Anne Vegusdal

• Lien, Anne; Palmer, Helen; Larsen, Jorunn; Svendsen, Monica Lian; Bomark, Nils-Erik & Krakstad, Beate Fast [Show all 7 contributors for this article] (2026). Building a Scientific Skill Set: A Design-Based Research Approach to Developing a Tool for Science Education and Beyond | Journal of the International Society for Teacher Education. Journal of the International Society for Teacher Education. ISSN 1029-5968. 30(1), p. 5–22. doi: 10.26522/jiste.v30i1.5268. Full text in Research Archive Show summary

  Life skills like problem-solving, communication, collaboration, and creative and critical thinking are closely tied to scientific practices in science education. However, there is ongoing debate about how to define and operationalize scientific practices for implementation in schools and teacher education. In Norway, these practices are a core element of the science curriculum, but their definition remains vague. To address this, we used a design-based research approach to develop a skills-based tool for teaching and learning scientific practices in schools and teacher education. The tool highlights twelve interrelated skills that support students’ engagement in scientific practices and their reflection on scientific processes. We describe the process of designing and developing the teaching tool, our design analysis of why and how the tool evolved, and three design principles to inform the development of a skills-based teaching tool to practice science. These principles highlight three critical features of the tool: it is dynamic and flexible, initiates active learning, and provides support for teachers.

• Nilsen, Hans Kristian & Vegusdal, Anne (2017). Mathematics at the enterprise: Industry, university and school working together to facilitate learning. In Dooley, Thérèse & Gueudet, Ghislaine (Ed.), Proceedings of the Tenth Congress of the European Society for Research in Mathematics Education (CERME 10). European Society for Research in Mathematics Education. ISSN 9781873769737. p. 1537–1544. Full text in Research Archive
• Ytteborg, Elisabeth; Vegusdal, Anne; Witten, P.Eckhard; Berge, Gerd Marit; Takle, Harald Rune & Østbye, Tone-Kari K [Show all 7 contributors for this article] (2010). Atlantic salmon (Salmo salar) muscle precursor cells differentiate into osteoblasts in vitro: Polyunsaturated fatty acids and hyperthermia influence gene expression and differentiation. Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. ISSN 1388-1981. 1801(2), p. 127–137. doi: 10.1016/j.bbalip.2009.10.001. Full text in Research Archive
• Stabell, Ole B. & Vegusdal, Anne (2010). Socializing makes thick-skinned individuals: on the density of epidermal alarm substance cells in cyprinid fish, the crucian carp (Carassius carassius). Journal of Comparative Physiology A. Sensory, neural, and behavioral physiology. ISSN 0340-7594. 196(9), p. 639–647. doi: 10.1007/s00359-010-0550-4. Full text in Research Archive Show summary

  In cyprinid fish, density of epidermal club cells (i.e. alarm substance cells) has been found to vary between lakes with different predator fauna. Because predators can be labelled with chemical cues from prey, we questioned if club cell density could be controlled indirectly by predators releasing prey cues. In particular, we suspected a possible feedback mechanism between chemical alarm signals and their cellular source. We raised crucian carp singly and in groups of four. For both rearing types, fish were exposed to skin extracts of either conspecifics or brown trout (without club cells), and provided either low or high food rations. Independent of rearing type, condition factor and club cell density increased with food ration size, but no change was found in club cell density following exposure to conspecific alarm signals. However, the density of club cells was found significantly higher for fish raised in groups than for fish raised alone. We conclude that an increased condition factor results in more club cells, but crucian carp may also possess an awareness of conspecific presence, given by higher club cell densities when raised in groups. This increase in club cell density may be induced by unknown chemical factors released by conspecifics.

• Berge, Gerd Marit; Witten, P. Eckhard; Bæverfjord, Grete; Vegusdal, Anne; Wadsworth, Simon & Ruyter, Bente (2009). Diets with different n-6/n-3 fatty acid ratio in diets for juvenile Atlantic salmon, effects on growth, body composition, bone development and eicosanoid production. Aquaculture. ISSN 0044-8486. 296(3-4), p. 299–308. doi: 10.1016/j.aquaculture.2009.08.029. Full text in Research Archive
• Kjær, Marte Avranden; Vegusdal, Anne; Berge, Gerd Marit; Galloway, Trina F.; Hillestad, Marie & Krogdahl, Åshild [Show all 8 contributors for this article] (2009). Characterisation of lipid transport in Atlantic cod (Gadus morhua) when fasted and fed high or low fat diets. Aquaculture. ISSN 0044-8486. 288(3-4), p. 325–336. doi: 10.1016/j.aquaculture.2008.12.022. Full text in Research Archive
• Todorcevic, Marijana; Kjær, Marte Avranden; Djakovic, Natasa; Vegusdal, Anne; Torstensen, Bente Elisabeth & Ruyter, Bente (2009). N-3 HUFAs affect fat deposition, susceptibility to oxidative stress, and apoptosis in Atlantic salmon visceral adipose tissue. Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. ISSN 1096-4959. 152(2), p. 135–143. doi: 10.1016/j.cbpb.2008.10.009. Full text in Research Archive Show summary

