library_construction_protocol: Total RNA was extracted using Trizol reagent kit (Invitrogen, Carlsbad, CA,USA) according to the manufacturer's protocol. RNA quality was evaluated (Agilent 2100 Bioanalyzer, Agilent Technologies, Palo Alto, CA, USA) and verified by RNase-free agarose gel electrophoresis. Next, mRNA was enriched (Oligo(dT) beads), fragmented, and reverse-transcribed (NEBNext Ultra RNA Library Prep Kit for Illumina, NEB #7530, New England Biolabs, Ipswich, MA, USA). The cDNA was end-repaired, A-tailed, adapter-ligated, purified (AMPure XP Beads, 1.0X), and PCR-amplified.