Project description:Stocking density is considered as a key factor determining the productivity of fish aquaculture systems. The transcriptomic response to crowding stress is, however, still poorly investigated. We aimed at the identification of potential biomarker genes via microarray analyses to get insight into molecular pathways modulated through density-induced stress in farmed rainbow trout Oncorhynchus mykiss. Transcriptome profiling in liver, kidney, and gills was complemented with behaviarol observation and analysis of classical plasma parameters. Individuals of two trout strains were exposed for eight days to definite stocking densities, 1 kg/m³ (low density); 10 kg/m³ (moderate); 18 kg/m³ (elevated); and 35 kg/m³ (high). Whereas stocking density had no significant effect on cortisol levels, plasma glucose levels were elevated in trout kept at high density. Pathway enrichment analyses confirmed the upregulation of HIF1a signaling in liver contributing to glucose homeostasis during stress conditions, while mTOR and PI3K/AKT signaling pathways were downregulated. Further perturbed hepatic pathways were involved in protein ubiquitination and the biosynthesis of cholesterol, retinol and glutathione. Three stocking density conditions were investigated: an uncrowded âmoderateâ density (MD: 10 kg trout/m³) , an elevated density (ED: 18 kg/m³ ), and high density (HD: 35 kg/m³). The experiment was performed twice with two strains of Steelhead rainbow trout (Troutlodge and Born trout), randomly assigned to identical glass tanks with MD (30 and 34 individuals), ED (60 and 64 individuals), and HD (120 and 140 individuals). Trout were sampled 8 d after experimental onset.
Project description:Stress represents a major factor negatively affecting fish welfare in aquaculture. The objective of the present study was to identify and evaluate informative indicators for the welfare of rainbow trout Oncorhynchus mykiss exposed to (A) a critical water temperature of 27 °C and (B) acute crowding of 100 kg/m3 combined with water temperature of 27 °C. In order to make an approximate assessment of the overall condition, we determined health index, spleen-somatic index and haematocrit and recorded the blood concentrations of haemoglobin, cortisol and glucose of rainbow trout under challenging versus control conditions. Moreover, we analysed the transcriptomic profiles of the spleen of the two stress-treatment and the reference groups to identify gene sets, which are specific for temperature stress alone or combined temperature and crowding stress.
Project description:Stocking density is considered as a key factor determining the productivity of fish aquaculture systems. The transcriptomic response to crowding stress is, however, still poorly investigated. We aimed at the identification of potential biomarker genes via microarray analyses to get insight into molecular pathways modulated through density-induced stress in farmed rainbow trout Oncorhynchus mykiss. Transcriptome profiling in liver, kidney, and gills was complemented with behaviarol observation and analysis of classical plasma parameters. Individuals of two trout strains were exposed for eight days to definite stocking densities, 1 kg/m³ (low density); 10 kg/m³ (moderate); 18 kg/m³ (elevated); and 35 kg/m³ (high). Whereas stocking density had no significant effect on cortisol levels, plasma glucose levels were elevated in trout kept at high density. Pathway enrichment analyses confirmed the upregulation of HIF1a signaling in liver contributing to glucose homeostasis during stress conditions, while mTOR and PI3K/AKT signaling pathways were downregulated. Further perturbed hepatic pathways were involved in protein ubiquitination and the biosynthesis of cholesterol, retinol and glutathione.
Project description:The aim of present study is to identify and quantify proteins involved in the events of fertilization and early embryo development using a label-free protein quantification method in rainbow trout (Oncorhynchus mykiss) as an economically important fish species in aquaculture.
Project description:A rapid decline in temperature poses a major challenge for poikilothermic fish. The gene expression of rainbow trout Oncorhynchus mykiss having undergone such a cold shock (0 °C) and a control (5 °C) were compared in a microarray-based study.