  We have investigated how n-3 highly unsaturated fatty acids (HUFAs) in the diet affect fatty acid (FA) utilization, fat storage and oxidative stress (OS) in Atlantic salmon (Salmo salar) white adipose tissue (WAT). Four groups of Atlantic salmon were fed for 21 weeks on one of the four diets supplemented with 23% (of dry matter) lipid. Docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3) levels increased from 10% of total FAs in the rapeseed oil (RO) diet, to 20% in the fish oil (FO) diet, and to 50% and 55% in the DHA-enriched and EPA-enriched diets, respectively. Increased dietary levels of n-3 HUFAs resulted in lower fat percentage in WAT. Furthermore, mitochondrial FA beta-oxidation activity was higher in the FO group than it was in the RO group. The relative levels of DHA and EPA in phospholipids (PLs) from WAT and mitochondrial membranes increased with the increasing dietary levels of these HUFAs. In general, the mitochondrial membrane PLs were characterised by lower relative levels of n-3 HUFAs and higher relative levels of linoleic acid (LA; 18:2 n-6) than WAT membrane PLs. The predominance of LA relative to n-3 HUFAs in mitochondrial membrane PLs may help to protect these PLs from peroxidation. Cytochrome c oxidase measurements revealed higher incidence of disrupted mitochondrial membranes in the DHA and EPA dietary groups than in the FO and RO dietary groups. This disruption further affected the mitochondrial function, resulting in a marked reduction in FA P-oxidation capacities. The reduction in mitochondrial function and the increase in the activity of superoxide dismutase (SOD) in the DHA and EPA groups showed that high dietary dose of DHA and EPA resulted in oxidative stress (OS). The increased activity of caspase 3 in the high n-3 HUFA groups suggested the induction of apoptosis and increased incidence of cell death in WAT, which may be one of the factors explaining the lower fat percentage found in these groups. (c) 2008 Elsevier Inc. All rights reserved.

• Kjær, Marte Avranden; Vegusdal, Anne; Gjøen, Tor; Rustan, Arild; Todorevic, M & Ruyter, B (2008). Effect of rapeseed oil and dietary n-3 fatty acids on triacylglycerol synthesis and secretion in Atlantic salmon hepatocytes. Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. ISSN 1388-1981. 1781. doi: 10.1016/j.bbalip.2007.12.004. Full text in Research Archive
• Kjær, Marte Avranden; Vegusdal, Anne; Gjøen, Tor; Rustan, Arild; Todorcevic, Marijana & Ruyter, Bente (2008). Effect of rapeseed oil and dietary n-3 fatty acids on triacylglycerol synthesis and secretion in Atlantic salmon hepatocytes. Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. ISSN 1388-1981. 1781(3), p. 112–122. doi: 10.1016/j.bbalip.2007.12.004. Full text in Research Archive Show summary

  Fish oil (FO) has traditionally been used as the dominating lipid component in fish feed. However, FO is a limited resource and the price varies considerably, which has led to an interest in using alternative oils, such as vegetable oils (VOs), in fish diets. It is far from clear how these VOs affect liver lipid secretion and fish health. The polyunsaturated fatty acids (PUFAs), eicosapentanoic acid (EPA) and docosahexanioc acid (DHA), reduce the secretion of lipoproteins rich in triacylglycerols (TAGs) in Atlantic salmon, as they do in humans. The mechanism by which n-3 fatty acids (FAs) in the diet reduce TAG secretion is not known. We have therefore investigated the effects of rapeseed oil (RO) and n-3 rich diets on the accumulation and secretion of H-3-glycerolipids by salmon hepatocytes. Salmon, of approximately 90 g were fed for 17 weeks on one of four diets supplemented with either 13.5% FO, RO, EPA-enriched oil or DHA-enriched oil until a final average weight of 310 g. Our results show that the dietary FA composition markedly influences the endogenous FA composition and lipid content of the hepatocytes. The intracellular lipid level in hepatocytes from fish fed RO diet and DHA diet were higher, and the expressions of the genes for microsomal transfer protein (MTP) and apolipoprotein A1 (Apo A1) were lower, than those in fish fed the two other diets. Secretion of hepatocyte glycerolipids was lower in fish fed the EPA diet and DHA diet than it was in fish fed the RO diet. Our results indicate that EPA and DHA possess different hypolipidemic properties. Both EPA and DHA inhibit TAG synthesis and secretion, but only EPA induces mitochondrial proliferation and reduce intracellular lipid. Expression of the gene for peroxisome proliferator-activated receptor alpha (PPAR alpha) was higher in the DHA dietary group than it was in the other groups. (C) 2008 Elsevier B.V. All rights reserved.

