Chromatin lysates were isolated from sonicated nuclei (from a 10-cm plate containing 1-2 x 106 cells) and histone-DNA interactions were extracted using an antibody against H3K27ac Libraries were prepared at Global Biologics (Missouri) using the Illumina ChIP-seq kit, beginning with 20-30ng of pooled DNA sample (from replicates). Barcodes were used to multiplex the sequencing run and the barcodes used were the following: CGATGT, TGACCA, ACAGTG, GCCAAT, CAGATC, CTTGTA. Libraries were sequenced on the HiSeq2000 according to the manufacturer's protocols at the University of Delaware