Project description:The hypoxia frequently occurs in natural aquatic systems and aquaculture environment due to the natural reasons and human factors such as extreme climate, high density farming, environmental pollution and global warming, which have gradually become a huge threat to aquatic ecosystem functions and aquatic organism survival, causing serious ecological damage and enormous economic losses. Rainbow trout (Oncorhynchus mykiss), as a hypoxia-sensitive fish species, is a good model to study hypoxia stress. The molecular regulation and oxidative stress of rainbow trout still remains unknown in response to environmental hypoxia and reoxygenation stress. In this study, the transcriptome and biochemical indexes of rainbow trout liver in response to hypoxia for different durations were analyzed to highlight the changes in the molecular regulation and oxidative stress.
Project description:The objective of this study was to identify and quantify proteomic profiles of intestine of rainbow trout (Oncorhynchus mykiss). Specific pathogen free rainbow trout (mean length 15 ± 1 cm) were maintained in recirculating de-chlorinated water at 19±1 °C. Prior to the experiment, fish were distributed between aquaria. The test groups were infected by immersion of Yersinia ruckeri CSF007-82 (biotype 1) and 7959-11 (biotype 2) strains. The control group was immersed similar with sterile broth medium. Fish were anaesthetized and sampled aseptically at different time points. Each intestine was washed three times with sterile phosphate-buffered saline containing a cocktail of mammalian protease inhibitors. Intestinal mucosa was scraped with a sterile large scalpel blade. Intestinal samples were snap-frozen in liquid nitrogen and stored at –80 °C.
Project description:The objective of this study was to identify and quantify proteomic profiles of spleen of rainbow trout Oncorhynchus mykiss. Specific pathogen free rainbow trout (mean length 15 ± 1 cm) were maintained in recirculating de-chlorinated water at 19±1 °C. Prior to the experiment, fish were distributed between 9 aquaria, 18 fish per aquarium. The test groups were infected by immersion of Yersinia ruckeri strains: CSF007-82 (biotype 1) and 7959-11 (biotype 2). The control group was immersed similar with sterile broth medium. There were 3 aquaria per each group (CSF007-82-infected, 7959-11-infected and control). Nine fish from infected and control fish groups were anaesthetized with MS-222 at 3, 9 and 28 days post exposure and sampled aseptically. Each spleen was washed three times with sterile phosphate-buffered saline containing a cocktail of mammalian protease inhibitors. Spleen samples were snap-frozen in liquid nitrogen and stored at –80 °C.
Project description:The sea-run phenotype of rainbow trout (Oncorhynchus mykiss), like other anadromous salmonids, present a juvenile stage fully adapted to life in freshwater known as parr. Development in freshwater is followed by the smolt stage, where preadaptations needed for seawater life are developed making fish ready to migrate to the ocean, after which event they become post-smolts. While these three life stages have been studied using a variety of approaches, proteomics has never been used for such purpose. The present study characterised the blood plasma proteome of parr, smolt and post-smolt rainbow trout using a gel electrophoresis liquid chromatography tandem mass spectrometry approach alone or in combination with low-abundant protein enrichment technology (combinatorial peptide ligand library). In total, 1,822 proteins were quantified, 17.95% of them being detected only in plasma post enrichment. Across all life stages, the most abundant proteins were ankyrin-2, DNA primase large subunit, actin, serum albumin, apolipoproteins, hemoglobin subunits, hemopexin-like proteins and complement C3. When comparing the different life stages, 17 proteins involved in mechanisms to cope with hyperosmotic stress and retinal changes, as well as the downregulation of nonessential processes in smolts, were significantly different between parr and smolt samples. On the other hand, 11 proteins related to increased growth in post-smolts, and also related to coping with hyperosmotic stress and to retinal changes, were significantly different between smolt and post-smolt samples. Overall, this study presents a series of proteins with the potential to complement current seawater-readiness assessment tests in rainbow trout, which can be measured non-lethally in an easily accessible biofluid. Furthermore, this study represents a first in-depth characterisation of the rainbow trout blood plasma proteome, having considered three life stages of the fish and used both fractionation alone or in combination with enrichment methods to increase protein detection.