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Cui W, Takahashi E, Morro B, Balseiro P, Albalat A, Pedrosa C, Mackenzie S, Nilsen TO, Sveier H, Ebbesson LO, Handeland SO, Shimizu M. Changes in circulating insulin-like growth factor-1 and its binding proteins in yearling rainbow trout during spring under natural and manipulated photoperiods and their relationships with gill Na +, K +-ATPase and body size. Comp Biochem Physiol A Mol Integr Physiol 2022; 268:111205. [PMID: 35346822 DOI: 10.1016/j.cbpa.2022.111205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/10/2022] [Accepted: 03/22/2022] [Indexed: 10/18/2022]
Abstract
Smoltification in salmonids occurs during spring in response to increasing photoperiod to prepare for marine life. Smoltification is associated with increased hypo-osmoregulatory ability and enhanced growth potential, mediated by growth hormone and insulin-like growth factor (IGF)-1. Rainbow trout is uniquely insensitive to the induction of smoltification-associated changes by photoperiod, such as the activation of gill Na+,K+-ATPase (NKA). We measured the circulating IGF-1 and IGF-binding protein (IGFBP)-2b levels in yearling rainbow trout exposed to natural and manipulated photoperiods during spring and correlated these with gill NKA activity and body size. Although the effect of photoperiod manipulation on body size and circulating IGF-1 and IGFBP-2b was negligible, they were positively correlated with gill NKA activity in fish under simulated natural photoperiod. We next pit-tagged yearling rainbow trout and fed them a restricted ration or to satiation under a natural photoperiod. In April, gill NKA activity was higher in the satiation group than in the restricted group and positively correlated with body size and growth rate. In addition, circulating IGFBP-2b was positively correlated with gill NKA, size and growth, whereas circulating IGF-1 was correlated only with size and growth. The relationship between circulating IGF-1 and growth intensified from May to June, suggesting that the IGF-1-growth relationship was disrupted in April when gill NKA was activated. Two additional IGFBPs were related to growth parameters but not to gill NKA activity. The present study suggests that circulating IGFBP-2b and IGF-1 mediate the size-dependent activation of gill NKA in yearling rainbow trout during spring.
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Affiliation(s)
- Wenda Cui
- Graduate School of Environmental Science, Hokkaido University, Kita 10, Nishi 5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Eisuke Takahashi
- Nanae Fresh-Water Station, Field Science Center for Northern Biosphere, Hokkaido University, 2-9-1 Sakura, Nanae, Kameda-gun, Hokkaido 041-1105, Japan
| | - Bernat Morro
- Institute of Aquaculture, University of Stirling, FK9 4LA Stirling, UK
| | - Pablo Balseiro
- NORCE AS, Nygårdsgaten 112, 5008 Bergen, Norway; Department of Biological Sciences, University of Bergen, Thormøhlens gate 53 A/B, 5020 Bergen, Norway
| | - Amaya Albalat
- Institute of Aquaculture, University of Stirling, FK9 4LA Stirling, UK
| | - Cindy Pedrosa
- NORCE AS, Nygårdsgaten 112, 5008 Bergen, Norway; Department of Biological Sciences, University of Bergen, Thormøhlens gate 53 A/B, 5020 Bergen, Norway
| | - Simon Mackenzie
- Institute of Aquaculture, University of Stirling, FK9 4LA Stirling, UK; NORCE AS, Nygårdsgaten 112, 5008 Bergen, Norway
| | - Tom O Nilsen
- NORCE AS, Nygårdsgaten 112, 5008 Bergen, Norway; Department of Biological Sciences, University of Bergen, Thormøhlens gate 53 A/B, 5020 Bergen, Norway
| | - Harald Sveier
- Lerøy Seafood Group ASA, Box 7600, 5020 Bergen, Norway
| | | | - Sigurd O Handeland
- NORCE AS, Nygårdsgaten 112, 5008 Bergen, Norway; Department of Biological Sciences, University of Bergen, Thormøhlens gate 53 A/B, 5020 Bergen, Norway
| | - Munetaka Shimizu
- Section of Aquatic Research, Field Science Center for Northern Biosphere, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido 041-8611, Japan.
