Extended Data Figure 7: Effects of dmc1 deletion or spo11 hypomorphic mutation on ZMM mutant phenotypes.

a, b, ZMM status is irrelevant in a dmc1 background. Broken chromosomes accumulate to similar levels in a dmc1 single mutant and dmc1 zmm double mutants. Representative pulsed-field gel Southern blots probed for chromosome IX are in a and Poisson-corrected quantification of DSBs is in b (mean ± s.d., 3 cultures). c, Reducing Spo11 activity in a zip3 mutant partially alleviates the prophase I delay/arrest. Meiotic progression was assessed by staining with DAPI (4′,6-diamidino-2-phenylindole) and measuring the percentage of cells that had completed meiosis I (MI) with or without completing meiosis II ( ± MII). Data are means ± s.d. for 3 cultures, except wild type and spo11-HA, each analysed once.