1
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Hardison EA, Eliason EJ. Diet effects on ectotherm thermal performance. Biol Rev Camb Philos Soc 2024. [PMID: 38616524 DOI: 10.1111/brv.13081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 03/20/2024] [Accepted: 03/26/2024] [Indexed: 04/16/2024]
Abstract
The environment is changing rapidly, and considerable research is aimed at understanding the capacity of organisms to respond. Changes in environmental temperature are particularly concerning as most animals are ectothermic, with temperature considered a key factor governing their ecology, biogeography, behaviour and physiology. The ability of ectotherms to persist in an increasingly warm, variable, and unpredictable future will depend on their nutritional status. Nutritional resources (e.g. food availability, quality, options) vary across space and time and in response to environmental change, but animals also have the capacity to alter how much they eat and what they eat, which may help them improve their performance under climate change. In this review, we discuss the state of knowledge in the intersection between animal nutrition and temperature. We take a mechanistic approach to describe nutrients (i.e. broad macronutrients, specific lipids, and micronutrients) that may impact thermal performance and discuss what is currently known about their role in ectotherm thermal plasticity, thermoregulatory behaviour, diet preference, and thermal tolerance. We finish by describing how this topic can inform ectotherm biogeography, behaviour, and aquaculture research.
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Affiliation(s)
- Emily A Hardison
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, 93106, USA
| | - Erika J Eliason
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, 93106, USA
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2
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Gill LT, Kennedy JR, Marshall KE. Proteostasis in ice: the role of heat shock proteins and ubiquitin in the freeze tolerance of the intertidal mussel, Mytilus trossulus. J Comp Physiol B 2023; 193:155-169. [PMID: 36593419 DOI: 10.1007/s00360-022-01473-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 12/09/2022] [Accepted: 12/19/2022] [Indexed: 01/03/2023]
Abstract
The bay mussel, Mytilus trossulus, is an animal that can survive extracellular ice formation. Depending on air and ocean temperatures, freeze tolerant intertidal organisms, like M. trossulus, may freeze and thaw many times during the winter. Freezing can cause protein denaturation, leading to an induction of the heat shock response with expression of chaperone proteins like the 70 kDa heat shock protein (HSP70), and an increase in ubiquitin-conjugated proteins. There has been little work on the mechanisms of freeze tolerance in intertidal species, limiting our understanding of this survival strategy. Additionally, this limited research has focused solely on the effects of single freezing events, but the act of repeatedly crossing the freezing threshold may present novel physiological or biochemical stressors that have yet to be discovered. Mytilus are important ecosystem engineers and provide habitat for other intertidal species, thus understanding their physiology under thermal extremes is important for preserving shoreline health. We predicted that repeated freeze exposures would increase mortality, upregulate HSP70 expression, and increase ubiquitin conjugates in mussels, relative to single, prolonged freeze exposures. Mytilus trossulus from Vancouver, Canada were repeatedly frozen for a combination of 1 × 8 h, 2 × 4 h, or 4 × 2 h. We then compared mortality, HSP70 expression, and the quantity of ubiquitin-conjugated proteins across experimental groups. We found a single 8-h freeze caused significantly more mortality than repeated freeze-thaw cycles. We also found that HSP70 and ubiquitinated protein was upregulated exclusively after freeze-thaw cycles, suggesting that freeze-thaw cycles offer a period of damage repair between freezes. This indicates that freeze-thaw cycles, which happen naturally in the intertidal, are crucial for M. trossulus survival in sub-zero temperatures.
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Affiliation(s)
- Lauren T Gill
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Jessica R Kennedy
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Katie E Marshall
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada.
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3
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Georgoulis I, Bock C, Lannig G, Pörtner HO, Feidantsis K, Giantsis IA, Sokolova IM, Michaelidis B. Metabolic remodeling caused by heat hardening in the Mediterranean mussel Mytilus galloprovincialis. J Exp Biol 2022; 225:285988. [PMID: 36426666 DOI: 10.1242/jeb.244795] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022]
Abstract
Organisms can modify and increase their thermal tolerance faster and more efficiently after a brief exposure to sublethal thermal stress. This response is called 'heat hardening' as it leads to the generation of phenotypes with increased heat tolerance. The aim of this study was to investigate the impact of heat hardening on the metabolomic profile of Mytilus galloprovincialis in order to identify the associated adjustments of biochemical pathways that might benefit the mussels' thermal tolerance. Thus, mussels were exposed sequentially to two different phases (heat hardening and acclimation phases). To gain further insight into the possible mechanisms underlying the metabolic response of the heat-hardened M. galloprovincialis, metabolomics analysis was complemented by the estimation of mRNA expression of phosphoenolpyruvate carboxykinase (PEPCK), pyruvate kinase (PK) and alternative oxidase (AOX) implicated in the metabolic pathways of gluconeogenesis, glycolysis and redox homeostasis, respectively. Heat-hardened mussels showed evidence of higher activity of the tricarboxylic acid (TCA) cycle and diversification of upregulated metabolic pathways, possibly as a mechanism to increase ATP production and extend survival under heat stress. Moreover, formate and taurine accumulation provide an antioxidant and cytoprotective role in mussels during hypoxia and thermal stress. Overall, the metabolic responses in non-heat-hardened and heat-hardened mussels underline the upper thermal limits of M. galloprovincialis, set at 26°C, and are in accordance with the OCLTT concept. The ability of heat-hardened mussels to undergo a rapid gain and slow loss of heat tolerance may be an advantageous strategy for coping with intermittent and often extreme temperatures.
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Affiliation(s)
- Ioannis Georgoulis
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
| | - Christian Bock
- Alfred Wegener Institute, Helmholtz-Centre for Polar and Marine Research, Integrative Ecophysiology, Postfach 120161, D-27515 Bremerhaven, Germany
| | - Gisela Lannig
- Alfred Wegener Institute, Helmholtz-Centre for Polar and Marine Research, Integrative Ecophysiology, Postfach 120161, D-27515 Bremerhaven, Germany
| | - Hans-O Pörtner
- Alfred Wegener Institute, Helmholtz-Centre for Polar and Marine Research, Integrative Ecophysiology, Postfach 120161, D-27515 Bremerhaven, Germany
| | - Konstantinos Feidantsis
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
| | - Ioannis A Giantsis
- Department of Animal Science, Faculty of Agricultural Sciences, University of Western Macedonia, GR-53100 Florina, Greece
| | - Inna M Sokolova
- Department of Marine Biology, Institute of Biological Sciences, University of Rostock, D-18055 Rostock, Germany
| | - Basile Michaelidis
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
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4
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Somero GN. Solutions: how adaptive changes in cellular fluids enable marine life to cope with abiotic stressors. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:389-413. [PMID: 37073170 PMCID: PMC10077225 DOI: 10.1007/s42995-022-00140-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/15/2022] [Indexed: 05/03/2023]
Abstract
The seas confront organisms with a suite of abiotic stressors that pose challenges for physiological activity. Variations in temperature, hydrostatic pressure, and salinity have potential to disrupt structures, and functions of all molecular systems on which life depends. During evolution, sequences of nucleic acids and proteins are adaptively modified to "fit" these macromolecules for function under the particular abiotic conditions of the habitat. Complementing these macromolecular adaptations are alterations in compositions of solutions that bathe macromolecules and affect stabilities of their higher order structures. A primary result of these "micromolecular" adaptations is preservation of optimal balances between conformational rigidity and flexibility of macromolecules. Micromolecular adaptations involve several families of organic osmolytes, with varying effects on macromolecular stability. A given type of osmolyte generally has similar effects on DNA, RNA, proteins and membranes; thus, adaptive regulation of cellular osmolyte pools has a global effect on macromolecules. These effects are mediated largely through influences of osmolytes and macromolecules on water structure and activity. Acclimatory micromolecular responses are often critical in enabling organisms to cope with environmental changes during their lifetimes, for example, during vertical migration in the water column. A species' breadth of environmental tolerance may depend on how effectively it can vary the osmolyte composition of its cellular fluids in the face of stress. Micromolecular adaptations remain an under-appreciated aspect of evolution and acclimatization. Further study can lead to a better understanding of determinants of environmental tolerance ranges and to biotechnological advances in designing improved stabilizers for biological materials.
