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Thoral E, Dargère L, Medina-Suárez I, Clair A, Averty L, Sigaud J, Morales A, Salin K, Teulier L. Non-lethal sampling for assessment of mitochondrial function does not affect metabolic rate and swimming performance. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220483. [PMID: 38186271 PMCID: PMC10772603 DOI: 10.1098/rstb.2022.0483] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 09/26/2023] [Indexed: 01/09/2024] Open
Abstract
A fundamental issue in the metabolic field is whether it is possible to understand underlying mechanisms that characterize individual variation. Whole-animal performance relies on mitochondrial function as it produces energy for cellular processes. However, our lack of longitudinal measures to evaluate how mitochondrial function can change within and among individuals and with environmental context makes it difficult to assess individual variation in mitochondrial traits. The aims of this study were to test the repeatability of muscle mitochondrial metabolism by performing two biopsies of red muscle, and to evaluate the effects of biopsies on whole-animal performance in goldfish Carassius auratus. Our results show that basal mitochondrial respiration and net phosphorylation efficiency are repeatable at 14-day intervals. We also show that swimming performance (optimal cost of transport and critical swimming speed) was repeatable in biopsied fish, whereas the repeatability of individual oxygen consumption (standard and maximal metabolic rates) seemed unstable over time. However, we noted that the means of individual and mitochondrial traits did not change over time in biopsied fish. This study shows that muscle biopsies allow the measurement of mitochondrial metabolism without sacrificing animals and that two muscle biopsies 14 days apart affect the intraspecific variation in fish performance without affecting average performance of individuals. This article is part of the theme issue 'The evolutionary significance of variation in metabolic rates'.
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Affiliation(s)
- Elisa Thoral
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F-69622, Villeurbanne, France
- Department of Biology, Section for Evolutionary Ecology, Lund University, Sölvegatan 37, Lund 223 62, Sweden
| | - Lauréliane Dargère
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F-69622, Villeurbanne, France
| | - Ione Medina-Suárez
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, Unidad Asociada ULPGC-CSIC, Campus de Taliarte, 35214 Telde, Gran Canaria, Canary Islands, Spain
| | - Angéline Clair
- Plateforme Animalerie Conventionnelle et Sauvage Expérimentale de la Doua (ACSED), Fédération de Recherche 3728, Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENS-Lyon, INRAE, INSA, VetAgroSup 69622, Villeurbanne, France
| | - Laetitia Averty
- Plateforme Animalerie Conventionnelle et Sauvage Expérimentale de la Doua (ACSED), Fédération de Recherche 3728, Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENS-Lyon, INRAE, INSA, VetAgroSup 69622, Villeurbanne, France
| | - Justine Sigaud
- Plateforme Animalerie Conventionnelle et Sauvage Expérimentale de la Doua (ACSED), Fédération de Recherche 3728, Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENS-Lyon, INRAE, INSA, VetAgroSup 69622, Villeurbanne, France
| | - Anne Morales
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F-69622, Villeurbanne, France
| | - Karine Salin
- Ifremer, CNRS, RD, Laboratory of Environmental Marine Sciences, Université de Brest, 29280 Plouzané, France
| | - Loïc Teulier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F-69622, Villeurbanne, France
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Roussel D, Le Coadic M, Rouanet JL, Duchamp C. Skeletal muscle metabolism in sea-acclimatized king penguins. I. Thermogenic mechanisms. J Exp Biol 2020; 223:jeb233668. [PMID: 32968000 DOI: 10.1242/jeb.233668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/10/2020] [Indexed: 12/25/2022]
Abstract
At fledging, king penguin juveniles undergo a major energetic challenge to overcome the intense and prolonged energy demands for thermoregulation and locomotion imposed by life in cold seas. Among other responses, sea acclimatization triggers fuel selection in skeletal muscle metabolism towards lipid oxidation in vitro, which is reflected by a drastic increase in lipid-induced thermogenesis in vivo However, the exact nature of skeletal muscle thermogenic mechanisms (shivering and/or non-shivering thermogenesis) remains undefined. The aim of the present study was to determine in vivo whether the capacity for non-shivering thermogenesis was enhanced by sea acclimatization. We measured body temperature, metabolic rate, heart rate and shivering activity in fully immersed king penguins (Aptenodytes patagonicus) exposed to water temperatures ranging from 12 to 29°C. Results from terrestrial pre-fledging juveniles were compared with those from sea-acclimatized immature penguins (hereafter 'immatures'). The capacity for thermogenesis in water was as effective in juveniles as in immatures, while the capacity for non-shivering thermogenesis was not reinforced by sea acclimatization. This result suggests that king penguins mainly rely on skeletal muscle contraction (shivering or locomotor activity) to maintain endothermy at sea. Sea-acclimatized immature penguins also exhibited higher shivering efficiency and oxygen pulse (amount of oxygen consumed or energy expended per heartbeat) than pre-fledging juvenile birds. Such increase in shivering and cardiovascular efficiency may favor a more efficient activity-thermoregulatory heat substitution providing penguins with the aptitude to survive the tremendous energetic challenge imposed by marine life in cold circumpolar oceans.
