cells were fixed with 1% formaldehyde for 10 min. After fixation, nuclei were isolated, the nuclear DNA was digested by micrococcal nuclease to 150-200 bp DNA fragments, the DNA fragments with attached proteins were resuspended in SDS-containing lysis buffer, and immunoprecipitated by antibodies against various histone modifications. For Illumina Hi-Seq 2500 sequencing we used New England BioLabs NEBNext ChIP-Seq library preparation reagent set for Illumina and and constructed library as described in the E6240 instruction manual. For SOLiD sequencing we used Applied Biosystems SOLiD 4 System and constructed library as described in the SOLiD 4 System Library Preparation Guide.