design: First-strand cDNA was synthesized by the HiScriptIII 1st Strand cDNA Synthesis Kit in the presence of specific reagents to ensure that only RNA was used as template. Double-stranded cDNA was synthesized using DNA Polymerase I Klenow Fragment exo (Vazyme, Nanjing, China), dNTP mix (Thermo Fisher), and random hexamer primer (Thermo Fisher) and was purified with Agencourt AMPure XP beads (Beckman, CA, USA). Next, the DNA libraries were prepared using the TruePrepTM DNA Library Prep Kit V2 for Illumina (Vazyme).