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Affiliation(s)
- Damien Roussel
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Marion Le Coadic
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Jean-Louis Rouanet
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Claude Duchamp
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
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Roussel D, Marmillot V, Monternier PA, Bourguignon A, Toullec G, Romestaing C, Duchamp C. Skeletal muscle metabolism in sea-acclimatized king penguins. II. Improved efficiency of mitochondrial bioenergetics. J Exp Biol 2020; 223:jeb233684. [PMID: 32967994 DOI: 10.1242/jeb.233684] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/10/2020] [Indexed: 08/25/2023]
Abstract
At fledging, juvenile king penguins (Aptenodytes patagonicus) must overcome the tremendous energetic constraints imposed by their marine habitat, including during sustained extensive swimming activity and deep dives in cold seawater. Both endurance swimming and skeletal muscle thermogenesis require high mitochondrial respiratory capacity while the submerged part of dive cycles repeatedly and greatly reduces oxygen availability, imposing a need for solutions to conserve oxygen. The aim of the present study was to determine in vitro whether skeletal muscle mitochondria become more 'thermogenic' to sustain heat production or more 'economical' to conserve oxygen in sea-acclimatized immature penguins (hereafter 'immatures') compared with terrestrial juveniles. Rates of mitochondrial oxidative phosphorylation were measured in permeabilized fibers and mitochondria from the pectoralis muscle. Mitochondrial ATP synthesis and coupling efficiency were measured in isolated muscle mitochondria. The mitochondrial activities of respiratory chain complexes and citrate synthase were also assessed. The results showed that respiration, ATP synthesis and respiratory chain complex activities in pectoralis muscles were increased by sea acclimatization. Furthermore, muscle mitochondria were on average 30-45% more energy efficient in sea-acclimatized immatures than in pre-fledging juveniles, depending on the respiratory substrate used (pyruvate, palmitoylcarnitine). Hence sea acclimatization favors the development of economical management of oxygen, decreasing the oxygen needed to produce a given amount of ATP. This mitochondrial phenotype may improve dive performance during the early marine life of king penguins, by extending their aerobic dive limit.
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Affiliation(s)
- Damien Roussel
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Vincent Marmillot
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Pierre-Axel Monternier
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Aurore Bourguignon
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Gaëlle Toullec
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Caroline Romestaing
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
| | - Claude Duchamp
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622 Villeurbanne, France
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Rey B, Duchamp C, Roussel D. Uncoupling effect of palmitate is exacerbated in skeletal muscle mitochondria of sea-acclimatized king penguins ( Aptenodytes patagonicus ). Comp Biochem Physiol A Mol Integr Physiol 2017. [DOI: 10.1016/j.cbpa.2017.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Enstipp MR, Bost CA, Le Bohec C, Bost C, Le Maho Y, Weimerskirch H, Handrich Y. Apparent changes in body insulation of juvenile king penguins suggest an energetic challenge during their early life at sea. J Exp Biol 2017; 220:2666-2678. [DOI: 10.1242/jeb.160143] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/17/2017] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Little is known about the early life at sea of marine top predators, like deep-diving king penguins (Aptenodytes patagonicus), although this dispersal phase is probably a critical phase in their life. Apart from finding favourable foraging sites, they have to develop effective prey search patterns as well as physiological capacities that enable them to capture sufficient prey to meet their energetic needs. To investigate the ontogeny of their thermoregulatory responses at sea, we implanted 30 juvenile king penguins and 8 adult breeders with a small data logger that recorded pressure and subcutaneous temperature continuously for up to 2.5 years. We found important changes in the development of peripheral temperature patterns of foraging juvenile king penguins throughout their first year at sea. Peripheral temperature during foraging bouts fell to increasingly lower levels during the first 6 months at sea, after which it stabilized. Most importantly, these changes re-occurred during their second year at sea, after birds had fasted for ∼4 weeks on land during their second moult. Furthermore, similar peripheral temperature patterns were also present in adult birds during foraging trips throughout their breeding cycle. We suggest that rather than being a simple consequence of concurrent changes in dive effort or an indication of a physiological maturation process, these seasonal temperature changes mainly reflect differences in thermal insulation. Heat loss estimates for juveniles at sea were initially high but declined to approximately half after ∼6 months at sea, suggesting that juvenile king penguins face a strong energetic challenge during their early oceanic existence.
