For ChIP, cells were sorted directly in nuclear isolation buffer containing RNAse inhibitor and protease inhibitor cocktail. For RNA-seq libraries, RNA was extracted using TriReagent, and dsCDNA was synthesized using Superscript III and Klenow fragment, respectively. For ChIP-seq libraries, DNA was extracted from immunoprecipitated DNA-protein complexes using phenol:chloroform:isoamyl alcohol 25:24:1. Adaptor ligation based library construction for paired-end Illumina sequencing.