The mRNA expression levels of P4a capsid core protein (p4a) of CEV and genes involved in immune responses in carp under CEV infection. (A, B, C) depicted are transcription rates of viral p4a, (D, E, F) type I interferon a2 (ifn a2), (G, H, I) myeloperoxidase (mpo) and (J, K, L) caspase 9 (casp9) encoding genes in gills and kidney of koi and AS carp after exposure to koi infected with CEV genogroup IIa and kept in freshwater or water supplemented with 0.5% NaCl. Analysis was performed with one-way or two-way ANOVA with strain and time-points as factors. The ANOVA was followed by subsequent pairwise multiple comparisons using the Holm-Sidak method. Significant differences between the control and infected are marked with * at p ≤ 0.05, with ** at p ≤ 0.01, with *** at p ≤ 0.001. The data are presented as box plots of 25% – 75% percentiles (±minimum and maximum values) with an indication of median as a horizontal line from n = 6 specimen