Extended Data Fig. 10: Model of Spo11-induced break formation.

a, AFM experiments suggest a model where the core complex binds a DNA duplex, bends it, then traps a second duplex. Perhaps DNA cleavage happens in the context of a trapped DNA junction, similar to Topo VI. After cleavage, Spo11 remains covalently attached to the DNA end through covalent and non-covalent interactions. b, Model of assembly of the DSB machinery. DNA-driven condensation by Rec114–Mei4–Mer2 is proposed to provide a platform that recruits the core complex, where it engages its DNA substrate⁵⁸. A hypothetical arrangement is shown where each dimer of core complexes captures a pair of DNA duplexes, which, for example, could be sister chromatids. c, Depletion of long oligos in Spo11 mutants with reduced DNA-binding activity is consistent with a model⁵⁷ where long oligos arise from occlusion of the DNA substrate by multiple Spo11 complexes that reduce access to MRX/Sae2.