RNA extracted with RNAeasy mini kit from Quiagen .  0.5ug of purified total RNA was depleted of ribosomal RNA using NEB rRNA depletion kit (E6310X). NEBNest Ultra II Directional RNA library kit (E7760L) for Illumina was used for library preparation following manufacturers instruction. Briefly, rRNA depleted fraction was fragmented, converted to double stranded cDNA and adapter ligated following end-repair and dA-tailing. Adapter-ligated libraries were generated by PCR using Illumina PE primers and the resulting purified cDNA libraries were applied to an Illumina flow for cluster generation followed by sequencing on an Illumina instrument following manufacturer's instructions.