           10ug DNaseI treated RNA was used to purify polyA+RNA fraction using the MACSTM mRNA Isolation Kit (Miltenyi Biotec, Germany). Double-stranded cDNA was synthesized from the purified polyA+RNA using SuperscriptTM Double-Stranded cDNA Synthesis kit (Invitrogen, USA) and random hexamer primers (Invitrogen) at a concentration of 5µM.  The cDNA was sheared for 25 min using Bioruptor UCD-200 (Diagenode SA, Belgium), and run in 8% PAGE. 200-250bp  DNA fraction was excised and eluted from the gel slice overnight at 4 °C in 300 µl of elution buffer (5:1, LoTE buffer (3 mM Tris-HCl, pH 7.5, 0.2 mM EDTA)-7.5 M ammonium acetate), and was purified using a Spin-X Filter Tube (Fisher Scientific) and by ethanol precipitation. The library was prepared by following the pair end library protocol (Illunima Inc., USA). Briefly, the DNA was subject to end-repair, and phosphorylation by T4 DNA polymerase, Klenow DNA Polymerase, and T4 polynucleotide kinase respectively in a single reaction, and then 3’ A overhangs generation by Klenow fragment (3’ to 5’ exo minus),  and ligated to Illumina PE adapters, which contain 5’ T overhangs.  The adapter-ligated products were purified on Qiaquick spin columns (Qiagen), then PCR-amplified with Phusion DNA Polymerase for 10 cycles using Illumina’s PE primer set (Illumina).  PCR products were purified on Qiaquick MinElute columns (Qiagen) and the DNA quality assessed and quantified using an Agilent DNA 1000 series II assay and Nanodrop 1000         