RNA extraction was performed using QIAGEN RNeasy Kit (Qiagen) following the manufacturer 's protocol. Then RNA Integrity Number (RIN) was measured using Agilent 2100 bio-Analyzer. Qubit RNA Assay Kits were used to measure RNA concentration. mRNA-seq libraries were prepared according to the TruSeq low sample protocol (Illumina, San Diego, CA, USA), starting with 1 µg of total RNA per sample.