Embryos were fixed with 2% Formalin for 30min at room temperature. Fixed chromatin was extracted using the FastPrep-24™ (MPI) homogenizer and sonicated using the Bioruptor (Diagenode) Libraries were prepared from chromatin IP and input samples using the NEBNext ultra DNA library prep kit for Illumina (NEB # 7370) and the NEBNext Multiplex Oligos for Illumina (NEB # E7335)