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Affiliation(s)
- Manfred R. Enstipp
- Université de Strasbourg, CNRS, IPHC, Département Ecologie, Physiologie et Ethologie, UMR 7178, F-67000 Strasbourg, France
- Centre d'Etudes Biologiques de Chizé, CNRS, UMR 7372, 79360 Villiers en Bois, France
| | - Charles-André Bost
- Centre d'Etudes Biologiques de Chizé, CNRS, UMR 7372, 79360 Villiers en Bois, France
| | - Céline Le Bohec
- Université de Strasbourg, CNRS, IPHC, Département Ecologie, Physiologie et Ethologie, UMR 7178, F-67000 Strasbourg, France
- Centre Scientifique de Monaco, Département de Biologie Polaire, 98000 MC, Monaco
- Laboratoire International Associé (LIA 647 BioSensib – CSM-CNRS-Unistra), 98000 MC, Monaco
| | - Caroline Bost
- Centre d'Etudes Biologiques de Chizé, CNRS, UMR 7372, 79360 Villiers en Bois, France
| | - Yvon Le Maho
- Université de Strasbourg, CNRS, IPHC, Département Ecologie, Physiologie et Ethologie, UMR 7178, F-67000 Strasbourg, France
- Centre Scientifique de Monaco, Département de Biologie Polaire, 98000 MC, Monaco
- Laboratoire International Associé (LIA 647 BioSensib – CSM-CNRS-Unistra), 98000 MC, Monaco
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, CNRS, UMR 7372, 79360 Villiers en Bois, France
| | - Yves Handrich
- Université de Strasbourg, CNRS, IPHC, Département Ecologie, Physiologie et Ethologie, UMR 7178, F-67000 Strasbourg, France
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Rey B, Dégletagne C, Duchamp C. Transcriptomic data analysis and differential gene expression of antioxidant pathways in king penguin juveniles ( Aptenodytes patagonicus) before and after acclimatization to marine life. Data Brief 2016; 9:549-555. [PMID: 27752524 PMCID: PMC5061121 DOI: 10.1016/j.dib.2016.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 09/07/2016] [Accepted: 09/14/2016] [Indexed: 12/23/2022] Open
Abstract
In this article, we present differentially expressed gene profiles in the pectoralis muscle of wild juvenile king penguins that were either naturally acclimated to cold marine environment or experimentally immersed in cold water as compared with penguin juveniles that never experienced cold water immersion. Transcriptomic data were obtained by hybridizing penguins total cDNA on Affymetrix GeneChip Chicken Genome arrays and analyzed using maxRS algorithm, “Transcriptome analysis in non-model species: a new method for the analysis of heterologous hybridization on microarrays” (Dégletagne et al., 2010) [1]. We focused on genes involved in multiple antioxidant pathways. For better clarity, these differentially expressed genes were clustered into six functional groups according to their role in controlling redox homeostasis. The data are related to a comprehensive research study on the ontogeny of antioxidant functions in king penguins, “Hormetic response triggers multifaceted anti-oxidant strategies in immature king penguins (Aptenodytes patagonicus)” (Rey et al., 2016) [2]. The raw microarray dataset supporting the present analyses has been deposited at the Gene Expression Omnibus (GEO) repository under accessions GEO: GSE17725 and GEO: GSE82344.
