library_construction_protocol: Cells were fixed with 1% formaldehyde for 30 minutes. After quenching and cell lysis, chromatin was sonicated using a Bandelin Sonopuls HD2070. DNA libraries were prepared by Genomic Facility at CIG, UNIL, Lausanne. Briefly, the DNA was fragmented by sonication (Covaris S2) to fragment sizes ranging from 220–250 bp. DNA libraries were prepared using the Ovation Ultralow Library Systems V2 Kit (NuGEN) including 15 cycles of PCR amplification. 20-30 million sequence reads were obtained on a NovaSeq 6000 system with 150-bp read length