library_construction_protocol: After RNA biotinylation and free biotin removal, biotinylated RNA was purified by streptavidin-coupled Dynabeads (Thermo, cat. no. 11205D). rRNA was depleted before library construction. Sequencing libraries were constructed by following the Illumina TruSeq RNA Library preparation protocol. Sequencing libraries were constructed by following the Illumina TruSeq RNA Library preparation protocol.