Comparative transcriptome analysis of Anguilla japonica livers following exposure to methylene blue

The thiazine dye methylene blue is widely used as a disinfectant and antidote in veterinary medicine. Here, we compared transcriptome differences in the liver of Anguilla japonica exposed to methylene blue using Illumina RNA sequencing technology. A total of 75,953,174 and 86,499,866 clean reads with an average length of 126 bp from control and treatment groups respectively. A total of 148,238 transcripts were assembled, with 62,152 components were assembled. Overall, 416,991 unigenes were checked against the National Center of Biotechnology Information, Non‐redundant, Cluster of Orthologous Groups (COG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Of these, 18,541 genes were judged to be differently expressed. The gene ontology (GO) terms “molecular function” and “biological process” were the most enriched in protein binding, followed by “ATP binding and regulation of transcription,” and “DNA‐dependent.” KEGG pathway analysis revealed significant enrichment of N‐glycan biosynthesis and the citrate cycle. This study determined that unigenes related to transmembrane transport and drug metabolism in A. japonica were differentially expressed following exposure to methylene blue. These findings can shed insight into the mechanism of methylene blue metabolism in this economically important species.