RNA was isolated using a RNeasy Micro Kit (Qiagen) following manufacturer's instructions and subsequently preserved at -80°C 220ng of total RNA per sample underwent a process of mRNA enrichment using NEBNext Poly(A) mRNA Magnetic Isolation Module (New England Biolabs). Afterwards, stranded cDNA libraries were generated using NEBNext Ultra II Directional RNA Library Prep Kit (New England Biolabs). Procedures were done downscaling 2/3 the initial volumes described in the user manual and one extra purification step was performed at the end of the protocol using Agencourt AMPure XP Beads (Beckman Coulter).