Different transcriptional response between susceptible and resistant common carp (Cyprinus carpio) fish hints on the mechanism of CyHV-3 disease resistance

Abstract

BackgroundInfectious disease outbreaks form major setbacks to aquaculture production and to further development of this important sector. Cyprinid herpes virus-3 (CyHV-3) is a dsDNA virus widely hampering production of common carp (Cyprinus carpio), one of the most farmed fish species worldwide. Genetically disease resistant strains are highly sought after as a sustainable solution to this problem. To study the genetic basis and cellular pathways underlying disease resistance, RNA-Seq was used to characterize transcriptional responses of susceptible and resistant fish at day 4 after CyHV-3 infection.ResultsIn susceptible fish, over four times more differentially expressed genes were up-regulated between day 0 and 4 compared to resistant fish. Susceptible and resistant fish responded distinctively to infection as only 55 (9%) of the up-regulated genes were shared by these two fish types. Susceptible fish elicited a typical anti-viral response, involving interferon and interferon responsive genes, earlier than resistant fish did. Furthermore, chemokine profiles indicated that the two fish types elicited different cellular immunity responses. A comparative phylogenetic approach assisted in chemokine copies annotation pointing to different orthologous copies common to bony-fishes and even carp-specific paralogs that were differentially regulated and contributed to the different response of these two fish types. Susceptible fish up-regulated more ccl19 chemokines, which attract T-cells and macrophages, the anti-viral role of which is established, whereas resistant fish up-regulated more cxcl8/il8 chemokines, which attract neutrophils, the antiviral role of which is unfamiliar.ConclusionsTaken together, by pointing out transcriptional differences between susceptible and resistant fish in response to CyHV-3 infection, this study unraveled possible genes and pathways that take part in disease resistance mechanisms in fish and thus, enhances our understanding of fish immunogenetics and supports the development of sustainable and safe aquaculture.

Integrative Transcriptomic Analysis Reveals the Immune Mechanism for A CyHV-3-Resistant Common Carp Strain

“…These findings were in line with TRIMs, which were found regulated in the survivors of breeding strain for group A and in the healthy control of non-breeding strain for group B. The above finding of TRIM is coincident with one of recent revealed CyHV-3 resistant related DEGs with identified QTLs (13). In the survivors from the breeding strain, the higher PI3K also suggests higher autophagy, since the PI3K/AKT/mTOR pathway enhances this process (48).…”

“…The first transcriptional analysis of carp anterior kidney mainly pointed out the important role of humoral immune responses, especially those related to immunoglobulin (1). Spleen transcriptomic analyses comparing the susceptible and resistant common carp revealed that the susceptible fish elicited a typical anti-viral interferon response, while the upregulated IL-8 attracted innate immune cells and related response may play an essential role in resistant fish (13).…”

Carp edema virus and immune response in carp (Cyprinuscarpio): Current knowledge

“…The subsequent focus was to reveal differences in the immune response among strains of common carp with incomparable sensitivity to viral infection. After using an RNA sequencing method, followed by transcriptome analysis of differentially expressed genes, it was found that susceptible fish responded to CyHV-3 infection with production of IFNs and ISGs more quickly than resistant ones (Tadmor-Levi et al, 2019). In another study, Adamek, Matras, et al (2019) (Adamek, Oschilewski, et al, 2017).…”

Transcriptional Profiles of Genes Related to Stress and Immune Response in Rainbow Trout (Oncorhynchus mykiss) Symptomatically or Asymptomatically Infected With Vibrio anguillarum

“…The previous studies showed that fish exhibit higher individual variations in response to pathogen infection (28)(29)(30). Genetic factors that favor the survival of asymptomatic individuals could be used as targets for selecting disease-resistant fish, thus reducing economic loss from infectious disease (31). Although accumulating studies have been focused on generating disease (or stress)-resistant fish strains, the mechanisms remain largely unknown (31,32).…”