• Todorcevic, Marijana; Vegusdal, Anne; Gjøen, Tor; Sundvold, Hilde; Torstensen, Bente & Kjær, Marte Avranden [Show all 7 contributors for this article] (2008). Changes in fatty acids metabolism during differentiation of Atlantic salmon preadipocytes; Effects of n-3 and n-9 fatty acids. Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. ISSN 1388-1981. 1781(6-7), p. 326–335. doi: 10.1016/j.bbalip.2008.04.014. Full text in Research Archive Show summary

  Atlantic salmon (Salmo salar) preadipocytes, isolated from visceral adipose tissue, differentiate from an unspecialized fibroblast like cell type to mature adipocytes filled with lipid droplets in culture. The expression of the adipogenic gene markers peroxisome proliferated activated receptor (PPAR) alpha, lipoprotein lipase (LPL), microsomal triglyceride transfer protein (MTP), fatty acid transport protein (FATP) 1 and fatty acid binding protein (FABP) 3 increased during differentiation. In addition, we describe a novel alternatively spliced form of PPAR gamma (PPAR gamma short), the expression of which increased during differentiation. Eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) lowered the triacylglycerol (TAG) accumulation in mature salmon adipocytes compared to oleic acid (18:1n-9, OA). This finding indicates that a reduced level of highly unsaturated n-3 fatty acids (HUFAs) in fish diets, when the traditional marine oil is exchanged for n-9 fatty acids (FAs) rich vegetable oils (VOs), may influence visceral fat deposition in salmonids. Moreover, major differences in the metabolism of EPA, DHA and OA at different stages during differentiation of adipocytes occur. Most of the EPA and DHA were oxidized in preadipocytes, while they were mainly stored in TAGs in mature adipocytes in contrast to OA which was primarily stored in TAGs at all stages of differentiation. (c) 2008 Elsevier B.V. All rights reserved.

• Kjær, Marte Avranden; Todorcevic, Marijana; Torstensen, Bente Elisabeth; Vegusdal, Anne & Ruyter, Bente (2008). Dietary n-3 HUFA affects mitochondrial fatty acid beta-oxidation capacity and susceptibility to oxidative stress in Atlantic salmon. Lipids. ISSN 0024-4201. 43(9), p. 813–827. doi: 10.1007/s11745-008-3208-z. Full text in Research Archive Show summary

  Atlantic salmon (Salmo salar) (90 g) were fed four different diets for 21 weeks (final weight 344 g). The levels of n-3 highly unsaturated fatty acids (HUFA) ranged from 11% of the total fatty acids (FA) in the low n-3 diet to 21% in the intermediate n-3 diet, to 55 and 58% in the high n-3 diets. The high n-3 diets were enriched with either docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA). Increasing dietary levels of n-3 HUFA led to increasing percentages (from 31 to 52%) of these FA in liver lipids. The group fed the highest level of DHA had higher expressions of peroxisome proliferator-activated receptor (PPAR) beta and the FA beta-oxidation genes acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase (CPT)-II, compared to the low n-3 groups. The high n-3 groups had reduced activity of mitochondrial cytochrome c oxidase and beta-oxidation capacity, together with increased activities of superoxide dismutase (SOD) and caspase-3 activities. In the group fed the highest level of n-3 HUFA, decreased percentages of major phospholipids (PL) in the mitochondrial and microsomal membranes of the liver were also apparent. The percentage of mitochondrial cardiolipin (Ptd(2)Gro) was 3.1 in the highest n-3 group compared to 6.6 in the intermediate group. These data clearly show an increased incidence of oxidative stress in the liver of fish fed the high n-3 diets.

• Todorcevic, Marijana; Vegusdal, Anne; Gjøen, Tor; Sundvold, H; Torstensen, BE & Kjær, Marte Avranden [Show all 7 contributors for this article] (2008). Changes in fatty acids metabolism during differentiation of Atlantic salmon preadipocytes; Effects of n-3 and n-9 fatty acids. Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. ISSN 1388-1981. 1781, p. 326–335. doi: 10.1016/j.bbalip.2008.04.014. Full text in Research Archive
• Nanton, Dominic; Vegusdal, Anne; Rørå, Anna Maria Bencze; Ruyter, Bente; Bæverfjord, Grete & Torstensen, Bente Elisabeth (2007). Muscle lipid storage pattern, composition, and adipocyte distribution in different parts of Atlantic salmon (Salmo salar) fed fish oil and vegetable oil. Aquaculture. ISSN 0044-8486. 265, p. 230–243. doi: 10.1016/j.aquaculture.2006.03.053. Full text in Research Archive Show summary