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2
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Morro B, Broughton R, Balseiro P, Handeland SO, Mackenzie S, Doherty MK, Whitfield PD, Shimizu M, Gorissen M, Sveier H, Albalat A. Endoplasmic reticulum stress as a key mechanism in stunted growth of seawater rainbow trout (Oncorhynchus mykiss). BMC Genomics 2021; 22:824. [PMID: 34781893 PMCID: PMC8594166 DOI: 10.1186/s12864-021-08153-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 11/01/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Rainbow trout (Oncorhynchus mykiss) is a salmonid species with a complex life-history. Wild populations are naturally divided into freshwater residents and sea-run migrants. Migrants undergo an energy-demanding adaptation for life in seawater, known as smoltification, while freshwater residents display these changes in an attenuated magnitude and rate. Despite this, in seawater rainbow trout farming all fish are transferred to seawater. Under these circumstances, weeks after seawater transfer, a significant portion of the fish die (around 10%) or experience growth stunting (GS; around 10%), which represents an important profitability and welfare issue. The underlying causes leading to GS in seawater-transferred rainbow trout remain unknown. In this study, we aimed at characterising the GS phenotype in seawater-transferred rainbow trout using untargeted and targeted approaches. To this end, the liver proteome (LC-MS/MS) and lipidome (LC-MS) of GS and fast-growing phenotypes were profiled to identify molecules and processes that are characteristic of the GS phenotype. Moreover, the transcription, abundance or activity of key proteins and hormones related to osmoregulation (Gill Na+, K + -ATPase activity), growth (plasma IGF-I, and liver igf1, igfbp1b, ghr1 and ctsl) and stress (plasma cortisol) were measured using targeted approaches. RESULTS No differences in Gill Na+, K + -ATPase activity and plasma cortisol were detected between the two groups. However, a significant downregulation in plasma IGF-I and liver igf1 transcription pointed at this growth factor as an important pathomechanism for GS. Changes in the liver proteome revealed reactive-oxygen-species-mediated endoplasmic reticulum stress as a key mechanism underlying the GS phenotype. From the lipidomic analysis, key observations include a reduction in triacylglycerols and elevated amounts of cardiolipins, a characteristic lipid class associated with oxidative stress, in GS phenotype. CONCLUSION While the triggers to the activation of endoplasmic reticulum stress are still unknown, data from this study point towards a nutritional deficiency as an underlying driver of this phenotype.
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Affiliation(s)
- Bernat Morro
- Institute of Aquaculture, University of Stirling, Stirling, UK
| | | | - Pablo Balseiro
- NORCE AS, Bergen, Norway.,Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Sigurd O Handeland
- NORCE AS, Bergen, Norway.,Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Simon Mackenzie
- Institute of Aquaculture, University of Stirling, Stirling, UK.,NORCE AS, Bergen, Norway
| | - Mary K Doherty
- Institute of Health Research and Innovation, Centre for Health Science, University of the Highlands and Islands, Scotland, UK
| | - Phillip D Whitfield
- Institute of Health Research and Innovation, Centre for Health Science, University of the Highlands and Islands, Scotland, UK.,Institute of Infection, Immunity and Inflammation, University of Glasgow, Scotland, UK
| | - Munetaka Shimizu
- Faculty of Fisheries Sciences, Hokkaido University, Sapporo, Japan
| | - Marnix Gorissen
- Department of Animal Ecology and Physiology, Radboud University, Institute of Water and Wetland Research, Nijmegen, The Netherlands
| | | | - Amaya Albalat
- Institute of Aquaculture, University of Stirling, Stirling, UK.
