Cells were sonicated using a Bioruptor UCD-200 sonicator (Diagenode). Sheared chromatin was immunoprecipitated with 2 μl of anti-H3K4me3 antibody (#07-473, Millipore) and 2 μl of Dynabeads M-280 magnetic beads (Sheep Anti-Mouse IgG, Sheep Anti-Rabbit IgG, Life Technologies) using the SX-8G IP-Star Automated System (Diagenode). ChIP samples were decrosslinked 65oC for 4 hr. After incubation the samples were treated with 0.2 mg/ml RNaseA (RNase Cocktail Enzyme Mix, Ambion, Life Technologies) and of 0.4 mg/ml ProteinaseK (Thermo Scientific). DNA was purified with DNA Clean kit & Concentrator TM-5 (Zymo Research) according to the manufacturer's protocol. Libraries were prepared using the supplied Ovation® Ultralow Systems Kit (NuGeneration Limited, England and Wales) according to the manufacturer's protocol. The barcoded libraries were quantified by Qubit 2.0 Fluorometer and validated with Agilent 2200 TapeStation analysis (Agilent Technologies, Inc.). Samples were sequenced with HiSeq 2500 (Illumina, San Diego, USA) producing 50 bp single-end sequences. Sequencing raw data was demultiplexed with CASAVA 1.8.2 software (Illumina, San Diego, USA).