ATAC-Seq - Nuclei were extracted from 10 eye-antennal discs . FAIRE-Seq - 150 Head complexes were first dissected, fixed and lysed. 200 eye-antennal discs were the uncrosslinked and sonicated, phenol chloroform extraction was used for DNA purification. ChIP-Seq - 750 Head complexes were first fixed, 1000 eye-antennal discs were then dissected and sonicated. Sonicated chromatin was then immunoprecipitated and purified using magnetic beads ATAC-Seq libraries were prepared using a simple PCR reaction with adapters based against the transpon sequence. FAIRE-Seq and ChIP-Seq libraries were prepared using standard Illumina Protocols.