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3
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Morro B, Doherty MK, Balseiro P, Handeland SO, MacKenzie S, Sveier H, Albalat A. Plasma proteome profiling of freshwater and seawater life stages of rainbow trout (Oncorhynchus mykiss). PLoS One 2020; 15:e0227003. [PMID: 31899766 PMCID: PMC6941806 DOI: 10.1371/journal.pone.0227003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/09/2019] [Indexed: 01/18/2023] Open
Abstract
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.
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Affiliation(s)
- Bernat Morro
- Institute of Aquaculture, University of Stirling, Stirling, Scotland, United Kingdom
- * E-mail:
| | - Mary K. Doherty
- Institute of Health Research and Innovation, Centre for Health Science, University of the Highlands and Islands, Inverness, Scotland, United Kingdom
| | | | | | - Simon MacKenzie
- Institute of Aquaculture, University of Stirling, Stirling, Scotland, United Kingdom
- NORCE AS, Universitetet i Bergen, Bergen, Norway
| | - Harald Sveier
- Lerøy Seafood Group ASA, Universitetet i Bergen, Bergen, Norway
| | - Amaya Albalat
- Institute of Aquaculture, University of Stirling, Stirling, Scotland, United Kingdom
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Gharbi N, Mota V, Terjesen BF, Kolarevic J, Ytteborg E, Ebbesson L, Handeland SO, Nilsen TO. Effects of High Environmental CO
2
Levels on Atlantic Salmon Post‐Smolts. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.544.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Naouel Gharbi
- Environment, Integrative Fish BiologyNorwegian Research Center (NORCE)BergenNorway
| | - Vasco Mota
- Production Biology department (Nofima)NofimaTromsøNorway
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Lai F, Kalananthan T, Berg GM, Murashita K, Gomes AS, Handeland SO, Rønnestad I. Brain Distribution of Key Neuropeptides Involved in Appetite Control in Atlantic Salmon,
Salmo Salar
(L.). FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.729.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Floriana Lai
- Biological SciencesUniversity of BergenBergenNorway
| | | | | | - Koji Murashita
- Biological SciencesUniversity of BergenBergenNorway
- Research Center for Aquaculture Systems, National Research Institute of Aquaculture, Japan Fisheries Research and Education AgencyMieJapan
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Balseiro P, Moe Ø, Gamlem I, Shimizu M, Sveier H, Nilsen TO, Kaneko N, Ebbesson L, Pedrosa C, Tronci V, Nylund A, Handeland SO. Comparison between Atlantic salmon Salmo salar post-smolts reared in open sea cages and in the Preline raceway semi-closed containment aquaculture system. J Fish Biol 2018; 93:567-579. [PMID: 29952001 DOI: 10.1111/jfb.13659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 05/06/2018] [Indexed: 06/08/2023]
Abstract
The use of closed containment (CCS) or semi-closed containment systems (S-CCS) for Atlantic salmon Salmo salar aquaculture is under evaluation in Norway. One such system is the Preline S-CCS, a floating raceway system that pumps water from 35 m depth creating a constant current through the system. Exposing fish to moderate water currents is considered aerobic exercise and it is often perceived as positive for fish welfare, growth, food utilization, muscle development and cardiac health. The present study compared fish reared in the Preline S-CCS and in a reference open pen. Samples were taken in fresh water before being transferred to the seawater systems and after 1, 2 and 4 months in seawater and analysed for growth, mortality, muscle development and plasma insulin-like growth factor I (IGF-I) levels. Moreover, gene transcription were determined in the skeletal muscle [igf-I, insulin-like growth factor 1 receptor a (igf1ra) and insulin-like growth factor 1 binding protein 1a (igf1bp1a)] and cardiac transcription factors [myocyte-specific enhancer factor 2C (mef2c), gata4 and vascular endothelial growth factor (vegf)]. While the results suggest that post-smolts in Preline S-CCS were smaller than reference fish, fish from Preline S-CCS have less accumulated mortality at the end of the experiment and showed 2.44 times more small muscle fibres than the reference group fish after 4 months in seawater. These results confirmed what was previously observed in the second generation of Preline. Similar levels of big muscle fibres between Preline S-CCS and reference suggest a similar hypertrophy of muscle fibres even with lower IGF-I expression in the Preline S-CCS. Cardiac gene transcription suggests cardiac hypertrophy was observed after 4 months in seawater in the Preline S-CCS group. Altogether, Preline S-CCS is a promising technology able to produce more robust S. salar with a faster growth and lower mortality in the subsequent standard open cage system growth period.
