Lysates were clarified from sonicated nuclei and histone-DNA complexes were isolated with antibody. ChIP-Seq libraries were prepared with NEB reagents as previously described. Briefly, DNA was end-repaired and the blunt, phosphorylated ends were treated to yield a protruding 3- 'A' base for ligation of Illumina's adapters which have a single 'T' base overhang at the 3' end. After adapter ligation DNA was PCR amplified with Illumina primers and library fragments of ~250 bp were band isolated from an agarose gel.