a, Resection-mediated ssDNA formation at an HO DSB in wild-type SAE2 (filled squares), sae2-S267A (open triangle), sae2-S267E (open diamonds) or empty vector (solid circles) at indicated times after HO induction at the MAT locus (left), 5 kb downstream of MAT (centre) or LEU2 locus (right). b, Wild-type SAE2 (squares) or sae2-S267E (diamonds) strains containing Cdc28-as1 were grown as in a but in the presence of dimethylsulphoxide (filled symbols) or 1NM-PP1 (open symbols). Results are shown as means ± s.d. (n = 5).