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Affiliation(s)
- George N. Somero
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 USA
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5
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Somero GN. The Goldilocks Principle: A Unifying Perspective on Biochemical Adaptation to Abiotic Stressors in the Sea. ANNUAL REVIEW OF MARINE SCIENCE 2022; 14:1-23. [PMID: 34102065 DOI: 10.1146/annurev-marine-022521-102228] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The ability of marine organisms to thrive over wide ranges of environmental stressors that perturb structures of proteins, nucleic acids, and lipids illustrates the effectiveness of adaptation at the biochemical level. A critical role of these adaptations is to achieve a proper balance between structural rigidity, which is necessary for maintaining three-dimensional conformation, and flexibility, which is required to allow changes in conformation during function. The Goldilocks principle refers to this balancing act, wherein structural stability and functional properties are poised at values that are just right for the environment the organism faces. Achieving this balance involves changes in macromolecular sequence and adaptive change in the composition of the aqueous or lipid milieu in which macromolecules function. This article traces the development of the field of biochemical adaptation throughout my career and shows how comparative studies of marine animals from diverse habitats have shed light on fundamental properties of life common to all organisms.
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Affiliation(s)
- George N Somero
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, California 93950, USA;
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6
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Winnikoff JR, Haddock SHD, Budin I. Depth- and temperature-specific fatty acid adaptations in ctenophores from extreme habitats. J Exp Biol 2021; 224:jeb242800. [PMID: 34676421 PMCID: PMC8627573 DOI: 10.1242/jeb.242800] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 10/13/2021] [Indexed: 11/20/2022]
Abstract
Animals are known to regulate the composition of their cell membranes to maintain key biophysical properties in response to changes in temperature. For deep-sea marine organisms, high hydrostatic pressure represents an additional, yet much more poorly understood, perturbant of cell membrane structure. Previous studies in fish and marine microbes have reported correlations with temperature and depth of membrane-fluidizing lipid components, such as polyunsaturated fatty acids. Because little has been done to isolate the separate effects of temperature and pressure on the lipid pool, it is still not understood whether these two environmental factors elicit independent or overlapping biochemical adaptive responses. Here, we use the taxonomic and habitat diversity of the phylum Ctenophora to test whether distinct low-temperature and high-pressure signatures can be detected in fatty acid profiles. We measured the fatty acid composition of 105 individual ctenophores, representing 21 species, from deep and shallow Arctic, temperate, and tropical sampling locales (sea surface temperature, -2° to 28°C). In tropical and temperate regions, remotely operated submersibles (ROVs) enabled sampling down to 4000 m. We found that among specimens with body temperatures 7.5°C or colder, depth predicted fatty acid unsaturation levels. In contrast, in the upper 200 m of the water column, temperature predicted fatty acid chain lengths. Taken together, our findings suggest that lipid metabolism may be specialized with respect to multiple physical variables in diverse marine environments. Largely distinct modes of adaptation to depth and cold imply that polar marine invertebrates may not find a ready refugium from climate change in the deep.
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Affiliation(s)
- Jacob R. Winnikoff
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd., Moss Landing, CA 95039, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 1156 High St., Santa Cruz, CA 95064, USA
| | - Steven H. D. Haddock
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd., Moss Landing, CA 95039, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 1156 High St., Santa Cruz, CA 95064, USA
| | - Itay Budin
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
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7
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Hermaniuk A, van de Pol ILE, Verberk WCEP. Are acute and acclimated thermal effects on metabolic rate modulated by cell size? A comparison between diploid and triploid zebrafish larvae. J Exp Biol 2021; 224:jeb227124. [PMID: 33257437 DOI: 10.1242/jeb.227124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 11/19/2020] [Indexed: 12/13/2022]
Abstract
Being composed of small cells may carry energetic costs related to maintaining ionic gradients across cell membranes as well as benefits related to diffusive oxygen uptake. Here, we test the hypothesis that these costs and benefits of cell size in ectotherms are temperature dependent. To study the consequences of cell size for whole-organism metabolic rate, we compared diploid and triploid zebrafish larvae differing in cell size. A fully factorial design was applied combining three different rearing and test temperatures that allowed us to distinguish acute from acclimated thermal effects. Individual oxygen consumption rates of diploid and triploid larvae across declining levels of oxygen availability were measured. We found that both acute and acclimated thermal effects affected the metabolic response. In comparison with triploids, diploids responded more strongly to acute temperatures, especially when reared at the highest temperature. These observations support the hypothesis that animals composed of smaller cells (i.e. diploids) are less vulnerable to oxygen limitation in warm aquatic habitats. Furthermore, we found slightly improved hypoxia tolerance in diploids. By contrast, warm-reared triploids had higher metabolic rates when they were tested at acute cold temperature, suggesting that being composed of larger cells may provide metabolic advantages in the cold. We offer two mechanisms as a potential explanation of this result, related to homeoviscous adaptation of membrane function and the mitigation of developmental noise. Our results suggest that being composed of larger cells provides metabolic advantages in cold water, while being composed of smaller cells provides metabolic advantages in warm water.