  The effects of dietary oil source on lipid storage were evaluated in harvest size Atlantic salmon fed fish (FO) or vegetable oil (VO) based diets from start-feeding. Final weight and fat content were not significantly different for salmon fed FO and VO diets over a 27 month period. Fish fed these diets were scanned by computerized X-ray tomography (CT) and the whole body scans partitioned into two equal sections according to distance in longitudinal direction. Visible depot fat (area % of soft tissues) and mixed tissue fat levels were significantly higher in the anterior compared to posterior sections, but longitudinal fat distribution was not affected by diet. Differences in the fatty acid (FA) composition of the FO and VO diets were reflected in the tissues (white muscle, red muscle, white muscle myosepta, belly flap and visceral fat) of Atlantic salmon fed these diets. Lipid levels in these tissues were not significantly different for salmon fed FO and VO diets. No obvious differences were observed histologically in the lipid storage patterns of these tissues for salmon fed FO and VO diets. Visceral fat and belly flap tissues were predominated by adipocytes and contained the highest levels of total lipid and triacylglycerol (TAG) per g wet weight for the tissues tested. The red muscle contained higher lipid levels than the white muscle (>4 fold for salmon fed the same FO or VO diet). Intracellular lipid droplets were observed by light microscopy in oil red 0 stained frozen sections of the red muscle but not observed to any extent in the white muscle (dorsal, lateral and ventral) for salmon fed FO and VO diets. Observations at higher magnifications, however, revealed small lipid droplets located in close association with mitochondria in the cytoplasm of white muscle cells. High densities of adipocytes were observed in the myosepta of red and white muscle for salmon fed FO and VO diets. White muscle myosepta had a significantly higher total lipid content and proportion of TAG than the white muscle. The belly flap, myosepta and visceral fat, (adipocyte-rich, lipid storage tissues) contained a higher proportion of TAG and monounsaturated FA as well as a lower proportion of polar lipid and n-3 polyunsaturated FA compared to the muscle tissues. (C) 2007 Elsevier B.V, All rights reserved.

• Østbye, Tone-Kari K; Bardal, Tora; Vegusdal, Anne; Frang, Ola T.; Kjørsvik, Elin & Andersen, Øivind (2007). Molecular cloning of the Atlantic salmon activin receptor IIB cDNA - Localization of the receptor and myostatin in vivo and in vitro in muscle cells. Comparative Biochemistry and Physiology - Part D:Genomics and Proteomics. ISSN 1744-117X. 2, p. 101–111. doi: 10.1016/j.cbd.2006.12.003. Full text in Research Archive
• Gjøen, Tor; Kleveland, Ellen Johanne; Moya-Falcn, C; Moya-Falcón, Corina; Froystad, MK & Frøystad, Marianne K. [Show all 11 contributors for this article] (2007). Effects of dietary thia fatty acids on lipid composition, morphology and macrophage function of Atlantic salmon (Salmo salar L.) kidney. Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. ISSN 1096-4959. 148(1), p. 103–111. doi: 10.1016/j.cbpb.2007.04.021. Full text in Research Archive
• Gjøen, Tor; Kleveland, Ellen Johanne; Moya-Falcon, Corina; Frøystad, Marianne K.; Vegusdal, Anne & Hvattum, Erlend [Show all 8 contributors for this article] (2007). Effects of dietary thia fatty acids on lipid composition, morphology and macrophage function of Atlantic salmon (Salmo salar L.) kidney. Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. ISSN 1096-4959. 148. Full text in Research Archive Show summary

  High lipid levels are being used in modem salmonid diets to promote rapid growth; however there is a limiting supply of the traditional fish oils as the fish farming industry expands. One way to utilize the lipid sources better, could be to find ways to stimulate fatty acid (FA) oxidation so that Atlantic salmon use more energy for muscle growth and less for storage in pet visceral adipose tissue. We have previously shown that dietary inclusion of the thia FA tetradecylthioacetic acid (TTA) promoted hepatic beta-oxidation and reduced total body lipid levels. However, dietary TTA also had some negative effects, leading to accumulation of sulfone and sulfoxide metabolites of TTA in the kidney and increasing mortality rates, particularly at low water temperatures. Therefore we also wish to investigate the effects of TTA on kidney function at high and low temperatures, including some immune system parameters. The production of leukotriene B-4 (LTB4) and prostaglandin E-2 (PGE(2)) immunoreactive material from exogenously added arachidonic acid in isolated head kidney macrophages was affected by both diet and temperature. The phagocytic activity in these cells was reduced by DTA in the 12 degrees C group and there was significantly higher protein degradation in head kidney macrophages at 12 degrees C compared to 5 degrees C in all dietary groups. Interestingly, the incorporation of thia FAs in the kidney was higher at 5 degrees C (0.3% TTA and 0.6% DTA) than at 12 degrees C (0.1% TTA and 0.5% DTA). Additionally, there were lower levels of saturated FAs, while higher levels of polyunsaturated FAs (PUFAs) in the kidney of TTA fed fish at 5 degrees C. We also observed temperature-independent tubular dilatation and a reduction in the density of melanomacrophages of the kidney in salmon fed TTA. Nevertheless, the rnRNA expression of some immune-relevant genes in head kidney tissue was not affected by TTA-inclusion in salmon diets. In conclusion, it is clear that 0.6% TTA-inclusion in the feed leads to changes in the kidney function particularly at low water temperatures. (C) 2007 Elsevier Inc. All rights reserved.

