Cells were cross linked in 1% formaldehyde and quenched with glycine prior to incubation in lysis buffer, and sonicated six times with 5 min cycles of 30s on/off o a Bioruptor sonicator. Samples were immunoprecipitated with either GAF, CLAMP, or MSL3 antibodies, and DNA clean-up was performed including RNase and Proteinase-K digestion steps. Libraries were prepared using the NEBNext Ultra II DNA library prep kit