Genomic DNA was isolated using QIAGEN All-prep kit Libraries were prepared according to NEB's instructions accompanying the NEBNext® ChIP-seq Library Prep Reagent set for Illumina. Adapter ligated DNA was PCR amplified with Illumina primers for 15 cycles. The purified DNA was captured on an Illumina flow cell for cluster generation. Libraries were sequenced on the Hi-Seq 1000 following the manufacturer's protocols.