• Kleveland, Ellen Johanne; Syvertsen, Berit Lyng; Ruyter, Bente; Vegusdal, Anne; Jørgensen, Sven Martin & Gjøen, Tor (2006). Characterization of scavenger receptor class B, type I in Atlantic salmon (Salmo salar L.). Lipids. ISSN 0024-4201. 41(11), p. 1017–1027.. Full text in Research Archive
• Kleveland, Ellen Johanne; Ruyter, B; Vegusdal, Anne; Sundvold, H; Berge, RK & Gjøen, Tor (2006). Effects of 3-thia fatty acids on expression of some lipid related genes in Atlantic salmon (Salmo salar L.). Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. ISSN 1096-4959. 145, p. 239–248. Full text in Research Archive
• Ruyter, Bente; Moya-Falcon, C; Rosenlund, G. & Vegusdal, Anne (2006). Fat content and morphology of liver and intestine of Atlantic salmon (Salmo salar): Effects of temperature and dietary soybean oil. Aquaculture. ISSN 0044-8486. 252, p. 441–452. doi: 10.1016/j.aquaculture.2005.07.014. Full text in Research Archive Show summary

  We investigate the effect of adding soybean oil (SO) to the diet of Atlantic salmon and water temperature on lipid composition and morphology of the liver and intestine. The fish were fed fish meal-based diets supplemented with either 100% fish oil (100% FO), 50% soybean oil (50% SO) or 100% soybean oil (100% SO) for 950 day degrees at 5 and at 12 degrees C. Fish fed the 50% SO and 100% SO diets had higher percentages of 18:2n - 6 and 18:1n - 9 in the triacylglycerol (TAG) fractions of liver and intestine than fish fed the 100% FO diet, at both temperatures. In addition, the percentages of 20:5n - 3 and 22:6n - 3 were considerably lower, while the percentages of 20:4n - 6 and 20:4n - 3 were higher in the phospholipids (PL) fractions of both liver and intestine of fish fed diets containing SO. Both morphological and chemical analyses revealed higher accumulation of fat both in the intestine and liver at 5 than at 12 T. Diets, on the other hand, did not affect the fat content of the intestine on the contrary to what was found in the liver. Fish fed the 100% SO diet had higher accumulation of fat in the liver than fish fed the 100% FO diet at 5 T. The higher fat accumulation in liver from 100% SO fed fish seemed to be mainly caused by a selective accumulation of 18:2n - 6 and 18:1n - 9. (c) 2005 Elsevier B.V. All rights reserved.

• Vegusdal, Anne; Gjøen, Tor; Berge, Rolf Kristian; Thomassen, Magny Skinlo & Ruyter, Bente (2005). Effect of 18 : 1n-9, 20 : 5n-3, and 22 : 6n-3 on lipid accumulation and secretion by Atlantic salmon hepatocytes. Lipids. ISSN 0024-4201. 40(5), p. 477–486. doi: 10.1007/s11745-005-1407-z. Full text in Research Archive Show summary

  We have studied the effects of dietary FA on the accumulation and secretion of [3H]glycerolipids by salmon hepatocytes in culture. Atlantic salmon were fed diets supplemented with either 100% soybean oil (SO) or 100% fish oil (FO), and grew from an initial weight of 113±5 g to a final weight of 338 ±19 g. Hepatocytes were isolated from both dietary groups and incubated with [3H]glycerol in an FA-free medium; a medium supplemented with 0.75 mM of one of three FA—18∶1n−9, 20∶5n−3, or 22∶6n−3—or a medium supplemented with 0.75 mM of the sulfur-substituted FA analog tetradecylthioacetic acid (TTA), which cannot undergo β-oxidation. Incubations were allowed to proceed for 1,2,6, or 24 h. The rate of the secretion of radioactive glycerolipids with no FA added was 36% lower from hepatocytes isolated from fish fed the FO diet than it was from hepatocytes isolated from fish fed the SO diet. Hepatocytes incubated with 18∶1n−9 secreted more [3H]TAG than when incubated with no FA, whereas hepatocytes incubated with 20∶5n−3 or TTA secreted less labeled TAG than when incubated with no FA. This observation was independent of the feeding group. Hepatocytes incubated with 22∶6n−3 secreted the highest amounts of total [3H]glycerolipids compared with the other treatments, owing to increased secretion of phospholipids and mono- and diacylglycerols (MDG). In contrast, the same amounts of [3H]TAG were secreted from these cells as from cells incubated in an FA-free medium. The lipid-lowering effect of FO is thus independent of 22∶6n−3, showing that 20∶5n−3 is the FA that is responsible for the lipid-lowering effect. The ratio of TAG to MDG in lipids secreted from hepatocytes to which 20∶5n−3 or TTA had been added was lower than that in lipids secreted from hepatocytes incubated with 18∶1n−9 or 22∶6n−3, suggesting that the last step in TAG synthesis was inhibited. Morphometric measurements revealed that hepatocytes incubated with 20∶5n−3 accumulated significantly more cellular lipid than cells treated with 18∶1n−9, 22∶6n−3, TTA, or no treatment. The area occupied by mitochondria was also greater in these cells. The present study shows that dietary FO reduces TAG secretion from salmon hepatocytes and that 20∶5n−3 mediates this effect.

