1
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Dick MF, Hobson KA, Guglielmo CG. Experimental evidence that EPA and DHA are dietary requirements in a migratory shorebird, but they do not affect muscle oxidative capacity. J Exp Biol 2024; 227:jeb246105. [PMID: 38300135 PMCID: PMC10911131 DOI: 10.1242/jeb.246105] [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: 05/10/2023] [Accepted: 01/10/2024] [Indexed: 02/02/2024]
Abstract
Dietary n-3 long chain polyunsaturated fatty acids (LCPUFAs) are hypothesized to be natural doping agents in migratory shorebirds, enabling prolonged flight by increasing membrane fluidity and oxidative capacity of the flight muscles. Animals can obtain n-3 LCPUFAs from the diet or by conversion of dietary α-linolenic acid, 18:3 n-3. However, the capacity to meet n-3 LCPUFA requirements from 18:3 n-3 varies among species. Direct tests of muscle oxidative enhancement and fatty acid conversion capacity are lacking in marine shorebirds that evolved eating diets rich in n-3 LCPUFAs. We tested whether the presence and type of dietary fatty acids influence the fatty acid composition and flight muscle oxidative capacity in western sandpipers (Calidris mauri). Sandpipers were fed diets low in n-3 PUFAs, high in 18:3 n-3, or high in n-3 LCPUFAs. Dietary fatty acid composition was reflected in multiple tissues, and low intake of n-3 LCPUFAs decreased the abundance of these fatty acids in all tissues, even with a high intake of 18:3 n-3. This suggests that 18:3 n-3 cannot replace n-3 LCPUFAs, and dietary n-3 LCPUFAs are required for sandpipers. Flight muscle indicators of enzymatic oxidative capacity and regulators of lipid metabolism did not change. However, the n-3 LCPUFA diet was associated with increased FAT/CD36 mRNA expression, potentially benefitting fatty acid transport during flight. Our study suggests that flight muscle lipid oxidation is not strongly influenced by n-3 PUFA intake. The type of dietary n-3 PUFA strongly influences the abundance of n-3 LCPUFAs in the body and could still impact whole-animal performance.
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Affiliation(s)
- Morag F. Dick
- Department of Biology, Centre for Animals on the Move, Advanced Facility for Avian Research, Western University, London, ON, Canada, N6A 5B7
| | - Keith A. Hobson
- Department of Biology, Centre for Animals on the Move, Advanced Facility for Avian Research, Western University, London, ON, Canada, N6A 5B7
| | - Christopher G. Guglielmo
- Department of Biology, Centre for Animals on the Move, Advanced Facility for Avian Research, Western University, London, ON, Canada, N6A 5B7
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2
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Carter WA, DeMoranville KJ, Trost L, Bryła A, Działo M, Sadowska ET, Bauchinger U, Pierce B, McWilliams SR. Dietary fatty acids and flight-training influence the expression of the eicosanoid hormone prostacyclin in songbirds. Comp Biochem Physiol A Mol Integr Physiol 2024; 288:111561. [PMID: 38056555 DOI: 10.1016/j.cbpa.2023.111561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/08/2023]
Abstract
Diet shifts can alter tissue fatty acid composition in birds, which is subsequently related to metabolic patterns. Eicosanoids, short-lived fatty acid-derived hormones, have been proposed to mediate these relationships but neither baseline concentrations nor the responses to diet and exercise have been measured in songbirds. We quantified a stable derivative of the vasodilatory eicosanoid prostacyclin in the plasma of male European Starlings (Sturnus vulgaris, N = 25) fed semisynthetic diets with either high (PUFA) or low (MUFA) amounts of n6 fatty acid precursors to prostacyclin. Plasma samples were taken from each bird before, immediately after, and two days following a 15-day flight-training regimen that a subset of birds (N = 17) underwent. We found elevated prostacyclin levels in flight-trained birds fed the PUFA diet compared to those fed the MUFA diet and a positive relationship between prostacyclin and body condition, indexed by fat score. Prostacyclin concentrations also significantly decreased at the final time point. These results are consistent with the proposed influences of precursor availability (i.e., dietary fatty acids) and regulatory feedback associated with exercise (i.e., fuel supply and inflammation), and suggest that prostacyclin may be an important mediator of dietary influence on songbird physiology.
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Affiliation(s)
- Wales A Carter
- Department of Resources Science, University of Rhode Island, Kingston, RI, USA.
| | | | - Lisa Trost
- Department for Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Amadeusz Bryła
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Maciej Działo
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Edyta T Sadowska
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Ulf Bauchinger
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Barbara Pierce
- Department of Biology, Sacred Heart University, Fairfield, CT, USA
| | - Scott R McWilliams
- Department of Resources Science, University of Rhode Island, Kingston, RI, USA
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3
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Fowler MA, Wong JB, Harrison AL. Oxidative physiology of two small and highly migratory Arctic seabirds: Arctic terns ( Sterna paradisaea) and long-tailed jaegers ( Stercorarius longicaudus). CONSERVATION PHYSIOLOGY 2023; 11:coad060. [PMID: 37916041 PMCID: PMC10616233 DOI: 10.1093/conphys/coad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 04/21/2023] [Accepted: 08/14/2023] [Indexed: 11/03/2023]
Abstract
Arctic ecosystems are changing rapidly. The tundra supports nesting migratory seabirds that spend most of their year over the ocean. Migrations are demanding, but it is unclear how physiological capability may equip organisms to respond to their changing environments. For two migratory seabird species nesting in Alaska, USA, the Arctic tern (n = 10) and the long-tailed jaeger (n = 8), we compared oxidative physiology and aerobic capacity measured during incubation and we recorded individual movement paths using electronic tracking tags. Within species, we hypothesized that individuals with longer-distance migrations would show higher oxidative stress and display better aerobic capacity than shorter-distance migrants. We examined blood parameters relative to subsequent fall migration in jaegers and relative to previous spring migration in terns. We present the first measurements of oxidative stress in these species and the first migratory movements of long-tailed jaegers in the Pacific Ocean. Arctic terns displayed positive correlation of oxidative variables, or better integration than jaegers. Relative to physiological sampling, pre-breeding northward migration data were available for terns and post-breeding southward data were available for jaegers. Terns reached a farther maximum distance from the colony than jaegers (16 199 ± 275 km versus 10 947 ± 950 km) and rate of travel northward (447 ± 41.8 km/day) was positively correlated with hematocrit, but we found no other relationships. In jaegers, there were no relationships between individuals' physiology and southward rate of travel (193 ± 52.3 km/day) or migratory distance. While it is not clear whether the much longer migrations of the terns is related to their better integration, or to another factor, our results spark hypotheses that could be evaluated through a controlled phylogenetic study. Species with better integration may be less susceptible to environmental factors that increase oxidative stress, including thermal challenges or changes in prey distribution as the Arctic climate changes rapidly.
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Affiliation(s)
- Melinda A. Fowler
- Department of Biology/Chemistry. Springfield College, 263 Alden Street, Springfield, MA 01109 USA
| | - Joanna B. Wong
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Bird Migration, Swiss Ornithological Institute, 6204 Sempach, Switzerland
| | - Autumn-Lynn Harrison
- Smithsonian‘s National Zoo and Conservation Biology Institute, Migratory Bird Center, 3001 Connecticut Avenue, NW, Washington, DC. 20008 USA
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4
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Blood Metabolites and Profiling Stored Adipose Tissue Reveal the Differential Migratory Strategies of Eurasian Reed and Sedge Warblers. BIRDS 2022. [DOI: 10.3390/birds3040024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
The overall speed of bird migration is limited by the amount of fuel stores acquired during the initial phases of migration. The ability to mobilize fat is crucial for migratory birds that can exhibit different migratory strategies. Birds mobilize triglycerides during nocturnal flight thus increasing circulating fatty acids and glycerol to meet the metabolic demands of flight. Eurasian Reed (Acrocephalus scirpaceus) and Sedge (Acrocephalus schoenobaenus) Warblers were captured at Portuguese stopover sites during spring and autumn migration. These species were selected based on their different migration strategies and dietary preferences during migration. Blood metabolites and fat composition were analyzed to determine their nutritional states. Sedge Warblers had higher blood triglyceride and glycerol levels during post-flight fasting than in non-fasting periods. Furthermore, Sedge Warblers had higher triglyceride and glycerol levels than Eurasian Reed Warblers in both post-flight fasting and non-fasting condition. The differences found may reflect distinct approaches in re-feeding activity (e.g., feeding intensely) associated with the number of stopovers during migratory cycle. Dietary preferences affect the fat composition available for oxidation during long-term exercise in migratory flight. Nuclear magnetic resonance analysis of subcutaneous fat composition revealed that Sedge Warblers presented higher levels of polyunsaturated fatty acid levels than Eurasian Reed Warblers. The distinct lipidic profiles observed and differences in feeding ecology may explain the different migration strategies of these species. Overall and despite their ecological similarity, our study species showed pronounced differences in blood metabolites levels and subcutaneous fatty acids composition, likely attributed to the migratory strategy and foraging preferences during their migratory cycle.
