Chemical inhibition of Top2a pre-MZT does not affect cell cycle profile at 27 hpf. A) Schematic of the experimental procedure. 1-2 cell stage embryos were treated with 100 μM ICRF-193 for 3.5 hours when the drug was removed and the cell cycle profile analysed at 27 hpf. B-C) Flow cytometry analysis of cell cycle profiles of wt (B) and mutant (C) embryos. D) Table documenting the percentage of cells in cell cycle phases following ICRF-193 treatment.