title: Hyper-resistance of meiotic cells to radiation due to a strong expression of a single recA-like gene in Caenorhabditis elegans.
abstract: Sensitivity of meiotic cells to DNA damaging agents is little understood. We have demonstrated that the meiotic pachytene nuclei in the Caenorhabditis elegans gonad are hyper-resistant to X-ray irradiation, but not to UV irradiation, whereas the early embryonic cells after fertilization and the full grown oocytes are not. The Ce-rdh-1 gene [RAD51, DMC1 (LIM15), homolog 1 or Ce-rad-51], which is essential for the meiotic recombination, is the only bacterial recA-like gene in the nematode genome, and is strongly expressed in the meiotic cells. Following silencing of the Ce-rdh-1 gene by RNA interference, the meiotic cells become more sensitive to X-ray irradiation than the early embryonic cells. This is the first report that meiotic cells are hyper-resistant to DNA strand breaks due to the high level of expression of the enzyme(s) involved in meiotic homologous recombination.
authors.affiliation: Institute of Genetic Ecology, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takanami
authors.forename: A
authors.initials: A
authors.lastname: Mori
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: A
authors.initials: A
authors.lastname: Higashitani
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000528:radiation effects*; D029742:Caenorhabditis elegans Proteins; D002875:Chromosomes / Q000235:genetics / Q000528:radiation effects; D004249:DNA Damage / Q000235:genetics / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D017238:Genes, Helminth / Q000235:genetics*; D017403:In Situ Hybridization; D008540:Meiosis / Q000235:genetics / Q000528:radiation effects*; D009865:Oocytes / Q000378:metabolism / Q000528:radiation effects; D012330:RNA, Double-Stranded / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051135:Rad51 Recombinase; D011836:Radiation Tolerance; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic / Q000235:genetics / Q000528:radiation effects; D014965:X-Rays
chemical_list: D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D051135:Rad51 Recombinase; D011938:Rec A Recombinases; C495148:rad-51 protein, C elegans