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5
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Peraldi P, Loubat A, Chignon-Sicard B, Dani C, Ladoux A. Identification of Human Breast Adipose Tissue Progenitors Displaying Distinct Differentiation Potentials and Interactions with Cancer Cells. Biomedicines 2022; 10:biomedicines10081928. [PMID: 36009475 PMCID: PMC9406003 DOI: 10.3390/biomedicines10081928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/26/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022] Open
Abstract
Breast adipose tissue (AT) participates in the physiological evolution and remodeling of the mammary gland due to its high plasticity. It is also a favorable microenvironment for breast cancer progression. However, information on the properties of human breast adipose progenitor cells (APCs) involved in breast physiology or pathology is scant. We performed differential enzymatic dissociation of human breast AT lobules. We isolated and characterized two populations of APCs. Here we report that these distinct breast APC populations selectively expressed markers suitable for characterization. The population preferentially expressing ALPL (MSCA1) showed higher adipogenic potential. The population expressing higher levels of INHBA and CD142 acquired myofibroblast characteristics upon TGF-β treatment and a myo-cancer-associated fibroblast profile in the presence of breast cancer cells. This population expressed the immune checkpoint CD274 (PD-L1) and facilitated the expansion of breast cancer mammospheres compared with the adipogenic population. Indeed, the breast, as with other fat depots, contains distinct types of APCs with differences in their ability to specialize. This indicates that they were differentially involved in breast remodeling. Their interactions with breast cancer cells revealed differences in the potential for tumor dissemination and estrogen receptor expression, and these differences might be relevant to improve therapies targeting the tumor microenvironment.
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Affiliation(s)
- Pascal Peraldi
- CNRS, INSERM, iBV, Université Côte d’Azur, 06107 Nice, France
| | - Agnès Loubat
- CNRS, INSERM, iBV, Université Côte d’Azur, 06107 Nice, France
| | - Bérengère Chignon-Sicard
- CNRS, INSERM, iBV, Université Côte d’Azur, 06107 Nice, France
- Department of Plastic and Reconstructive Surgery, Pasteur 2 Hospital, Université Côte d’Azur, 06107 Nice, France
| | - Christian Dani
- CNRS, INSERM, iBV, Université Côte d’Azur, 06107 Nice, France
| | - Annie Ladoux
- CNRS, INSERM, iBV, Université Côte d’Azur, 06107 Nice, France
- CNRS, Institute of Biology Valrose (iBV), University of Nice Sophia-Antipolis, 28 Avenue de Valombrose, CEDEX 2, 06107 Nice, France
- Correspondence:
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6
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Wone BWM, Swanson DL. Metabolic Profiling and Integration of Metabolomic and Transcriptomic Data From Pectoralis Muscle Reveal Winter-Adaptive Metabolic Responses of Black-Capped Chickadee and American Goldfinch. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.866130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Seasonal changes, such as alterations in food availability or type and cold conditions, present challenges to free-living birds living in highly seasonal climates. Small birds respond to such challenges through seasonal metabolic flexibility, which better matches seasonal metabolic phenotypes to environmental conditions and can improve fitness. To better understand the mechanistic basis of this metabolic flexibility, we conducted a large-scale metabolic profiling of pectoralis muscle in black-capped chickadees (Poecile atricapillus) and American goldfinches (Spinus tristis), which are small, year-round bird species of temperate-zones. We analyzed muscle samples using non-biased, global metabolomics profiling technology based on UHLC/MS/MS2 platforms. A total of 582 metabolites was characterized for summer and winter season samples. Chickadees showed greater seasonal separation of global metabolite profiles than goldfinches, which is consistent with previous transcriptomic studies of pectoralis muscle in these two species. Reduced levels of amino acids during winter occurred in both species and might reflect decreasing dietary protein intake, amino acid shuttling to other pathways for thermogenesis and/or elevated rates of protein turnover in the pectoralis muscle. Concomitant decreased abundances in tricarboxylic acid cycle (TCA) metabolites suggest faster cycling of the oxidative phosphorylation pathway in winter to meet the metabolic demands of thermogenesis. Accordingly, chickadees displayed shifts toward lipid oxidation in winter, whereas goldfinches showed winter declines in ketone bodies, which suggests increased energy demand or subtle changes in substrate availability. Beyond the winter-specific changes in metabolite abundances, integration of the metabolomic and the transcriptomic data revealed a landscape of gene–metabolite associations related to the winter-adaptive metabolic response. This landscape of gene–metabolite pairs was overrepresented by pathways associated with transport of small molecules, metabolism of amino acids and derivatives, activation and biosynthesis of fatty acid derivatives, and biosynthesis and metabolism of nicotinate and nicotinamide derivatives. Collectively, our results suggest that increased levels of NADH and its derivatives in the pectoralis muscle are a potential novel mechanism for increasing winter metabolic output, fueled by lipids, for thermogenesis during winter.
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7
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DeMoranville KJ, Carter WA, Pierce BJ, McWilliams SR. Flight and dietary antioxidants influence antioxidant expression and activity in a migratory bird. Integr Org Biol 2021; 4:obab035. [PMID: 35112051 PMCID: PMC8802218 DOI: 10.1093/iob/obab035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 11/05/2021] [Accepted: 12/23/2021] [Indexed: 11/17/2022] Open
Abstract
Ecologically relevant factors such as exercise and diet quality can directly influence how physiological systems work including those involved in maintaining oxidative balance; however, to our knowledge, no studies to date have focused on how such factors directly affect expression of key components of the endogenous antioxidant system (i.e., transcription factors, select antioxidant genes, and corresponding antioxidant enzymes) in several metabolically active tissues of a migratory songbird. We conducted a three-factor experiment that tested the following hypotheses: (H1) Daily flying over several weeks increases the expression of transcription factors NRF2 and PPARs as well as endogenous antioxidant genes (i.e., CAT, SOD1, SOD2, GPX1, GPX4), and upregulates endogenous antioxidant enzyme activities (i.e., CAT, SOD, GPx). (H2) Songbirds fed diets composed of more 18:2n-6 PUFA are more susceptible to oxidative damage and thus upregulate their endogenous antioxidant system compared with when fed diets with less PUFA. (H3) Songbirds fed dietary anthocyanins gain additional antioxidant protection and thus upregulate their endogenous antioxidant system less compared with songbirds not fed anthocyanins. Flight training increased the expression of 3 of the 6 antioxidant genes and transcription factors measured in the liver, consistent with H1, but for only one gene (SOD2) in the pectoralis. Dietary fat quality had no effect on antioxidant pathways (H2), whereas dietary anthocyanins increased the expression of select antioxidant enzymes in the pectoralis, but not in the liver (H3). These tissue-specific differences in response to flying and dietary antioxidants are likely explained by functional differences between tissues as well as fundamental differences in their turnover rates. The consumption of dietary antioxidants along with regular flying enables birds during migration to stimulate the expression of genes involved in antioxidant protection likely through increasing the transcriptional activity of NRF2 and PPARs, and thereby demonstrates for the first time that these relevant ecological factors affect the regulation of key antioxidant pathways in wild birds. What remains to be demonstrated is how the extent of these ecological factors (i.e., intensity or duration of flight, amounts of dietary antioxidants) influences the regulation of these antioxidant pathways and thus oxidative balance.
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Affiliation(s)
| | - Wales A Carter
- Dept. of Natural Resources Science, University of Rhode Island, Kingston RI 02881
| | | | - Scott R McWilliams
- Dept. of Natural Resources Science, University of Rhode Island, Kingston RI 02881
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8
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McWilliams S, Carter W, Cooper-Mullin C, DeMoranville K, Frawley A, Pierce B, Skrip M. How Birds During Migration Maintain (Oxidative) Balance. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.742642] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Animals dynamically adjust their physiology and behavior to survive in changing environments, and seasonal migration is one life stage that demonstrates these dynamic adjustments. As birds migrate between breeding and wintering areas, they incur physiological demands that challenge their antioxidant system. Migrating birds presumably respond to these oxidative challenges by up-regulating protective endogenous systems or accumulating dietary antioxidants at stopover sites, although our understanding of the pre-migration preparations and mid-migration responses of birds to such oxidative challenges is as yet incomplete. Here we review evidence from field and captive-bird studies that address the following questions: (1) Do migratory birds build antioxidant capacity as they build fat stores in preparation for long flights? (2) Is oxidative damage an inevitable consequence of oxidative challenges such as flight, and, if so, how is the extent of damage affected by factors such as the response of the antioxidant system, the level of energetic challenge, and the availability of dietary antioxidants? (3) Do migratory birds ‘recover’ from the oxidative damage accrued during long-duration flights, and, if so, does the pace of this rebalancing of oxidative status depend on the quality of the stopover site? The answer to all these questions is a qualified ‘yes’ although ecological factors (e.g., diet and habitat quality, geographic barriers to migration, and weather) affect how the antioxidant system responds. Furthermore, the pace of this dynamic physiological response remains an open question, despite its potential importance for shaping outcomes on timescales ranging from single flights to migratory journeys. In sum, the antioxidant system of birds during migration is impressively dynamic and responsive to environmental conditions, and thus provides ample opportunities to study how the physiology of migratory birds responds to a changing and challenging world.