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Affiliation(s)
- Adam Hermaniuk
- Department of Evolutionary and Physiological Ecology, Faculty of Biology, University of Białystok, Ciołkowskiego 1J, 15-245 Białystok, Poland
| | - Iris L E van de Pol
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Wilco C E P Verberk
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands
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8
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Fields PA, Eraso A. A year in the salt marsh: Seasonal changes in gill protein expression in the temperate intertidal mussel Geukensia demissa. MARINE ENVIRONMENTAL RESEARCH 2020; 161:105088. [PMID: 32798780 DOI: 10.1016/j.marenvres.2020.105088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/12/2020] [Accepted: 07/19/2020] [Indexed: 06/11/2023]
Abstract
Organisms living in temperate and polar regions experience extensive seasonal changes in the physical and biotic environment, including temperature, insolation, and food availability, among other factors. Sessile intertidal organisms respond to such seasonal fluctuations largely through physiological and biochemical means, because their behavioral responses are severely limited. In this study, we used a proteomic approach to examine changes in seasonal protein expression of gill from the intertidal mussel Geukensia demissa, a keystone species of the western Atlantic salt marsh, over the course of one year. Gill tissue of mussels collected in summer had the greatest number of proteins significantly increased in abundance (37 of 592 spots detected on two-dimensional polyacrylamide gels), although autumn mussels revealed a comparable proportion of up-regulated proteins (31 spots). In contrast, the number of proteins changing in abundance in winter and spring mussels were substantially smaller (15 and 9, respectively). Identification of these proteins revealed both expected and unanticipated changes to the proteome. Maintenance of gill cilia dominates in the summer when filter-feeding is most active, as evidenced by cytoskeletal proteins such as tektin-4 and tubulin isoforms; a signal of protection from heat stress is also present in summer (e.g., heat shock cognate 70). In autumn oxidative stress protection (peroxiredoxin-5 and manganese-containing superoxide dismutase) and aerobic ATP synthetic capacity (ATP synthase subunits a and delta) appear to increase. In winter a signal of cold-induced oxidative stress is apparent (Mn-SOD and NADP-dependent isocitrate dehydrogenase), perhaps in association with heavy metal toxicity and exposure to pathogens. Gill tissue from spring shows relatively little environmental acclimatization, other than a possible increase in protein synthesis capacity.
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Affiliation(s)
- Peter A Fields
- Biology Department, PO Box 3003, Franklin & Marshall College, Lancaster, PA, USA, 17604.
| | - Ariel Eraso
- Biology Department, PO Box 3003, Franklin & Marshall College, Lancaster, PA, USA, 17604; Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, 1945 Colorado Avenue, Denver, CO, 80309, USA
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9
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Moyen NE, Somero GN, Denny MW. Mussel acclimatization to high, variable temperatures is lost slowly upon transfer to benign conditions. J Exp Biol 2020; 223:jeb222893. [PMID: 32457061 DOI: 10.1242/jeb.222893] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 05/18/2020] [Indexed: 12/18/2022]
Abstract
Climate change is increasing the temperature variability animals face, and thermal acclimatization allows animals to adjust adaptively to this variability. Although the rate of heat acclimatization has received some study, little is known about how long these adaptive changes remain without continuing exposure to heat stress. This study explored the rate at which field acclimatization states are lost when temperature variability is minimized during constant submersion. California mussels (Mytilus californianus) with different acclimatization states were collected from high- and low-zone sites (∼12 versus ∼5°C daily temperature ranges, respectively) and then kept submerged at 15°C for 8 weeks. Each week, the cardiac thermal performance of mussels was measured as a metric of acclimatization state: critical (Tcrit) and flatline (Tflat) temperatures were recorded. Over 8 weeks of constant submersion, the mean Tcrit of high-zone mussels decreased by 1.07°C from baseline, but low-zone mussels' mean Tcrit was unchanged. High- and low-zone mussels' mean maximum heart rate (HR) and resting HR decreased ∼12 and 35%, respectively. Tflat was unchanged in both groups. These data suggest that Tcrit and HR are more physiologically plastic in response to the narrowing of an animal's daily temperature range than Tflat is, and that an animal's prior acclimatization state (high versus low) influences the acclimatory capacity of Tcrit Approximately 2 months were required for the cardiac thermal performance of the high-zone mussels to reach that of the low-zone mussels, suggesting that acclimatization to high and variable temperatures may persist long enough to enable these animals to cope with intermittent bouts of heat stress.
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Affiliation(s)
- Nicole E Moyen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 94305, USA
| | - George N Somero
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 94305, USA
| | - Mark W Denny
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 94305, USA
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10
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Gleason LU, Strand EL, Hizon BJ, Dowd WW. Plasticity of thermal tolerance and its relationship with growth rate in juvenile mussels ( Mytilus californianus). Proc Biol Sci 2019; 285:rspb.2017.2617. [PMID: 29669896 DOI: 10.1098/rspb.2017.2617] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/23/2018] [Indexed: 12/29/2022] Open
Abstract
Complex life cycles characterized by uncertainty at transitions between larval/juvenile and adult environments could favour irreversible physiological plasticity at such transitions. To assess whether thermal tolerance of intertidal mussels (Mytilus californianus) adjusts to post-settlement environmental conditions, we collected juveniles from their thermally buffered microhabitat from high- and low-shore locations at cool (wave-exposed) and warm (wave-protected) sites. Juveniles were transplanted to unsheltered cages at the two low sites or placed in a common garden. Juveniles transplanted to the warm site for one month in summer had higher thermal tolerance, regardless of origin site. By contrast, common-garden juveniles from all sites had lower tolerance indistinguishable from exposed site transplants. After six months in the field plus a common garden period, there was a trend for higher thermal tolerance at the protected site, while reduced thermal tolerance at both sites indicated seasonal acclimatization. Thermal tolerance and growth rate were inversely related after one but not six months; protected-site transplants were more tolerant but grew more slowly. In contrast to juveniles, adults from low-shore exposed and protected sites retained differences in thermal tolerance after common garden treatment in summer. Both irreversible and reversible forms of plasticity must be considered in organismal responses to changing environments.
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Affiliation(s)
- Lani U Gleason
- Department of Biology, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045, USA .,Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA 95819, USA
| | - Emma L Strand
- Department of Biology, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045, USA
| | - Brian J Hizon
- Department of Biology, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045, USA
| | - W Wesley Dowd
- Department of Biology, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045, USA.,School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
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11
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Denny M. Performance in a variable world: using Jensen's inequality to scale up from individuals to populations. CONSERVATION PHYSIOLOGY 2019; 7:coz053. [PMID: 31528348 PMCID: PMC6736373 DOI: 10.1093/conphys/coz053] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/07/2019] [Accepted: 07/05/2019] [Indexed: 05/06/2023]
Abstract
Body temperature affects plants' and animals' performance, but these effects are complicated by thermal variation through time within an individual and variation through space among individuals in a population. This review and synthesis describes how the effects of thermal variation-in both time and space-can be estimated by applying a simple, nonlinear averaging scheme. The method is first applied to the temporal variation experienced by an individual, providing an estimate of the individual's average performance. The method is then applied to the scale-dependent thermal variation among individuals, which is modelled as a 1/f-noise phenomenon. For an individual, thermal variation reduces average performance, lowers the temperature of maximum performance (Topt ) and contracts the range of viable temperatures. Thermal variation among individuals similarly reduces performance and lowers Topt , but increases the viable range of average temperatures. These results must be viewed with caution, however, because they do not take into account the time-dependent interaction between body temperature and physiological plasticity. Quantifying these interactions is perhaps the largest challenge for ecological and conservation physiologists as they attempt to predict the effects of climate change.
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Affiliation(s)
- Mark Denny
- Hopkins Marine Station of Stanford University, 120 Ocean View Blvd., Pacific Grove, California, 93950 USA
- Corresponding author: Hopkins Marine Station of Stanford University, 120 Ocean View Blvd., Pacific Grove, California, 93950 USA.
