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Haverinen J, Badr A, Eskelinen M, Vornanen M. Three steps down: Metabolic depression in winter-acclimatized crucian carp (Carassius carassius L.). Comp Biochem Physiol A Mol Integr Physiol 2024; 287:111537. [PMID: 37858704 DOI: 10.1016/j.cbpa.2023.111537] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 10/13/2023] [Accepted: 10/15/2023] [Indexed: 10/21/2023]
Abstract
Acclimatization of certain ectothermic vertebrates to winter conditions is associated with reduced energy consumption (winter dormancy). Principally, this may be achieved by reducing movement activity, depression of basal cellular functions, or by switching from aerobic to anaerobic energy production to sustain low energy consumption during anoxia. Therefore, we determined standard (SMR), routine (RMR) and anoxic (AMR) metabolic rates in summer- (SumA; 20 °C) and winter-acclimatized (WinA; 2 °C) crucian carp (Carassius carassius), an anoxia-tolerant teleost fish. At 20 °C, RMR was 39% lower in WinA than SumA fish (p < 0.05), indicating reduced movements in winter. SMR, measured for the first time in crucian carp, was 45% lower in WinA than SumA fish at 10 °C (p < 0.05), indicating significant reduction of energy consumption in vital cellular processes. At 2 °C, AMR - measured from ethanol production- was 78% and 97% of the SMR and RMR levels at the same temperature, respectively. The current study revealed that the winter dormancy in anoxia-tolerant crucian carp is achieved in 3 different steps: (1) by active reduction of SMR, possibly in anticipation of seasonal anoxia, (2) acute Arrhenius Q10 effect that slows SMR as well as RMR, and (3) direct response to the absence of oxygen (AMR). Furthermore, the anoxic energy production was strongly dependent on body mass with scaling exponents of -0.335 and - 0.421 for WinA and SumA fish, respectively.
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Affiliation(s)
- Jaakko Haverinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland.
| | - Ahmed Badr
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland; Zoology Department, Faculty of Science, Sohag University, 82524 Sohag, Egypt
| | - Markus Eskelinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
| | - Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
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2
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Rowsey LE, Reeve C, Savoy T, Speers-Roesch B. Thermal constraints on exercise and metabolic performance do not explain the use of dormancy as an overwintering strategy in the cunner (Tautogolabrus adspersus). J Exp Biol 2024; 227:jeb246741. [PMID: 38044850 PMCID: PMC10906487 DOI: 10.1242/jeb.246741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/24/2023] [Indexed: 12/05/2023]
Abstract
Winter cold slows ectotherm physiology, potentially constraining activities and ecological opportunities at poleward latitudes. Yet, many fishes are winter-active, facilitated by thermal compensation that improves cold performance. Conversely, winter-dormant fishes (e.g. cunner, Tautogolabrus adspersus) become inactive and non-feeding overwinter. Why are certain fishes winter-dormant? We hypothesized that winter dormancy is an adaptive behavioural response arising in poleward species that tolerate severe, uncompensated constraints of cold on their physiological performance. We predicted that below their dormancy threshold of 7--8°C, exercise and metabolic performance of cunner are greatly decreased, even after acclimation (i.e. shows above-normal, uncompensated thermal sensitivity, Q10>1-3). We measured multiple key performance metrics (e.g. C-start maximum velocity, chase swimming speed, aerobic scope) in cunner after acute exposure to 26-2°C (3°C intervals using 14°C-acclimated fish) or acclimation (5-8 weeks) to 14-2°C (3°C intervals bracketing the dormancy threshold). Performance declined with cooling, and the acute Q10 of all six performance rate metrics was significantly greater below the dormancy threshold temperature (Q10,acute8-2°C=1.5-4.9, mean=3.3) than above (Q10,acute14-8°C=1.1-1.9, mean=1.5), inferring a cold constraint. However, 2°C acclimation (temporally more relevant to seasonal cooling) improved performance, abolishing the acute constraint (Q10,acclimated8-2°C=1.4-3.0, mean=2.0; also cf. Q10,acclimated14-8°C=1.2-2.9, mean=1.7). Thus, dormant cunner show partial cold-compensation of exercise and metabolic performance, similar to winter-active species. However, responsiveness to C-start stimuli was greatly cold-constrained even following acclimation, suggesting dormancy involves sensory limitation. Thermal constraints on metabolic and exercise physiology are not significant drivers of winter dormancy in cunner. In fact, compensatory plasticity at frigid temperatures is retained even in a dormant fish.
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Affiliation(s)
- Lauren E. Rowsey
- Department of Biological Sciences, University of New Brunswick Saint John, 100 Tucker Park Road, Saint John, NB E2L 4L5, Canada
| | - Connor Reeve
- Department of Biological Sciences, University of New Brunswick Saint John, 100 Tucker Park Road, Saint John, NB E2L 4L5, Canada
| | - Tyler Savoy
- Department of Biological Sciences, University of New Brunswick Saint John, 100 Tucker Park Road, Saint John, NB E2L 4L5, Canada
| | - Ben Speers-Roesch
- Department of Biological Sciences, University of New Brunswick Saint John, 100 Tucker Park Road, Saint John, NB E2L 4L5, Canada
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3
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Gerber L, MacSween CE, Staples JF, Gamperl AK. Cold-induced metabolic depression in cunner (Tautogolabrus adspersus): A multifaceted cellular event. PLoS One 2022; 17:e0271086. [PMID: 35917356 PMCID: PMC9345476 DOI: 10.1371/journal.pone.0271086] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/22/2022] [Indexed: 11/19/2022] Open
Abstract
Metabolic depression and dormancy (i.e., stopping/greatly reducing activity and feeding) are strategies used by many animals to survive winter conditions characterized by food shortages and cold temperatures. However, controversy exists on whether the reduced metabolism of some fishes at cold temperatures is due to dormancy alone, or also involves active metabolic depression. Thus, we acclimated winter-dormant cunner [Tautogolabrus adspersus, a north temperate wrasse which in Newfoundland is at the northern limit of its distribution] and winter-active Atlantic salmon (Salmo salar) to winter (0°C; 8h light: 16h dark) and summer (10°C; 16h light: 8 h dark) conditions, and measured the thermal sensitivity of ATP-producing and O2-consuming processes in isolated liver mitochondria and hepatocytes when exposed in vitro to temperatures from 20 to 0°C and 10 to 0°C, respectively. We found that: 1) liver mitochondrial State 3 respiration and hepatocyte O2 consumption in cunner were only ~ one-third and two-thirds of that measured in salmon, respectively, at all measurement temperatures; 2) cunner mitochondria also have proton conductance and leak respiration (State 4) values that are only approximately one-third of those in salmon; 3) the mitochondria of cunner show a dramatic reduction in respiratory control ratio (from ~ 8 to 3), and a much greater drop in State 3 respiration, between 10 and 5°C (Q10 values in 10- and 0°C-acclimated fish of 14.5 and 141.2, respectively), as compared with salmon (3.9 and 9.6, respectively); and 4) lowering temperature from 5 to 0°C resulted in ~ 40 and 30% reductions in hepatocyte O2 consumption due to non-mitochondrial respiration and Na+-K+-ATPase activity, respectively, in cunner, but not in salmon. Collectively, these results highlight the intrinsic capacity for metabolic depression in hepatocytes and mitochondria of cunner, and clearly suggest that several cellular processes play a role in the reduced metabolic rates exhibited by some fishes at cold temperatures.
