design: Polyadenylated mRNA was enriched using oligo(dT) magnetic beads, and mRNA was reverse-transcribed into cDNA with the SMARTer PCR cDNA Synthesis Kit. The cDNA was amplified via PCR, yielding sufficient total cDNA after optimized. Full-length cDNA subjected to damage repair, end repair, and ligation with SMARTbell to construct a full-length transcriptome library. Exonuclease digestion was performed to remove unligated adapter sequences, resulting in the final SMRTbell library.