library_construction_protocol: Tissue was homogenized in Trizol. RNA was extracted using commercial kits according to the manufacturer's instructions (Zymo RNA Clean & Concentrator-5 Kit and QIAGEN RNEasy Plus Mini Kit). First strand cDNA synthesis was performed by reverse transcribing polyA mRNAs using an oligo(dT) primer that also adds on a common primer sequence. RNA/DNA duplexes were removed by RNase H treatment. TdTomato self-reporting transcripts (SRTs) were amplified by PCR. PCR products were tagmented and indexed using the Illumina Nextera XT library preparation kit.