Comparative Transcriptomic Analysis of the Liver and Spleen in Ussuri Catfish (Pseudobagrus ussuriensis) Challenged with Polyriboinosinic Polyribocytidylic Acid (Poly(I:C))

Poly (I:C), a viral mimic, is capable of activating the antiviral immune mechanisms in teleosts. In this study, we investigated the transcriptional responses of Ussuri Catfish (Pseudobagrus ussuriensis) to poly (I:C) stimulation at 3 and 48 h, focusing on the similarities and differences in antiviral mechanisms exhibited in the liver and spleen. At 3 h, the signaling pathways that were concurrently enriched in both the spleen and liver include JAK-STAT, TNF, NF-κB, RIG-I-like receptor, and NOD-like receptor. At 48 h, the signaling pathways that were concurrently enriched in both the spleen and liver include JAK-STAT signaling and cellular homeostasis processes. However, in the liver, the signaling pathways that responded to poly (I:C) stimulation at both 3 and 48 h are cytokine–cytokine receptor interaction and RIG-I-like receptor signaling. In the spleen, the signaling pathways that responded to poly (I:C) stimulation at both 3 and 48 h are Hippo signaling, Wnt signaling, TGF-β signaling, and ECM-receptor interaction. Ultimately, the pathways that were enriched in the intersection genes across all groups are JAK-STAT signaling, NK cell-mediated cytotoxicity, and ECM-receptor interaction, and the core genes identified in the intersection genes of all groups are PTPRS, HECW1, and ERN1 (IRE1), along with UMAD, DKK1, CSH, and RTKN2. Through this study, we identified the key signaling pathways and core genes involved in the antiviral response of Ussuri catfish. These findings provide valuable insights into the antiviral mechanisms of Ussuri catfish.