First- and second-strand cDNA synthesis was performed using a SuperScript double-stranded cDNA synthesis kit (Invitrogen, CA) with random hexamer primers. The resulting cDNA fragments were subjected to end repair, phosphorylation, and adenylation at the 3 ends, followed by adaptor ligation according to Illumina library preparation guidelines. Fragments of approximately 300 bp were selected using 2% low-range ultra-agarose gel electrophoresis. The libraries were then amplified by PCR using Phusion DNA polymerase (NEB) for 15 cycles. After quantification using a Qubit 4.0 fluorometer, the libraries were sequenced on an Illumina NovaSeq 6000 platform to generate paired-end reads (2  150 bp).