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9
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Cornelius JM, Hahn TP, Robart AR, Vernasco BJ, Zahor DL, Glynn KJ, Navis CJ, Watts HE. Seasonal Patterns of Fat Deposits in Relation to Migratory Strategy in Facultative Migrants. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.691808] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Physiological preparations for migration generally reflect migratory strategy. Migrant birds fuel long-distance flight primarily with lipids, but carrying excess fuel is costly; thus, the amount of fat deposited prior to departure often reflects the anticipated flight duration or distance between refueling bouts. Seasonal pre-migratory deposition of fat is well documented in regular seasonal migrants, but is less described for more facultative species. We analyze fat deposits of free-living birds across several taxa of facultative migrants in the songbird subfamily Carduelinae, including house finches (Haemorhous mexicanus), American goldfinches (Spinus tristis), pine siskins (Spinus pinus) and four different North American ecotypes of red crossbills (Loxia curvirostra), to evaluate seasonal fat deposition during facultative migratory periods. Our data suggest that the extent of seasonal fat deposits corresponds with migratory tendency in these facultative taxa. Specifically, nomadic red crossbills with a seasonally predictable annual movement demonstrated relatively large seasonal fat deposits coincident with the migratory periods. In contrast, pine siskins, thought to be more variable in timing and initiation of nomadic movements, had smaller peaks in fat deposits during the migratory season, and the partial migrant American goldfinch and the resident house finch showed no peaks coincident with migratory periods. Within the red crossbills, those ecotypes that are closely associated with pine habitats showed larger peaks in fat deposits coincident with autumn migratory periods and had higher wing loading, whereas those ecotypes associated with spruces, Douglas-fir and hemlocks showed larger peaks coincident with spring migratory periods and lower wing loading. We conclude that population averages of fat deposits do reflect facultative migration strategies in these species, as well as the winter thermogenic challenges at the study locations. A difference in seasonal fattening and wing loading among red crossbill ecotypes is consistent with the possibility that they differ in their migratory biology, and we discuss these differences in light of crossbill reproductive schedules and phenologies of different conifer species.
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10
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Twining CW, Bernhardt JR, Derry AM, Hudson CM, Ishikawa A, Kabeya N, Kainz MJ, Kitano J, Kowarik C, Ladd SN, Leal MC, Scharnweber K, Shipley JR, Matthews B. The evolutionary ecology of fatty-acid variation: Implications for consumer adaptation and diversification. Ecol Lett 2021; 24:1709-1731. [PMID: 34114320 DOI: 10.1111/ele.13771] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 12/20/2021] [Accepted: 04/09/2021] [Indexed: 12/20/2022]
Abstract
The nutritional diversity of resources can affect the adaptive evolution of consumer metabolism and consumer diversification. The omega-3 long-chain polyunsaturated fatty acids eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) have a high potential to affect consumer fitness, through their widespread effects on reproduction, growth and survival. However, few studies consider the evolution of fatty acid metabolism within an ecological context. In this review, we first document the extensive diversity in both primary producer and consumer fatty acid distributions amongst major ecosystems, between habitats and amongst species within habitats. We highlight some of the key nutritional contrasts that can shape behavioural and/or metabolic adaptation in consumers, discussing how consumers can evolve in response to the spatial, seasonal and community-level variation of resource quality. We propose a hierarchical trait-based approach for studying the evolution of consumers' metabolic networks and review the evolutionary genetic mechanisms underpinning consumer adaptation to EPA and DHA distributions. In doing so, we consider how the metabolic traits of consumers are hierarchically structured, from cell membrane function to maternal investment, and have strongly environment-dependent expression. Finally, we conclude with an outlook on how studying the metabolic adaptation of consumers within the context of nutritional landscapes can open up new opportunities for understanding evolutionary diversification.
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Affiliation(s)
- Cornelia W Twining
- Max Planck Institute of Animal Behavior, Radolfzell, Germany.,Limnological Institute, University of Konstanz, Konstanz-Egg, Germany
| | - Joey R Bernhardt
- Department of Biology, McGill University, Montréal, QC, Canada.,Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Alison M Derry
- Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, QC, Canada
| | - Cameron M Hudson
- Department of Fish Ecology and Evolution, Eawag, Center of Ecology, Evolution and Biochemistry, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Asano Ishikawa
- Ecological Genetics Laboratory, National Institute of Genetics, Shizuoka, Japan
| | - Naoki Kabeya
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology (TUMSAT, Tokyo, Japan
| | - Martin J Kainz
- WasserCluster Lunz-Inter-university Center for Aquatic Ecosystems Research, Lunz am See, Austria
| | - Jun Kitano
- Ecological Genetics Laboratory, National Institute of Genetics, Shizuoka, Japan
| | - Carmen Kowarik
- Department of Aquatic Ecology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Sarah Nemiah Ladd
- Ecosystem Physiology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Miguel C Leal
- ECOMARE and CESAM - Centre for Environmental and Marine Studies and Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Kristin Scharnweber
- Department of Ecology and Genetics; Limnology, Uppsala University, Uppsala, Sweden.,University of Potsdam, Plant Ecology and Nature Conservation, Potsdam-Golm, Germany
| | - Jeremy R Shipley
- Max Planck Institute of Animal Behavior, Radolfzell, Germany.,Department of Fish Ecology and Evolution, Eawag, Center of Ecology, Evolution and Biochemistry, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Blake Matthews
- Department of Fish Ecology and Evolution, Eawag, Center of Ecology, Evolution and Biochemistry, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
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11
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Carter WA, DeMoranville KJ, Pierce BJ, McWilliams SR. Dietary linoleic acid, antioxidants, and flight training influence the activity of oxidative enzymes in European Starlings (Sturnus vulgaris). J Comp Physiol B 2021; 191:357-370. [PMID: 33559031 DOI: 10.1007/s00360-021-01345-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 12/18/2020] [Accepted: 01/18/2021] [Indexed: 11/24/2022]
Abstract
Multiple studies have demonstrated that diet (e.g., fatty acid composition, antioxidants) and exercise training affect the metabolic performance of songbirds during aerobic activity, although the physiological mechanisms that cause such an effect remain unclear. We tested the hypothesis that elevated proportions of dietary linoleic acid (18:2n6) and amounts of dietary anthocyanins (a hydrophilic antioxidant class) influence the activity and protein expression of oxidative enzymes in flight and leg muscle of European Starlings (Sturnus vulgaris N = 96), a subset of which were flown over 15 days in a wind tunnel. Carnitine palmitoyl transferase (CPT) and citrate synthase (CS) activity displayed 18:2n6-dependent relationships with soluble protein concentration. Lactate dehydrogenase (LDH) was similarly related to protein concentration although also dependent on both dietary anthocyanins and flight training. 3-Hydroxyacyl CoA Dehydrogenase (HOAD) activity increased throughout the experiment in flight muscle, whereas this relationship was dependent on dietary anthocyanins in the leg muscle. Soluble protein concentration also increased throughout the experiment in the flight muscle, but was unrelated to date in the leg muscle, instead being influenced by both dietary anthocyanins and flight training. Training also produced additive increases in CPT and leg muscle HOAD activity. FAT/CD36 expression was related to both dietary 18:2n6 and training and changed over the course of the experiment. These results demonstrate a notable influence of our diet manipulations and flight training on the activity of these key oxidative enzymes, and particularly CPT and CS. Such influence suggests a plausible mechanism linking diet quality and metabolic performance in songbirds.
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Affiliation(s)
- Wales A Carter
- Department of Natural Resources Science, University of Rhode Island, 1 Greenhouse Rd, Kingston, RI, 02881, USA.
| | - Kristen J DeMoranville
- Department of Natural Resources Science, University of Rhode Island, 1 Greenhouse Rd, Kingston, RI, 02881, USA
| | - Barbara J Pierce
- Department of Biology, Sacred Heart University, Fairfield, CT, 06825, USA
| | - Scott R McWilliams
- Department of Natural Resources Science, University of Rhode Island, 1 Greenhouse Rd, Kingston, RI, 02881, USA
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12
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Young KG, Vanderboor CM, Regnault TRH, Guglielmo CG. Species-specific metabolic responses of songbird, shorebird, and murine cultured myotubes to n-3 polyunsaturated fatty acids. Am J Physiol Regul Integr Comp Physiol 2020; 320:R362-R376. [PMID: 33356878 DOI: 10.1152/ajpregu.00249.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Migratory birds may benefit from diets rich in polyunsaturated fatty acids (PUFAs) that could improve exercise performance. Previous investigations suggest that different types of birds may respond differently to PUFA. We established muscle myocyte cell culture models from muscle satellite cells of a migratory passerine songbird (yellow-rumped warbler, Setophaga coronata coronata) and a nonpasserine shorebird (sanderling, Calidris alba). We differentiated and treated avian myotubes and immortalized murine C2C12 myotubes with n-3 PUFA docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and with monounsaturated oleic acid (OA) to compare effects on aerobic performance, metabolic enzyme activities, key fatty acid (FA) transporters, and expression of peroxisome proliferator-activated receptors (PPARs). Sanderling and C2C12 myotubes increased expression of PPARs with n-3 PUFA treatments, whereas expression was unchanged in yellow-rumped warblers. Both sanderlings and yellow-rumped warblers increased expression of fatty acid transporters, whereas C2C12 cells decreased expression following n-3 PUFA treatments. Only yellow-rumped warbler myotubes increased expression of some metabolic enzymes, whereas the sanderling and C2C12 cells were unchanged. PUFA supplementation in C2C12 myotubes increased mitochondrial respiratory chain efficiency, whereas sanderlings increased proton leak-associated respiration and maximal respiration (measurements were not made in warblers). This research indicates that songbirds and shorebirds respond differently to n-3 PUFA and provides support for the hypothesis that n-3 PUFA increase the aerobic capacity of migrant shorebird muscle, which may improve overall endurance flight performance.
