RNA was extracted using Trizol reagent (Life technologies). RNAse free DNaseI (Sigma) was used to eliminate DNA contamination and the treated RNA was purified with RNeasy mini kit (Qiagen). For ChIP, ESCs were fixed with 1% formaldehyde for 10 minutes. After quenching and cell lysis, chromatin were sonicated using a E220 focused-ultrasonicator (Covaris). 100 µg sheared chromatin, 5 µg antibody, and 50 µl protein A/G beads (Santa Cruz) were used for each immunoprecipitation. Immunoprecipitated DNA were purified after washing, eluting, and reverse-crosslinking and submitted for library preparation. ChIP-seq libraries were prepared using the KAPA HTP Library Preparation Kit complemented with NEXTflex DNA Barcodes from Bioo Scientific. 10 ng of DNA was used as starting material for input and ip samples. Libraries were amplified using 13 cycles on the thermocycler. Post amplification libraries were size selected at 250- 450bp in length using Agencourt AMPure XP beads from Beckman Coulter. Libraries were validated using the Agilent High Sensitivity DNA Kit. RNA-seq libraries were prepared using the Illumina TruSeq Stranded Total RNA Preparation Kit with Ribo-Depletion. Input RNA quality was validated using the Agilent RNA 6000 Nano Kit. 200ng-1 µg of total RNA was used as starting material. Libraries were validated using the Agilent DNA 1000 Kit