library_construction_protocol: Total RNA was isolated from tissues using Trizol (Life Technologies, Paisley, UK) or the RNeasy kit (QIAGEN, Manchester, UK) according to manufacturer's protocol. Genomic DNA was removed from 500ng of total RNA using the genomic DNA eliminator column from RNeasy Plus Micro Kit (QIAGEN) and rRNA removed using RiboZero (Epicentre, Wisconsin, USA) following manufacturer's instructions. Strand-specific libraries were created using NEBNext Ultra Directional RNA Library Prep Kit for Illumina (NEB, Hitchin, Herts, UK) and 20ng of the rRNA depleted RNA. Final libraries were quantified using qPCR and clustered at a molarity of 14.5 pM, sequencing was performed on an Illumina HiSeq 2500 using 2x76 cycles of version 3 SBS chemistry.