Regulatory factors controlling muscle mass : competition between innate immune function and anabolic signals in regulation of atrogin-1 in Atlantic salmon

The research was supported by an industrial PhD studentship between University of Aberdeen and by BioMar Ltd., for Z. Heidari.Peer reviewedPostprin

Integration of Transcriptome, Gross Morphology and Histopathology in the Gill of Sea Farmed Atlantic Salmon (Salmo salar) : Lessons from Multi-site Sampling

Funding statement The study was supported by the Scottish Aquaculture Innovation Centre (SAIC grant SL 2017 08, ‘Nutritional Aspects of Gill Disease in Atlantic Salmon’) and co-funded by BioMar and Scottish Sea Farms (SSF). ACKNOWLEDGMENTS We thank SSF farm personnel for accommodating our research, performing gross morphology scoring and helping with sampling. Edinburgh Genomics is partly supported through core grants from NERC (R8/H10/56), MRC (MR/K001744/1), and BBSRC (BB/J004243/1). We also thank two reviewers for their comments on the earlier draft of the article. EK dedicates this paper to her late mother, Irena Król.Peer reviewedPublisher PD

Dietary Yeast Cell Wall Extract Alters the Proteome of the Skin Mucous Barrier in Atlantic Salmon (Salmo salar) : Increased Abundance and Expression of a Calreticulin-Like Protein

Funding: This work was supported by a studentship from BioMar Ltd. to GM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Developing an experimental challenge model for gill disease caused by gelatinous zooplankton

Harmful zooplankton, such as jellyfish or cnidarians, play an important role in gill disease development, but there is a lack of scientific and technical understanding of the interactions between gelatinous zooplankton and fish gills that can only be obtained through a lab-based challenge model using lab-reared organisms. Such a model does not exist, so we set out to develop one. We were able to produce a pre-determined quantity of gelatinous zooplankton at a pre-determined point in time, transport them, and challenge salmon with these live gelatinous zooplankton, and present initial results. Currently we are optimizing the model. When developed further, the model is intended to be used as a tool to improve understanding of the role of gelatinous zooplankton in gill disease, identify host responses and assess techniques to mitigate the effects of gelatinous zooplankton on gill health

Developing an experimental challenge model for gill disease caused by gelatinous zooplankton

Harmful zooplankton, such as jellyfish or cnidarians, play an important role in gill disease development, but there is a lack of scientific and technical understanding of the interactions between gelatinous zooplankton and fish gills that can only be obtained through a lab-based challenge model using lab-reared organisms. Such a model does not exist, so we set out to develop one. We were able to produce a pre-determined quantity of gelatinous zooplankton at a pre-determined point in time, transport them, and challenge salmon with these live gelatinous zooplankton, and present initial results. Currently we are optimizing the model. When developed further, the model is intended to be used as a tool to improve understanding of the role of gelatinous zooplankton in gill disease, identify host responses and assess techniques to mitigate the effects of gelatinous zooplankton on gill health

Developing an experimental challenge model for gill disease caused by gelatinous zooplankton

Harmful zooplankton, such as jellyfish or cnidarians, play an important role in gill disease development, but there is a lack of scientific and technical understanding of the interactions between gelatinous zooplankton and fish gills that can only be obtained through a lab-based challenge model using lab-reared organisms. Such a model does not exist, so we set out to develop one. We were able to produce a pre-determined quantity of gelatinous zooplankton at a pre-determined point in time, transport them, and challenge salmon with these live gelatinous zooplankton, and present initial results. Currently we are optimizing the model. When developed further, the model is intended to be used as a tool to improve understanding of the role of gelatinous zooplankton in gill disease, identify host responses and assess techniques to mitigate the effects of gelatinous zooplankton on gill health

Influence of conjugated linoleic acid (CLA) or tetradecylthioacetic acid (TTA) on growth, lipid composition, fatty acid metabolism and lipid gene expression of rainbow trout (Oncorhynchus mykiss L.)