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Affiliation(s)
- Kevin G Young
- Department of Biology, Advanced Facility for Avian Research, Western University, London, Ontario, Canada
| | - Christina M Vanderboor
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Timothy R H Regnault
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Obstetrics and Gynaecology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Children's Health Research Institute, Lawson Health Research Institute, London, Ontario, Canada
| | - Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, Western University, London, Ontario, Canada
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13
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McWilliams S, Pierce B, Wittenzellner A, Langlois L, Engel S, Speakman JR, Fatica O, DeMoranville K, Goymann W, Trost L, Bryla A, Dzialo M, Sadowska E, Bauchinger U. The energy savings-oxidative cost trade-off for migratory birds during endurance flight. eLife 2020; 9:60626. [PMID: 33306947 PMCID: PMC7733536 DOI: 10.7554/elife.60626] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 12/03/2020] [Indexed: 12/30/2022] Open
Abstract
Elite human and animal athletes must acquire the fuels necessary for extreme feats, but also contend with the oxidative damage associated with peak metabolic performance. Here, we show that a migratory bird with fuel stores composed of more omega-6 polyunsaturated fats (PUFA) expended 11% less energy during long-duration (6 hr) flights with no change in oxidative costs; however, this short-term energy savings came at the long-term cost of higher oxidative damage in the omega-6 PUFA-fed birds. Given that fatty acids are primary fuels, key signaling molecules, the building blocks of cell membranes, and that oxidative damage has long-term consequences for health and ageing, the energy savings-oxidative cost trade-off demonstrated here may be fundamentally important for a wide diversity of organisms on earth.
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Affiliation(s)
- Scott McWilliams
- Department of Natural Resources Science, University of Rhode Island, Kingston, United States
| | - Barbara Pierce
- Department of Biology, Sacred Heart University, Fairfield, United States
| | | | - Lillie Langlois
- Department of Natural Resources Science, University of Rhode Island, Kingston, United States
| | - Sophia Engel
- Max Planck Institute for Ornithology, Starnberg, Germany
| | - John R Speakman
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, United Kingdom
| | - Olivia Fatica
- Department of Biology, Sacred Heart University, Fairfield, United States
| | - Kristen DeMoranville
- Department of Natural Resources Science, University of Rhode Island, Kingston, United States
| | | | - Lisa Trost
- Max Planck Institute for Ornithology, Starnberg, Germany
| | - Amadeusz Bryla
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Maciej Dzialo
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Edyta Sadowska
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland.,Nencki Institute of Experimental Biology PAS, Warszawa, Poland
| | - Ulf Bauchinger
- Nencki Institute of Experimental Biology PAS, Warszawa, Poland
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14
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DeMoranville KJ, Carter WA, Pierce BJ, McWilliams SR. Flight training in a migratory bird drives metabolic gene expression in the flight muscle but not liver, and dietary fat quality influences select genes. Am J Physiol Regul Integr Comp Physiol 2020; 319:R637-R652. [PMID: 32966121 DOI: 10.1152/ajpregu.00163.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Training and diet are hypothesized to directly stimulate key molecular pathways that mediate animal performance, and flight training, dietary fats, and dietary antioxidants are likely important in modulating molecular metabolism in migratory birds. This study experimentally investigated how long-distance flight training, as well as diet composition, affected the expression of key metabolic genes in the pectoralis muscle and the liver of European starlings (Sturnus vulgaris, n = 95). Starlings were fed diets composed of either a high or low polyunsaturated fatty acid (PUFA; 18:2n-6) and supplemented with or without a water-soluble antioxidant, and one-half of these birds were flight trained in a wind-tunnel while the rest were untrained. We measured the expression of 7 (liver) or 10 (pectoralis) key metabolic genes in flight-trained and untrained birds. Fifty percent of genes involved in mitochondrial metabolism and fat utilization were upregulated by flight training in the pectoralis (P < 0.05), whereas flight training increased the expression of only one gene responsible for fatty acid hydrolysis [lipoprotein lipase (LPL)] in the liver (P = 0.04). Dietary PUFA influenced the gene expression of LPL and fat transporter fatty acid translocase (CD36) in the pectoralis and one metabolic transcription factor [peroxisome proliferator-activated receptor (PPAR)-α (PPARα)] in the liver, whereas dietary antioxidants had no effect on the metabolic genes measured in this study. Flight training initiated a simpler causal network between PPARγ coactivators, PPARs, and metabolic genes involved in mitochondrial metabolism and fat storage in the pectoralis. Molecular metabolism is modulated by flight training and dietary fat quality in a migratory songbird, indicating that these environmental factors will affect the migratory performance of birds in the wild.
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Affiliation(s)
- Kristen J DeMoranville
- Department of Natural Resources Science, University of Rhode Island, Kingston, Rhode Island
| | - Wales A Carter
- Department of Natural Resources Science, University of Rhode Island, Kingston, Rhode Island
| | - Barbara J Pierce
- Department of Biology, Sacred Heart University, Fairfield, Connecticut
| | - Scott R McWilliams
- Department of Natural Resources Science, University of Rhode Island, Kingston, Rhode Island
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15
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Jensen JK, Isaksson C, Eikenaar C, Andersson MN. Migrant blackbirds, Turdus merula, have higher plasma levels of polyunsaturated fatty acids compared to residents, but not enhanced fatty acid unsaturation index. Ecol Evol 2020; 10:10196-10206. [PMID: 33005375 PMCID: PMC7520213 DOI: 10.1002/ece3.6681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/05/2020] [Accepted: 07/24/2020] [Indexed: 01/30/2023] Open
Abstract
Birds have been observed to have dietary preferences for unsaturated fatty acids during migration. Polyunsaturated fatty acids (PUFAs) may increase the exercise performance of migrant birds; however, PUFAs are also peroxidation prone and might therefore incur increased costs in terms of enhanced oxidative damage in migratory individuals. To shed light on this potential constraint, we analyzed plasma fatty acid (FA) composition and estimated the unsaturation index as a proxy for susceptibility to lipid peroxidation of migrants and residents of the partially migratory common blackbird (Turdus merula) at a stopover site during autumn migration. As predicted, migrant birds had higher relative and absolute levels of PUFAs compared to resident birds. This included the strictly dietary ω-3 PUFA α-linolenic acid, suggesting a dietary and/or storage preference for these FAs in migrants. Interestingly, the FA unsaturation index did not differ between migrants and residents. These findings suggest a mechanism where birds alter their levels of metabolic substrate without simultaneously increasing the susceptibility of the substrate to lipid peroxidation. In summary, our results are in line with the hypothesis that increased exercise performance during migration might be constrained by oxidative stress, which is manifested in changes in the composition of key FAs to retain the unsaturation index constant despite the increased levels of peroxidizable PUFAs.
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Affiliation(s)
- Johan Kjellberg Jensen
- Department of BiologyLund UniversityLundSweden
- Centre for Environmental and Climate Research (CEC)Lund UniversityLundSweden
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16
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Carter WA, DeMoranville KJ, Pierce BJ, McWilliams SR. The effects of dietary linoleic acid and hydrophilic antioxidants on basal, peak, and sustained metabolism in flight-trained European starlings. Ecol Evol 2020; 10:1552-1566. [PMID: 32076533 PMCID: PMC7029098 DOI: 10.1002/ece3.6010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/13/2019] [Accepted: 12/20/2019] [Indexed: 01/05/2023] Open
Abstract
Dietary micronutrients have the ability to strongly influence animal physiology and ecology. For songbirds, dietary polyunsaturated fatty acids (PUFAs) and antioxidants are hypothesized to be particularly important micronutrients because of their influence on an individual's capacity for aerobic metabolism and recovery from extended bouts of exercise. However, the influence of specific fatty acids and hydrophilic antioxidants on whole-animal performance remains largely untested. We used diet manipulations to directly test the effects of dietary PUFA, specifically linoleic acid (18:2n6), and anthocyanins, a hydrophilic antioxidant, on basal metabolic rate (BMR), peak metabolic rate (PMR), and rates of fat catabolism, lean catabolism, and energy expenditure during sustained flight in a wind tunnel in European starlings (Sturnus vulgaris). BMR, PMR, energy expenditure, and fat metabolism decreased and lean catabolism increased over the course of the experiment in birds fed a high (32%) 18:2n6 diet, while birds fed a low (13%) 18:2n6 diet exhibited the reverse pattern. Additionally, energy expenditure, fat catabolism, and flight duration were all subject to diet-specific effects of whole-body fat content. Dietary antioxidants and diet-related differences in tissue fatty acid composition were not directly related to any measure of whole-animal performance. Together, these results suggest that the effect of dietary 18:2n6 on performance was most likely the result of the signaling properties of 18:2n6. This implies that dietary PUFA influence the energetic capabilities of songbirds and could strongly influence songbird ecology, given their availability in terrestrial systems.
