Caenorhabditis elegans DSB-3 reveals conservation and divergence among protein complexes promoting meiotic double-strand breaks

Significance Faithful inheritance of chromosomes during meiosis depends on the formation and repair of double-strand DNA breaks (DSBs), which are generated through the activity of a topoisomerase-like protein known as Spo11. Spo11 exhibits strong conservation throughout eukaryotes, presumably reflecting constraints imposed by its biochemical activity, but auxiliary proteins that collaborate with Spo11 to promote and regulate DSB formation are less well conserved. Here we investigate a cohort of proteins comprising a complex required for meiotic DSB formation inCaenorhabditis elegans , providing evidence for both conservation with and divergence from homologous complexes in other organisms. This work highlights the evolutionary malleability of protein complexes that serve essential, yet auxiliary, roles in fundamental biological processes that are central to reproduction.