PRO-seq: Nuclear RUN-on was performed using biotinlated NTPs on nuclei isolated from S2 cells treated with either DMSO or TSA for desired time. Sodium hydroxide was used to hydrolyse the biotynlated nascent RNA synthesised to average fragment size of 100-150. Hydrolysed fragment were isolated using streptavidin coated magnetic beads ChIP-seq: Chromatin lysates prepared from difffrent treatments were cleared from sonicated nuclei and histone-DNA complexes were isolated with antibody. ATAC-seq: Crude nuclear extract suitable for ATAC-seq from S2 cells treated with drugs was prepared in ATAC lysis buffer (10mM Tris pH 7.4, 10mM NaCl, 3mM MgCl2 0.1% IGEPAL), followed by tagmentation using Tn5 Transposase (Illumina, 15027865). Tagmented DNA was purified using Agencourt AMPure XP beads (Beckman coutler, A63880) PRO-seq: 3' adaptors were ligated to isolated RNA which were decapped prior to 5' adaptor ligation. cDNA was generated from these adaptor ligated RNAs and libraries were generated uning Illumina Tru-seq small-RNA adaptors for sequencing. ChIP-seq: Libraries from input and immunoprecipitated DNA were prepared with NEBNext® Ultra™ II DNA Library Prep kit (NEB, E7645) . ATAC-seq: DNA after Tagmentation were amplified using primers from Nextera Index Kit (Illumina, FC-121-1012).