3'-end-enriched oligo(dT) primed cDNA
Total RNA was treated with RQ1 RNase-free DNase I and subjected to two rounds of poly(A)  selection. First strand cDNA synthesis was initiated with 5'-T15VN-3' oligonucleotide. After incubation with RNase H and E. coli DNA polymerase I, double-stranded cDNA was fragmented with DNase I and cDNA fragments corresponding in size to about 200 bp were size-selected on an agarose gel. The cDNA ends were repaired, a single dA was added at the 3' ends and genomic adapters (Illumina, Inc. All rights reserved.) were added. Libraries were enriched by limited PCR and purified on an agarose gel.