Required for the homologous recombination repair of DNA double strand breaks, thereby playing a role in chromosome integrity (PubMed:15798199, PubMed:16843491). Acts by targeting rad-51 to sites of DNA damage and stabilizing rad-51-DNA filaments by blocking ATP hydrolysis catalyzed by rad-51 (PubMed:15798199, PubMed:16843491, PubMed:17483448, PubMed:18779660). Promotes rad-51 mediated displacement-loop (D-loop) formation during strand invasion between the invading single-stranded DNA (ssDNA) and the homologous duplex DNA (PubMed:16843491). Also functions independently of rad-51 in DNA double-strand break (DSB) repair by promoting DNA single-strand annealing (SSA) when the homologous recombination (HR) and non-homologous end joining (NHEJ) pathways are compromised (PubMed:15798199, PubMed:16843491). Binds selectively to single-stranded (ssDNA) via its C-terminus (PubMed:15798199). Involved in telomere maintenance and replicative senescence (PubMed:27761361). Interacts (via N-terminus) with rad-51; regulates rad-51 recruitment to sites of DNA double strand breaks (PubMed:15798199, PubMed:17483448). Diffusely localized in the nucleus. Recruited to sites of DNA damage upon induction of DNA double strand breaks by ionizing radiation (IR) or in meiosis. Expressed in the germline, with highest expression in cells undergoing oogenesis. The BRCA2 repeat-like region is required for rad-51 binding. Mutant animals are egg-laying defective and exhibit a reduced brood size and high embryonic lethality (PubMed:15798199, PubMed:18779660). Impaired formation of rad-51 foci and accumulation of rpa-1 foci in the meiotic region of the germline in mutants either untreated or treated with ionizing radiation (IR), indicating impaired DNA double strand break repair by homologous recombination (PubMed:15798199, PubMed:18779660). Decompaction of chromatin, chromosome aggregation and aberrant number of bivalent chromosomes during meiosis (PubMed:15798199, PubMed:18779660). In a telomerase trt-1 mutant background, RNAi-mediated knockdown leads to telomere shortening in early generations, to telomere elongation in late generations and to a delay in generational replicative senescence (PubMed:27761361).