BioProject

Infectious pancreatic necrosis (IPN) is widespread disease with global distribution and highly contagious, which leads to severe economic problems both freshwater and saltwater, particularly in the Atlantic salmon (Salmo salar). More...

Infectious pancreatic necrosis (IPN) is widespread disease with global distribution and highly contagious, which leads to severe economic problems both freshwater and saltwater, particularly in the Atlantic salmon (Salmo salar). In this work we analyzed and evaluated gene expression profiles in resistant and susceptible families associated to S. salar exposed to IPNV in order to understand the defense mechanisms mounted by resistant fish in combating infection. Experimentally, 29 families with known pedigree and variability were infected by immersion with 1x106 PFU/ml of IPNV, and a gamma frailty model analysis based on Kaplan-Meier mortality curves were obtained to identify and classify families as susceptible or resistant. Samples of head kidney tissue were obtained at day 1 and 5 post-infection from susceptible and resistant families and pooled to analyse their expression pattern with realt-ime PCR and one-color salmon-specific oligonucleotide microarray (21K). The microarray results showed clear differences in both families, where resistant fish presented an over-expression of genes associated with endocrine function, and a down-regulation of genes associated principally with tissue differentiation, metabolism protein degradation, cell signaling and immunological process. Moreover qPCR analysis using as target a number of transcripts associated with immunological processes showed the same trend observing a higher expression in susceptible than resistant families, indicating significant differences for CCL-19, CCRγc, IL-12, IFN-α, and IFN-γ. Overall design: The one-color oligonucleotide microarrays included in this study was performed using pooled samples from each families at two different post-infection time condition. In the case of susceptible families were chosen at 1 day post-infection (dpi) the families 5352 (n = 2) and 5469 (n = 2) and at 5 dpi the families 5629 (n = 2) and 5637 (n = 2), whereas in resistant families were selected at 1 dpi the families 5459 (n =3) and 5761 (n =3), and at 5 dpi the families 5463 (n =3) and 5764 (n =3). Less...