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Affiliation(s)
- Lucie Gerber
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John’s, NL, Canada
| | - Courtney E. MacSween
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John’s, NL, Canada
| | - James F. Staples
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - A. Kurt Gamperl
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John’s, NL, Canada
- * E-mail:
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4
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Reid CH, Patrick PH, Rytwinski T, Taylor JJ, Willmore WG, Reesor B, Cooke SJ. An updated review of cold shock and cold stress in fish. JOURNAL OF FISH BIOLOGY 2022; 100:1102-1137. [PMID: 35285021 DOI: 10.1111/jfb.15037] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/23/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Temperature is critical in regulating virtually all biological functions in fish. Low temperature stress (cold shock/stress) is an often-overlooked challenge that many fish face as a result of both natural events and anthropogenic activities. In this study, we present an updated review of the cold shock literature based on a comprehensive literature search, following an initial review on the subject by M.R. Donaldson and colleagues, published in a 2008 volume of this journal. We focus on how knowledge on cold shock and fish has evolved over the past decade, describing advances in the understanding of the generalized stress response in fish under cold stress, what metrics may be used to quantify cold stress and what knowledge gaps remain to be addressed in future research. We also describe the relevance of cold shock as it pertains to environmental managers, policymakers and industry professionals, including practical applications of cold shock. Although substantial progress has been made in addressing some of the knowledge gaps identified a decade ago, other topics (e.g., population-level effects and interactions between primary, secondary and tertiary stress responses) have received little or no attention despite their significance to fish biology and thermal stress. Approaches using combinations of primary, secondary and tertiary stress responses are crucial as a research priority to better understand the mechanisms underlying cold shock responses, from short-term physiological changes to individual- and population-level effects, thereby providing researchers with better means of quantifying cold shock in laboratory and field settings.
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Affiliation(s)
- Connor H Reid
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | | | - Trina Rytwinski
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
- Canadian Centre for Evidence-Based Conservation, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Ontario, Canada
| | - Jessica J Taylor
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
- Canadian Centre for Evidence-Based Conservation, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Ontario, Canada
| | | | | | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
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5
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Reeve C, Rowsey LE, Speers-Roesch B. Inactivity and the passive slowing effect of cold on resting metabolism as the primary drivers of energy savings in overwintering fishes. J Exp Biol 2022; 225:275086. [PMID: 35315489 PMCID: PMC9124485 DOI: 10.1242/jeb.243407] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 03/07/2022] [Indexed: 11/20/2022]
Abstract
Winter dormancy is a seasonal survival strategy common among temperate ectotherms, characterized by inactivity, fasting, and low metabolic rates. Previous reports of metabolic rate depression (MRD) in winter-dormant ectotherms, including many fishes, may result from confounding influences of temperature-dependent variation in activity on metabolic rate measurements. We hypothesize that, as demonstrated recently in the winter-dormant cunner (Tautogolabrus adspersus), inactivity and the passive physicochemical (Arrhenius) effect of cold on standard metabolic rate (SMR) are the common primary mechanisms underlying the low metabolic rates among winter-dormant fishes. Using automated video tracking, we investigated threshold temperatures for winter dormancy onset (major reductions in activity, increased sheltering, and fasting) in four phylogenetically-diverse teleost species reported to be winter dormant: cunner, pumpkinseed sunfish (Lepomis gibbosus), American eel (Anguilla rostrata), and mummichog (Fundulus heteroclitus). All species showed large activity and feeding reductions, but the magnitude of change and dormancy threshold temperature was species-specific. We propose that a continuum of overwintering responses exists among fishes from dormant to lethargic to active. The relationship between activity and metabolic rate was then measured using video-recorded automated respirometry during acute cooling and following cold acclimation in pumpkinseed, mummichog, and eel. In all species, activity and metabolic rate were strongly correlated at all temperatures, and cooling caused reduced activity and metabolic rate. When variation in activity was controlled for across temperatures spanning the dormancy thresholds, the thermal sensitivity of metabolic rate including SMR indicated the predominance of passive physicochemical influences (mean Q10<3.5), rather than active MRD. Activity reductions and physicochemical slowing of metabolism due to cold appear to be the primary energy saving mechanisms in overwintering fishes.
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Affiliation(s)
- Connor Reeve
- Department of Biological Sciences, University of New Brunswick, Saint John, New Brunswick, E2L 4L5, Canada
| | - Lauren E Rowsey
- Department of Biological Sciences, University of New Brunswick, Saint John, New Brunswick, E2L 4L5, Canada
| | - Ben Speers-Roesch
- Department of Biological Sciences, University of New Brunswick, Saint John, New Brunswick, E2L 4L5, Canada
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6
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Porter E, Clow K, Sandrelli R, Gamperl A. Acute and chronic cold exposure differentially affect cardiac control, but not cardiorespiratory function, in resting Atlantic salmon (S almo salar). Curr Res Physiol 2022; 5:158-170. [PMID: 35359619 PMCID: PMC8960890 DOI: 10.1016/j.crphys.2022.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/19/2022] [Accepted: 03/14/2022] [Indexed: 02/07/2023] Open
Abstract
No studies have examined the effects of cold temperatures (∼0-1 °C) on in vivo cardiac function and control, and metabolism, in salmonids. Thus, we examined: 1) how acclimation to 8 °C vs. acclimation (>3 weeks) or acute exposure (8-1 °C at 1 °C h-1) to 1 °C influenced cardiorespiratory parameters in resting Atlantic salmon; and 2) if/how the control of cardiac function was affected. Oxygen consumption ( M ˙ O 2 ) and cardiac function [i.e., heart rate (f H) and cardiac output (Q ˙ ) ] were 50% lower in the acutely cooled and 1oC-acclimated salmon as compared to 8 °C fish, whereas stroke volume (VS) was unchanged. Intrinsic f H was not affected by whether the fish were acutely exposed or acclimated to 1 °C (values ∼51, 24 and 21 beats min-1 in 8 and 1 °C-acclimated fish, and 8-1 °C fish, respectively), and in all groups f H was primarily under adrenergic control/tone (cholinergic tone 13-18%; adrenergic tone 37-70%). However, β-adrenergic blockade resulted in a 50% increase in VS in the 1oC-acclimated group, and this was surprising as circulating catecholamine levels were ∼1-3 nM in all groups. Overall, the data suggest that this species has a limited capacity to acclimate to temperatures approaching 0 °C. However, we cannot exclude the possibility that cardiac and metabolic responses are evoked when salmon are cooled to ∼ 0-1 °C, and that this prevented further declines in these parameters (i.e., they 'reset' quickly). Our data also provide further evidence that VS is temperature insensitive, and strongly suggest that changes in adrenoreceptor mediated control of venous pressure/capacitance occur when salmon are acclimated to 1 °C.
