library_construction_protocol: RNA was isolated and purified from snap-frozen cells using the RNeasy Mini Kit (Qiagen) according to the manufacturer's instructions. The purification included a DNase treatment using the RNase-free DNase Set. Purified RNA was submitted to the Genomics Facility at the Babraham Institute for library preparation and RNAseq. Overall RNA quality was assessed using the Agilent TapeStation (RIN scores > 9). cDNA libraries were constructed using Watchmaker DNA Library Prep Kits.