Expression of virus-responsive genes in tissues of exercised and swim performance groups post IPN challenge. Improved survival after IPN challenge was associated with the expression of virus responsive genes (VRGs) as assessed by qPCR. Higher expression levels of VRGs in cardiac tissue of poor compared to good swimmers from the Lint regime (A), and in head kidney of poor compared to good swimmers from the control group (B) reflected the overall higher mortality of poor swimmers in comparison to the good swimmers. Further, VRGs expression in both tissues was in concordance with differences in survival between interval (Lint) and constant speed (Control and Medium) training regimes. Bars represent expression ratio ± SEM relative to a pooled control sample and normalized against two reference genes (18S rRNA and elongation factor 1α) with correction for PCR efficiency. For A and B, each bar is a composed index of 6 (n = 8 fish/swim-performance/regime) and 8 (n = 5 fish/swim-performance/regime) VRGs, respectively. Genes included: RSAD2 (radical S-adenosyl methionine domain containing protein2) (A + B), IFIT5 (interferon-induced protein with tetratricopeptide repeats 5) (A + B), STAT1 (signal transducer and activator of transcription 1) (A + B), VHSV2 (viral haemorrhagic septicaemia virus-inducible protein) (A + B), BAF (barrier-to-autointegration factor) (A + B), GIG1 (interferon-inducible Gig1) (A + B), RIG-I (DEAD/H (Asp-Glu-Ala-Asp/His) box polypeptide) (B), MDA5 (interferon induced with helicase C domain 1) (B). abc: Denotes significant difference (p < 0.05; paired t-test) between training regimes. Other symbols (*§) denotes significant difference (p < 0.05; paired t-test) between poor and good swimmers within each training regime.