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Affiliation(s)
- Wales A. Carter
- Department of Natural Resources ScienceUniversity of Rhode IslandKingstonRIUSA
| | | | | | - Scott R. McWilliams
- Department of Natural Resources ScienceUniversity of Rhode IslandKingstonRIUSA
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17
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Price ER, Sirsat TS, Sirsat SKG, Dzialowski EM. Sarcoplasmic reticulum Ca 2+-ATPase (SERCA) activity during the transition to endothermy in an altricial bird. ACTA ACUST UNITED AC 2019; 222:222/13/jeb201111. [PMID: 31253731 DOI: 10.1242/jeb.201111] [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: 02/02/2019] [Accepted: 05/30/2019] [Indexed: 01/15/2023]
Abstract
Sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) is a transmembrane pump critical to muscle calcium cycling during contraction, and SERCA has also been proposed as the basis for a non-shivering thermogenesis mechanism in birds. Despite its potential importance to both shivering and non-shivering thermogenesis, the activity of this transporter has rarely been studied in altricial birds, and never during the developmental transition from ectothermy to endothermy. Here, we describe SERCA activity in the pectoralis muscle and heart ventricle of red-winged blackbird (Agelaius phoeniceus) nestlings, fledglings and adults. Additionally, using a diet manipulation, we tested the hypothesis that muscle SERCA activity is affected by dietary fatty acid composition, as has been shown in some previous studies. In blackbird hearts, SERCA activity increased throughout development and into adulthood, conspicuously jumping higher just prior to fledging. In pectoralis muscle, SERCA activity increased throughout the nestling period, but then declined after fledging, an effect we attribute to remodeling of the muscle from a primarily heat-generating organ to a primarily force-generating organ. SERCA activity of the pectoralis muscle was correlated with the proportion of linoleic acid in muscle phospholipids when including all ages in the control group. However, in diet-manipulated birds, there was no consistent relationship between SERCA activity and muscle membrane fatty acid composition at any tested age (5-9 days old). It is unclear whether SERCA might be affected by developmental changes in fatty acid composition at younger ages.
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Affiliation(s)
- Edwin R Price
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Tushar S Sirsat
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Sarah K G Sirsat
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Edward M Dzialowski
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
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18
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Voigt CC, Rosner E, Guglielmo CG, Currie SE. Fatty acid profiles of the European migratory common noctule bat (Nyctalus noctula). Naturwissenschaften 2019; 106:33. [PMID: 31201542 DOI: 10.1007/s00114-019-1627-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 12/21/2022]
Abstract
In animals, fatty acids (FA) are essential as structural components in membranes and for energy storage in adipocytes. Here, we studied the relative proportions of FA in a mammal with extreme changes in metabolic rates. Common noctule bats (Nyctalus noctula) switch from energetically demanding long-distance migration at high metabolic rates to regular torpor with extremely low metabolic rates. We found that composition of FA categories differed between adipose tissue types (white adipose tissue (WAT) vs brown adipose tissue (BAT)) and muscle tissue types (skeletal vs heart), but not between sexes. We found oleic acid to be the most abundant FA in all studied tissues. Concentrations of polyunsaturated FA (PUFA) were not always higher in muscular tissue compared with adipocyte tissue, even though high concentrations of PUFA are considered beneficial for low body temperatures in torpor. In all tissues, we observed a high content in monounsaturated fatty acids (MUFA), possibly to compensate for a low PUFA content in the diet. Ratios of ω6/ω3 were lower in the heart than in skeletal muscles of common noctules. Three FA (palmitic, oleic, and linoleic acid) accounted for about 70% of the FA in adipose tissue, which is similar to proportions observed in migrating birds, yet migrating birds generally have a higher PUFA content in muscle and adipose tissues than bats. Bats seem to contrast with other mammals in having a high MUFA content in all tissues. We conclude that FA profiles of bats differ largely from those of most cursorial mammals and instead are-with the exception of MUFA-similar to those of migrating birds.
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Affiliation(s)
- Christian C Voigt
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, 10315, Berlin, Germany.
| | - Elisabeth Rosner
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, 10315, Berlin, Germany.,Zoological Institute and Museum, Ernst-Moritz-Arndt-University Greifswald, 17487, Greifswald, Germany
| | - Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, ON, Canada
| | - Shannon E Currie
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, 10315, Berlin, Germany
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19
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Carter WA, Whiteman JP, Cooper-Mullin C, Newsome SD, McWilliams SR. Dynamics of Individual Fatty Acids in Muscle Fat Stores and Membranes of a Songbird and Its Functional and Ecological Importance. Physiol Biochem Zool 2019; 92:239-251. [PMID: 30741598 DOI: 10.1086/702667] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although tissue fatty acid (FA) composition has been linked to whole-animal performance (e.g., aerobic endurance, metabolic rate, postexercise recovery) in a wide range of animal taxa, we do not adequately understand the pace of changes in FA composition and its implications for the ecology of animals. Therefore, we used a C4 to C3 diet shift experiment and compound-specific δ13C analysis to estimate the turnover rates of FAs in the polar and neutral fractions of flight muscle lipids (corresponding to membranes and lipid droplets) of exercised and sedentary zebra finches (Taeniopygia guttata). Turnover was fastest for linoleic acid (LA; 18:2n6) and palmitic acid (PA; 16:0), with 95% replacement times of 10.8-17.7 d in the polar fraction and 17.2-32.8 d in the neutral fraction, but was unexpectedly slow for the long-chain polyunsaturated FAs (LC-PUFAs) arachidonic acid (20:4n6) and docosahexaenoic acid (22:6n3) in the polar fraction, with 95% replacement in 64.9-136.5 d. Polar fraction LA and PA turnover was significantly faster in exercised birds (95% replacement in 8.5-13.3 d). Our results suggest that FA turnover in intramuscular lipid droplets is related to FA tissue concentrations and that turnover does not change in response to exercise. In contrast, we found that muscle membrane FA turnover is likely driven by a combination of selective LC-PUFA retention and consumption of shorter-chain FAs in energy metabolism. The unexpectedly fast turnover of membrane-associated FAs in muscle suggests that songbirds during migration could substantially remodel their membranes within a single migration stopover, and this may have substantial implications for how the FA composition of diet affects energy metabolism of birds during migration.
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20
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Dick MF, Guglielmo CG. Flight muscle protein damage during endurance flight is related to energy expenditure but not dietary polyunsaturated fatty acids in a migratory bird. ACTA ACUST UNITED AC 2019; 222:222/5/jeb187708. [PMID: 30824569 DOI: 10.1242/jeb.187708] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/28/2018] [Indexed: 12/14/2022]
Abstract
Migration poses many physiological challenges for birds, including sustaining high intensity aerobic exercise for hours or days. A consequence of endurance flight is the production of reactive oxygen species (ROS). ROS production may be influenced by dietary polyunsaturated fatty acids (PUFA), which, although prone to oxidative damage, may limit mitochondrial ROS production and increase antioxidant capacity. We examined how flight muscles manage oxidative stress during flight, and whether dietary long-chain PUFA influence ROS management or damage. Yellow-rumped warblers were fed diets low in PUFA, or high in long-chain n-3 or n-6 PUFA. Flight muscle was sampled from birds in each diet treatment at rest or immediately after flying for up to a maximum of 360 min in a wind tunnel. Flight increased flight muscle superoxide dismutase activity but had no effect on catalase activity. The ratio of glutathione to glutathione disulphide decreased during flight. Oxidative protein damage, indicated by protein carbonyls, increased with flight duration (Pearson r=0.4). Further examination of just individuals that flew for 360 min (N=15) indicates that oxidative damage was related more to total energy expenditure (Pearson r=0.86) than to flight duration itself. This suggests that high quality individuals with higher flight efficiency have not only lower energy costs but also potentially less oxidative damage to repair after arrival at the destination. No significant effects of dietary long-chain PUFA were observed on antioxidants or damage. Overall, flight results in oxidative stress and the degree of damage is likely driven more by energy costs than fatty acid nutrition.