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12
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Facchini L, Losito I, Cataldi TRI, Palmisano F. Seasonal variations in the profile of main phospholipids in Mytilus galloprovincialis mussels: A study by hydrophilic interaction liquid chromatography-electrospray ionization Fourier transform mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:1-20. [PMID: 28892241 DOI: 10.1002/jms.4029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/01/2017] [Accepted: 09/05/2017] [Indexed: 06/07/2023]
Abstract
A systematic characterization of phosphatidylcholines and phosphatidylethanolamines in mussels of sp Mytilus galloprovincialis was performed by high-efficiency hydrophilic interaction liquid chromatography combined with electrospray ionization and Fourier transform mass spectrometry (FTMS), based on a quadrupole-Orbitrap hybrid spectrometer. The FTMS/MS experiments under high collisional energy dissociation conditions, complemented by low-energy collisionally induced dissociation MSn (n = 2,3) experiments, performed in a linear ion trap mass spectrometer, were exploited for structural elucidation purposes. The described approach led to an unprecedented characterization of the mussel phospholipidome, with 185 phosphatidylcholines and 131 phosphatidylethanolamines species recognized, distributed among diacylic, plasmanylic, and plasmenylic forms. This was the starting point for the evaluation of the effects of season (in particular, of sea temperature) on the profile of those phospholipids. To this aim, a set of mussel samples retrieved from commercial sources in different periods of the year was considered. Principal component analysis revealed a clear separation between samples collected in periods characterized by cold, intermediate, or warm sea temperatures, respectively. In particular, an enrichment in phospholipids containing unsaturated side chains was observed in mussels collected from cold seawaters (winter-early spring), thus confirming the general model previously elaborated to explain the adaptation of marine invertebrates, including some bivalve molluscs, to low temperatures. On the other hand, relevant levels of plasma(e)nylic and acylic phospholipids bearing either saturated or non-methylene-interrupted side chains were found in mussels collected in warm seawaters (typical of summer and early autumn, at Italian latitudes). This finding opened interesting perspectives towards the development of strategies able to prevent global warming-related mussel losses in aquacultural plants.
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Affiliation(s)
- Laura Facchini
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126, Bari, Italy
| | - Ilario Losito
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126, Bari, Italy
- Centro Interdipartimentale SMART, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126, Bari, Italy
| | - Tommaso R I Cataldi
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126, Bari, Italy
- Centro Interdipartimentale SMART, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126, Bari, Italy
| | - Francesco Palmisano
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126, Bari, Italy
- Centro Interdipartimentale SMART, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126, Bari, Italy
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13
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Gleason LU, Miller LP, Winnikoff JR, Somero GN, Yancey PH, Bratz D, Dowd WW. Thermal history and gape of individual Mytilus californianus correlate with oxidative damage and thermoprotective osmolytes. J Exp Biol 2017; 220:4292-4304. [DOI: 10.1242/jeb.168450] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 09/24/2017] [Indexed: 12/22/2022]
Abstract
ABSTRACT
The ability of animals to cope with environmental stress depends – in part – on past experience, yet knowledge of the factors influencing an individual's physiology in nature remains underdeveloped. We used an individual monitoring system to record body temperature and valve gaping behavior of rocky intertidal zone mussels (Mytilus californianus). Thirty individuals were selected from two mussel beds (wave-exposed and wave-protected) that differ in thermal regime. Instrumented mussels were deployed at two intertidal heights (near the lower and upper edges of the mussel zone) and in a continuously submerged tidepool. Following a 23-day monitoring period, measures of oxidative damage to DNA and lipids, antioxidant capacities (catalase activity and peroxyl radical scavenging) and tissue contents of organic osmolytes were obtained from gill tissue of each individual. Univariate and multivariate analyses indicated that inter-individual variation in cumulative thermal stress is a predominant driver of physiological variation. Thermal history over the outplant period was positively correlated with oxidative DNA damage. Thermal history was also positively correlated with tissue contents of taurine, a thermoprotectant osmolyte, and with activity of the antioxidant enzyme catalase. Origin site differences, possibly indicative of developmental plasticity, were only significant for catalase activity. Gaping behavior was positively correlated with tissue contents of two osmolytes. Overall, these results are some of the first to clearly demonstrate relationships between inter-individual variation in recent experience in the field and inter-individual physiological variation, in this case within mussel beds. Such micro-scale, environmentally mediated physiological differences should be considered in attempts to forecast biological responses to a changing environment.
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Affiliation(s)
- Lani U. Gleason
- Loyola Marymount University, Department of Biology, 1 LMU Drive, Los Angeles, CA 90045, USA
| | - Luke P. Miller
- San Jose State University, Department of Biological Sciences, One Washington Square, San Jose, CA 95192, USA
| | - Jacob R. Winnikoff
- Hopkins Marine Station of Stanford University, 120 Oceanview Boulevard, Pacific Grove, CA 93950, USA
| | - George N. Somero
- Hopkins Marine Station of Stanford University, 120 Oceanview Boulevard, Pacific Grove, CA 93950, USA
| | - Paul H. Yancey
- Whitman College, Biology Department, 345 Boyer Avenue, Walla Walla, WA 99362, USA
| | - Dylan Bratz
- Whitman College, Biology Department, 345 Boyer Avenue, Walla Walla, WA 99362, USA
| | - W. Wesley Dowd
- Loyola Marymount University, Department of Biology, 1 LMU Drive, Los Angeles, CA 90045, USA
- Washington State University, School of Biological Sciences, PO Box 644236, Pullman, WA 99164, USA
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Jimenez AG, Jayawardene S, Alves S, Dallmer J, Dowd WW. Micro-scale environmental variation amplifies physiological variation among individual mussels. Proc Biol Sci 2017; 282:20152273. [PMID: 26645201 DOI: 10.1098/rspb.2015.2273] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The contributions of temporal and spatial environmental variation to physiological variation remain poorly resolved. Rocky intertidal zone populations are subjected to thermal variation over the tidal cycle, superimposed with micro-scale variation in individuals' body temperatures. Using the sea mussel (Mytilus californianus), we assessed the consequences of this micro-scale environmental variation for physiological variation among individuals, first by examining the latter in field-acclimatized animals, second by abolishing micro-scale environmental variation via common garden acclimation, and third by restoring this variation using a reciprocal outplant approach. Common garden acclimation reduced the magnitude of variation in tissue-level antioxidant capacities by approximately 30% among mussels from a wave-protected (warm) site, but it had no effect on antioxidant variation among mussels from a wave-exposed (cool) site. The field-acclimatized level of antioxidant variation was restored only when protected-site mussels were outplanted to a high, thermally stressful site. Variation in organismal oxygen consumption rates reflected antioxidant patterns, decreasing dramatically among protected-site mussels after common gardening. These results suggest a highly plastic relationship between individuals' genotypes and their physiological phenotypes that depends on recent environmental experience. Corresponding context-dependent changes in the physiological mean-variance relationships within populations complicate prediction of responses to shifts in environmental variability that are anticipated with global change.
