Project description:Through 8 generations of selection, our group has developed a strain of rainbow trout that exhibits high growth rates on an economically and environmentally sustainable all plant protein, high-soy diet. The selected strain also shows superior performance in bacterial and viral disease challenges compared to commercial trout strains, and even a strain specifically selected over many generations for viral and bacterial disease resistance. The selection criteria was strictly focused on performance on plant-based diets, and therefore the physiological mechanisms responsible for the strain’s superior disease resistance remain unresolved. To better characterize the physiological mechanism behind the superior performance of the selected strain we compared the intestinal gene expression of the select strain to that of a commercial control line of trout during an experimental bacterial infection with Flavobacterium psychrophilum (Fp) (CSF 259-93), the causative agent of bacterial cold water disease (BCWD) in salmonids. At 65 days post hatch, all female rainbow trout from the select and commercial strain were stocked separately into four 150L tanks each, at a density of 45 fish per tank. For both strains of trout, three tanks of fish were experimentally infected with Fp by intramuscular injection and one control tank was mock challenged by sham injection. Sampling was conducted at 5 days post challenge (dpc) (Early Infection) and 21 dpc (Late/Recovered Infection). Two intestinal samples from each tank were pooled and two pools from each tank were utilized for RNAseq library preparation. The select strain of trout showed significantly better survival rates (Log-Rank Test, p < 0.0001) over the 21 day infection period, with 70 and 95 % mortality among the select and commercial strain, respectively. Reads from the RNAseq samples were quantified at the transcript level prior to evaluating differential transcript usage and differential gene expression between the strains of trout, infection time points, and disease status.
Project description:In a context of fast development of aquaculture, infections by Flavobacterium psychrophilum, a member of the family Flavobacteriaceae, are a major sanitary concern for the salmonid farming industry worldwide. Several phenotypic traits related to pathogenesis have been documented for this bacterium, but molecular factors involved remain poorly characterized. Here, we conducted a global study of adaptation to outside- and within-host environments using a combination of in vitro transcriptomic and computational approaches. The repertoire of transcription start sites and transcriptional units was established using 5’-end and global RNA-Seq. Responses to environmental conditions were explored by expression profiling across conditions, including host-related stresses, exposure to fish mucus and plasma, growth on blood, osmotic changes or freshwater. Analysis of these data allowed to identify many new regulatory elements including alternative sigma-factors promoters, 5’ cis-encoded and trans-acting RNAs. It also revealed interconnected regulations linked to specific environmental conditions for a wide range of biological processes: proteolytic activity, iron acquisition, fatty acids metabolism, respiration under low-oxygen concentration, protein secretion and folding, efflux pumps as well as adhesion and spreading. Results reported here constitute an important resource for guiding basic and applied research on this important pathogen, and a dedicated website is provided to facilitate their exploration.
Project description:Catfish farming remains number one among U.S. aquaculture production. Flavobacterium columnare, the causative agent of columnaris disease, produces substantial mortality during the production of freshwater farmed finfish species. F. columnare is ubiquitous in the aquatic environment, and outbreaks of disease are often triggered during the spring and summer months of the catfish production cycle. As food fish production continues to increase, the frequency of columnaris disease will only continue to rise within the aquaculture industry and thus new preventative measures will be required. Vaccination against different fish pathogens has proven to be an effective disease management practice within the aquaculture industry. To evaluate the immunological effect of bath immunization on catfish with a recombinant F. columnare DNAk protein vaccine, we performed RNA sequencing on skin samples from control and rDNAK immunized catfish at different time intervals. We evaluated the different gene expression patterns between the groups with a focus on identifying differences in innate and adaptive immune function.
