library_construction_protocol: The isolation of RNA was conducted using TriPure Isolation Reagent (Roche, cat. no. 11667165001) following manufacturer's protocol. mRNA was enriched using oligo(dT) beads and fragmented randomly by adding fragmentation buffer. The cDNA was synthesized by using mRNA template and random hexamers primer, after which a custom second-strand synthesis buffer (Illumina) , dNTPs, RNase H and DNA polymerase I are added to initiate the second-strand synthesis. After a series of terminal repair, ligation and sequencing adaptor ligation, the double-stranded cDNA library was completed through size selection and PCR enrichment.