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Affiliation(s)
- Ana Gabriela Jimenez
- Department of Biology, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045
| | - Sarah Jayawardene
- Department of Chemistry and Biochemistry, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045
| | - Shaina Alves
- Department of Chemistry and Biochemistry, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045
| | - Jeremiah Dallmer
- Department of Biology, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045
| | - W Wesley Dowd
- Department of Biology, Loyola Marymount University, 1 LMU Drive, Los Angeles, CA 90045
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Liefting M, Cosijn J, Ellers J. Synergistic effect of daily temperature fluctuations and matching light-dark cycle enhances population growth and synchronizes oviposition behavior in a soil arthropod. JOURNAL OF INSECT PHYSIOLOGY 2017; 96:108-114. [PMID: 27751889 DOI: 10.1016/j.jinsphys.2016.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/08/2016] [Accepted: 10/10/2016] [Indexed: 06/06/2023]
Abstract
Some major aspects of insect life, like development time and reproduction, can benefit from fluctuating temperatures rather than a constant temperature regime. The benefit of fluctuating temperature has generally been attributed to the non-linear properties of the relationship of many life history traits with temperature. Daily temperature rise, however, usually coincide with the light phase of the photoperiodic cycle and there could be a benefit in linking daily temperature fluctuations with light and dark phases e.g. to anticipate the change in temperature. Such synergistic effects have primarily been studied in the light of activity patterns and gene expression, but have not yet been shown to extend to population dynamics and aspects of individual fitness like oviposition behavior. We therefore explored possible synergistic effects on life history traits of the springtail Orchesella cincta. We first test the primary effect of ecologically relevant temperature fluctuations of different amplitudes on population growth and total population mass. The slowest population growth was observed in the constant temperature regime treatment and the highest population growth in the regime with high amplitude fluctuations. In a second experiment, population growth and oviposition rhythm were measured under four different regimes; a constant light and temperature regime, thermoperiod only, photoperiod only and thermoperiod and photoperiod aligned as under natural conditions. The regime in which thermoperiod was aligned with photoperiod resulted in a higher population growth than could be realized by either factor alone. Also, significantly fewer eggs were laid in the constant temperature/light regime than in the other three regimes, strongly suggesting that this regime is stressful to O. cincta. Additionally, the fraction of eggs laid at night was highest in the regime with the combined temperature and light cycle. In conclusion, our results show that under these experimental conditions there is a synergistic effect of daily temperature fluctuations in combination with light/dark phases that can considerably influence important life history traits and affect behavior. Such effects are likely to be relevant under natural conditions.
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Affiliation(s)
- Maartje Liefting
- Animal Ecology, Faculty of Earth and Life Sciences, De Boelelaan 1085, 1081 HV Amsterdam, VU University Amsterdam, The Netherlands.
| | - Jarno Cosijn
- Animal Ecology, Faculty of Earth and Life Sciences, De Boelelaan 1085, 1081 HV Amsterdam, VU University Amsterdam, The Netherlands
| | - Jacintha Ellers
- Animal Ecology, Faculty of Earth and Life Sciences, De Boelelaan 1085, 1081 HV Amsterdam, VU University Amsterdam, The Netherlands
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16
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Colinet H, Renault D, Javal M, Berková P, Šimek P, Koštál V. Uncovering the benefits of fluctuating thermal regimes on cold tolerance of drosophila flies by combined metabolomic and lipidomic approach. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1736-1745. [DOI: 10.1016/j.bbalip.2016.08.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/21/2016] [Accepted: 08/15/2016] [Indexed: 11/15/2022]
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Dubousquet V, Gros E, Berteaux-Lecellier V, Viguier B, Raharivelomanana P, Bertrand C, Lecellier GJ. Changes in fatty acid composition in the giant clam Tridacna maxima in response to thermal stress. Biol Open 2016; 5:1400-1407. [PMID: 27543058 PMCID: PMC5087672 DOI: 10.1242/bio.017921] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Temperature can modify membrane fluidity and thus affects cellular functions and physiological activities. This study examines lipid remodelling in the marine symbiotic organism, Tridacna maxima, during a time series of induced thermal stress, with an emphasis on the morphology of their symbiont Symbiodinium First, we show that the French Polynesian giant clams harbour an important proportion of saturated fatty acids (SFA), which reflects their tropical location. Second, in contrast to most marine organisms, the total lipid content in giant clams remained constant under stress, though some changes in their composition were shown. Third, the stress-induced changes in fatty acid (FA) diversity were accompanied by an upregulation of genes involved in lipids and ROS pathways. Finally, our microscopic analysis revealed that for the giant clam's symbiont, Symbiodinium, thermal stress led to two sequential cell death processes. Our data suggests that the degradation of Symbiodinium cells could provide an additional source of energy to T maxima in response to heat stress.
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Affiliation(s)
- Vaimiti Dubousquet
- EPHE, PSL Research University, UPVD-CNRS, USR3278 CRIOBE, 98729 Moorea, French Polynesia University of French Polynesia-Ifremer-ILM-IRD, UMR241 EIO, BP 6570, 98702 Faa'a, Tahiti, French Polynesia Département de recherche agronomique appliquée, Service du développement rural, BP 100, Papeete, Tahiti 98713, French Polynesia
| | - Emmanuelle Gros
- EPHE, PSL Research University, UPVD-CNRS, USR3278 CRIOBE, 66860 Perpignan, France
| | - Véronique Berteaux-Lecellier
- EPHE, PSL Research University, UPVD-CNRS, USR3278 CRIOBE, 98729 Moorea, French Polynesia Laboratoire d'Excellence "CORAIL", 58 Avenue Paul Alduy, 66860 Perpignan Cedex, France
| | - Bruno Viguier
- EPHE, PSL Research University, UPVD-CNRS, USR3278 CRIOBE, 66860 Perpignan, France
| | - Phila Raharivelomanana
- University of French Polynesia-Ifremer-ILM-IRD, UMR241 EIO, BP 6570, 98702 Faa'a, Tahiti, French Polynesia
| | - Cédric Bertrand
- EPHE, PSL Research University, UPVD-CNRS, USR3278 CRIOBE, 66860 Perpignan, France
| | - Gaël J Lecellier
- EPHE, PSL Research University, UPVD-CNRS, USR3278 CRIOBE, 98729 Moorea, French Polynesia Université Paris-Saclay/Versailles-Saint Quentin en Yvelines, 55 Avenue de Paris, 78035 Versailles Cedex, France Laboratoire d'Excellence "CORAIL", 58 Avenue Paul Alduy, 66860 Perpignan Cedex, France
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18
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Williams CM, Buckley LB, Sheldon KS, Vickers M, Pörtner HO, Dowd WW, Gunderson AR, Marshall KE, Stillman JH. Biological Impacts of Thermal Extremes: Mechanisms and Costs of Functional Responses Matter. Integr Comp Biol 2016; 56:73-84. [PMID: 27252194 DOI: 10.1093/icb/icw013] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Thermal performance curves enable physiological constraints to be incorporated in predictions of biological responses to shifts in mean temperature. But do thermal performance curves adequately capture the biological impacts of thermal extremes? Organisms incur physiological damage during exposure to extremes, and also mount active compensatory responses leading to acclimatization, both of which alter thermal performance curves and determine the impact that current and future extremes have on organismal performance and fitness. Thus, these sub-lethal responses to extreme temperatures potentially shape evolution of thermal performance curves. We applied a quantitative genetic model and found that beneficial acclimatization and cumulative damage alter the extent to which thermal performance curves evolve in response to thermal extremes. The impacts of extremes on the evolution of thermal performance curves are reduced if extremes cause substantial mortality or otherwise reduce fitness differences among individuals. Further empirical research will be required to understand how responses to extremes aggregate through time and vary across life stages and processes. Such research will enable incorporating passive and active responses to sub-lethal stress when predicting the impacts of thermal extremes.
