RNA from sorted cells was isolated using RNeasy Micro Kit (QIAGEN) and quantified using nanodrop and Agilent bioanalyzer. RNA-seq libraries were prepared according to SMART-seq2 protocol, with the following modifications: PCR preamplification to 10-12 cycles, two rounds beads cleanup with 1:1 ratio after cDNA synthesis, and 0.6-0.8 dual beads cleanup for Nextera XT DNA-seq library purification. Each library was bar-coded and then pooled for sequencing run with 50bp single-read sequencing protocol.