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Affiliation(s)
- Morag F Dick
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada, N6A 5B7
| | - Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada, N6A 5B7
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21
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Dick MF, Guglielmo CG. Dietary polyunsaturated fatty acids influence flight muscle oxidative capacity but not endurance flight performance in a migratory songbird. Am J Physiol Regul Integr Comp Physiol 2019; 316:R362-R375. [PMID: 30624975 DOI: 10.1152/ajpregu.00206.2018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The migratory flights of birds are primarily fueled by fat; however, certain fatty acids may also enhance flight performance and the capacity to oxidize fat. The natural doping hypothesis posits that n-3 long-chain polyunsaturated fatty acids (PUFA) increase membrane fluidity and aerobic and fatty acid oxidative enzymes in the flight muscles, which enables prolonged endurance flight. Support for this hypothesis is mixed, and there is no empirical evidence for increased flight performance. We fed yellow-rumped warblers ( Setophaga coronata coronata) diets enriched in either n-3 or n-6 long-chain PUFA or low in long-chain PUFA and evaluated flight muscle metabolism and endurance performance in a wind tunnel flights lasting up to 6 h. Fatty acid profiles of muscle phospholipids confirmed enrichment of the targeted dietary fatty acids, whereas less substantial differences were observed in adipose triacylglycerol. Contrary to the predictions, feeding n-3 PUFA decreased peroxisome proliferator-activated receptors-β mRNA abundance and muscle oxidative enzyme activities. However, changes in muscle metabolism were not reflected in whole animal performance. No differences were observed in flight performance among diet treatments in terms of endurance capacity, energy costs, or fuel composition. These measures of flight performance were more strongly influenced by body mass and flight duration. Overall, we found no support for the natural doping hypothesis in a songbird. Furthermore, we caution against extending changes in flight muscle metabolic enzymes or fatty acid composition to changes to migratory performance without empirical evidence.
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Affiliation(s)
- Morag F Dick
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario , London, Ontario , Canada
| | - Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario , London, Ontario , Canada
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22
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Hamilton A, Ly J, Robinson JR, Corder KR, DeMoranville KJ, Schaeffer PJ, Huss JM. Conserved transcriptional activity and ligand responsiveness of avian PPARs: Potential role in regulating lipid metabolism in mirgratory birds. Gen Comp Endocrinol 2018; 268:110-120. [PMID: 30114400 DOI: 10.1016/j.ygcen.2018.08.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 06/18/2018] [Accepted: 08/07/2018] [Indexed: 01/04/2023]
Abstract
Migratory birds undergo metabolic remodeling in tissues, including increased lipid storage in white adipose and fatty acid uptake and oxidation in skeletal muscle, to optimize energy substrate availability and utilization in preparation for long-distance flight. Different tissues undergo gene expression changes in keeping with their specialized functions and driven by tissue specific transcriptional pathways. Peroxisome proliferator-activated receptors (PPARs) are lipid-activated nuclear receptors that regulate metabolic pathways involved in lipid and glucose utilization or storage in mammals. To examine whether PPARs might mediate fatty acid activation of metabolic gene programs that would be relevant during pre-migratory fattening, we used gray catbird as the focal species. PPAR isoforms cloned from catbird share high amino acid identity with mammalian homologs (% vs human): gcPPARα (88.1%), gcPPARδ (87.3%), gcPPARγ (91.2%). We tested whether gcPPARs activated fatty acid (FA) utilization genes using Lpl and Cpt1b gene promoter-luciferase reporters in mammalian cell lines. In C2C12 mouse myocytes gcPPARα was broadly activated by the saturated and unsaturated FAs tested; while gcPPARδ showed highest activation by the mono-unsaturated FA, 18:1 oleic acid (+80%). In CV-1 monkey kidney cells gcPPARγ responded to the poly-unsaturated fatty acid, 20:5 eicosapentaenoic acid (+60%). Moreover, in agreement with their structural conservation, gcPPARs were activated by isoform selective synthetic agonists similar to the respective mammalian isoform. Adenoviral mediated over-expression of PPARα in C2C12 myocytes induced expression of genes involved in fatty acid transport, including Cd36/Fat, as well as Cpt1b, which mediates a key rate limiting step of mitochondrial β-oxidation. These gene expression changes correlated with increased lipid droplet accumulation in C2C12 myoblasts and differentiated myotubes and enhanced β-oxidation in myotubes. Collectively, the data predict that the PPARs play a conserved role in gray catbirds to regulate lipid metabolism in target tissues that undergo metabolic remodeling throughout the annual migratory cycle.
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Affiliation(s)
- Angelica Hamilton
- Department of Molecular and Cellular Endocrinology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Jennifer Ly
- Department of Molecular and Cellular Endocrinology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Jasmine R Robinson
- Department of Molecular and Cellular Endocrinology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Keely R Corder
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | | | | | - Janice M Huss
- Department of Molecular and Cellular Endocrinology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA.
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23
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Yap KN, Serota MW, Williams TD. The Physiology of Exercise in Free-Living Vertebrates: What Can We Learn from Current Model Systems? Integr Comp Biol 2018; 57:195-206. [PMID: 28662569 DOI: 10.1093/icb/icx016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
SYNOPSIS Many behaviors crucial for survival and reproductive success in free-living animals, including migration, foraging, and escaping from predators, involve elevated levels of physical activity. However, although there has been considerable interest in the physiological and biomechanical mechanisms that underpin individual variation in exercise performance, to date, much work on the physiology of exercise has been conducted in laboratory settings that are often quite removed from the animal's ecology. Here we review current, laboratory-based model systems for exercise (wind or swim tunnels for migration studies in birds and fishes, manipulation of exercise associated with non-migratory activity in birds, locomotion in lizards, and wheel running in rodents) to identify common physiological markers of individual variation in exercise capacity and/or costs of increased activity. Secondly, we consider how physiological responses to exercise might be influenced by (1) the nature of the activity (i.e., voluntary or involuntary, intensity, and duration), and (2) resource acquisition and food availability, in the context of routine activities in free-living animals. Finally, we consider evidence that the physiological effects of experimentally-elevated activity directly affect components of fitness such as reproduction and survival. We suggest that developing more ecologically realistic laboratory systems, incorporating resource-acquisition, functional studies across multiple physiological systems, and a life-history framework, with reproduction and survival end-points, will help reveal the mechanisms underlying the consequences of exercise, and will complement studies in free-living animals taking advantage of new developments in wildlife-tracking.
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Affiliation(s)
- Kang Nian Yap
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British V5A 1S6, Canada, Columbia
| | - Mitchell W Serota
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British V5A 1S6, Canada, Columbia
| | - Tony D Williams
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British V5A 1S6, Canada, Columbia
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24
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Carter WA, Cooper-Mullin C, McWilliams SR. Turnover of muscle lipids and response to exercise differ between neutral and polar fractions in a model songbird, the zebra finch. ACTA ACUST UNITED AC 2018; 221:jeb.168823. [PMID: 29444847 DOI: 10.1242/jeb.168823] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 02/01/2018] [Indexed: 01/12/2023]
Abstract
The turnover rates of tissues and their constituent molecules give us insights into animals' physiological demands and their functional flexibility over time. Thus far, most studies of this kind have focused on protein turnover, and few have considered lipid turnover despite an increasing appreciation of the functional diversity of this class of molecules. We measured the turnover rates of neutral and polar lipids from the pectoralis muscles of a model songbird, the zebra finch (Taeniopygia guttata, N=65), in a 256 day C3/C4 diet shift experiment, with tissue samples taken at 10 time points. We also manipulated the physiological state of a subset of these birds with a 10 week flight training regimen to test the effect of exercise on lipid turnover. We measured lipid δ13C values via isotope ratio mass spectrometry (IRMS) and estimated turnover in different fractions and treatment groups with non-linear mixed-effect regression. We found a significant difference between the mean retention times (τ) of neutral and polar lipids (t119=-2.22, P=0.028), with polar lipids (τ=11.80±1.28 days) having shorter retention times than neutral lipids (τ=19.47±3.22 days). When all birds were considered, we also found a significant decrease in the mean retention time of polar lipids in exercised birds relative to control birds (difference=-2.2±1.83 days, t56=-2.37, P=0.021), but not neutral lipids (difference=4.2± 7.41 days, t56=0.57, P=0.57). A larger, more variable neutral lipid pool and the exposure of polar lipids in mitochondrial membranes to oxidative damage and increased turnover provide mechanisms consistent with our results.
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Affiliation(s)
- Wales A Carter
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
| | - Clara Cooper-Mullin
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
| | - Scott R McWilliams
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
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Abstract
Migratory birds are physiologically specialized to accumulate massive fat stores (up to 50-60% of body mass), and to transport and oxidize fatty acids at very high rates to sustain flight for many hours or days. Target gene, protein and enzyme analyses and recent -omic studies of bird flight muscles confirm that high capacities for fatty acid uptake, cytosolic transport, and oxidation are consistent features that make fat-fueled migration possible. Augmented circulatory transport by lipoproteins is suggested by field data but has not been experimentally verified. Migratory bats have high aerobic capacity and fatty acid oxidation potential; however, endurance flight fueled by adipose-stored fat has not been demonstrated. Patterns of fattening and expression of muscle fatty acid transporters are inconsistent, and bats may partially fuel migratory flight with ingested nutrients. Changes in energy intake, digestive capacity, liver lipid metabolism and body temperature regulation may contribute to migratory fattening. Although control of appetite is similar in birds and mammals, neuroendocrine mechanisms regulating seasonal changes in fuel store set-points in migrants remain poorly understood. Triacylglycerol of birds and bats contains mostly 16 and 18 carbon fatty acids with variable amounts of 18:2n-6 and 18:3n-3 depending on diet. Unsaturation of fat converges near 70% during migration, and unsaturated fatty acids are preferentially mobilized and oxidized, making them good fuel. Twenty and 22 carbon n-3 and n-6 polyunsaturated fatty acids (PUFA) may affect membrane function and peroxisome proliferator-activated receptor signaling. However, evidence for dietary PUFA as doping agents in migratory birds is equivocal and requires further study.