• Vegusdal, Anne; Østbye, Tone-Kari K; Tran, TN; Gjøen, Tor & Ruyter, B (2004). Beta-oxidation, esterification, and secretion of radiolabeled fatty acids in cultivated Atlantic salmon skeletal muscle cells. Lipids. ISSN 0024-4201. 39(7), p. 649–658. Full text in Research Archive
• Kolstad, Kari; Vegusdal, Anne; Bæverfjord, Grete & Einen, Olai (2004). Quantification of fat deposits and fat distribution in Atlantic halibut (Hippoglossus hippoglossus L.) using computerised X-ray tomography (CT). Aquaculture. ISSN 0044-8486. 229, p. 255–264. doi: 10.1016/S0044-8486(03)00354-5. Full text in Research Archive Show summary

  Fifty adult 1–8 kg Atlantic halibut were subjected to computerised X-ray tomography (CT) to evaluate CT as a non-destructive measure of relative size of fat deposits and lean tissue, and to estimate fat content. Preliminary examinations of dissected tissues showed a clear separation and no overlap in CT values for pure fat deposits and lean tissue. The estimated proportions of fat deposits and lean tissue (area%) varied significantly between five CT-scans collected in the longitudinal direction of the halibut, and the scan across the longitudinal mid-line was considered to be the most relevant for the whole halibut fillet. Fat percentage of a cutlet determined after ethyl acetate extraction correlated well (r2=0.85, P<0.001) with CT measured fat deposit area (%), which shows that CT can be used as a non-destructive method to predict fat content in halibut.

• Denstadli, Vegard; Vegusdal, Anne; Krogdahl, Åshild; McKellep, Anne Marie Bakke; Berge, Gerd Marit & Holm, Halvor [Show all 8 contributors for this article] (2004). Lipid absorption in different segments of the gastrointestinal tract of Atlantic salmon (Salmo salar L.). Aquaculture. ISSN 0044-8486. 240(1-4), p. 385–398. doi: 10.1016/j.aquaculture.2004.06.030. Full text in Research Archive Show summary

  Gastrointestinal lipid absorption in Atlantic salmon was studied following force-feeding with a standard grower diet to which isotope-labelled free fatty acid (FFA) [1-(14)C]-decanoic acid ((14)C- 10:0) and triacylglycerol (TAG) [9, 10-(3)H(N)]-triolein (trioleic acid; (3)H-18:1) were added. Following force-feeding, the 15 fish, with an average weight of 704 g, were kept in five circular tanks, three fish per tank, supplied with seawater (salinity, 32 g l(-1)). At 3, 6, 12, 18 and 48 h, the fish from one tank were killed, and the gastrointestinal (GI) tract was removed and divided into six segments: stomach (ST), anterior, mid, and distal pyloric ceca (PCA, PCM, and PCD, respectively), mid intestine (MI), and distal intestine (DI). The levels of radioactivity (dpm [disintegrations per minute] mug(-1) tissue) from the (14)C-10:0 and the (3)H-18:1 substrates were measured in tissue samples from each segment, allowing an estimation of the amounts of fatty acid substrates absorbed from the lumen into the intestinal cells. The highest levels of radioactivity from both fatty acid substrates were measured in tissue from pyloric ceca (PC) 12 to 18 h after force-feeding. The level of radioactivity from the (14)C-10:0 substrate was significantly higher in the PCA than in the PCM and PCD, while there was no clear difference in the level of radioactivity from the (3)H-18:1 substrate measured among the different PC tissue segments and the level measured in MI. The level of radioactivity in tissue from DI was negligible to low for both fatty acid substrates. Total lipid accumulation in tissue from PCM, MI and DI was quantified morphometrically at each sampling point using light microscopy and image analysis. These results confirmed the findings from the isotope study, where the highest levels of fat were present at 12 and 18 h following force-feeding. In conclusion, PC was the most important site for fatty acid absorption in the GI tract of Atlantic salmon. (C) 2004 Elsevier B.V. All rights reserved.

