Drosophila SL2 cells stably transfected with FLAG-HA-HMR under a CuSO4 inducible promoter (pMT) were grown at 26˚C in Schneider Drosophila medium (Invitrogen) supplemented with 10% fetal calf serum and antibiotics (100 units/mL penicillin and 100 μg/mL streptomycin). Transfected cells were selected with 20 ug/mL Hygromycin B. Cells were grown to confluence in 550 mL flasks and induced for 20-24h with 250 uM CuSO4 before harvesting for chromatin immunoprecipitation.Chromatin immunoprecipitation was essentially performed as in Gerland et al., 2017. For each ChIP reaction, chromatin isolated from 1–2 x 106 cells was incubated with rat anti-HMR 2C10 antibody pre-coupled to Protein A/G Sepharose through a rabbit IgG anti-rat. ChIP-seq Library