RNA degradation and contamination was monitored on 1% agarose gels.RNA purity was checked using the NanoPhotometer® spectrophotometer.RNA concentration was measured using Qubit® RNA Assay Kit in Qubit® 2.0 Flurometer.RNA integrity was assessed using the RNA Nano 6000 Assay Kit of the Agilent   Bioanalyzer 2100 system. RNA libraries were prepared for sequencing using standard Illumina protocols.