• Vegusdal, Anne; Ostbye, TK; Tran, Thien Ngoc; Gjøen, Tor & Ruyter, Bente (2004). Beta-oxidation, esterification, and secretion of radiolabeled fatty acids in cultivated Atlantic salmon skeletal muscle cells. Lipids. ISSN 0024-4201. 39(7), p. 649–658. Full text in Research Archive
• Vegusdal, Anne; Sundvold, Hilde; Gjøen, Tor & Ruyter, Bente (2003). An in vitro method for studying the proliferation and differentiation of Atlantic salmon preadipocytes. Lipids. ISSN 0024-4201. 38(3), p. 289–296. doi: 10.1007/s11745-003-1063-3. Full text in Research Archive Show summary

  The aim of the present study was to develop a cell culture system for studying the proliferation and differentiation of preadipocytes isolated from Atlantic salmon adipose tissue. The expression of proliferating cell nuclear antigen (PCNA) was used as a marker for cell proliferation. The cells started to proliferate within 48 h after seeding and continued to proliferate throughout the culture period of 2 wk. Undifferentiated preadipocytes showed a fibroblast-like morphology with a homogeneous cytoplasm devoid of lipid droplets. At confluence, an exogenous lipid mixture was added to the cell cultures. The preadipocytes became larger and rounder during the subsequent days, and the cytoplasm gradually filled with lipid-rich droplets. These droplets were revealed by oil red O staining. Immunocytochemical staining showed that differentiated adipocytes expressed detectable levels of the three regulatory proteins associated with adipocyte differentiation: peroxisome proliferator-activated receptor gamma (PPARgamma), CCAAT/enhancer binding protein a (C/EBPalpha), and leptin. The cells also showed activity of glycerol-3-phosphate dehydrogenase (GPDH) (EC 1.1.1.8), a biochemical marker of adipocyte differentiation. The morphological and biochemical data presented here show that fish preadipocytes have properties that are similar to those of preadipocytes in mammals. We conclude therefore that salmon adipose tissue contains a sizable population of preadipocytes. Exogenous lipids promote the activation of adipose-related genes and induce the differentiation of fish preadipocytes in vitro.

• Skjervold, Per Olav; Rørå, Anna Maria Bencze; Fjæra, Svein Olav; Vegusdal, Anne; Vorre, Aase & Einen, Olai (2001). Effects of pre-, in-, or post-rigor filleting of live chilled Atlantic salmon. Aquaculture. ISSN 0044-8486. 194(3-4), p. 315–326. doi: 10.1016/S0044-8486(00)00531-7. Full text in Research Archive Show summary

  Atlantic salmon (Salmo salar) was chilled to a core temperature of approximately 1 degreesC prior to harvest. Groups of 10 fish were filleted 2 h after harvest (pre-rigor), 1 and 2 days after harvest tin-rigor), and finally, 5 days after harvest (post-rigor). 7 and 14 days after harvesting and 7 and 14 days after filleting the fillets were evaluated according to various quality parameters. The incidence and severity of gaping were significantly reduced with earlier filleting. The differences became even more pronounced as the fillets were stored. Fillet yield, water binding capacity and fillet weight loss did not differ among the experimental groups, but there was a positive effect of pre-rigor filleting on visual colour. The pre-rigor fillets were significantly thicker than those filleted post-rigor indicating a change in fillet shape due to when filleting was performed after harvest. (C) 2001 Elsevier Science B.V. All rights reserved.

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• Svingen-Austestad, Anna; Lien, Anne; Larsen, Jorunn; Fiskvatn, Kari; Falck, Åsa Lipka & Enberg, Cecilia [Show all 7 contributors for this article] (2019). LAB (skala 1:1) – Hva er observasjon? Full text in Research Archive
• Vegusdal, Anne & Nilsen, Hans Kristian (2016). Lærerstudenter med Lektor2 på pensum. Naturfag. ISSN 1504-4564. p. 44–45. Full text in Research Archive
• Nilsen, Hans Kristian; Vegusdal, Anne & Dean, Evert (2016). Mathematics at the Enterprise, University and School (MathEUS). Full text in Research Archive
• Vegusdal, Anne & Evert, Dean (2016). Mathematics at the Enterprise, University and School (MathEUS). Full text in Research Archive
• Nilsen, Hans Kristian & Vegusdal, Anne (2015). MathEUS – Matematikk med mening. Et FoU-samarbeid mellom skole, universitet og arbeidsliv. Full text in Research Archive
• Stabell, OB & Vegusdal, Anne (2009). Socializing Increases Club Cell Number in Crucian Carp. Chemical Senses. ISSN 0379-864X. 34(3), p. E65–E65. Full text in Research Archive
• Stabell, Ole B. & Vegusdal, Anne (2009). Socializing Increases Club Cell Number in Crucian Carp. Chemical Senses. ISSN 0379-864X. p. 65–65. Full text in Research Archive Show summary