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Affiliation(s)
- E.S. Porter
- Dept. of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL, A1C 5S7, Canada
| | - K.A. Clow
- Dept. of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL, A1C 5S7, Canada
| | - R.M. Sandrelli
- Dept. of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL, A1C 5S7, Canada
| | - A.K. Gamperl
- Dept. of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL, A1C 5S7, Canada
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7
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Denny MW, Dowd WW. Physiological Consequences of Oceanic Environmental Variation: Life from a Pelagic Organism's Perspective. ANNUAL REVIEW OF MARINE SCIENCE 2022; 14:25-48. [PMID: 34314598 DOI: 10.1146/annurev-marine-040221-115454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
To better understand life in the sea, marine scientists must first quantify how individual organisms experience their environment, and then describe how organismal performance depends on that experience. In this review, we first explore marine environmental variation from the perspective of pelagic organisms, the most abundant life forms in the ocean. Generation time, the ability to move relative to the surrounding water (even slowly), and the presence of environmental gradients at all spatial scales play dominant roles in determining the variation experienced by individuals, but this variation remains difficult to quantify. We then use this insight to critically examine current understanding of the environmental physiology of pelagic marine organisms. Physiologists have begun to grapple with the complexity presented by environmental variation, and promising frameworks exist for predicting and/or interpreting the consequences for physiological performance. However, new technology needs to be developed and much difficult empirical work remains, especially in quantifying response times to environmental variation and the interactions among multiple covarying factors. We call on the field of global-change biology to undertake these important challenges.
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Affiliation(s)
- Mark W Denny
- Hopkins Marine Station, Stanford University, Pacific Grove, California 93950, USA;
| | - W Wesley Dowd
- School of Biological Sciences, Washington State University, Pullman, Washington 99164, USA;
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8
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Schleger IC, Pereira DMC, Resende AC, Romão S, Herrerias T, Neundorf AKA, Sloty AM, Guimarães IM, de Souza MRDP, Carster GP, Donatti L. Cold and warm waters: energy metabolism and antioxidant defenses of the freshwater fish Astyanax lacustris (Characiformes: Characidae) under thermal stress. J Comp Physiol B 2021; 192:77-94. [PMID: 34591144 DOI: 10.1007/s00360-021-01409-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/19/2021] [Accepted: 09/20/2021] [Indexed: 12/27/2022]
Abstract
Subtropical fish are exposed to seasonal variations in temperature that impose a set of adaptations on their metabolism necessary for the maintenance of homeostasis. In this study, we addressed the effects of temperature variation on the metabolism of Astyanax lacustris, a species of freshwater fish common in the subtropical region of Brazil. Biomarkers of carbohydrate and protein metabolism, antioxidant defense, and oxidative damage were evaluated in the liver of A. lacustris exposed to low (15 °C) and high (31 °C) temperature thermal shock, with controls at 23 °C for 2, 6, 12, 24, 48, 72, and 96 h. A high energy demand was observed during the first 48 h of exposure to 15 °C, which is necessary for metabolic adjustment at low temperatures, with an increase in glycolysis, citric acid cycle, and amino acid catabolism. In addition, at 31 °C, glucose was exported in the first 12 h of exposure, and an increase in the citric acid cycle suggested acetyl-CoA as the pathway substrate, originating from the oxidation of lipids. The antioxidant defenses did not change at 15 °C, as opposed to 31 °C, in which there were changes in several antioxidant defense markers, indicating a response to the production of ROS. However, oxidative stress was observed at both temperatures, with oxidative damage detected by lipid peroxidation at 15 °C and protein carbonylation at 31 °C.
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Affiliation(s)
- Ieda Cristina Schleger
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil
| | - Diego Mauro Carneiro Pereira
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil
| | - Anna Carolina Resende
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil
| | - Silvia Romão
- Federal University of Fronteira Sul, Laranjeiras do Sul, Paraná, Brazil
| | | | - Ananda Karla Alves Neundorf
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil
| | | | - Ivan Moyses Guimarães
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil
| | - Maria Rosa Dmengeon Pedreiro de Souza
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil
| | - Guilherme Prosperi Carster
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil
| | - Lucélia Donatti
- Adaptive Biology Laboratory, Department of Cell Biology, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, s/n, Jardim das Américas, CEP 81531-970, Curitiba, Paraná, 19031, Brazil.
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9
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Moran CJ, Jebb KE, Travitz L, Coughlin DJ, Gerry SP. Thermal acclimation leads to variable muscle responses in two temperate labrid fishes. J Exp Biol 2020; 223:jeb235226. [PMID: 33106300 DOI: 10.1242/jeb.235226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/22/2020] [Indexed: 11/20/2022]
Abstract
Temperature can be a key abiotic factor in fish distribution, as it affects most physiological processes. Specifically, temperature can affect locomotor capabilities, especially as species are exposed to temperatures nearing their thermal limits. In this study, we aimed to understand the effects of temperature on muscle in two labrids that occupy the Northwest Atlantic Ocean. When exposed to cold temperatures in autumn, cunner (Tautogolabrus adspersus) and tautog (Tautoga onitis) go into a state of winter dormancy. Transitions into dormancy vary slightly, where tautog will make short migrations to overwintering habitats while cunner overwinter in year-round habitats. To understand how muscle function changes with temperature, we held fish for 4 weeks at either 5 or 20°C and then ran muscle kinetic and workloop experiments at 5, 10 and 20°C. Following experiments, we used immunohistochemistry staining to identify acclimation effects on myosin isoform expression. Muscle taken from warm-acclimated cunner performed the best, whereas there were relatively few differences among the other three groups. Cunner acclimated at both temperatures downregulated the myosin heavy chain, suggesting a transition in fiber type from slow-oxidative to fast-glycolytic. This change did not amount to a detectable difference in muscle power production and kinetics. However, overall poor performance at cold temperatures could force these fishes into torpor to overwinter. Tautog, alternatively, retained myosin heavy chains, which likely increases locomotor capabilities when making short migrations to overwintering habitats.
