we mixed the samples with 200 µL of 1-bromo-3-chloropropane (Sigma Aldrich) and centrifuged at 4˚C for 15 minutes at 16,000 x g. We removed the aqueous phase and passed it through a QIAshredder column (Qiagen) at 21,000 x g for 2 minutes. RNA was extracted using the Qiagen AllPrep DNA/RNA system. An additional on-column DNase I treatment was performed for all extractions. two hundred nanograms of RNA was used as the input for the Illumina stranded mRNA prep, ligation kit (Illumina) to generate sequencing libraries following the manufacturer's protocol.