Embryos were sonicated 7 times, 20 seconds each, at 20% output. Cic-DNA complexes were isolated using magnetic protein G dynabead and GFP antibody. DNA was uncrosslinked from protein and purified. Purified ChIP and input DNA were prepared for Illumina sequencing using the NEBNext Ultra II DNA Library Prep Kit for Illumina (E7645S). The primers used for multiplexing the library came from the NEBNext Multiplex Oligos for Illumina Kit (E7335S).