library_construction_protocol: Cells were trypsinized and centrifuged at 310 x g for 5 minutes, then transferred to 1.5 ml tube, washed with PBS twice, snap frozen with ethanol-dry ice bath. One microgram of total RNA per each time point was used as the input to an mRNA capture with oligo-dT coated magnetic beads. The mRNA was fragmented, and then a random-primed cDNA synthesis was performed. The resulting double-strand cDNA was used as the input to a standard Illumina library prep (TruSeq Stranded mRNA LT library prep kit, Illumina) with end-repair, adapter ligation and PCR amplification being performed to generate the library.