 protein, C elegans
  • Caenorhabditis elegans Proteins
  • DNA, Helminth
  • Recombinant Fusion Proteins