Project description:Rainbow trout (1000 fish) was exposed to the bacterial pathogen F. psychrophilum by simple bath challenge without any pre-treatment with hydrogen peroxide. Samples (fin clip for Affymetrix QTL analysis) were taken from 167 moribund fish during the course of infection. When mortality/morbidity ended (day 40) we euthanized a total of 197 specimens of the remaining fish and took samples for DNA (QTL analysis) and assigned the status: Survivor. For gene expression analysis we took samples from gill, spleen and liver between day 11 and 15 from fish with clinical signs (CS) and no clinical signs (NCS), whereas samples from survivors were taken at day 40.
Project description:The myxozoan Tetracapsuloides bryosalmonae is the causative agent of proliferative kidney disease (PKD) – a disease of salmonid fishes, notably of the commercially farmed rainbow trout Oncorhynchus mykiss. Both wild and farmed salmonids are threatened by this virulent/deadly disease, which is often expressed by swollen kidneys. In order to understand the causes and consequences of the disease, we studied the immune response towards the parasite. To profile the influence of the disease on these cells, we produced a transcriptome of teleost RBCs in health and disease. Compared to erythrocytes originating from healthy fish, PKD fundamentally altered RBCs in their metabolism, adhesion, and response to inflammation.
Project description:In a context of fast development of aquaculture, infections by Flavobacterium psychrophilum, a member of the family Flavobacteriaceae, are a major sanitary concern for the salmonid farming industry worldwide. Several phenotypic traits related to pathogenesis have been documented for this bacterium, but molecular factors involved remain poorly characterized. Here, we conducted a global study of adaptation to outside- and within-host environments using a combination of in vitro transcriptomic and computational approaches. The repertoire of transcription start sites and transcriptional units was established using 5’-end and global RNA-Seq. Responses to environmental conditions were explored by expression profiling across conditions, including host-related stresses, exposure to fish mucus and plasma, growth on blood, osmotic changes or freshwater. Analysis of these data allowed to identify many new regulatory elements including alternative sigma-factors promoters, 5’ cis-encoded and trans-acting RNAs. It also revealed interconnected regulations linked to specific environmental conditions for a wide range of biological processes: proteolytic activity, iron acquisition, fatty acids metabolism, respiration under low-oxygen concentration, protein secretion and folding, efflux pumps as well as adhesion and spreading. Results reported here constitute an important resource for guiding basic and applied research on this important pathogen, and a dedicated website is provided to facilitate their exploration.
Project description:In a context of fast development of aquaculture, infections by Flavobacterium psychrophilum, a member of the family Flavobacteriaceae, are a major sanitary concern for the salmonid farming industry worldwide. Several phenotypic traits related to pathogenesis have been documented for this bacterium, but molecular factors involved remain poorly characterized. Here, we conducted a global study of adaptation to outside- and within-host environments using a combination of in vitro transcriptomic and computational approaches. The repertoire of transcription start sites and transcriptional units was established using 5’-end and global RNA-Seq. Responses to environmental conditions were explored by expression profiling across conditions, including host-related stresses, exposure to fish mucus and plasma, growth on blood, osmotic changes or freshwater. Analysis of these data allowed to identify many new regulatory elements including alternative sigma-factors promoters, 5’ cis-encoded and trans-acting RNAs. It also revealed interconnected regulations linked to specific environmental conditions for a wide range of biological processes: proteolytic activity, iron acquisition, fatty acids metabolism, respiration under low-oxygen concentration, protein secretion and folding, efflux pumps as well as adhesion and spreading. Results reported here constitute an important resource for guiding basic and applied research on this important pathogen, and a dedicated website is provided to facilitate their exploration.
Project description:YerA41 is a myoviridae bacteriophage that was originally isolated due its ability to infect Yersinia ruckeri bacteria, the causative agent of enteric redmouth disease of salmonid fish. Several attempts to determine its genomic DNA sequence using traditional and next generation sequencing technologies failed, indicating that the phage genome is modified such way that it is an unsuitable template for PCR amplification and sequencing. To determine the YerA41 genome sequence we isolated RNA from phage-infected Y. ruckeri cells at different time points post-infection, and sequenced it. The host-genome specific reads were substracted and de novo assembly was performed on the unaligned reads.