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Affiliation(s)
| | | | | | - Mathew Vickers
- Station d'Ecologie Théorique et Expérimentale, Moulis, 09200, UMR 5321, CNRS 2 route du CNRS, France
| | - Hans-Otto Pörtner
- Alfred Wegener Institute, Helmholtz Center for Marine and Polar Research, 27570 Bremerhaven, Germany
| | - W Wesley Dowd
- Loyola Marymount University, Los Angeles, CA, USA 90045
| | - Alex R Gunderson
- *University of California, Berkeley, CA, USA 94720 San Francisco State University, Tiburon, CA, USA 94132
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Tagliarolo M, McQuaid CD. Field Measurements Indicate Unexpected, Serious Underestimation of Mussel Heart Rates and Thermal Tolerance by Laboratory Studies. PLoS One 2016; 11:e0146341. [PMID: 26840775 PMCID: PMC4739526 DOI: 10.1371/journal.pone.0146341] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 11/05/2015] [Indexed: 02/07/2023] Open
Abstract
Attempts to predict the response of species to long-term environmental change are generally based on extrapolations from laboratory experiments that inevitably simplify the complex interacting effects that occur in the field. We recorded heart rates of two genetic lineages of the brown mussel Perna perna over a full tidal cycle in-situ at two different sites in order to evaluate the cardiac responses of the two genetic lineages present on the South African coast to temperature and the immersion/emersion cycle. "Robomussel" temperature loggers were used to monitor thermal conditions at the two sites over one year. Comparison with live animals showed that robomussels provided a good estimate of mussel body temperatures. A significant difference in estimated body temperatures was observed between the sites and the results showed that, under natural conditions, temperatures regularly approach or exceed the thermal limits of P. perna identified in the laboratory. The two P. perna lineages showed similar tidal and diel patterns of heart rate, with higher cardiac activity during daytime immersion and minimal values during daytime emersion. Comparison of the heart rates measured in the field with data previously measured in the laboratory indicates that laboratory results seriously underestimate heart rate activity, by as much as 75%, especially during immersion. Unexpectedly, field estimates of body temperatures indicated an ability to tolerate temperatures considered lethal on the basis of laboratory measurements. This suggests that the interaction of abiotic conditions in the field does not necessarily raise vulnerability to high temperatures.
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Affiliation(s)
- Morgana Tagliarolo
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
- * E-mail:
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20
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Torossian J, Kordas R, Helmuth B. Cross-Scale Approaches to Forecasting Biogeographic Responses to Climate Change. ADV ECOL RES 2016. [DOI: 10.1016/bs.aecr.2016.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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21
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Dowd WW, King FA, Denny MW. Thermal variation, thermal extremes and the physiological performance of individuals. J Exp Biol 2015; 218:1956-67. [DOI: 10.1242/jeb.114926] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
ABSTRACT
In this review we consider how small-scale temporal and spatial variation in body temperature, and biochemical/physiological variation among individuals, affect the prediction of organisms' performance in nature. For ‘normal’ body temperatures – benign temperatures near the species' mean – thermal biology traditionally uses performance curves to describe how physiological capabilities vary with temperature. However, these curves, which are typically measured under static laboratory conditions, can yield incomplete or inaccurate predictions of how organisms respond to natural patterns of temperature variation. For example, scale transition theory predicts that, in a variable environment, peak average performance is lower and occurs at a lower mean temperature than the peak of statically measured performance. We also demonstrate that temporal variation in performance is minimized near this new ‘optimal’ temperature. These factors add complexity to predictions of the consequences of climate change. We then move beyond the performance curve approach to consider the effects of rare, extreme temperatures. A statistical procedure (the environmental bootstrap) allows for long-term simulations that capture the temporal pattern of extremes (a Poisson interval distribution), which is characterized by clusters of events interspersed with long intervals of benign conditions. The bootstrap can be combined with biophysical models to incorporate temporal, spatial and physiological variation into evolutionary models of thermal tolerance. We conclude with several challenges that must be overcome to more fully develop our understanding of thermal performance in the context of a changing climate by explicitly considering different forms of small-scale variation. These challenges highlight the need to empirically and rigorously test existing theories.
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Affiliation(s)
- W. Wesley Dowd
- Loyola Marymount University, Department of Biology, Los Angeles, CA 90045, USA
| | - Felicia A. King
- Hopkins Marine Station of Stanford University, Pacific Grove, CA 93950, USA
| | - Mark W. Denny
- Hopkins Marine Station of Stanford University, Pacific Grove, CA 93950, USA
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22
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Lockwood BL, Connor KM, Gracey AY. The environmentally tuned transcriptomes of Mytilus mussels. J Exp Biol 2015; 218:1822-33. [DOI: 10.1242/jeb.118190] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
ABSTRACT
Transcriptomics is a powerful tool for elucidating the molecular mechanisms that underlie the ability of organisms to survive and thrive in dynamic and changing environments. Here, we review the major contributions in this field, and we focus on studies of mussels in the genus Mytilus, which are well-established models for the study of ecological physiology in fluctuating environments. Our review is organized into four main sections. First, we illustrate how the abiotic forces of the intertidal environment drive the rhythmic coupling of gene expression to diel and tidal cycles in Mytilus californianus. Second, we discuss the challenges and pitfalls of conducting transcriptomic studies in field-acclimatized animals. Third, we examine the link between transcriptomic responses to environmental stress and biogeographic distributions in blue mussels, Mytilus trossulus and Mytilus galloprovincialis. Fourth, we present a comparison of transcriptomic datasets and identify 175 genes that share common responses to heat stress across Mytilus species. Taken together, these studies demonstrate that transcriptomics can provide an informative snapshot of the physiological state of an organism within an environmental context. In a comparative framework, transcriptomics can reveal how natural selection has shaped patterns of transcriptional regulation that may ultimately influence biogeography.