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Affiliation(s)
- Clinton J Moran
- The Citadel Biology Department, 171 Moultrie Street, Charleston, SC 29409, USA
- Biology Department, Fairfield University, 1073 N. Benson Road, Fairfield, CT 06824, USA
| | - Kamryn E Jebb
- Biology Department, Fairfield University, 1073 N. Benson Road, Fairfield, CT 06824, USA
| | - Leksi Travitz
- Widener University, Department of Biology, One University Place, Chester, PA 19013, USA
| | - David J Coughlin
- Widener University, Department of Biology, One University Place, Chester, PA 19013, USA
| | - Shannon P Gerry
- Biology Department, Fairfield University, 1073 N. Benson Road, Fairfield, CT 06824, USA
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10
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Vasquez I, Cao T, Chakraborty S, Gnanagobal H, O’Brien N, Monk J, Boyce D, Westcott JD, Santander J. Comparative Genomics Analysis of Vibrio anguillarum Isolated from Lumpfish ( Cyclopterus lumpus) in Newfoundland Reveal Novel Chromosomal Organizations. Microorganisms 2020; 8:E1666. [PMID: 33121102 PMCID: PMC7716436 DOI: 10.3390/microorganisms8111666] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/31/2022] Open
Abstract
Vibrio anguillarum is a Gram-negative marine pathogen causative agent of vibriosis in a wide range of hosts, including invertebrates and teleosts. Lumpfish (Cyclopterus lumpus), a native fish of the North Atlantic Ocean, is utilized as cleaner fish to control sea lice (Lepeophtheirus salmonis) infestations in the Atlantic salmon (Salmo salar) aquaculture industry. V. anguillarum is one of the most frequent bacterial pathogens affecting lumpfish. Here, we described the phenotype and genomic characteristics of V. anguillarum strain J360 isolated from infected cultured lumpfish in Newfoundland, Canada. Koch's postulates determined in naïve lumpfish showed lethal acute vibriosis in lumpfish. The V. anguillarum J360 genome was shown to be composed of two chromosomes and two plasmids with a total genome size of 4.56 Mb with 44.85% G + C content. Phylogenetic and comparative analyses showed that V. anguillarum J360 is closely related to V. anguillarum strain VIB43, isolated in Scotland, with a 99.8% genome identity. Differences in the genomic organization were identified and associated with insertion sequence elements (ISs). Additionally, V. anguillarum J360 does not possess a pJM1-like plasmid, typically present in virulent isolates from the Pacific Ocean, suggesting that acquisition of this extrachromosomal element and the virulence of V. anguillarum J360 or other Atlantic isolates could increase.
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Affiliation(s)
- Ignacio Vasquez
- Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University, Logy Bay, NL A1C 5S7, Canada; (I.V.); (T.C.); (S.C.); (H.G.)
| | - Trung Cao
- Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University, Logy Bay, NL A1C 5S7, Canada; (I.V.); (T.C.); (S.C.); (H.G.)
| | - Setu Chakraborty
- Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University, Logy Bay, NL A1C 5S7, Canada; (I.V.); (T.C.); (S.C.); (H.G.)
| | - Hajarooba Gnanagobal
- Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University, Logy Bay, NL A1C 5S7, Canada; (I.V.); (T.C.); (S.C.); (H.G.)
| | - Nicole O’Brien
- Department of Fisheries and Land Resources, Aquatic Animal Health Division, Government of Newfoundland and Labrador, St. John’s, NL A1E 3Y5, Canada;
| | - Jennifer Monk
- Dr. Joe Brown Aquatic Research Building (JBARB), Department of Ocean Sciences, Memorial University of Newfoundland, Logy Bay, NL A1C 5S7, Canada; (J.M.); (D.B.)
| | - Danny Boyce
- Dr. Joe Brown Aquatic Research Building (JBARB), Department of Ocean Sciences, Memorial University of Newfoundland, Logy Bay, NL A1C 5S7, Canada; (J.M.); (D.B.)
| | - Jillian D. Westcott
- Fisheries and Marine Institute, Memorial University of Newfoundland, St. John’s, NL A1C 5R3, Canada;
| | - Javier Santander
- Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University, Logy Bay, NL A1C 5S7, Canada; (I.V.); (T.C.); (S.C.); (H.G.)
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11
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Niu Y, Cao W, Storey KB, He J, Wang J, Zhang T, Tang X, Chen Q. Metabolic characteristics of overwintering by the high-altitude dwelling Xizang plateau frog, Nanorana parkeri. J Comp Physiol B 2020; 190:433-444. [PMID: 32274534 DOI: 10.1007/s00360-020-01275-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 03/20/2020] [Accepted: 03/27/2020] [Indexed: 12/12/2022]
Abstract
The Xizang plateau frog, Nanorana parkeri, has the highest altitudinal distribution of all frogs in the world and survives the cold of winter without feeding by entering into a hibernating state. However, little attention has been paid to its physiological and biochemical characteristics that support overwintering underwater in small ponds. Here, we measured metabolic rate and heart rate, and collected liver and muscle samples from N. parkeri in summer and winter for analysis of mitochondrial respiration rate, and activities and relative mRNA transcript expression of metabolic enzymes. Compared with summer-collected frogs, both resting metabolic rate and heart rate were significantly reduced in winter-collected frogs. Both state 3 and state 4 respiration of liver mitochondria were also significantly reduced in winter but muscle mitochondria showed a decline only in state 3 respiration in winter. The activities and corresponding mRNA expression of cytochrome c oxidase showed a marked decline in winter, whereas the activities and corresponding mRNA expression of lactate dehydrogenase increased in winter-collected frogs, compared to summer. The thermal sensitivity (Q10 values) for state 3 respiration rate by liver mitochondria, and activities of lactate dehydrogenase, and cytochrome c oxidase all increased in winter-collected frogs, compared with summer frogs, suggesting that overwintering frogs were more sensitive to changes in external temperature. Enzyme changes mainly result from lower overall quantities of these enzymes as well as post-translational modifications. We conclude that overwintering N. parkeri exhibit a seasonal, temperature-independent suppression of metabolism that is mediated at multiple levels: physiological, mitochondrial, gene expression and enzyme activity levels.
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Affiliation(s)
- Yonggang Niu
- School of Life Sciences, Dezhou University, Dezhou, China.,Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China.,State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
| | - Wangjie Cao
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Kenneth B Storey
- Department of Biology, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Jie He
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Jinzhou Wang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Tao Zhang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Xiaolong Tang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Qiang Chen
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China. .,State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China.
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12
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Scott KY, Matthew R, Woolcock J, Silva M, Lemieux H. Adjustments in the control of mitochondrial respiratory capacity to tolerate temperature fluctuations. ACTA ACUST UNITED AC 2019; 222:jeb.207951. [PMID: 31439652 DOI: 10.1242/jeb.207951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/14/2019] [Indexed: 12/19/2022]
Abstract
As the world's climate changes, life faces an evolving thermal environment. Mitochondrial oxidative phosphorylation (OXPHOS) is critical to ensure sufficient cellular energy production, and it is strongly influenced by temperature. The thermally induced changes to the regulation of specific steps within the OXPHOS process are poorly understood. In our study, we used the eurythermal species of planarian Dugesia tigrina to study the thermal sensitivity of the OXPHOS process at 10, 15, 20, 25 and 30°C. We conducted cold acclimation experiments where we measured the adjustment of specific steps in OXPHOS at two assay temperatures (10 and 20°C) following 4 weeks of acclimation under normal (22°C) or low (5°C) temperature conditions. At the low temperature, the contribution of the NADH pathway to the maximal OXPHOS capacity, in a combined pathway (NADH and succinate), was reduced. There was partial compensation by an increased contribution of the succinate pathway. As the temperature decreased, OXPHOS became more limited by the capacity of the phosphorylation system. Acclimation to the low temperature resulted in positive adjustments of the NADH pathway capacity due, at least in part, to an increase in complex I activity. The acclimation also resulted in a better match between OXPHOS and phosphorylation system capacities. Both of these adjustments following acclimation were specific to the low assay temperature. We conclude that there is substantial plasticity in the mitochondrial OXPHOS process following thermal acclimation in D. tigrina, and this probably contributes to the wide thermal range of the species.
