Single-strand annealing mediates the conservative repair of double-strand DNA breaks in homologous recombination-defective germ cells of Caenorhabditis elegans.

•A missense mutation of a Rad54 homolog in C. elegans decreases ATPase activity.•Rad54 in C. elegans promotes the dissociation of Rad51 from the synapsed DNA intermediates not the prior association of Rad51to double-strand DNA breaks.•The single-strand annealing pathway actively repairs double-strand DNA breaks in the C. elegans germ cells defective in homologous recombination.