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Affiliation(s)
- Pablo Balseiro
- Uni Research Environment, Uni Research AS, Bergen, Norway
| | - Øyvind Moe
- Uni Research Environment, Uni Research AS, Bergen, Norway
| | - Ingrid Gamlem
- Uni Research Environment, Uni Research AS, Bergen, Norway
| | - Munetaka Shimizu
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan
| | | | - Tom O Nilsen
- Uni Research Environment, Uni Research AS, Bergen, Norway
| | - Nobuto Kaneko
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan
| | - Lars Ebbesson
- Uni Research Environment, Uni Research AS, Bergen, Norway
| | - Cindy Pedrosa
- Uni Research Environment, Uni Research AS, Bergen, Norway
| | | | - Are Nylund
- Department of Biology, University of Bergen, Bergen, Norway
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7
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Handeland SO, Imsland AK, Nilsen TO, Ebbesson LOE, Hosfeld CD, Pedrosa C, Toften H, Stefansson SO. Osmoregulation in Atlantic salmon Salmo salar smolts transferred to seawater at different temperatures. J Fish Biol 2014; 85:1163-1176. [PMID: 25098608 DOI: 10.1111/jfb.12481] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 06/23/2014] [Indexed: 06/03/2023]
Abstract
In order to investigate how changes in gill Na(+) , K(+) -ATPase (NKA) α1a and α1b subunits, Na(+) , K(+) , 2Cl(-) co-transporter (NKCC1) and the apical cystic fibrosis trans-membrane conductance regulator-I (CFTR-I) transcripts in wild strain of Atlantic salmon, Salmo salar, smolts are affected by temperature during spring, hatchery-reared parr (mean ± s.e. fork length = 14·1 ± 0·5; mean ± s.e. body mass = 28·5 ± 4·5 g) originating from broodstock from the Vosso river (western Norway) were acclimated to three temperature regimes (4·1, 8·1 and 12·9° C) in May and reared under gradually increasing salinity between May and June. Changes in plasma Na(+) , haematocrit (Hct) and PCO2 were monitored in order to assess and compare key physiological changes with the transcriptional changes in key ion transporters. The temperatures reflect the natural temperature range in the River Vosso during late spring. Overall, higher gill NKA α1b mRNA levels, gill NKCC1a levels and CFTR-I levels were observed in the 4·1° C group compared to the 11·9° C group. This coincided with a 2-3 week period with decreased Hct and PCO2 and may indicate a critical window when smolts suffer from reduced physical performance during migration. Further research is needed to confirm the potential interaction between ecological and physiological conditions on mortality of hatchery-reared smolts from River Vosso during their natural migration.
