Cells were sorted by flow cytometry into lysis buffer and extracted for RNA using Single cell purification kit (Norgen Biotek SKU51800). Samples from sorts executed on different days were pooled into three samples per genotype, containing 33,000-105,000 cells (about 15-70 ng total RNA) per sample. RNA concentration and quality were analysed by Tapestation Bioanalyzer 4150. Libraries were amplified and prepared with QuantSeq (Lexogen) following standard protocol.