library_construction_protocol: RNA quality (RIN) was determined on an Agilent 2100 Bioanalyzer using an Agilent RNA 6000 Nano kit. One microgram of each sample was used to generate mRNA libraries following the Illumina TruSeq Stranded mRNA Sample Preparation Guide following the low sample protocol Final cDNA libraries were quantitated using Qubit dsDNA BR assay kit. The quality of the libraries was determined by running each on an Agilent 2100 Bioanalyzer using the DNA 1000 kit. Smear analysis was performed using Agilent 2100 Expert Software (Version B.02.09.SI725 (SR1)) with a range of 200-600bp to determine average size of each library. Size and concentration were then used to calculate the molarity of each library. All libraries were pooled and denatured following the standard normalization method in the Illumina Denature and Dilute Libraries Guide for the NextSeq System. Denatured libraries were loaded onto an Illumina NextSeq 550 v2 High output reagent cartridge at a final concentration of 1.8pM in HT1 buffer. Illumina Denatured PhiX control library v3 was also included at 1% concentration Single end 75bp single index sequencing was performed on an Illumina High flow cell v2.5 (#20024907) yielding approximately 15M SE reads per sample.