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Affiliation(s)
- S O Handeland
- Uni Research AS, 5020 Bergen, Norway; Bergen University College, 5020 Bergen Norway
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8
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Handeland SO, Imsland AK, Björnsson BT, Stefansson SO. Long-term effects of photoperiod, temperature and their interaction on growth, gill Na⁺, K⁺-ATPase activity, seawater tolerance and plasma growth-hormone levels in Atlantic salmon Salmo salar. J Fish Biol 2013; 83:1197-1209. [PMID: 24580662 DOI: 10.1111/jfb.12215] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 07/09/2013] [Indexed: 06/03/2023]
Abstract
This study was undertaken to examine the long-term effects of photoperiod, temperature and their interaction on growth, gill Na⁺,K⁺-ATPase (NKA) activity, seawater tolerance and plasma growth-hormone levels in Atlantic salmon Salmo salar pre-smolts and smolts. The fish (mean ± s.e. initial body mass = 15·9 ± 0·4 g) were reared on two photoperiods (continuous light, LL, and simulated natural photoperiod, LDN, 60° 25' N) and two temperatures (8·3 and 12·7° C) from June to May of the following year. Mean body mass was affected by photoperiod, temperature and their interactions. Both temperature groups on LL developed peak levels in gill NKA activity from October to November, 4-5 months prior to the natural season for the parr-smolt transformation. Fish at 12° C showed peak levels in NKA activity 4-6 weeks before the fish at 8° C. Fish in all four experimental groups showed maximum NKA activity within a similar size range (113-162 g). The present findings further indicate that smoltification in S. salar is to some extent driven by size, and that S. salar will develop smolt characteristics, e.g. a marked increase in NKA activity, within a similar size range. Faster-growing S. salar will, thus, reach this size threshold at a relatively younger age.
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Affiliation(s)
- S O Handeland
- Uni Environment, Uni Research AS, N-5020 Bergen, Norway
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9
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Nilsen TO, Ebbesson LOE, Handeland SO, Kroglund F, Finstad B, Angotzi AR, Stefansson SO. Atlantic salmon (Salmo salar L.) smolts require more than two weeks to recover from acidic water and aluminium exposure. Aquat Toxicol 2013; 142-143:33-44. [PMID: 23948076 DOI: 10.1016/j.aquatox.2013.07.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 07/16/2013] [Accepted: 07/20/2013] [Indexed: 06/02/2023]
Abstract
The detrimental effects of acid rain and aluminium (Al) on salmonids have been extensively studied, yet knowledge about the extent and rate of potential recovery after exposures to acid and Al episodes is limited. Atlantic salmon smolts in freshwater (FW) were exposed for 2 and 7-day episodes (ACID2 and ACID7, respectively) to low pH (5.7±0.2) and inorganic aluminium (Ali; 40±4 μg) and then transferred to good water quality, control water (CW; pH 6.8±0.1; <14±2 μg Ali). Al accumulation on gills after 2 and 7 days of acid/Al exposure was 35.3±14.1 and 26.6±1.8 μg g(-1) dry weight, respectively. These elevated levels decreased 2 days post transfer to CW and remained higher than in control (CON; 5-10 μg Ali) for two weeks. Plasma Na(+) levels in ACID2 and ACID7 smolts decreased to 141±0.8 and 138.6±1.4mM, respectively, and remained significantly lower than CON levels for two weeks post transfer to CW. Similarly, plasma Cl(-) levels in ACID7 smolts (124.3±2.8mM) were significantly lower than in CON, with Cl(-) levels remaining significantly lower in ACID7 (126.2±4.8 mM) and ACID2 (127.6±3.7 mM) than in CON following 9 and 14 days post-transfer to CW, respectively. ACID2 and ACID7 smolts sustained elevated plasma glucose levels post transfer to CW suggesting elevated stress for more than a week following exposure. While gill Na(+), K(+)-ATPase (NKA) activity was only slightly affected in ACID2 and not in ACID7 smolts in FW, acid/Al exposure resulted in a transient decrease in NKA activity following SW exposure in both groups. Acid/Al episodes had limited impact on isoform specific NKA α-subunit mRNA during exposure. However, the transfer of ACID2 and ACID7 smolts to CW showed an increase in NKAα1a mRNA (the FW isoform) and inhibited the up-regulation of NKAα1b (the SW isoform), probably resulting in higher abundance of the enzyme favouring ion uptake. Gill caspase 3B gene transcription did not change in acid/Al treated smolts, indicating no increased apoptosis in gills. ACID2 and ACID7 treatments resulted in lower smolt-related gill transcription of the gene encoding the tight junction protein claudin 10e compared to CON, while the gene encoding claudin 30 showed lower mRNA expression only after 11 days SW exposure in ACID7 fish. Our data suggest that acid/Al conditions affect ion perturbations through a combination of alteration of the preparatory increase in paracellular permeability and negative impact on the SW type NKA α-subunit mRNA transcripts, and raise major concerns regarding the recovery of physiological disruption in smolts following acid/Al exposure. Smolts may require more than two weeks to fully recover from even short moderate episodes of acid/Al exposure. Acid/Al exposure thus probably has greater impact on salmon populations than previously acknowledged.
