College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China.
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China.
Fish Shellfish Immunol. 2023 Feb;133:108546. doi: 10.1016/j.fsi.2023.108546. Epub 2023 Jan 14.
Rainbow trout (Oncorhynchus mykiss) is a species of cold-water fish with important economic values, widely cultivated worldwide. However, the outbreak of infectious hematopoietic necrosis virus (IHNV) caused the large-scale death of rainbow trout and seriously restricted the development of the trout farming industry. In this study, the changes of immune parameters in different periods (6-, 12-, 24-, 48-, 72-, 96-, 120-, and 144 h post-infection (hpi)), transcriptome profiles of 48 hpi (T48G) compared to control (C48G), and key immune-related genes expression patterns were measured in rainbow trout gill following IHNV challenge through biochemical methods, RNA sequencing (RNA-seq), and quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that alkaline phosphatase (AKP), acid phosphatase (ACP), total superoxide dismutase (T-SOD), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities, as well as lysozyme (LZM) and malonaldehyde (MDA) content decreased and then increased during infection, and remained at a high level after 48 hpi (P < 0.05), whereas catalase (CAT) activity showed a significant peak at 48 hpi (P < 0.05). The mRNA and miRNA analysis identified 4343 differentially expressed genes (DEGs) and 11 differentially expressed miRNAs (DEMs), and numerous immune-related DEGs involved in the Toll-like receptor signaling pathway, apoptosis, DNA replication, p53 signaling, RIG-I-like receptor signaling pathway, and NOD-like receptor signaling pathway and expression were significantly up-regulated in T48Gm group, including tlr3, tlr7, tlr8, traf3, ifih1, trim25, dhx58, ddh58, hsp90a.1, nlrc3, nlrc5, socs3, irf3, irf7, casp7, mx1, and vig2. The integrated analysis identified several important miRNAs (ola-miR-27d-3p_R+5, gmo-miR-124-3-5p, ssa-miR-301a-5p_L+2, and ssa-miR-146d-3p) that targeted key immune-related DEGs. Expression analysis showed that tlr3, tlr7, traf3, ifih1, dhx58, hap90a.1, irf3, irf7, and mx1 genes increased and then decreased during infection, and peaked at 72 hpi (P < 0.05). However, trim25 expression peaked at 96 hpi (P < 0.05). This study contributes to understanding immune response of rainbow trout against IHNV infection, and provides new insights into the immune regulation mechanisms and disease resistance breeding studies.
虹鳟（Oncorhynchus mykiss）是一种具有重要经济价值的冷水鱼类，广泛分布于世界各地。然而，传染性造血器官坏死病毒（IHNV）的爆发导致虹鳟大量死亡，严重限制了鳜鱼养殖业的发展。在这项研究中，通过生化方法、RNA 测序（RNA-seq）和定量实时聚合酶链反应（qRT-PCR）测量了 IHNV 感染后不同时间点（6、12、24、48、72、96、120 和 144 小时感染后（hpi））、转录组谱 48 hpi（T48G）与对照（C48G）相比虹鳟鱼鳃中免疫参数的变化以及关键免疫相关基因的表达模式。结果表明，碱性磷酸酶（AKP）、酸性磷酸酶（ACP）、总超氧化物歧化酶（T-SOD）、丙氨酸氨基转移酶（ALT）和天冬氨酸氨基转移酶（AST）活性以及溶菌酶（LZM）和丙二醛（MDA）含量在感染过程中先降低后升高，并在 48 hpi 后保持高水平（P<0.05），而过氧化氢酶（CAT）活性在 48 hpi 时显著升高（P<0.05）。mRNA 和 miRNA 分析鉴定了 4343 个差异表达基因（DEGs）和 11 个差异表达 miRNA（DEMs），许多参与 Toll 样受体信号通路、细胞凋亡、DNA 复制、p53 信号通路、RIG-I 样受体信号通路和 NOD 样受体信号通路的免疫相关 DEGs在 T48Gm 组中显著上调，包括 tlr3、tlr7、tlr8、traff3、ifih1、trim25、dhx58、ddh58、hsp90a.1、nlrc3、nlrc5、soc3、irf3、irf7、casp7、mx1 和 vig2。综合分析确定了几个重要的 miRNA（ola-miR-27d-3p_R+5、gmo-miR-124-3-5p、ssa-miR-301a-5p_L+2 和 ssa-miR-146d-3p），它们靶向关键免疫相关的 DEGs。表达分析显示，tlr3、tlr7、traff3、ifih1、dhx58、hap90a.1、irf3、irf7 和 mx1 基因在感染过程中先增加后减少，并在 72 hpi 时达到峰值（P<0.05）。然而，trim25 的表达在 96 hpi 时达到峰值（P<0.05）。本研究有助于了解虹鳟鱼对 IHNV 感染的免疫反应，并为免疫调节机制和抗病性育种研究提供了新的见解。
