TotalRNA was isolated using the RNAdvance Cell v2 kit (Beckmann-Coulter). Quality and quantity of isolated RNA was analyzed with the Bioanalyzer RNA Pico Chip (Agilent). cDNA synthesis was performed with the SMART-Seq v4 Ultra Low Input RNA kit (Takara) following the manufacturers protocol with 12 cycles of PCR amplification. Input amount were 1ng of each RNA sample. cDNA was measured with Bioanalyzer DNA HS Chip (Agilent) and 300pg of amplified cDNA were used for library preparation with the Nextera XP DNA library Preparation Kit (Illumina).  Libraries were analyzed with a Bioanalyzer DNA HS Chip (Agilent) and quantified by qPCR following guidelines from Illumina and using Kapa SYBR mastermix (Kapa Biosystems). After the normalization of all libraries to 2nM, 13 samples each were pooled and sequenced on two single-end runs (1x100bp, dual-index) on a HiSeq2500 (Illumina) using HiSeq Rapid v2 chemistry (Illumina). Demultiplexing was done with the bcl2fastq software (v2.20.0.422).