library_construction_protocol: Total RNA was extracted using TRIzol reagent following the manufacturer's instructions. RNA quantity and quality were assessed by NanoDrop and agarose gel electrophoresis. PolyA-enriched mRNA was isolated from total RNA and used to prepare sequencing libraries with the Illumina TruSeq mRNA library preparation protocol. Libraries were constructed through mRNA fragmentation, cDNA synthesis, end repair, A-tailing, adapter ligation, and PCR amplification.