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Affiliation(s)
- Benjamin Rey
- Université de Lyon, F-69000, Lyon, Université Lyon 1, CNRS - Laboratoire de Biométrie et Biologie Evolutive, F-69622 Villeurbanne Cedex, France
| | - Cyril Dégletagne
- Université de Lyon, F-69000, Lyon, Université Lyon 1, CNRS - Laboratoire d׳Ecologie des Hydrosystèmes Naturels et Anthropisés, F-69622 Villeurbanne Cedex, France
| | - Claude Duchamp
- Université de Lyon, F-69000, Lyon, Université Lyon 1, CNRS - Laboratoire d׳Ecologie des Hydrosystèmes Naturels et Anthropisés, F-69622 Villeurbanne Cedex, France
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Rey B, Dégletagne C, Bodennec J, Monternier PA, Mortz M, Roussel D, Romestaing C, Rouanet JL, Tornos J, Duchamp C. Hormetic response triggers multifaceted anti-oxidant strategies in immature king penguins (Aptenodytes patagonicus). Free Radic Biol Med 2016; 97:577-587. [PMID: 27449544 DOI: 10.1016/j.freeradbiomed.2016.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 06/10/2016] [Accepted: 07/18/2016] [Indexed: 12/11/2022]
Abstract
Repeated deep dives are highly pro-oxidative events for air-breathing aquatic foragers such as penguins. At fledging, the transition from a strictly terrestrial to a marine lifestyle may therefore trigger a complex set of anti-oxidant responses to prevent chronic oxidative stress in immature penguins but these processes are still undefined. By combining in vivo and in vitro approaches with transcriptome analysis, we investigated the adaptive responses of sea-acclimatized (SA) immature king penguins (Aptenodytes patagonicus) compared with pre-fledging never-immersed (NI) birds. In vivo, experimental immersion into cold water stimulated a higher thermogenic response in SA penguins than in NI birds, but both groups exhibited hypothermia, a condition favouring oxidative stress. In vitro, the pectoralis muscles of SA birds displayed increased oxidative capacity and mitochondrial protein abundance but unchanged reactive oxygen species (ROS) generation per g tissue because ROS production per mitochondria was reduced. The genes encoding oxidant-generating proteins were down-regulated in SA birds while mRNA abundance and activity of the main antioxidant enzymes were up-regulated. Genes encoding proteins involved in repair mechanisms of oxidized DNA or proteins and in degradation processes were also up-regulated in SA birds. Sea life also increased the degree of fatty acid unsaturation in muscle mitochondrial membranes resulting in higher intrinsic susceptibility to ROS. Oxidative damages to protein or DNA were reduced in SA birds. Repeated experimental immersions of NI penguins in cold-water partially mimicked the effects of acclimatization to marine life, modified the expression of fewer genes related to oxidative stress but in a similar way as in SA birds and increased oxidative damages to DNA. It is concluded that the multifaceted plasticity observed after marine life may be crucial to maintain redox homeostasis in active tissues subjected to high pro-oxidative pressure in diving birds. Initial immersions in cold-water may initiate an hormetic response triggering essential changes in the adaptive antioxidant response to marine life.
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Affiliation(s)
- Benjamin Rey
- Université de Lyon, Université Lyon 1, CNRS - Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France; Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Cyril Dégletagne
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
| | - Jacques Bodennec
- Université de Lyon, Université Lyon 1, CNRS - Neuroscience Research Centre, Villeurbanne, France.
| | - Pierre-Axel Monternier
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
| | - Mathieu Mortz
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
| | - Damien Roussel
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
| | - Caroline Romestaing
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
| | - Jean-Louis Rouanet
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
| | - Jeremy Tornos
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
| | - Claude Duchamp
- Université de Lyon; Université Lyon 1, CNRS - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Villeurbanne Cedex, France.
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Lipid-induced thermogenesis is up-regulated by the first cold-water immersions in juvenile penguins. J Comp Physiol B 2016; 186:639-50. [PMID: 26924130 DOI: 10.1007/s00360-016-0975-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/01/2016] [Accepted: 02/16/2016] [Indexed: 10/22/2022]
Abstract
The passage from shore to marine life is a critical step in the development of juvenile penguins and is characterized by a fuel selection towards lipid oxidation concomitant to an enhancement of lipid-induced thermogenesis. However, mechanisms of such thermogenic improvement at fledging remain undefined. We used two different groups of pre-fledging king penguins (Aptenodytes patagonicus) to investigate the specific contribution of cold exposure during water immersion to lipid metabolism. Terrestrial penguins that had never been immersed in cold water were compared with experimentally cold-water immersed juveniles. Experimentally immersed penguins underwent ten successive immersions at approximately 9-10 °C for 5 h over 3 weeks. We evaluated adaptive thermogenesis by measuring body temperature, metabolic rate and shivering activity in fully immersed penguins exposed to water temperatures ranging from 12 to 29 °C. Both never-immersed and experimentally immersed penguins were able to maintain their homeothermy in cold water, exhibiting similar thermogenic activity. In vivo, perfusion of lipid emulsion at thermoneutrality induced a twofold larger calorigenic response in experimentally immersed than in never-immersed birds. In vitro, the respiratory rates and the oxidative phosphorylation efficiency of isolated muscle mitochondria were not improved with cold-water immersions. The present study shows that acclimation to cold water only partially reproduced the fuel selection towards lipid oxidation that characterizes penguin acclimatization to marine life.
