In the 'Transcriptomics' module, over 3,897 RNA-seq libraries representing 131 diverse organs, tissues, and treatments across 44 species have been processed. The portal includes four functional modules: single/multiple-species gene expression profiles, tissue-specific genes, and comparative transcriptomics. Users can analyze and compare 3,897 gene expression profiles, identify genes specifically expressed in certain tissues, and investigate differentially expressed genes associated with key traits or biological processes using this portal.
The quality of the RNA sequencing reads was assessed using FastQC (v0.11.9) (https://www.bioinformatics.babraham.ac.uk/projects/fastqc/). Barcode adaptors and low-quality reads (read quality < 70 for paired-end reads) were removed by fastp (v.0.23.0) [1]. The filtered reads were then aligned to the reference genomes separately using Hisat2 (v2.1.0) [2] with default parameters. BAM files containing the aligned reads were processed with StringTie (v1.3.3b) [3] to measure gene expression levels. Gene-level raw count data files were generated using featureCounts (v1.6.4) [4]. The raw count data were imported into Bioconductor package DESeq2 [5] in R to identify the differentially expressed genes(DEGs). Genes with a log2 fold change ≥ 1 or ≤ -1 and an FDR (False Discovery Rate) ≤ were considered DEGs.