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Affiliation(s)
- Katrina Y Scott
- Faculty Saint-Jean, University of Alberta, Edmonton, AB, Canada, T6C 4G9
| | - Rebecca Matthew
- Faculty Saint-Jean, University of Alberta, Edmonton, AB, Canada, T6C 4G9
| | - Jennifer Woolcock
- Faculty Saint-Jean, University of Alberta, Edmonton, AB, Canada, T6C 4G9
| | - Maise Silva
- Faculty Saint-Jean, University of Alberta, Edmonton, AB, Canada, T6C 4G9.,Faculdade de Tecnologia e Ciências, Salvador, Bahia, 41741-590, Brazil
| | - Hélène Lemieux
- Faculty Saint-Jean, University of Alberta, Edmonton, AB, Canada, T6C 4G9 .,Department of Medicine, Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada, T6G 2R7
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13
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Song J, Brill RW, McDowell JR. Plasticity in Standard and Maximum Aerobic Metabolic Rates in Two Populations of an Estuarine Dependent Teleost, Spotted Seatrout ( Cynoscion nebulosus). BIOLOGY 2019; 8:biology8020046. [PMID: 31197073 PMCID: PMC6627818 DOI: 10.3390/biology8020046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/16/2019] [Accepted: 06/11/2019] [Indexed: 01/28/2023]
Abstract
We studied the effects of metabolic cold adaptation (MCA) in two populations of a eurythermal species, spotted seatrout (Cynoscion nebulosus) along the U.S. East Coast. Fish were captured from their natural environment and acclimated at control temperatures 15 °C or 20 °C. Their oxygen consumption rates, a proxy for metabolic rates, were measured using intermittent flow respirometry during acute temperature decrease or increase (2.5 °C per hour). Mass-specific standard metabolic rates (SMR) were higher in fish from the northern population across an ecologically relevant temperature gradient (5 °C to 30 °C). SMR were up to 37% higher in the northern population at 25 °C and maximum metabolic rates (MMR) were up to 20% higher at 20 °C. We found evidence of active metabolic compensation in the southern population from 5 °C to 15 °C (Q10 < 2), but not in the northern population. Taken together, our results indicate differences in metabolic plasticity between the northern and southern populations of spotted seatrout and provide a mechanistic basis for predicting population-specific responses to climate change.
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Affiliation(s)
- Jingwei Song
- Virginia Institute of Marine Science, William & Mary, P.O. Box 1346, Gloucester Point, VA 23062, USA.
| | - Richard W Brill
- Virginia Institute of Marine Science, William & Mary, P.O. Box 1346, Gloucester Point, VA 23062, USA.
| | - Jan R McDowell
- Virginia Institute of Marine Science, William & Mary, P.O. Box 1346, Gloucester Point, VA 23062, USA.
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14
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Song M, Zhao J, Wen HS, Li Y, Li JF, Li LM, Tao YX. The impact of acute thermal stress on the metabolome of the black rockfish (Sebastes schlegelii). PLoS One 2019; 14:e0217133. [PMID: 31125355 PMCID: PMC6534312 DOI: 10.1371/journal.pone.0217133] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 05/06/2019] [Indexed: 11/26/2022] Open
Abstract
Acute change in water temperature causes heavy economic losses in the aquaculture industry. The present study investigated the metabolic and molecular effects of acute thermal stress on black rockfish (Sebastes schlegelii). Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based metabolomics was used to investigate the global metabolic response of black rockfish at a high water temperature (27°C), low water temperature (5°C) and normal water temperature (16°C). Metabolites involved in energy metabolism and basic amino acids were significantly increased upon acute exposure to 27°C (P < 0.05), and no change in metabolite levels occurred in the low water temperature group. However, certain fatty acid levels were elevated after cold stress (P < 0.05), and this effect was not observed in the 27°C group, suggesting that acute high and low temperature exposures caused different physiological responses. Using quantitative real-time PCR, we analyzed the expression of ubiquitin (ub), hypoxia-inducible factor (hif), lactate dehydrogenase (ldh), and acetyl-CoA carboxylase (acac). Higher expression levels of ub, hif, and ldh (P < 0.05) were observed in the high water temperature group, but no changes in these expression levels occurred in the low water temperature group. Our findings provide a potential metabolic profile for black rockfish when exposed to acute temperature stress and provide some insights into host metabolic and molecular responses to thermal stress.
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Affiliation(s)
- Min Song
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean University of China, Qingdao, P. R. China
| | - Ji Zhao
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean University of China, Qingdao, P. R. China
| | - Hai-Shen Wen
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean University of China, Qingdao, P. R. China
- * E-mail: (HSW); (YL)
| | - Yun Li
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean University of China, Qingdao, P. R. China
- * E-mail: (HSW); (YL)
| | - Ji-Fang Li
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean University of China, Qingdao, P. R. China
| | - Lan-Min Li
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean University of China, Qingdao, P. R. China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States of America
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15
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Moran CJ, Neubauer DL, Rzucidlo CL, Gerry SP. Temperature constrains locomotion and muscle function in two temperate labrids. Comp Biochem Physiol A Mol Integr Physiol 2018; 227:172-178. [PMID: 30347246 DOI: 10.1016/j.cbpa.2018.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 10/14/2018] [Indexed: 11/24/2022]
Abstract
Winter quiescence in fishes is not uncommon, however understanding the mechanisms that cause dormancy are poorly understood. This study highlights the physiological stress temperature places on locomotor musculature and its consequences on whole organism locomotion. Cunner and tautog experience temperatures ranging from 0 to 25 °C and enter dormancy at ~10 °C. We aimed to address the question: how do winter temperatures affect steady swimming and muscle contraction kinetics in cunner? Fishes were collected and housed at 5, 10, 15, or 20 °C. Gait transition speed and fin beat frequency were measured at each acclimation temperature. Twitch and tetanus kinetics were recorded from the aerobic locomotor muscle, which is responsible for the power stroke during swimming. Fish acclimated to colder temperatures (5, 10 °C) demonstrated lower gait transition speeds than the warm temperature treatments. Similarly, twitch kinetics were slower in muscle acclimated at ≤10 °C. Locomotor muscle from tautog was significantly slower to contract and relax than cunner when tested at 5 and 10 °C. These results suggest that muscle acclimation differs in these closely related labrids from the same habitat. Additionally, these results suggest that cunner locomotor musculature can maintain greater performance at a wider range of temperatures. Cunner occupy more northern latitudes which likely allows for greater performance shifts in response to temperature. However, when temperatures get cold enough muscle function is reduced, perhaps contributing to their overwintering ecology.