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Affiliation(s)
- Brent L. Lockwood
- Department of Biology, University of Vermont, 120 Marsh Life Science, 109 Carrigan Drive, Burlington, VT 05405, USA
| | - Kwasi M. Connor
- Marine Environmental Biology, University of Southern California, 3616 Trousdale Pkwy, Los Angeles, CA 90089, USA
| | - Andrew Y. Gracey
- Marine Environmental Biology, University of Southern California, 3616 Trousdale Pkwy, Los Angeles, CA 90089, USA
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Hyde D, Pearson T, Qari S, Bowler K. Adaptive considerations of temperature dependence of neuromuscular function in two species of summer- and winter-caught Crab (Carcinus maenas and Cancer pagurus). J Comp Physiol B 2015; 185:629-36. [PMID: 25994492 DOI: 10.1007/s00360-015-0912-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 05/06/2015] [Accepted: 05/13/2015] [Indexed: 11/29/2022]
Abstract
The aim of this study was to determine seasonal differences in the temperature dependence of neuromuscular parameters of the dactylopodite walking leg closer muscle in two species of freshly caught summer and winter decapod crabs. The relatively stenothermal Cancer pagurus (Cp) and eurythermal Carcinus maenas (Cm) muscle resting potential (RP) hyperpolarised significantly with increasing experimental temperature. The muscle RP in Cm was seasonally dependent at acute temperatures above 20 °C whereas in Cp no seasonal effect was observed. The latent period of the muscle excitatory junction potential (EJP) following tonic motor nerve stimulation was significantly longer in winter-caught crabs in both species, although the effect was significantly more marked in Cp than Cm. Summer-caught Cp had larger excitatory junction potentials (EJPs) than did winter-caught crabs, a seasonal effect not seen in Cm. In contrast, marked seasonal differences were found in the EJP decay time constant in Cm having significantly longer time constants in winter-caught crabs, where no seasonal difference was found in Cp. These results suggest that different seasonal effects of neuromuscular parameters between Cm and Cp may reflect different strategies of response to their different seasonal temperature environments.
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Affiliation(s)
- D Hyde
- Department of Biological and Biomedical Sciences, University of Durham, South Road, Durham, DH1 3LE, UK,
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Lipidomics Reveals Mitochondrial Membrane Remodeling Associated with Acute Thermoregulation in a Rodent with a Wide Thermoneutral Zone. Lipids 2014; 49:715-30. [DOI: 10.1007/s11745-014-3900-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/20/2014] [Indexed: 12/13/2022]
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25
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Bjelde B, Todgham A. Thermal physiology of the fingered limpet Lottia digitalis under emersion and immersion. J Exp Biol 2013; 216:2858-69. [DOI: 10.1242/jeb.084178] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Summary
Marine animals living high in the rocky intertidal zone experience long durations of aerial-emersion, sometimes enduring rapid increases in temperature. To date, much of our understanding of the thermal physiology of intertidal organisms comes from studies in which organisms are exposed to increasing temperatures when immersed, with the added effect of aerial emersion rarely considered. In this study, we examined the physiological response of the finger limpet, Lottia digitalis, to increases in temperature under both immersed and emersed conditions. We investigated the thermal sensitivity and upper temperature tolerance of limpets through assessments of cardiac performance, metabolic rate, glycogen depletion and maintenance of protein integrity. Cardiac performance in response to ecologically relevant increases in temperature was similar in emersed and immersed limpets from 15 to 35°C and showed multiple break patterns in heart rate as temperature was increased. Overall, emersed limpets had a greater upper thermal limit on cardiac performance with the ability to maintain heart rate 3-5°C higher than immersed limpets. Metabolism in limpets also differed significantly between emersion and immersion, where a significant depression in aerobic metabolic rate was observed under immersion with increasing temperature. Greater levels of ubiquitin-conjugated proteins were found under emersed conditions compared to immersed limpets. Maintaining cardiac performance and aerobic metabolism to higher temperatures under emersed conditions is likely reflective of physiological adaptations to live in an aerially exposed environment. Measured field temperatures where fingered limpets were collected demonstrated that limpets have a narrow thermal safety margin for aerobic performance, and currently experience multiple days where summer temperatures might exceed their threshold limits.
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Ronges D, Walsh JP, Sinclair BJ, Stillman JH. Changes in extreme cold tolerance, membrane composition and cardiac transcriptome during the first day of thermal acclimation in the porcelain crab Petrolisthes cinctipes. ACTA ACUST UNITED AC 2012; 215:1824-36. [PMID: 22573761 DOI: 10.1242/jeb.069658] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Intertidal zone organisms can experience transient freezing temperatures during winter low tides, but their extreme cold tolerance mechanisms are not known. Petrolisthes cinctipes is a temperate mid-high intertidal zone crab species that can experience wintertime habitat temperatures below the freezing point of seawater. We examined how cold tolerance changed during the initial phase of thermal acclimation to cold and warm temperatures, as well as the persistence of cold tolerance during long-term thermal acclimation. Thermal acclimation for as little as 6 h at 8°C enhanced cold tolerance during a 1 h exposure to -2°C relative to crabs acclimated to 18°C. Potential mechanisms for this enhanced tolerance were elucidated using cDNA microarrays to probe for differences in gene expression in cardiac tissue of warm- and cold-acclimated crabs during the first day of thermal acclimation. No changes in gene expression were detected until 12 h of thermal acclimation. Genes strongly upregulated in warm-acclimated crabs represented immune response and extracellular/intercellular processes, suggesting that warm-acclimated crabs had a generalized stress response and may have been remodelling tissues or altering intercellular processes. Genes strongly upregulated in cold-acclimated crabs included many that are involved in glucose production, suggesting that cold acclimation involves increasing intracellular glucose as a cryoprotectant. Structural cytoskeletal proteins were also strongly represented among the genes upregulated in only cold-acclimated crabs. There were no consistent changes in composition or the level of unsaturation of membrane phospholipid fatty acids with cold acclimation, which suggests that neither short- nor long-term changes in cold tolerance are mediated by changes in membrane fatty acid composition. Overall, our study demonstrates that initial changes in cold tolerance are likely not regulated by transcriptomic responses, but that gene-expression-related changes in homeostasis begin within 12 h, the length of a tidal cycle.
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Affiliation(s)
- Daria Ronges
- Romberg Tiburon Center and Department of Biology, San Francisco State University, Tiburon, CA 94920, USA
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27
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Place SP, Menge BA, Hofmann GE. Transcriptome profiles link environmental variation and physiological response of Mytilus californianus between Pacific tides. Funct Ecol 2011; 26:144-155. [PMID: 22563136 DOI: 10.1111/j.1365-2435.2011.01924.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
SUMMARY: The marine intertidal zone is characterized by large variation in temperature, pH, dissolved oxygen and the supply of nutrients and food on seasonal and daily time scales. These oceanic fluctuations drive of ecological processes such as recruitment, competition and consumer-prey interactions largely via physiological mehcanisms. Thus, to understand coastal ecosystem dynamics and responses to climate change, it is crucial to understand these mechanisms.Here we utilize transcriptome analysis of the physiological response of the mussel Mytilus californianus at different spatial scales to gain insight into these mechanisms. We used mussels inhabiting different vertical locations within Strawberry Hill on Cape Perpetua, OR and Boiler Bay on Cape Foulweather, OR to study inter- and intra-site variation of gene expression.The results highlight two distinct gene expression signatures related to the cycling of metabolic activity and perturbations to cellular homeostasis. Intermediate spatial scales show a strong influence of oceanographic differences in food and stress environments between sites separated by ~65 km.Together, these new insights into environmental control of gene expression may allow understanding of important physiological drivers within and across populations.