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Fongy A, Romestaing C, Blanc C, Lacoste-Garanger N, Rouanet JL, Raccurt M, Duchamp C. Ontogeny of muscle bioenergetics in Adélie penguin chicks (Pygoscelis adeliae). Am J Physiol Regul Integr Comp Physiol 2013; 305:R1065-75. [DOI: 10.1152/ajpregu.00137.2013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ontogeny of pectoralis muscle bioenergetics was studied in growing Adélie penguin chicks during the first month after hatching and compared with adults using permeabilized fibers and isolated mitochondria. With pyruvate-malate-succinate or palmitoyl-carnitine as substrates, permeabilized fiber respiration markedly increased during chick growth (3-fold) and further rose in adults (1.4-fold). Several markers of muscle fiber oxidative activity (cytochrome oxidase, citrate synthase, hydroxyl-acyl-CoA dehydrogenase) increased 6- to 19-fold with age together with large rises in intermyofibrillar (IMF) and subsarcolemmal (SS) mitochondrial content (3- to 5-fold) and oxidative activities (1.5- to 2.4-fold). The proportion of IMF relative to SS mitochondria increased with chick age but markedly dropped in adults. Differences in oxidative activity between mitochondrial fractions were reduced in adults compared with hatched chicks. Extrapolation of mitochondrial to muscle respirations revealed similar figures with isolated mitochondria and permeabilized fibers with carbohydrate-derived but not with lipid-derived substrates, suggesting diffusion limitations of lipid substrates with permeabilized fibers. Two immunoreactive fusion proteins, mitofusin 2 (Mfn2) and optic atrophy 1 (OPA1), were detected by Western blots on mitochondrial extracts and their relative abundance increased with age. Muscle fiber respiration was positively related with Mfn2 and OPA1 relative abundance. Present data showed by two complementary techniques large ontogenic increases in muscle oxidative activity that may enable birds to face thermal emancipation and growth in childhood and marine life in adulthood. The concomitant rise in mitochondrial fusion protein abundance suggests a role of mitochondrial networks in the skeletal muscle processes of bioenergetics that enable penguins to overcome harsh environmental constraints.
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Affiliation(s)
- Anaïs Fongy
- Université de Lyon, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1; Ecole Nationale des Travaux Publics de l'Etat; Centre National de la Recherche Scientifique, Villeurbanne, France
| | - Caroline Romestaing
- Université de Lyon, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1; Ecole Nationale des Travaux Publics de l'Etat; Centre National de la Recherche Scientifique, Villeurbanne, France
| | - Coralie Blanc
- Université de Lyon, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1; Ecole Nationale des Travaux Publics de l'Etat; Centre National de la Recherche Scientifique, Villeurbanne, France
| | - Nicolas Lacoste-Garanger
- Université de Lyon, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1; Ecole Nationale des Travaux Publics de l'Etat; Centre National de la Recherche Scientifique, Villeurbanne, France
| | - Jean-Louis Rouanet
- Université de Lyon, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1; Ecole Nationale des Travaux Publics de l'Etat; Centre National de la Recherche Scientifique, Villeurbanne, France
| | - Mireille Raccurt
- Université de Lyon, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1; Ecole Nationale des Travaux Publics de l'Etat; Centre National de la Recherche Scientifique, Villeurbanne, France
| | - Claude Duchamp
- Université de Lyon, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1; Ecole Nationale des Travaux Publics de l'Etat; Centre National de la Recherche Scientifique, Villeurbanne, France
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Metabolic response to lipid infusion in fasting winter-acclimatized king penguin chicks (Aptenodytes patagonicus). Comp Biochem Physiol A Mol Integr Physiol 2013; 165:1-6. [DOI: 10.1016/j.cbpa.2013.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 02/13/2013] [Accepted: 02/13/2013] [Indexed: 11/22/2022]
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