Abstract：As a commercially important marine aquaculture species, Takifugu flavidus frequently challenged by Vibrio anguillarum, a major bacterial pathogen. However, the molecular pattern governing host-pathogen interactions remains poorly understood. To elucidate the molecular patterns underlying host-pathogen interactions, this study conducted transcriptome analysis of T. flavidus liver at 24 h post-infection (hpi). A total of 3 370 differentially expressed genes (DEGs) were identified comprising 1 930 upregulated and 1 440 downregulated genes. GO functional annotation indicated that these genes were significantly enriched in important biological processes such as cytokine-mediated signaling, immune response, cellular response to lipopolysaccharide, B cell proliferation, chemotaxis, iron ion transport, and apoptosis. KEGG pathway analysis further revealed significant enrichment in key immune-related pathways, including Toll-like receptor (TLR), retinoic acid-inducible gene-I-like receptor (RLR), NOD-like receptor (NLR) and mitogen-activated protein kinase (MAPK) signaling pathways. To validate the transcriptomic data, 52 DEGs from 4 immune-related pathways were analyzed via qRT-PCR, demonstrating consistent expression trends with RNA-seq results. This study systematically analyzed the liver transcriptome characteristics of the T. flavidus in response to V. anguillarum infection, providing new theoretical basis for elucidating the immune mechanism of fish against bacterial infections.
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