Total RNA from purified iOLs were prepared using Illumina RNA-Seq Preparation Kit and subjected to 150-bp double-end sequencing with an Illumina sequencer as previously described56. At least 20 million clean reads of sequencing depth were obtained for each sample. RNA-seq raw data were initially filtered to obtain clean data after quality control. Clean data were aligned to the mouse genome (mm10) or rat genome (rn6) by HISAT257. Raw counts for each gene were calculated by Htseq58. StringTie was used to estimate the expression level of detected genes59. DEGs were defined as genes with FDR less than 0.001 and fold change larger than 1.5.
