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Auteur Lamarre, S.G.; Ditlecadet, D.; McKenzie, D.J.; Bonnaud, L.; Driedzic, W.R.
Titre Mechanisms of protein degradation in mantle muscle and proposed gill remodeling in starved Sepia officinalis Type Article scientifique
Année 2012 Publication Revue Abrégée Am. J. Physiol.-Regul. Integr. Comp. Physiol.
Volume (down) 303 Numéro 4 Pages R427-R437
Mots-Clés Rna; cathepsin; cephalopod; cephalopods; gadus-morhua l; growth; metabolic enzymes; metabolism; octopus-vulgaris; polyubiquitin; proteasome; rainbow-trout; skeletal-muscle; squid; starvation; triglyceride; trout oncorhynchus-mykiss
Résumé Lamarre SG, Ditlecadet D, McKenzie DJ, Bonnaud L, Driedzic WR. Mechanisms of protein degradation in mantle muscle and proposed gill remodeling in starved Sepia officinalis. Am J Physiol Regul Integr Comp Physiol 303: R427-R437, 2012. First published May 30, 2012; doi:10.1152/ajpregu.00077.2012.-Cephalopods have relatively high rates of protein synthesis compared to rates of protein degradation, along with minimal carbohydrate and lipid reserves. During food deprivation on board protein is catabolized as a metabolic fuel. The aim of the current study was to assess whether biochemical indices of protein synthesis and proteolytic mechanisms were altered in cuttlefish, Sepia officinalis, starved for 7 days. In mantle muscle, food deprivation is associated with a decrease in protein synthesis, as indicated by a decrease in the total RNA level and dephosphorylation of key signaling molecules, such as the eukaryote binding protein, 4E-BP1 (regulator of translation) and Akt. The ubiquitination-proteasome system (UPS) is activated as shown by an increase in the levels of proteasome beta-subunit mRNA, polyubiquitinated protein, and polyubiquitin mRNA. As well, cathepsin activity levels are increased, suggesting increased proteolysis through the lysosomal pathway. Together, these mechanisms could supply amino acids as metabolic fuels. In gill, the situation is quite different. It appears that during the first stages of starvation, both protein synthesis and protein degradation are enhanced in gill. This is based upon increased phosphorylation of 4E-BP1 and enhanced levels of UPS indicators, especially 20S proteasome activity and polyubiquitin mRNA. It is proposed that an increased protein turnover is related to gill remodeling perhaps to retain essential hemolymph-borne compounds.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0363-6119 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 702
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Auteur Killen, S.S.; Marras, S.; McKenzie, D.J.
Titre Fast growers sprint slower: effects of food deprivation and re-feeding on sprint swimming performance in individual juvenile European sea bass Type Article scientifique
Année 2014 Publication Revue Abrégée Journal of Experimental Biology
Volume (down) 217 Numéro 6 Pages 859-865
Mots-Clés Compensatory growth; Ecophysiology; Food deprivation; Foraging; Locomotion; atlantic; catch-up growth; cod; dicentrarchus-labrax; ecological performance; gadus-morhua; long-term starvation; metabolic responses; salmon; teleost fish; trade-off; trade-offs; trout oncorhynchus-mykiss
Résumé While many ectothermic species can withstand prolonged fasting without mortality, food deprivation may have sublethal effects of ecological importance, including reductions in locomotor ability. Little is known about how such changes in performance in individual animals are related to either mass loss during food deprivation or growth rate during re-feeding. This study followed changes in the maximum sprint swimming performance of individual European sea bass, Dicentrarchus labrax, throughout 45 days of food deprivation and 30 days of re-feeding. Maximum sprint speed did not show a significant decline until 45 days of food deprivation. Among individuals, the reduction in sprinting speed at this time was not related to mass loss. After 30 days of re-feeding, mean sprinting speed had recovered to match that of control fish. Among individuals, however, maximum sprinting speed was negatively correlated with growth rate after the resumption of feeding. This suggests that the rapid compensatory growth that occurs during re-feeding after a prolonged fast carries a physiological cost in terms of reduced sprinting capacity, the extent of which shows continuous variation among individuals in relation to growth rate. The long-term repeatability of maximum sprint speed was low when fish were fasted or fed a maintenance ration, but was high among control fish fed to satiation. Fish that had been previously food deprived continued to show low repeatability in sprinting ability even after the initiation of ad libitum feeding, probably stemming from variation in compensatory growth among individuals and its associated negative effects on sprinting ability. Together, these results suggest that food limitation can disrupt hierarchies of maximum sprint performance within populations. In the wild, the cumulative effects on locomotor capacity of fasting and re-feeding could lead to variable survival among individuals with different growth trajectories following a period of food deprivation.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0022-0949 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 601
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Auteur Lefevre, S.; Domenici, P.; McKenzie, D.J.