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Affiliation(s)
- Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada N6A5B7
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26
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Price ER, Sirsat TS, Sirsat SKG, Curran T, Venables BJ, Dzialowski EM. The membrane pacemaker hypothesis: novel tests during the ontogeny of endothermy. J Exp Biol 2018; 221:jeb.174466. [DOI: 10.1242/jeb.174466] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/14/2018] [Indexed: 01/09/2023]
Abstract
The ‘membrane pacemaker’ hypothesis proposes a biochemical explanation for among-species variation in resting metabolism, based on the positive correlation between membrane docosahexaenoic acid (DHA) and metabolic rate. We tested this hypothesis using a novel model, altricial red-winged blackbird nestlings, predicting that the proportion of DHA in muscle and liver membranes should increase with the increasing metabolic rate of the nestling as it develops endothermy. We also used a dietary manipulation, supplementing the natural diet with fish oil (high DHA) or sunflower oil (high linoleic acid) to alter membrane composition and then assessed metabolic rate. In support of the membrane pacemaker hypothesis, DHA proportions increased in membranes from pectoralis muscle, muscle mitochondria, and liver during post-hatch development. By contrast, elevated dietary DHA had no effect on resting metabolic rate, despite causing significant changes to membrane lipid composition. During cold challenges, higher metabolic rates were achieved by birds that had lower DHA and higher linoleic acid in membrane phospholipids. Given the mixed support for this hypothesis, we conclude that correlations between membrane DHA and metabolic rate are likely spurious, and should be attributed to a still-unidentified confounding variable.
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Affiliation(s)
- Edwin R. Price
- Department of Biological Sciences, University of North Texas, Denton TX, 76201, USA
| | - Tushar S. Sirsat
- Department of Biological Sciences, University of North Texas, Denton TX, 76201, USA
- Current address: Department of Biology, State University of New York Potsdam, Potsdam NY 13676, USA
| | - Sarah K. G. Sirsat
- Department of Biological Sciences, University of North Texas, Denton TX, 76201, USA
- Current address: Department of Biology, State University of New York Potsdam, Potsdam NY 13676, USA
| | - Thomas Curran
- Department of Biological Sciences, University of North Texas, Denton TX, 76201, USA
| | - Barney J. Venables
- Department of Biological Sciences, University of North Texas, Denton TX, 76201, USA
| | - Edward M. Dzialowski
- Department of Biological Sciences, University of North Texas, Denton TX, 76201, USA
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Cooper-Mullin C, McWilliams SR. The role of the antioxidant system during intense endurance exercise: lessons from migrating birds. ACTA ACUST UNITED AC 2017; 219:3684-3695. [PMID: 27903627 DOI: 10.1242/jeb.123992] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During migration, birds substantially increase their metabolic rate and burn fats as fuel and yet somehow avoid succumbing to overwhelming oxidative damage. The physiological means by which vertebrates such as migrating birds can counteract an increased production of reactive species (RS) are rather limited: they can upregulate their endogenous antioxidant system and/or consume dietary antioxidants (prophylactically or therapeutically). Thus, birds can alter different components of their antioxidant system to respond to the demands of long-duration flights, but much remains to be discovered about the complexities of RS production and antioxidant protection throughout migration. Here, we use bird migration as an example to discuss how RS are produced during endurance exercise and how the complex antioxidant system can protect against cellular damage caused by RS. Understanding how a bird's antioxidant system responds during migration can lend insights into how antioxidants protect birds during other life-history stages when metabolic rate may be high, and how antioxidants protect other vertebrates from oxidative damage during endurance exercise.
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Affiliation(s)
- Clara Cooper-Mullin
- The Department of Natural Resources Science, The University of Rhode Island, 105 Coastal Institute, 1 Greenhouse Road, Kingston, RI 02881, USA
| | - Scott R McWilliams
- The Department of Natural Resources Science, The University of Rhode Island, 105 Coastal Institute, 1 Greenhouse Road, Kingston, RI 02881, USA
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Quinn J, Hamilton D, Hebert C. Fatty acid composition and concentration of alternative food of Semipalmated Sandpipers (Calidris pusilla) in the upper Bay of Fundy, Canada. CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0246] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Semipalmated Sandpipers (Calidris pusilla (L., 1766)) that migrate through the upper Bay of Fundy, Canada, depend on a rich food supply to fuel their continued migration. Although past studies have reported a diet dominated by the amphipod Corophium volutator (Pallas, 1766), an animal rich in n–3 polyunsaturated fatty acids (PUFAs), recent evidence suggests that sandpiper diets are broad. This is beneficial in that it allows Semipalmated Sandpipers to respond to a changing food base, but quality of food is also important. PUFAs are important in providing the energy required by migrating birds and may play a role in migratory preparation. We assessed fatty acid (FA) concentrations and proportions in three common food items. We found that polychaetes should adequately meet the needs of migrating sandpipers in terms of FA composition. Concentrations of FAs in biofilm were low, but proportionally, n–3 PUFAs were well represented, particularly in biofilm collected in Shepody Bay, where it forms a substantial part of the sandpiper diet. Therefore, provided that birds can consume a sufficient volume of biofilm, it is also probably a suitable source of essential FAs. Our results suggest that Semipalmated Sandpipers in the Bay of Fundy can meet their FA needs with a variety of dietary options.
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Affiliation(s)
- J.T. Quinn
- Department of Biology, Mount Allison University, 63B York Street, Sackville, NB E4L 1G7, Canada
| | - D.J. Hamilton
- Department of Biology, Mount Allison University, 63B York Street, Sackville, NB E4L 1G7, Canada
| | - C.E. Hebert
- Environment and Climate Change Canada, Science and Technology Branch, National Wildlife Research Centre, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
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McCue MD, Albach A, Salazar G. Previous Repeated Exposure to Food Limitation Enables Rats to Spare Lipid Stores during Prolonged Starvation. Physiol Biochem Zool 2017; 90:63-74. [PMID: 28051943 DOI: 10.1086/689323] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The risk of food limitation and, ultimately, starvation dates back to the dawn of heterotrophy in animals, yet starvation remains a major factor in the regulation of modern animal populations. Researchers studying starvation more than a century ago suggested that animals subjected to sublethal periods of food limitation are somehow more tolerant of subsequent starvation events. This possibility has received little attention over the past decades, yet it is highly relevant to modern science for two reasons. First, animals in natural populations are likely to be exposed to bouts of food limitation once or more before they face prolonged starvation, during which the risk of mortality becomes imminent. Second, our current approach to studying starvation physiology in the laboratory focuses on nourished animals with no previous exposure to nutritional stress. We examined the relationship between previous exposure to food limitation and potentially adaptive physiological responses to starvation in adult rats and found several significant differences. On two occasions, rats were fasted until they lost 20% of their body mass maintained lower body temperatures, and had presumably lower energy requirements when subjected to prolonged starvation than their naive cohort that never experienced food limitation. These rats that were trained in starvation also had lower plasma glucose set -points and reduced their reliance on endogenous lipid oxidation. These findings underscore (1) the need for biologists to revisit the classic hypothesis that animals can become habituated to starvation, using a modern set of research tools; and (2) the need to design controlled experiments of starvation physiology that more closely resemble the dynamic nature of food availability.
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Viegas I, Araújo PM, Rocha AD, Villegas A, Jones JG, Ramos JA, Masero JA, Alves JA. Metabolic plasticity for subcutaneous fat accumulation in a long distance migratory bird traced by 2H2O. J Exp Biol 2017; 220:1072-1078. [DOI: 10.1242/jeb.150490] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 12/30/2016] [Indexed: 11/20/2022]
Abstract
The migrant black-tailed godwit (Limosa limosa) traditionally used natural wetlands in the Iberian Peninsula preparing for migratory flights by feeding mainly in estuaries. In recent decades this species has become increasingly dependent on rice fields, thereby relying on a plant-based diet for fueling. Dietary fatty acids (FA) seem to be determinant to the composition of accumulated subcutaneous fat in migratory birds. It is still unclear whether metabolic plasticity allows for modification and/or synthesis of FA, contributing for a lipid profile that enables a successful migratory performance.
Deuterated water was administered to captive black-tailed godwits submitted to two diets (fly larvae vs. rice) and the incorporation of deuterium (2H) into subcutaneous triglycerides was analysed by NMR. A recently developed localized biopsy method for sampling subcutaneous fat was employed with ulterior successful release of all birds into the wild. The average chemical structure reflected mostly a mixture of saturated and monounsaturated 16- and 18-carbon FA, a profile frequently found in migrant birds. Significantly higher levels of polyunsaturated FA, as well as detectable levels of n-3 FA were observed in fly larvae-fed birds. Excess 2H-enrichments in FA revealed significantly higher rates of fractional de novo lipogenesis and FA desaturation capacity in rice-fed birds.
