Circular RNAs (circRNAs), a class of non-coding RNAs, play an important role in regulating various biological processes. In the present study, circRNAs from the Megalobrama amblycephala liver were identified at five different time points post Aeromonas hydrophila using RNA-seq technology. A total of 250 circRNAs were identified, of which 106 were differentially expressed (DE) in ten pairwise comparisons. GO and KEGG analyses showed that the parental genes of DE circRNAs were enriched in phagocytosis, complement and coagulation cascades, and Fc gamma R-mediated phagocytosis pathways. According to ceRNA hypothesis, the interaction network of circRNAs, miRNAs and mRNAs was constructed. Moreover, WGCNA was conducted, and five specific modules significantly related to bacterial infection were identified. All the above results reveal the important role of circRNAs in immune response, which enriches the information of circRNAs in teleost, and helps to understand the immune response mechanism of M. amblycephala to A. hydrophila.

环状RNA（circRNAs）是一类非编码RNA，在调节各种生物过程中发挥着重要作用。在本研究中，在嗜水气单胞菌后的五个不同时间点鉴定了来自芨芨草肝脏的circRNA使用 RNA-seq 技术。共鉴定出 250 个 circRNA，其中 106 个在 10 个成对比较中差异表达（DE）。GO 和 KEGG 分析表明，DE circRNA 的亲本基因在吞噬作用、补体和凝血级联反应以及 Fc γ R 介导的吞噬作用途径中富集。根据ceRNA假说，构建了circRNAs、miRNAs和mRNAs的相互作用网络。此外，进行了WGCNA，并确定了与细菌感染显着相关的五个特定模块。以上结果揭示了circRNAs在免疫反应中的重要作用，丰富了硬骨鱼中circRNAs的信息，有助于了解M. amblycephala对A. hydrophila的免疫反应机制。