library_construction_protocol: Freshly dissected tissue from 3 animals was pooled together, disaggregated, lysed to nuclei, and frozen at -80 until ChIP was performed with Abcam ab4729 antibodies.  Input samples are background DNA that have not been immunoprecipitated. Libraries were prepared from eluted DNA using KAPA LTP library kits (KK8230) using Bioo Scientific index adapters, size-selected using AmpureXP beads (Beckman Coulter, Brea, CA, USA) and quality checked by Qubit 2.0 and Bioanalyzer (Agilent 2100). Samples were sequenced to a depth of 20-30M reads per replicate on an Illumina HiSeq 2500 sequencer using a TruSeq SBS sequencing kit, version 4, in single-end format with fragment length of 100 bp.