library_construction_protocol: Total RNA was extracted using standard hot phenol chloroform extraction. A fixed quantity of total RNA plus a fixed quantity of in vitro transcribed 4-thiouracil labeled s. pombe derived spike-in RNAs were combined for each sample. 4-thiouracil labeled RNA was purified via biotinylation and pull-down with streptavidin beads. Libraries were constructed via multiplexed primer extension sequencing (MPE-seq)