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Affiliation(s)
- Clinton J Moran
- Department of Biology, Fairfield University, 1073 N. Benson Rd, Fairfield, CT 06824, USA; Department of Biology, The Citadel, 171 Moultrie St. Charleston, SC 29409, USA.
| | - David L Neubauer
- Department of Biology, Fairfield University, 1073 N. Benson Rd, Fairfield, CT 06824, USA
| | - Caroline L Rzucidlo
- Department of Biology, Fairfield University, 1073 N. Benson Rd, Fairfield, CT 06824, USA
| | - Shannon P Gerry
- Department of Biology, Fairfield University, 1073 N. Benson Rd, Fairfield, CT 06824, USA.
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16
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Speers-Roesch B, Norin T, Driedzic WR. The benefit of being still: energy savings during winter dormancy in fish come from inactivity and the cold, not from metabolic rate depression. Proc Biol Sci 2018; 285:20181593. [PMID: 30185640 PMCID: PMC6158517 DOI: 10.1098/rspb.2018.1593] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 08/13/2018] [Indexed: 12/26/2022] Open
Abstract
Winter dormancy is used by many animals to survive the cold and food-poor high-latitude winter. Metabolic rate depression, an active downregulation of resting cellular energy turnover and thus standard (resting) metabolic rate (SMR), is a unifying strategy underlying the persistence of organisms in such energy-limited environments, including hibernating endotherms. However, controversy exists about its involvement in winter-dormant aquatic ectotherms. To address this debate, we conducted simultaneous, multi-day measurements of whole-animal oxygen consumption rate (a proxy of metabolic rate) and spontaneous movement in a model winter-dormant marine fish, the cunner (Tautogolabrus adspersus). Winter dormancy in cunner involved a dampened diel rhythm of metabolic rate, such that a low and stable metabolic rate persisted throughout the 24 h day. Based on the thermal sensitivity (Q10) of SMR as well as correlations of metabolic rate and movement, the reductions in metabolic rate were not attributable to metabolic rate depression, but rather to reduced activity under the cold and darkness typical of the winter refuge among substrate. Previous reports of metabolic rate depression in cunner, and possibly other fish species, during winter dormancy were probably confounded by variation in activity. Unlike hibernating endotherms, and excepting the few fish species that overwinter in anoxic waters, winter dormancy in fishes, as exemplified by cunner, need not involve metabolic rate depression. Rather, energy savings come from inactivity combined with passive physico-chemical effects of the cold on SMR, demonstrating that thermal effects on activity can greatly influence temperature-metabolism relationships, and illustrating the benefit of simply being still in energy-limited environments.
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Affiliation(s)
- Ben Speers-Roesch
- Department of Ocean Sciences, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada A1C 5S7
| | - Tommy Norin
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK
| | - William R Driedzic
- Department of Ocean Sciences, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada A1C 5S7
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17
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Chung DJ, Bryant HJ, Schulte PM. Thermal acclimation and subspecies-specific effects on heart and brain mitochondrial performance in a eurythermal teleost (Fundulus heteroclitus). J Exp Biol 2017; 220:1459-1471. [DOI: 10.1242/jeb.151217] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/30/2017] [Indexed: 01/09/2023]
Abstract
Mitochondrial performance may play a role in setting whole-animal thermal tolerance limits and their plasticity, but the relative roles of adjustments in mitochondrial performance across different highly aerobic tissues remain poorly understood. We compared heart and brain mitochondrial responses to acute thermal challenges and to thermal acclimation using high-resolution respirometry in two locally adapted subspecies of Atlantic killifish (Fundulus heteroclitus). We predicted that 5°C acclimation to would result in compensatory increases in mitochondrial performance, while 33°C acclimation would cause suppression of mitochondrial function to minimize the effects of high temperature on mitochondrial metabolism. In contrast, acclimation to both 33 and 5°C decreased mitochondrial performance compared to fish acclimated to 15°C. These adjustments could represent an energetic cost saving mechanism at temperature extremes. Acclimation responses were similar in both heart and brain; however, this effect was smaller in the heart which might indicate its importance in maintaining whole-animal thermal performance. Alternatively, larger acclimation effects in the brain might indicate greater thermal sensitivity compared to the heart. We detected only modest differences between subspecies that were dependent on the tissue assayed. These data demonstrate extensive plasticity in mitochondrial performance following thermal acclimation in killifish, and indicate that the extent of these responses differs between tissues, highlighting the importance and complexity of mitochondrial regulation in thermal acclimation in eurytherms.
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Affiliation(s)
- Dillon James Chung
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
| | - Heather J. Bryant
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
| | - Patricia M. Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
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18
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Metabolic and regulatory responses involved in cold acclimation in Atlantic killifish, Fundulus heteroclitus. J Comp Physiol B 2016; 187:463-475. [PMID: 27787665 DOI: 10.1007/s00360-016-1042-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/30/2016] [Accepted: 10/13/2016] [Indexed: 01/08/2023]
Abstract
Ectotherms often respond to prolonged cold exposure by increasing mitochondrial capacity via elevated mitochondrial volume density [V V(mit,f)]. In fish, higher V V(mit,f) is typically associated with increased expression of nuclear respiratory factor 1 (Nrf1), a transcription factor that induces expression of nuclear-encoded respiratory genes. To examine if nrf1 expression or the expression of other genes that regulate mitochondrial biogenesis contribute to changes in whole-organism metabolic rate during cold acclimation, we examined the time course of changes in the expression of these genes and in metabolic rate in Atlantic killifish, Fundulus heteroclitus. Cold acclimation rapidly decreased metabolic rate, but increased the expression of nrf1 more gradually, with a time course that depended on how rapidly the fish were transitioned to low temperature. Cold-induced nrf1 expression was not associated with increases in biochemical indicators of mitochondrial respiratory capacity, suggesting that cold-induced mitochondrial biogenesis may occur without increases in oxidative capacity in this species. These observations imply that changes in nrf1 expression and metabolic rate due to cold acclimation occur through different physiological mechanisms, and that increases in V V(mit,f) are likely not directly related to changes in metabolic rate with cold acclimation in this species. However, nrf1 expression differed between northern and southern killifish subspecies regardless of acclimation temperature, consistent with observed differences in metabolic rate and V V(mit,f) at 5 °C between these subspecies. Taken together, these results reveal substantial complexity in the regulation of V V(mit,f) and mitochondrial capacity with temperature in fish and the relationship of these parameters to metabolic rate.
