DNA library construction and sequencing

This was done as reported before [91]. Briefly, RNA quality was assessed by Agilent 2100 Bioanalyzer with an RNA 6000 Nano Chip (Agilent Technologies, USA). The NEBNExt Poly(A) mRNA Magnetic Isolation Module (New England Biolabs, USA) was used to purify the mRNA using oligo-dT beads. The NEBNext Ultra Directional RNA Library Prep Kit (NEB) and NEBNext Mulitplex Oligos for Illumina (NEB) were used to construct complementary DNA (cDNA) libraries for Illumina sequencing. The libraries were sequenced in an Illumina HiSeq 2500 DNA sequencer, utilizing 125 bp single end sequencing flow cell with a HiSeq Reagent Kit v4 (Illumina, USA).