Lysates were clarified from sonicated nuclei, and histone-DNA complexes were isolated with antibody (H3K4me1: abcam, ab8895 (lot: GR61280-1); H3K4me2: abcam, ab7766 (lot: GR102810-1); H3K4me3: Millipore, 17-614 (lot: 2109590); H3K27ac: abcam, ab4729 (lot: GR81163-1)). Libraries were prepared according to Illumina's instructions accompanying the DNA Sample Kit.