title: Arabidopsis RAD51C gene is important for homologous recombination in meiosis and mitosis.
abstract: Rad51 is a homolog of the bacterial RecA recombinase, and a key factor in homologous recombination in eukaryotes. Rad51 paralogs have been identified from yeast to vertebrates. Rad51 paralogs are thought to play an important role in the assembly or stabilization of Rad51 that promotes homologous pairing and strand exchange reactions. We previously characterized two RAD51 paralogous genes in Arabidopsis (Arabidopsis thaliana) named AtRAD51C and AtXRCC3, which are homologs of human RAD51C and XRCC3, respectively, and described the interaction of their products in a yeast two-hybrid system. Recent studies showed the involvement of AtXrcc3 in DNA repair and functional role in meiosis. To determine the role of RAD51C in meiotic and mitotic recombination in higher plants, we characterized a T-DNA insertion mutant of AtRAD51C. Although the atrad51C mutant grew normally during vegetative developmental stage, the mutant produced aborted siliques, and their anthers did not contain mature pollen grains. Crossing of the mutant with wild-type plants showed defective male and female gametogeneses as evidenced by lack of seed production. Furthermore, meiosis was severely disturbed in the mutant. The atrad51C mutant also showed increased sensitivity to gamma-irradiation and cisplatin, which are known to induce double-strand DNA breaks. The efficiency of homologous recombination in somatic cells in the mutant was markedly reduced relative to that in wild-type plants.
authors.affiliation: Department of Plant Biotechnology, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Abe
authors.forename: Keishi
authors.initials: K
authors.lastname: Osakabe
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nakayama
authors.forename: Masaki
authors.initials: M
authors.lastname: Endo
authors.forename: Akemi
authors.initials: A
authors.lastname: Tagiri
authors.forename: Setsuko
authors.initials: S
authors.lastname: Todoriki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Seiichi
authors.initials: S
authors.lastname: Toki
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D002945:Cisplatin / Q000633:toxicity; D003432:Cross-Linking Reagents / Q000633:toxicity; D004249:DNA Damage; D004269:DNA, Bacterial / Q000235:genetics; D018744:DNA, Plant / Q000187:drug effects / Q000235:genetics; D005720:Gamma Rays; D017343:Genes, Plant; D008540:Meiosis / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D009154:Mutation; D030821:Plants, Genetically Modified; D011995:Recombination, Genetic
chemical_list: D029681:Arabidopsis Proteins; C464448:AtRAD51C protein, Arabidopsis; D003432:Cross-Linking Reagents; D004269:DNA, Bacterial; D018744:DNA, Plant; C036483:T-DNA; D002945:Cisplatin