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19
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Vornanen M. The temperature dependence of electrical excitability in fish hearts. J Exp Biol 2016; 219:1941-52. [DOI: 10.1242/jeb.128439] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 05/17/2016] [Indexed: 01/08/2023]
Abstract
ABSTRACT
Environmental temperature has pervasive effects on the rate of life processes in ectothermic animals. Animal performance is affected by temperature, but there are finite thermal limits for vital body functions, including contraction of the heart. This Review discusses the electrical excitation that initiates and controls the rate and rhythm of fish cardiac contraction and is therefore a central factor in the temperature-dependent modulation of fish cardiac function. The control of cardiac electrical excitability should be sensitive enough to respond to temperature changes but simultaneously robust enough to protect against cardiac arrhythmia; therefore, the thermal resilience and plasticity of electrical excitation are physiological qualities that may affect the ability of fishes to adjust to climate change. Acute changes in temperature alter the frequency of the heartbeat and the duration of atrial and ventricular action potentials (APs). Prolonged exposure to new thermal conditions induces compensatory changes in ion channel expression and function, which usually partially alleviate the direct effects of temperature on cardiac APs and heart rate. The most heat-sensitive molecular components contributing to the electrical excitation of the fish heart seem to be Na+ channels, which may set the upper thermal limit for the cardiac excitability by compromising the initiation of the cardiac AP at high temperatures. In cardiac and other excitable cells, the different temperature dependencies of the outward K+ current and inward Na+ current may compromise electrical excitability at temperature extremes, a hypothesis termed the temperature-dependent depression of electrical excitation.
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Affiliation(s)
- Matti Vornanen
- University of Eastern Finland, Department of Environmental and Biological Sciences, PO Box 111, Joensuu 80101, Finland
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20
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Varis J, Haverinen J, Vornanen M. Lowering Temperature is the Trigger for Glycogen Build-Up and Winter Fasting in Crucian Carp (Carassius carassius). Zoolog Sci 2016; 33:83-91. [PMID: 26853873 DOI: 10.2108/zs150072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Seasonal changes in physiology of vertebrate animals are triggered by environmental cues including temperature, day-length and oxygen availability. Crucian carp (Carassius carassius) tolerate prolonged anoxia in winter by using several physiological adaptations that are seasonally activated. This study examines which environmental cues are required to trigger physiological adjustments for winter dormancy in crucian carp. To this end, crucian carp were exposed to changing environmental factors under laboratory conditions: effects of declining water temperature, shortening day-length and reduced oxygen availability, separately and in different combinations, were examined on glycogen content and enzyme activities involved in feeding (alkaline phosphatase, AP) and glycogen metabolism (glycogen synthase, GyS; glycogen phosphorylase, GP). Lowering temperature induced a fall in activity of AP and a rise in glycogen content and rate of glycogen synthesis. Relative mass of the liver, and glycogen concentration of liver, muscle and brain increased with lowering temperature. Similarly activity of GyS in muscle and expression of GyS transcripts in brain were up-regulated by lowering temperature. Shortened day-length and oxygen availability had practically no effects on measured variables. We conclude that lowering temperature is the main trigger in preparation for winter anoxia in crucian carp.
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Affiliation(s)
- Joonas Varis
- Department of Biology, University of Eastern Finland, Yliopistokatu 7, 80101 Joensuu, Natura-building, Finland
| | - Jaakko Haverinen
- Department of Biology, University of Eastern Finland, Yliopistokatu 7, 80101 Joensuu, Natura-building, Finland
| | - Matti Vornanen
- Department of Biology, University of Eastern Finland, Yliopistokatu 7, 80101 Joensuu, Natura-building, Finland
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21
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Abstract
Many environmental conditions can constrain the ability of animals to obtain sufficient food energy, or transform that food energy into useful chemical forms. To survive extended periods under such conditions animals must suppress metabolic rate to conserve energy, water, or oxygen. Amongst small endotherms, this metabolic suppression is accompanied by and, in some cases, facilitated by a decrease in core body temperature-hibernation or daily torpor-though significant metabolic suppression can be achieved even with only modest cooling. Within some ectotherms, winter metabolic suppression exceeds the passive effects of cooling. During dry seasons, estivating ectotherms can reduce metabolism without changes in body temperature, conserving energy reserves, and reducing gas exchange and its inevitable loss of water vapor. This overview explores the similarities and differences of metabolic suppression among these states within adult animals (excluding developmental diapause), and integrates levels of organization from the whole animal to the genome, where possible. Several similarities among these states are highlighted, including patterns and regulation of metabolic balance, fuel use, and mitochondrial metabolism. Differences among models are also apparent, particularly in whether the metabolic suppression is intrinsic to the tissue or depends on the whole-animal response. While in these hypometabolic states, tissues from many animals are tolerant of hypoxia/anoxia, ischemia/reperfusion, and disuse. These natural models may, therefore, serve as valuable and instructive models for biomedical research.
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Affiliation(s)
- James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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22
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Alzaid A, Hori TS, Hall JR, Rise ML, Gamperl AK. Cold-induced changes in stress hormone and steroidogenic transcript levels in cunner (Tautogolabrus adspersus), a fish capable of metabolic depression. Gen Comp Endocrinol 2015; 224:126-35. [PMID: 26188716 DOI: 10.1016/j.ygcen.2015.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 07/13/2015] [Accepted: 07/15/2015] [Indexed: 10/23/2022]
Abstract
The cunner (Tautogolabrus adspersus) is a fish with a wide latitudinal distribution that is capable of going into metabolic depression during the winter months, and thus, represents a unique model to investigate the impacts of cold temperatures on the stress response. In this study, we measured resting (pre-stress) plasma cortisol levels in 10 °C and 0 °C acclimated cunner from Newfoundland, and both catecholamine and cortisol levels after they were given a standardized handling stress (i.e. 1 min air exposure). In addition, we cloned and characterized cDNAs for several key genes of the cortisol-axis [cytochrome P450scc, steroidogenic acute regulatory protein (StAR) and a glucocorticoid receptor (GR) most likely to be an ortholog of the teleost GR2], determined the tissue distribution of their transcripts, and measured their constitutive (i.e. pre-stress) transcript levels in individuals acclimated to both temperatures. In cunner acclimated to 0 °C, post-stress epinephrine and norepinephrine levels were much lower (by approximately 9- and 5-fold, respectively) compared to 10 °C acclimated fish, and these fish had relatively low resting cortisol levels (~15 ngml(-1)) and showed a typical post-stress response. In contrast, those acclimated to 10 °C had quite high resting cortisol levels (~75 ngml(-1)) that actually decreased (to ~20 ngml(-1)) post-stress before returning to pre-stress levels. Finally, fish acclimated to 10 °C had higher P450scc transcript levels in the head kidney and lower levels of GR transcript in both the head kidney and liver. Taken together, these results suggest that: (1) temperature has a profound effect on the stress response of this species; and (2) although the ancestors of this species inhabited warm waters (i.e. they are members of the family Labridae), populations of cunner from colder regions may show signs of stress at temperatures as low as 10 °C.
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Affiliation(s)
- Abdullah Alzaid
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Tiago S Hori
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Jennifer R Hall
- Aquatic Research Cluster, CREAIT Network, Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - A Kurt Gamperl
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada.