This novel and non-lethal tracer method revealed the capacity of this species to alter its lipid metabolism to compensate for a poorer dietary lipid contribution. Due to its versatility, adapting this method to other scenarios and/or other migratory species is considered feasible and cost-effective.
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Affiliation(s)
- Ivan Viegas
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
- CFE - Center for Functional Ecology, Department Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Pedro M. Araújo
- MARE – Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Afonso D. Rocha
- MARE – Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Auxiliadora Villegas
- Conservation Biology Research Group, Área de Zoología, Universidad de Extremadura, Avenida de Elvas s/n, 06071 Badajoz, Spain
| | - John G. Jones
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Jaime A. Ramos
- MARE – Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - José A. Masero
- Conservation Biology Research Group, Área de Zoología, Universidad de Extremadura, Avenida de Elvas s/n, 06071 Badajoz, Spain
| | - José A. Alves
- CESAM, Dep. Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3180-193 Aveiro, Portugal
- University of Iceland, South Iceland Research Centre, Fjölheimer, Bankavegur IS-800 Selfoss, Iceland
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Abstract
The skeletal muscle phenotype is subject to considerable malleability depending on use as well as internal and external cues. In humans, low-load endurance-type exercise leads to qualitative changes of muscle tissue characterized by an increase in structures supporting oxygen delivery and consumption, such as capillaries and mitochondria. High-load strength-type exercise leads to growth of muscle fibers dominated by an increase in contractile proteins. In endurance exercise, stress-induced signaling leads to transcriptional upregulation of genes, with Ca(2+) signaling and the energy status of the muscle cells sensed through AMPK being major input determinants. Several interrelated signaling pathways converge on the transcriptional co-activator PGC-1α, perceived to be the coordinator of much of the transcriptional and post-transcriptional processes. Strength training is dominated by a translational upregulation controlled by mTORC1. mTORC1 is mainly regulated by an insulin- and/or growth-factor-dependent signaling cascade as well as mechanical and nutritional cues. Muscle growth is further supported by DNA recruitment through activation and incorporation of satellite cells. In addition, there are several negative regulators of muscle mass. We currently have a good descriptive understanding of the molecular mechanisms controlling the muscle phenotype. The topology of signaling networks seems highly conserved among species, with the signaling outcome being dependent on the particular way individual species make use of the options offered by the multi-nodal networks. As a consequence, muscle structural and functional modifications can be achieved by an almost unlimited combination of inputs and downstream signaling events.
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Affiliation(s)
- Hans Hoppeler
- Emeritus Department of Anatomy, University of Bern, Baltzerstrasse 2, Bern 9 CH-3000, Switzerland
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32
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How essential fats affect bird performance and link aquatic ecosystems and terrestrial consumers. Proc Natl Acad Sci U S A 2016; 113:11988-11990. [PMID: 27790978 DOI: 10.1073/pnas.1614106113] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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33
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Gladyshev MI, Popova ON, Makhutova ON, Zinchenko TD, Golovatyuk LV, Yurchenko YA, Kalachova GS, Krylov AV, Sushchik NN. Comparison of fatty acid compositions in birds feeding in aquatic and terrestrial ecosystems. CONTEMP PROBL ECOL+ 2016. [DOI: 10.1134/s1995425516040065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
While the words “fit” and “healthy” are often used synonymously in everyday language, the terms have entirely separate meanings. Fitness describes the ability to perform a given exercise task, and health explains a person’s state of well-being, where physiological systems work in harmony. Although we typically view athletes as fit and healthy, they often are not. The global term we place on unhealthy athletes is the overtraining syndrome. In this current opinion, we propose that two primary drivers may contribute to the development of the overtraining syndrome, namely high training intensity and the modern-day highly processed, high glycemic diet. Both factors elicit a sympathetic response through the hypothalamic-pituitary-adrenal axis, in turn driving systemic reactive oxygen species production, inflammation, and a metabolic substrate imbalance towards carbohydrate and away from fat oxidation, manifesting in an array of symptoms often labeled as the overtraining syndrome. Ultimately, these symptoms reveal an unhealthy athlete. We argue that practitioners, scientists, and athletes may work towards health and alleviate overtraining syndrome by lowering training intensity and removing processed and/or high glycemic foods from the diet, which together enhance fat oxidation rates. Athletes should be fit and healthy.
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Williams JB. The (Mostly) Good, the (Few) Bad, and the (Couple of) Ugly Chapters in Sturkie’s Avian PhysiologySturkie’s Avian Physiology. Edited by Colin G. Scanes. Waltham, MA: Academic Press, 2014. ISBN 978-0-124-07160-5. Physiol Biochem Zool 2015. [DOI: 10.1086/682700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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36
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Schai-Braun SC, Reichlin TS, Ruf T, Klansek E, Tataruch F, Arnold W, Hackländer K. The European Hare (Lepus europaeus): A Picky Herbivore Searching for Plant Parts Rich in Fat. PLoS One 2015; 10:e0134278. [PMID: 26230115 PMCID: PMC4521881 DOI: 10.1371/journal.pone.0134278] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/26/2015] [Indexed: 11/18/2022] Open
Abstract
European hares of both sexes rely on fat reserves, particularly during the reproduc-tive season. Therefore, hares should select dietary plants rich in fat and energy. However, hares also require essential polyunsaturated fatty acids (PUFA) such as linoleic acid (LA) and alpha-linolenic acid (ALA) to reproduce and survive. Although hares are able to absorb PUFA selectively in their gastrointestinal tract, it is unknown whether this mechanism is sufficient to guarantee PUFA supply. Thus, diet selection may involve a trade-off between a preference for energy versus a preference for crucial nutrients, namely PUFA. We compared plant and nutrient availability and use by hares in an arable landscape in Austria over three years. We found that European hares selected their diet for high energy content (crude fat and crude protein), and avoided crude fibre. There was no evidence of a preference for plants rich in LA and ALA. We conclude that fat is the limiting resource for this herbivorous mammal, whereas levels of LA and ALA in forage are sufficiently high to meet daily requirements, especially since their uptake is enhanced by physiological mechanisms. Animals selected several plant taxa all year round, and preferences did not simply correlate with crude fat content. Hence, European hares might not only select for plant taxa rich in fat, but also for high-fat parts of preferred plant taxa. As hares preferred weeds/grasses and various crop types while avoiding cereals, we suggest that promoting heterogeneous habitats with high crop diversity and set-asides may help stop the decline of European hares throughout Europe.
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Affiliation(s)
- Stéphanie C. Schai-Braun
- Department of Integrative Biology and Biodiversity Research, Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
- * E-mail:
| | - Thomas S. Reichlin
- Division of Animal Welfare, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Vienna, Austria
| | - Erich Klansek
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Vienna, Austria
| | - Frieda Tataruch
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Vienna, Austria
| | - Walter Arnold
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Vienna, Austria
| | - Klaus Hackländer
- Department of Integrative Biology and Biodiversity Research, Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
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Seasonal metabolic variation over two years in an Afrotropical passerine bird. J Therm Biol 2015; 52:58-66. [PMID: 26267499 DOI: 10.1016/j.jtherbio.2015.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/14/2015] [Accepted: 05/14/2015] [Indexed: 11/21/2022]
Abstract
Seasonal trends in metabolic parameters are well established in avian populations from highly seasonal environments, however, seasonal trends in metabolism of birds from lower latitudes (and of Afrotropical birds in particular) are not well understood. We investigated seasonal trends in metabolism for a small (10-12g) Afrotropical bird, the Cape White-eye (Zosterops virens), using flow-through respirometry in two summers and two winters. There was no seasonal difference in body mass between consecutive seasons. The lower critical limit of thermoneutrality was lower in winter (23°C) than in summer (28°C), as expected for a small Afrotropical bird. In the first year of the study, mean whole animal basal metabolic rate (BMR) of Cape White-eyes was significantly lower in winter than in summer, while in the second year of the study this trend was reversed, and in the middle two seasons there was no significant difference in BMR. Differences in mean temperature and mean rainfall between seasons could not account for the seasonal trends in BMR. We conclude that seasonal trends in avian BMR may vary between years, within a population.
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Arnold W, Giroud S, Valencak TG, Ruf T. Ecophysiology of Omega Fatty Acids: A Lid for Every Jar. Physiology (Bethesda) 2015; 30:232-40. [DOI: 10.1152/physiol.00047.2014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Omega fatty acids affect various physiological functions, such as locomotion, cardiac function, and thermogenesis. We highlight evidence from animal models that points to pathways by which specific omega fatty acids exert differential effects. We suggest that optimizing the omega fatty acid composition of tissues involves trade-offs between costs and benefits of specific fatty acids.
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Affiliation(s)
- Walter Arnold
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Austria
| | - Sylvain Giroud
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Austria
| | - Teresa G. Valencak
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Austria
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Austria
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