RNA was extracted with Qiagen RNeasy Midi Kit (Qiagen USA, Valencia, CA). RNA quantity was estimated using an ND-1000 Spectrophotometer (NanoDrop USA, Wilmington, DE). RNA quality was verified using Agilent Bioanalyser 2100 LabChip and Agilent RNA 6000 Nano kit (Agilent Technologies, USA) and evaluated on an agarose gel (2%) stained with ethidium bromide. cDNA synthesis and normalization protocol was taken from Novaes et al. [24] with minor modifications: The cDNA was synthesized from 1-2 µg of RNA and the adaptors incorporated weren’t removed by SfiI digestion.