Genetic and cytological characterization of the recombination protein RAD-51 in Caenorhabditis elegans.
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.
Alpi
Arno
A
Max Planck Institute for Biochemistry, Am Klopferspitz 18a, 82152 Martinsried, Germany.
Pasierbek
Pawel
P
Gartner
Anton
A
Loidl
Josef
J
D000818:Animals; D017209:Apoptosis; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin; D019457:Chromosome Breakage; D002874:Chromosome Mapping; D004260:DNA Repair; D017353:Gene Deletion; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008540:Meiosis / Q000235:genetics; D010641:Phenotype; D011418:Prophase; D051135:Rad51 Recombinase; D011938:Rec A Recombinases / Q000235:genetics*; D011995:Recombination, Genetic
D029742:Caenorhabditis elegans Proteins; D002843:Chromatin; D051135:Rad51 Recombinase; D011938:Rec A Recombinases; C495148:rad-51 protein, C elegans