Total cellular RNA was extracted from C57bl6 adult mouse epididymal cauda using the RNeasy mini kit (QIAGEN GmBH, Hilden, Germany), and on-column DNase treatment was performed. Total RNA concentration was quantified by Qubit (Invitrogen) and quality checked by Bioanalyzer (Agilent). Briefly index is added during initial pA priming and pooled samples amplified using template switching oligo. P5 is added by tagmentation by Nextera transposase and PCR. Shared NextSeq2000 run using P3 100cycle kit. (cDNA reads generated 100nt).