Endonuclease which, in association with baf-1, plays an essential role during embryogenesis in the DNA repair response following DNA damage probably by ensuring proper chromosome segregation (PubMed:22383942). Also required during postembryonic cell divisions after DNA damage caused by ionizing radiation to ensure normal cell proliferation (PubMed:22383942). Resolves chromatin bridges in late mitosis that result from incomplete DNA replication, defective chromosome condensation or unresolved recombination intermediates (PubMed:29463814). Together with brc-1, contributes to genome integrity by resolving mitotic chromatin bridges that result from incomplete processing of DNA breaks (PubMed:29463814). In parallel to the slx-1/mus-81 pathway, acts in processing early recombination intermediates in meiotic prophase I to prevent illegitimate recombination (PubMed:29879106). Also involved in processing remaining, erroneous recombination intermediates that persist into the second meiotic division (PubMed:29879106). Inhibited by EDTA. Localizes to foci-like structures outside the nucleus (PubMed:22383942, PubMed:29463814, PubMed:29879106). In pachytene, localizes to foci both in and outside of the nucleus (PubMed:29879106). Colocalizes with air-2 between dividing nuclei in meiosis II (PubMed:29879106). In mitosis, localizes to the center of chromatin bridges that are formed in response to DNA defects (PubMed:29463814). Forms initially a ring like structure encircling chromatin bridges between two separated daughter cells until in late telophase, localizes to the center of chromatin bridges (PubMed:29463814). Colocalizes with air-2 at the midbody (PubMed:29463814). Midbody localization depends on the formation of the central spindle and the midbody and on air-2 (PubMed:29463814). Colocalizes with the central spindle component zen-4 at the central spindle (PubMed:29463814). Expressed in embryos. Phosphorylated. Phosphorylated during telophase when localized at the midbody.