Lysates were clarified from sonicated nuclei and histone-DNA complexes were isolated with antibody. a ChIP-seq library was constructed using NEBNext® ChIP-seq sample preparation kit (E6200, New England Biolabs) according to the manufacturer’s protocol. Size-selection was performed by gel extraction after agarose gel electrophoresis or by magnetic separation using AMPure XP beads. Multiplexing sample preparation oligonucleotide kit (#PE-400-1001, Illumina) was used for index labelling. Sample quality was analyzed using an Agilent 2100 Bioanalyzer prior to sequencing.