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Affiliation(s)
- Tom O Nilsen
- Department of Biology, University of Bergen, Bergen High Technology Centre, N-5020, Norway.
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10
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Handeland SO, Imsland AK, Björnsson BT, Stefansson SO, Porter M. Physiology during smoltification in Atlantic salmon: effect of melatonin implants. Fish Physiol Biochem 2013; 39:1079-1088. [PMID: 23277099 DOI: 10.1007/s10695-012-9765-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/23/2012] [Indexed: 06/01/2023]
Abstract
Melatonin implants were used to override natural melatonin rhythm in groups of juvenile Atlantic salmon, Salmo salar, raised at simulated natural photoperiod (SNP) and constant light (LL) from mid-March until end of August. The experiment contained also both sham control (with non-melatonin implants) and control (no implants). No differences were found in the experimental variables between these two control groups. Growth and food intake were negatively affected by melatonin implantation. Overall, higher GH levels were observed in the SNP melatonin-implanted group, whereas no differences in GH levels were seen between the SNP control, LL control, or the LL melatonin-implanted groups. Highest food intake was seen in the LL control group. No differences in food intake were recorded between the LL melatonin-implanted and SNP control groups. Gill Na(+), K(+), ATPase (NKA) activity was influenced by time as well as the interaction between photoperiod and time. No differences in gill NKA activity or plasma chloride levels following transfer to seawater were seen between the groups with melatonin implants and their controls. Based on the present results, it seems apparent that melatonin does play a role in regulating food intake and growth in Atlantic salmon smolts.
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Affiliation(s)
- S O Handeland
- Uni Environment, Uni Research AS, 5006, Bergen, Norway
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11
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Grassie C, Braithwaite VA, Nilsson J, Nilsen TO, Teien HC, Handeland SO, Stefansson SO, Tronci V, Gorissen M, Flik G, Ebbesson LOE. Aluminum exposure impacts brain plasticity and behavior in Atlantic salmon (Salmo salar). J Exp Biol 2013; 216:3148-55. [DOI: 10.1242/jeb.083550] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
Aluminum (Al) toxicity occurs frequently in natural aquatic ecosystems as a result of acid deposition and natural weathering processes. Detrimental effects of Al toxicity on aquatic organisms are well known and can have consequences for survival. Fish exposed to Al in low pH waters will experience physiological and neuroendocrine changes that disrupt homeostasis and alter behavior. To investigate the effects of Al exposure to both brain and behavior, Atlantic salmon (Salmo salar) kept in water treated with Al (pH 5.7, 0.37±0.04 µmol 1-1 of Al) for 2 weeks were compared to fish kept in a control condition (pH 6.7, <0.04 µmol 1-1 of Al). Fish exposed to Al and acidic conditions had increased Al accumulation in the gills and decreased gill Na+, K+-ATPase activity, which impaired osmoreguatory capacity and caused physiological stress, indicated by elevated plasma cortisol and glucose levels. Here we show for the first time that exposure to Al in acidic conditions also impaired learning performance in a maze task. Al toxicity reduced the expression of NeuroD1 transcript levels in the forebrain of exposed fish. As in mammals, these data show that exposure to chronic stress, such as acidified Al, can reduce neural plasticity during behavioral challenges in salmon, and may impair coping ability to new environments.
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