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23
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Kelly NI, Alzaid A, Nash GW, Gamperl AK. Metabolic depression in cunner (Tautogolabrus adspersus) is influenced by ontogeny, and enhances thermal tolerance. PLoS One 2014; 9:e114765. [PMID: 25514755 PMCID: PMC4267729 DOI: 10.1371/journal.pone.0114765] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 11/13/2014] [Indexed: 11/18/2022] Open
Abstract
To examine the effect of ontogeny on metabolic depression in the cunner (Tautogolabrus adspersus), and to understand how ontogeny and the ability to metabolically depress influence this species' upper thermal tolerance: 1) the metabolic rate of 9°C-acclimated cunner of three size classes [0.2-0.5 g, young of the year (YOY); 3-6 g, small; and 80-120 g, large (adult)] was measured during a 2°C per day decrease in temperature; and 2) the metabolic response of the same three size classes of cunner to an acute thermal challenge [2°C h(-1) from 10°C until Critical Thermal Maximum, CTMax] was examined, and compared to that of the Atlantic cod (Gadus morhua). The onset-temperature for metabolic depression in cunner increased with body size, i.e. from 5°C in YOY cunner to 7°C in adults. In contrast, the extent of metabolic depression was ∼80% (Q10 = ∼15) for YOY fish, ∼65% (Q10 = ∼8) for small fish and ∼55% (Q10 = ∼5) for adults, and this resulted in the metabolic scaling exponent (b) gradually increasing from 0.84 to 0.92 between 9°C to 1°C. All size classes of cunner had significantly (approximately 60%) lower routine metabolic rates at 10°C than Atlantic cod. However, there was no species' difference in the temperature-induced maximum metabolic rate, and this resulted in factorial metabolic scope values that were more than two-fold greater for cunner, and CTMax values that were 6-9°C higher (∼21 vs. 28°C). These results: 1) show that ontogeny influences the temperature of initiation and the extent of metabolic depression in cunner, but not O2 consumption when in a hypometabolic state; and 2) suggest that the evolution of cold-induced metabolic depression in this northern wrasse species has not resulted in a trade-off with upper thermal tolerance, but instead, an enhancement of this species' metabolic plasticity.
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Affiliation(s)
- Nick I. Kelly
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Abdullah Alzaid
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Gordon W. Nash
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - A. Kurt Gamperl
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
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Lefevre S, Damsgaard C, Pascale DR, Nilsson GE, Stecyk JAW. Air breathing in the Arctic: influence of temperature, hypoxia, activity and restricted air access on respiratory physiology of the Alaska blackfish Dallia pectoralis. J Exp Biol 2014; 217:4387-98. [PMID: 25394628 PMCID: PMC4375840 DOI: 10.1242/jeb.105023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 10/28/2014] [Indexed: 01/21/2023]
Abstract
The Alaska blackfish (Dallia pectoralis) is an air-breathing fish native to Alaska and the Bering Sea islands, where it inhabits lakes that are ice-covered in the winter, but enters warm and hypoxic waters in the summer to forage and reproduce. To understand the respiratory physiology of this species under these conditions and the selective pressures that maintain the ability to breathe air, we acclimated fish to 5°C and 15°C and used respirometry to measure: standard oxygen uptake (Ṁ(O₂)) in normoxia (19.8 kPa P(O₂)) and hypoxia (2.5 kPa), with and without access to air; partitioning of standard Ṁ(O₂) in normoxia and hypoxia; maximum Ṁ(O₂) and partitioning after exercise; and critical oxygen tension (P(crit)). Additionally, the effects of temperature acclimation on haematocrit, haemoglobin oxygen affinity and gill morphology were assessed. Standard Ṁ(O₂) was higher, but air breathing was not increased, at 15°C or after exercise at both temperatures. Fish acclimated to 5°C or 15°C increased air breathing to compensate and fully maintain standard Ṁ(O₂) in hypoxia. Fish were able to maintain Ṁ(O₂) through aquatic respiration when air was denied in normoxia, but when air was denied in hypoxia, standard Ṁ(O₂) was reduced by ∼30-50%. P(crit) was relatively high (5 kPa) and there were no differences in P(crit), gill morphology, haematocrit or haemoglobin oxygen affinity at the two temperatures. Therefore, Alaska blackfish depends on air breathing in hypoxia and additional mechanisms must thus be utilised to survive hypoxic submergence during the winter, such as hypoxia-induced enhancement in the capacities for carrying and binding blood oxygen, behavioural avoidance of hypoxia and suppression of metabolic rate.
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Affiliation(s)
- Sjannie Lefevre
- Department of Biosciences, University of Oslo, Oslo 0316, Norway.
| | | | - Desirae R Pascale
- Department of Biological Sciences, University of Alaska Anchorage, AK 99508, USA
| | - Göran E Nilsson
- Department of Biosciences, University of Oslo, Oslo 0316, Norway
| | - Jonathan A W Stecyk
- Department of Biological Sciences, University of Alaska Anchorage, AK 99508, USA
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Hayes J, Volkoff H. Characterization of the endocrine, digestive and morphological adjustments of the intestine in response to food deprivation and torpor in cunner, Tautogolabrus adspersus. Comp Biochem Physiol A Mol Integr Physiol 2014; 170:46-59. [PMID: 24487303 DOI: 10.1016/j.cbpa.2014.01.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/24/2014] [Accepted: 01/24/2014] [Indexed: 11/16/2022]
Abstract
The cunner, Tautogolabrus adspersus, is a marine teleost endemic to the cold waters of the Northwest Atlantic Ocean. The cunner is non-migratory and is known for its remarkable ability to endure the freezing winter months with little to no food by entering a torpid/dormant state. To evaluate the physiological strategies employed by the cunner's intestinal tract to withstand food deprivation, fish were sampled for their gut after a four-week period of acute food deprivation during their summer (active/feeding) state, as well as after 4months of overwinter fasting. Digestive capacity was evaluated by measuring digestive enzyme activity and related mRNA transcript expression for trypsin, alkaline phosphatase, alanine aminopeptidase and lipase. In order to assess how gut hormones affect/are affected by acute fasting and torpor, we examined the intestinal mRNA expression of several putative appetite regulators, i.e. CCK, apelin, orexin and mTOR. Short-term summer fasting induced a reduction in the activity, but not the transcript expression, of all digestive enzymes examined as well as a reduction in gut apelin mRNA. Torpor induced a reduction in the activity of all enzymes with the exception of alanine aminopeptidase, and a decrease in mRNA levels of alanine aminopeptidase, orexin, CCK and mTOR. Our results suggest that both acute fasting and long-term fasting induce a reduction in the intestinal function of cunner, as evidenced by an overall decrease in the activities of digestive enzymes and mRNA expression of several factors involved in feeding and digestion.
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Affiliation(s)
- James Hayes
- Department of Biology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada; Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada
| | - Hélène Volkoff
- Department of Biology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada; Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
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