Fig. 5
Infection model and transcriptome analyses of trout OM with IHNV. a Scheme of the experimental strategy. Fish were infected by bathing with IHNV, and subsequently sacrificed at 0.5, 1, 4, 7, 14, 21, and 28 DPI for tissue sample collection. b Clinical signs of trout infected by IHNV at 4 DPI with exophthalmia and petechial hemorrhages. c Cumulative survival of IHNV-infected fish and control group. Statistical differences were assessed by the Log-rank (Mantel-Cox) test. d qPCR was applied to detect IHNV-N gene copies (Log10) in the trout Cor, BC, and FC collected at 0.5, 1, 4, 7, 14, 21, and 28 DPI (n = 6). e Venn diagrams showing the overlap of up- or downregulated genes detected by RNA-seq in the trout Cor, BC, and FC at 4 or 28 DPI versus control fish. f Heatmap plot of RNA-Seq studies for changed immune genes from the Cor, BC, and FC of IHNV-infected versus control fish measured at 4 and 28 DPI. g RNA-Seq data shows altered biological processes in the trout Cor, BC, and FC at 4 and 28 DPI versus control trout. h Heatmap plot of RNA-Seq studies for changed antivirus, anti-bacteria, and inflammation genes in the trout Cor, BC, and FC at 4 and 28 DPI. i, j Representative antiviral response (i) and inflammatory response (j) genes in the Cor, BC, and FC captured by LCM for control and IHNV-infected trout, and measured by qPCR. Gene expression levels in IHNV-infected fish were normalized to those in the control group, which were set as 1 (n = 9). Statistical differences were evaluated by unpaired Student’s t test. Data are presented as mean ± SEM of three biological duplicates. *p < 0.05, **p < 0.01, ***p < 0.001