  Club cells in the skin of cyprinid fish are assumed to contain ¿schreckstoff¿ that releases alarm behavior. Accordingly, they are also denoted alarm substance cells (ASC). In a North-American cyprinid, the number of ASC has been found higher in lakes with than without predator fish. We questioned if such an increase in ASC could result from exposure to alarm signals, released over time by predators labeled by prey odors? Crucian carp (Carassius carassius) develops a deep body in the presence of predator fish; an inducible defense attributed to alarm signal exposure. By exposing crucian carp to conspecific skin extract, we wanted to test if: 1) the number of ASC increases, and 2) any correlation exist between body depth increase and number of ASC. We raised crucian carp for 7 weeks in groups of four, or alone, and exposed them to either conspecific skin extract or skin extract of brown trout (control: does not possess ASC). In addition, all combinations of raising method and exposure type were duplicated, supplying fish with either a low or a high feed ratio. Independent of rearing type (group or single), body depth and condition factor increased in crucian carp with the size of their feed ratio, but no differences were found from exposure to conspecific skin extract. The number of ASC per mm of epidermis increased with feed ratio, and almost a 10-fold increase in number of ASC was found as a maximum. Thickness of epidermis increased with increased condition factor, as did the number of ASC in relation to epidermis thickness. An unexpected finding was that epidermis thickness, and thereby ASC, increased significantly more for fishes raised in groups than for fishes raised alone. We conclude that alarm substances in cyprinid fish, confirmed present when introducing extracts on day-1, may not be the chemical signals inducing body depth increase in crucian carp. However, increased availability of food, resulting in an increased condition factor, allows the fish to invest in more ASC. In addition, there seems to be a hitherto unknown awareness of conspecific proximity, expressed in an increased production of ASC. We speculate that this increase may also be induced by conspecific chemical signals.

• Kjær, Marte Avranden; Todorcevic, Marijana; Torstensen, Bente; Vegusdal, Anne & Ruyter, Bente (2008). N-3 fatty acids in Atlantic salmon diets alter liver gene expression, fatty acid metabolism and susceptibility to oxidative stress. Full text in Research Archive Show summary

  Changes in dietary fatty acid (FA) profile may affect lipid metabolism in Atlantic salmon in many ways. Dietary vegetable oils have for instance been shown to decrease the FA ¿-oxidation capacity and affect several genes, among these FA desaturases, mitochondrial proteins, transcription factors, co-activators and signal transducers. In addition, high levels of eicosapentanoic acid (EPA, 20:5n-3) is shown to induce mitochondrial proliferation. The major aims of this study were firstly to investigate how increasing dietary levels of n-3 FAs affect salmon liver FA metabolism and expression of lipid regulatory genes. Secondly, to investigate how high level of EPA and docosahexanioc acid (DHA, 22:6n-3) may influence the susceptibility to oxidative stress. Triplicate groups of Atlantic salmon (90 g mean initial weight) were fed for 21 weeks on one of four diets supplemented with 23 % lipid. EPA and DHA levels varied from 10 % of total FAs in the diet based on rapeseed oil (RO) to 19 % in the diet based on fish oil (FO), and further to approximately 50 and 55 % in the DHA-enriched and EPA-enriched diets, respectively. The fish were fed on these diets until they reached a final average weight of 344 g. Increasing dietary levels of n-3 FAs led to increasing percentages of these FAs in liver lipids, ranging from 30 to 48 % of total liver FAs. Relatively more of the 18:3n-3 in the RO diet than 20:5n-3 in the EPA-enriched diet was found as 22:6n-3 in liver lipids. However, a major increase in the percentage of the elongation product 22:5n-3 was found in liver from the EPA fed fish. These data were supported by decreased expression of ¿5- and ¿6-desaturase genes with increasing dietary levels of EPA and DHA. The diet with the highest level of DHA affected several of the lipid regulatory genes. Expression of peroxisome proliferator-activated receptor (PPAR) _b, thFA _b-oxidation genes acyl-CoA oxidase (ACO) and carnitine palmitoyl-rnsferase (CPT) II and genes for the transport proteins fatty acid binding protein (FABP10) and fatty acid transport protein (FATP1) were all increased compared to the RO group. The membrane lipids of mitochondria and microsomes are easily susceptible to reactive oxygen species (ROS). Increasing dietary levels of EPA and DHA clearly decreased the percentage of major phospholipids (PLs) in mitochondrial and microsomal membranes. The percentage of cardiolipin (CL) was 3.1 in the mitochondrial membrane of the EPA group compared to 6.6 in the FO group. There were three times higher incidence of membrane damage and lack of mitochondrial ¿-oxidation capacity together with increased super oxide dismutase (SOD) and caspase-3 activity in the EPA and DHA groups compared to the FO and RO groups. Clearly, the presence of oxidised lipid may have harmful effects on mitochondrial function. These results reveal new elements in favour of greater sensitivity of n-3 FAs to peroxidation in fish.

• Samulin, Johanna; Lien, Sigbjørn; Ruyter, Bente; Vegusdal, Anne; Grindflek, Eli & Sundvold, Hilde (2006). Proliferation and differentiation of porcine preadipocytes derived from subcutaneous and abdominal adipose tissue depots. Full text in Research Archive
• Denstadli, Vegard; Vegusdal, Anne; Krogdahl, Åshild; McKellep, Anne Marie Bakke; Berge, Gerd Marit & Hillestad, Marie [Show all 7 contributors for this article] (2004). Absorption and transport of oleic (18:1 n-9) and decanoic (C10:0) acids in Atlantic salmon (Salmo salar L) combined with histological determination of total fat in intestinal folds. Full text in Research Archive

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