Our objective was to test the hypotheses that conjugated linoleic acid (CLA) and/or tetradecylthioacetic acid (TTA) would have beneficial effects on the nutritional quality of rainbow trout (Oncorhynchus mykiss) through decreased lipid content of flesh or viscera, and increased levels of beneficial fatty acids including accumulation of CLA or TTA themselves. The specific aims of this study were to determine the effects of CLA and TTA on growth performance, lipid and fatty acid metabolism, and selected gene expression in commercial sized trout grown in seawater. Trout were fed for eight weeks on fish meal and fish oil diets containing either 0.5% or 1% CLA, or 0.5% TTA. The effects of the supplemented fatty acids on growth, feed efficiency, lipid contents, class compositions and fatty acid compositions of flesh and liver were determined, along with liver highly unsaturated fatty acid synthesis, activities of key enzymes of fatty acid oxidation in liver and muscle, and expression of carnitine palmitoyltransferase-I (CPT-I) and fatty acyl desaturase and elongase genes. Neither functional fatty acid had any effect on growth parameters, condition factor, viscero- and hepato-somatic indices or fillet colour, and there were no mortalities in any of the treatments. Dietary CLA, but not TTA, decreased the lipid content of liver, but neither fatty acid had any significant effect on lipid class compositions of liver and flesh. Both CLA and TTA were incorporated into tissue lipids, with higher percentages found in flesh compared to liver. In addition, production of hexaene fatty acid by liver microsomes was increased by dietary CLA or TTA, and both functional fatty acids increased the proportion of n-3 fatty acids in liver mainly due to increased 20:5n-3 and 22:6n-3. However, the expression of fatty acyl Δ6 desaturase was significantly lower in fish fed CLA or TTA, whereas the expression of PUFA elongase was increased, significantly so in fish fed 1% CLA. CPT-I activity was increased by TTA in liver and red muscle, and acyl CoA oxidase activity was increased by TTA in liver and CLA at the higher dietary inclusion level in red muscle. There was a clear trend for CPT-I expression to be increased in fish fed 0.5% CLA or TTA in all tissues although this was only significant in white muscle. The results showed that both CLA and TTA had effects on lipid metabolism that partly support the hypotheses tested. Although CLA or TTA did not enhance growth parameters, feed conversion or potential yield, nutritional quality could be enhanced, and sea-run trout fed CLA or TTA could be beneficial in the human diet through provision of bioactive fatty acids, with no detrimental effects on 20:5n-3 or 22:6n-3 levels

Influence of dietary conjugated linoleic acid (CLA) and tetradecylthioacetic acid (TTA) on growth, lipid composition and key enzymes of fatty acid oxidation in liver and muscle of Atlantic cod (Gadus morhua L.)

The aim of the present study was to determine the effects of conjugated linoleic acid (CLA) and tetradecylthioacetic acid (TTA) on growth performance, and lipid and fatty acid metabolism in Atlantic cod. The overall objective being to test the hypotheses that CLA and TTA have beneficial effects in cod culture including decreased liver size and proportion through decreased lipid content, and increased nutritional quality through effects on fatty acid compositions including accumulation of bioactive fatty acids, CLA and TTA, in flesh. Juvenile cod were fed for three months on fish meal and fish oil diets of basically commercial formulation, but containing either 0.5% or 1% CLA, or 0.5% TTA. The effects of the functional fatty acids on growth, feed efficiency, body proximate composition, liver weight and lipid composition, fatty acid compositions of flesh and liver, and key enzymes of fatty acid oxidation were determined. Dietary CLA and TTA had no effect on growth parameters in cod juveniles, but viscero- and hepato-somatic indices were increased in fish fed 0.5% CLA and TTA, respectively. Proximate composition of whole fish was not affected by CLA or TTA, and there were no major effects of either functional fatty acid on lipid contents and compositions of liver and flesh. Dietary CLA and TTA were both incorporated into tissue lipids, with CLA deposited to a greater extent in liver, whereas TTA was deposited to a greater extent in flesh. In liver, acyl CoA oxidase (ACO) activity, but not carnitine palmitoyltransferase-I (CPT-I), was increased by CLA, whereas dietary TTA increased both ACO and CPT-I activities. In contrast, ACO activity was reduced by both CLA and TTA in red and white muscle, whereas CPT-I activity was generally not affected by CLA and TTA in either muscle tissue. Therefore, the results only partially supported the hypotheses tested, as CLA and TTA had few beneficial effects in Atlantic cod and did not enhance growth parameters, or improve feed conversion or potential yield through decreased adiposity or liver lipid deposition. However, nutritional quality could be enhanced, and cod fed CLA and/or TTA could be beneficial in the human diet, through provision of bioactive fatty acids with no detrimental effects on n-3 PUFA levels

Proteomics in biomarker detection and monitoring of pancreas disease (PD) in atlantic salmon (Salmo salar)

The species of Salmonid Alphavirus (SAV) consists of six closely related subtypes and belongs to the genus Alphavirus within the family Togaviridae (McLouglin and Graham, 2007). SAV’s are the aetiological agent of pancreas disease (PD) and sleeping disease (SD) of farmed Atlantic salmon, Salmo salar, and rainbow trout, Oncorhynchus mykiss. These diseases cause significant loss to aquaculture production in Europe. PD is characterized by lethargy and other behavioural modifications, sequential acute necrosis of the pancreatic acinar cells, cardiomyopathy, and skeletal muscle fibrosis and degeneration. Since the characterisation of PD a number of diagnostic tools have been developed such as; histopathology, RT-PCR SAV detection, and pathogen-specific antibody detection. However, little focus has been placed on investigating the processes involved in the return to homeostasis from SAV infection/ PD and how biological indicators of disease could be used as non-destructive tools for its identification and monitoring of disease progress. Therefore, this study investigates the modification of the serum proteome profile caused by PD, using SAV3 as the aetiological agent, in order to identify serum biomarkers of PD