title: Whole-body transcriptome of selectively bred, resistant-, control-, and susceptible-line rainbow trout following experimental challenge with Flavobacterium psychrophilum.
abstract: Genetic improvement for enhanced disease resistance in fish is an increasingly utilized approach to mitigate endemic infectious disease in aquaculture. In domesticated salmonid populations, large phenotypic variation in disease resistance has been identified but the genetic basis for altered responsiveness remains unclear. We previously reported three generations of selection and phenotypic validation of a bacterial cold water disease (BCWD) resistant line of rainbow trout, designated ARS-Fp-R. This line has higher survival after infection by either standardized laboratory challenge or natural challenge as compared to two reference lines, designated ARS-Fp-C (control) and ARS-Fp-S (susceptible). In this study, we utilized 1.1 g fry from the three genetic lines and performed RNA-seq to measure transcript abundance from the whole body of naive and Flavobacterium psychrophilum infected fish at day 1 (early time-point) and at day 5 post-challenge (onset of mortality). Sequences from 24 libraries were mapped onto the rainbow trout genome reference transcriptome of 46,585 predicted protein coding mRNAs that included 2633 putative immune-relevant gene transcripts. A total of 1884 genes (4.0% genome) exhibited differential transcript abundance between infected and mock-challenged fish (FDR < 0.05) that included chemokines, complement components, tnf receptor superfamily members, interleukins, nod-like receptor family members, and genes involved in metabolism and wound healing. The largest number of differentially expressed genes occurred on day 5 post-infection between naive and challenged ARS-Fp-S line fish correlating with high bacterial load. After excluding the effect of infection, we identified 21 differentially expressed genes between the three genetic lines. In summary, these data indicate global transcriptome differences between genetic lines of naive animals as well as differentially regulated transcriptional responses to infection.
authors.affiliation: National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, United States Department of Agriculture Kearneysville, WV, USA.
authors.forename: David
authors.initials: D
authors.lastname: Marancik
authors.affiliation: National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, United States Department of Agriculture Kearneysville, WV, USA.
authors.forename: Guangtu
authors.initials: G
authors.lastname: Gao
authors.affiliation: Department of Biology, Middle Tennessee State University Murfreesboro, TN, USA.
authors.forename: Bam
authors.initials: B
authors.lastname: Paneru
authors.affiliation: Animal and Nutritional Sciences, West Virginia University Morgantown, WV, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Ma
authors.affiliation: High-Throughput Sequencing and Genotyping Unit, Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign Urbana, IL, USA.
authors.forename: Alvaro G
authors.initials: AG
authors.lastname: Hernandez
authors.affiliation: Department of Biology, Middle Tennessee State University Murfreesboro, TN, USA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Salem
authors.affiliation: Animal and Nutritional Sciences, West Virginia University Morgantown, WV, USA.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Yao
authors.affiliation: National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, United States Department of Agriculture Kearneysville, WV, USA.
authors.forename: Yniv
authors.initials: Y
authors.lastname: Palti
authors.affiliation: National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, United States Department of Agriculture Kearneysville, WV, USA.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Wiens
keywords: Flavobacterium psychrophilum; aquaculture; bacterial cold water disease; disease resistance; immune gene; rainbow trout genome; selective breeding; tnfrsf