Genetic and cytological characterization of the recombination protein RAD-51 in Caenorhabditis elegans

Chromosoma. 2003 Jul;112(1):6-16. doi: 10.1007/s00412-003-0237-5. Epub 2003 Apr 8.


We investigated the role of Caenorhabditis elegans rad-51 during meiotic prophase. We showed that rad-51 mutant worms are viable, have no defects in meiotic homology recognition and synapsis but exhibit abnormal chromosomal morphology and univalent formation at diakinesis. During meiosis RAD-51 becomes localized to distinct foci in nuclei of the transition zone of the gonad and is most abundant in nuclei at late zygotene/early pachytene. Foci then gradually disappear from chromosomes and no foci are observed in late pachytene. RAD-51 localization requires the recombination genes spo-11 and mre-11 as well as chk-2, which is necessary for homology recognition and presynaptic alignment. Mutational analysis with synapsis- and recombination-defective strains, as well as the analysis of strains bearing heterozygous translocation chromosomes, suggests that presynaptic alignment may be required for RAD-51 focus formation, whereas homologous synaptonemal complex formation is required to remove RAD-51 foci.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / physiology
  • Cell Nucleus / metabolism
  • Chromatin
  • Chromosome Breakage
  • Chromosome Mapping
  • DNA Repair
  • Gene Deletion
  • In Situ Hybridization, Fluorescence
  • Male
  • Meiosis / genetics
  • Phenotype
  • Prophase
  • Rad51 Recombinase
  • Rec A Recombinases / genetics*
  • Recombination, Genetic


  • Caenorhabditis elegans Proteins
  • Chromatin
  • Rad51 Recombinase
  • Rec A Recombinases
  • rad-51 protein, C elegans