Location: Cool and Cold Water Aquaculture ResearchTitle: Selective breeding improves rainbow trout resistance against bacterial cold water disease with little evidence for change in tolerance
Submitted to: Congress International Society Develop Comparative Immunology
Publication Type: Abstract Only
Publication Acceptance Date: 6/3/2015
Publication Date: 6/26/2015
Citation: Wiens, G.D., Marancik, D.P., Leeds, T.D. 2015. Selective breeding improves rainbow trout resistance against bacterial cold water disease with little evidence for change in tolerance. Congress International Society Develop Comparative Immunology. P628-12.
Technical Abstract: Animals exhibit two broadly-defined defense strategies upon pathogen exposure: resistance and tolerance. Resistance is a measure of the host's capacity to limit pathogen number, while tolerance is defined as the host's ability to limit the negative health impact of a defined pathogen load. Most animal populations' exhibit genetic variation in response to disease challenge, but the relative contribution of resistance and tolerance is unclear. Herein, we quantify the contribution of each defense strategy using two pedigreed genetic lines of rainbow trout selectively bred for either increased survival (ARS-Fp-R line) or decreased survival (ARS-Fp-S line) following challenge with Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD). We quantified pathogen load in 6 tissues and blood following either intraperitoneal or subcutaneous routes of infection, and quantified host health by measuring 18 plasma analytes as well as packed cell volume. The two genetic lines exhibited similar bacterial loads early after infection, while ARS-Fp-R line exhibited significantly lower pathogen loads in most tissues and blood by day 6 post-infection. To examine change in tolerance, we regressed plasma analyte concentration on pathogen load and found no differences in slopes between genetic lines with the exception of chloride. Proteomic profiling of ARS-Fp-R and ARS-Fp-S line fish using iTRAQ and 2D-LC-MS/MS analysis identified over 200 differentially expressed plasma proteins on day 6 post-infection. Taken together, our results indicate that selective breeding predominantly changed resistance, and not tolerance, resulting in modulation of the serum protein proteome in response to infection.