Titre Swimming in air-breathing fishes Type Article scientifique
Année 2014 Publication Revue Abrégée Journal of Fish Biology
Volume (down) 84 Numéro 3 Pages 661-681
Mots-Clés acid-base; aerobic metabolism; amia-calva; bimodal respiration; dicentrarchus-labrax; european sea-bass; exercise; exhaustive exercise; gar lepisosteus-platyrhincus; megalops-cyprinoides; pacific; partitioning; rainbow-trout; recovery; respiratory; tarpon; trout oncorhynchus-mykiss
Résumé Fishes with bimodal respiration differ in the extent of their reliance on air breathing to support aerobic metabolism, which is reflected in their lifestyles and ecologies. Many freshwater species undertake seasonal and reproductive migrations that presumably involve sustained aerobic exercise. In the six species studied to date, aerobic exercise in swim flumes stimulated air-breathing behaviour, and there is evidence that surfacing frequency and oxygen uptake from air show an exponential increase with increasing swimming speed. In some species, this was associated with an increase in the proportion of aerobic metabolism met by aerial respiration, while in others the proportion remained relatively constant. The ecological significance of anaerobic swimming activities, such as sprinting and fast-start manoeuvres during predator-prey interactions, has been little studied in air-breathing fishes. Some species practise air breathing during recovery itself, while others prefer to increase aquatic respiration, possibly to promote branchial ion exchange to restore acid-base balance, and to remain quiescent and avoid being visible to predators. Overall, the diversity of air-breathing fishes is reflected in their swimming physiology as well, and further research is needed to increase the understanding of the differences and the mechanisms through which air breathing is controlled and used during exercise.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0022-1112 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 877
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Auteur Jourdan-Pineau, H.; Dupont-Prinet, A.; Claireaux, G.; McKenzie, D.J.
Titre An Investigation of Metabolic Prioritization in the European Sea Bass, Dicentrarchus labrax Type Article scientifique
Année 2010 Publication Revue Abrégée Physiol. Biochem. Zool.
Volume (down) 83 Numéro 1 Pages 68-77
Mots-Clés Hypoxia; blood-flow; cardiac-performance; dynamic action; largemouth bass; oxygen-consumption; respiratory metabolism; salmo-gairdneri; swimming performance; trout oncorhynchus-mykiss
Résumé We investigated the ability of European sea bass (Dicentrarchus labrax) to respond simultaneously to the metabolic demands of specific dynamic action (SDA) and aerobic exercise and how this was influenced by moderate hypoxia (50% air saturation). At 3 h after feeding in normoxia at 20 degrees C, SDA raised the instantaneous oxygen uptake (Mo(2)) of sea bass by 47% +/- 18% (mean +/- SEM, N = 7) above their standard metabolic rate (SMR) when fasted. This metabolic load was sustained throughout an incremental exercise protocol until fatigue, with a 14% +/- 3% increase in their maximum aerobic metabolic rate (MMR) relative to their fasted rate. Their incremental critical swimming speed (U(crit)) did not differ between fasted and fed states. Thus, in normoxia, the bass were able to meet the combined oxygen demands of SDA and aerobic exercise. In hypoxia, the sea bass suffered a significant decline in MMR and U(crit) relative to their normoxic performance. The SDA response was similar to normoxia (84% +/- 24% above fasted SMR at 3 h after feeding), but although this load was sustained at low swimming speeds, it gradually disappeared as swimming speed increased. As a result, the hypoxic sea bass exhibited no difference in their fasted versus fed MMR. Hypoxic U(crit) did not, however, differ between fasted and fed states, indicating that the sea bass deferred their SDA to maintain exercise performance. The results demonstrate that, in normoxia, the sea bass possesses excess cardiorespiratory capacity beyond that required for maximal aerobic exercise. The excess capacity is lost when oxygen availability is limited in hypoxia, and, under these conditions, the sea bass prioritize exercise performance. Thus, environmental conditions (oxygen availability) had a significant effect on patterns of oxygen allocation in sea bass and revealed intrinsic prioritization among conflicting metabolic demands.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1522-2152 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 436
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Auteur van der Oost, R.; McKenzie, D.J.; Verweij, F.; Satumalay, C.; van der Molen, N.; Winter, M.J.; Chipman, J.K.
Titre Identifying adverse outcome pathways (AOP) for Amsterdam city fish by integrated field monitoring Type Article scientifique
Année 2020 Publication Revue Abrégée Environ. Toxicol. Pharmacol.
Volume (down) 74 Numéro Pages 103301
Mots-Clés Adverse outcome pathways; bioanalytical strategy; Biochemical & physiological biomarkers; biomarker responses; Ecological studies; eel anguilla-anguilla; environmental risk-assessment; Micropollutants risk assessment; oxygen-consumption; rainbow-trout; sole parophrys-vetulus; swimming performance; trout oncorhynchus-mykiss; xenobiotic-metabolizing enzymes
Résumé The European City Fish project aimed to develop a generic methodology for ecological risk assessment for urban rivers. Since traditional methods only consider a small fraction of substances present in the water cycle, biological effect monitoring is required for a more reliable assessment of the pollution status. A major challenge for environmental risk assessment (ERA) is the application of adverse outcome pathways (AOP), i.e. the linking of pollutant exposure via early molecular and biochemical changes to physiological effects and, ultimately, effects on populations and ecosystems. We investigated the linkage between responses at these different levels. Many AOP aspects were investigated, from external and internal exposure to different classes of micropollutants, via molecular key events (MICE) the impacts on organs and organisms (fish physiology), to changes in the population dynamics of fish. Risk assessment procedures were evaluated by comparing environmental quality standards, bioassay responses, biomarkers in caged and feral fish, and the impact on fish populations. Although no complete AOP was observed, indirect relationships linking pollutant exposure via MICE to impaired locomotion were demonstrated at the most polluted site near a landfill for chemical waste. The pathway indicated that several upstream key events requiring energy for stress responses and toxic defence are likely to converge at a single common MKE: increased metabolic demands. Both fish biomarkers and the bioanalytical SIMONI strategy are valuable indicators for micropollutant risks to fish communities.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1382-6689 ISBN Médium
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Notes WOS:000514007200016 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2753
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