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Affiliation(s)
- Sean P Place
- Department of Biological Sciences & Environment and Sustainability Program, University of South Carolina, Columbia, SC 29208 USA
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van Dooremalen C, Suring W, Ellers J. Fatty acid composition and extreme temperature tolerance following exposure to fluctuating temperatures in a soil arthropod. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:1267-1273. [PMID: 21704631 DOI: 10.1016/j.jinsphys.2011.05.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Revised: 05/30/2011] [Accepted: 05/31/2011] [Indexed: 05/31/2023]
Abstract
Ectotherms commonly adjust their lipid composition to ambient temperature to counteract detrimental thermal effects on lipid fluidity. However, the extent of lipid remodeling and the associated fitness consequences under continuous temperature fluctuations are not well-described. The objective of this study was to investigate the effect of repeated temperature fluctuations on fatty acid composition and thermal tolerance. We exposed the springtail Orchesella cincta to two constant temperatures of 5 and 20°C, and a continuously fluctuating treatment between 5 and 20°C every 2 days. Fatty acid composition differed significantly between constant low and high temperatures. As expected, animals were most cold tolerant in the low temperature treatment, while heat tolerance was highest under high temperature. Under fluctuating temperatures, fatty acid composition changed with temperature initially, but later in the experiment fatty acid composition stabilized and closely resembled that found under constant warm temperatures. Consistent with this, heat tolerance in the fluctuating temperature treatment was comparable to the constant warm treatment. Cold tolerance in the fluctuating temperature treatment was intermediate compared to animals acclimated to constant cold or warmth, despite the fact that fatty acid composition was adjusted to warm conditions. This unexpected finding suggests that in animals acclimated to fluctuating temperatures an additional underlying mechanism is involved in the cold shock response. Other aspects of homeoviscous adaptation may protect animals during extreme cold. This paper forms a next step to fully understand the functioning of ectotherms in more thermally variable environments.
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Affiliation(s)
- Coby van Dooremalen
- Animal Ecology Group, VU University Amsterdam, De Boelelaan 1085, Amsterdam, The Netherlands.
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Lu A, Wang H, Hou X, Li H, Cheng G, Wang N, Zhu X, Yu J, Luan W, Liu F, Xu J. Microarray analysis of gene expression profiles of rat small intestine in response to heat stress. ACTA ACUST UNITED AC 2011; 16:655-67. [PMID: 21482723 DOI: 10.1177/1087057111403928] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Ambient temperature is a critical factor that affects biological organisms in many ways. In this study, the authors investigated gene expression changes in rat small intestine in response to heat stress. Male Sprague-Dawley rats were randomly divided into control and heat-stressed groups. Both groups were housed at 25 °C, although the heat-stressed group was also subjected to 40 °C for 2 h each day for 10 successive days. Rats were sacrificed 1, 3, 6, and 10 days after heat treatment, and sections of their small intestine epithelial tissue were excised for morphological examination and microarray analyses. The rat rectal and body surface temperatures and serum cortisol levels were all significantly increased after heat treatment (p < 0.05). The jejuna were significantly damaged by 3 days after heat treatment began. Microarray analysis showed that 422 genes were differentially expressed, of which 290 genes were significantly upregulated and 132 genes were significantly downregulated. Subsequent bioinformatics analyses revealed that the differentially expressed genes were mainly related to stress, immune regulation, and metabolism processes. The bioinformatics analysis of the differentially expressed genes should be beneficial to further investigations on the underlying mechanisms involved in heat stress-induced damage in the small intestine.
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Affiliation(s)
- An Lu
- CAU-BUA TCVM Teaching & Research Team, College of Animal Science and Technology, Beijing University of Agriculture, Beijing 102206, P. R. China
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Hadamová M, Gvoždík L. Seasonal Acclimation of Preferred Body Temperatures Improves the Opportunity for Thermoregulation in Newts. Physiol Biochem Zool 2011; 84:166-74. [DOI: 10.1086/658202] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Van Dooremalen C, Koekkoek J, Ellers J. Temperature-induced plasticity in membrane and storage lipid composition: thermal reaction norms across five different temperatures. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:285-291. [PMID: 21115015 DOI: 10.1016/j.jinsphys.2010.11.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/21/2010] [Accepted: 11/22/2010] [Indexed: 05/30/2023]
Abstract
Temperature is a key environmental factor inducing phenotypic plasticity in a wide range of behavioral, morphological, and life history traits in ectotherms. The strength of temperature-induced responses in fitness-related traits may be determined by plasticity of the underlying physiological or biochemical traits. Lipid composition may be an important trait underlying fitness response to temperature, because it affects membrane fluidity as well as availability of stored energy reserves. Here, we investigate the effect of temperature on lipid composition of the springtail Orchesella cincta by measuring thermal reaction norms across five different temperatures after four weeks of cold or warm acclimation. Fatty acid composition in storage and membrane lipids showed a highly plastic response to temperature, but the responses of single fatty acids revealed deviations from the expectations based on HVA theory. We found an accumulation of C(18:2n6) and C(18:3n3) at higher temperatures and the preservation of C(20:4n6) across temperatures, which is contrary to the expectation of decreased unsaturation at higher temperatures. The thermal response of these fatty acids in O. cincta differed from the findings in other species, and therefore shows there is interspecific variation in how single fatty acids contribute to HVA. Future research should determine the consequences of such variation in terms of costs and benefits for the thermal performance of species.
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Affiliation(s)
- Coby Van Dooremalen
- Animal Ecology Group, VU University Amsterdam, De Boelelaan 1085, Amsterdam, The Netherlands.
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32
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Rais A, Miller N, Stillman JH. No evidence for homeoviscous adaptation in intertidal snails: analysis of membrane fluidity during thermal acclimation, thermal acclimatization, and across thermal microhabitats. MARINE BIOLOGY 2010; 157:2407-2414. [PMID: 24391251 PMCID: PMC3873056 DOI: 10.1007/s00227-010-1505-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 06/23/2010] [Indexed: 06/03/2023]
Abstract
Many eurythermal organisms alter composition of their membranes to counter perturbing effects of environmental temperature variation on membrane fluidity, a process known as homeoviscous adaptation. Marine intertidal gastropods experience uniquely large thermal excursions that challenge the functional integrity of their membranes on tidal and seasonal timescales. This study measured and compared membrane fluidity in marine intertidal snail species under three scenarios: (1) laboratory thermal acclimation, (2) thermal acclimatization during a hot midday low tide, and (3) thermal acclimatization across the vertical intertidal zone gradient in temperature. For each scenario, we used fluorescence polarization of the membrane probe DPH to measure membrane fluidity in individual samples of gill and mantle tissue. A four-week thermal acclimation of Tegula funebralis to 5, 15, and 25°C did not induce differences in membrane fluidity. Littorina keenae sampled from two thermal microhabitats at the beginning and end of a hot midday low tide exhibited no significant differences in membrane fluidity, either as a function of time of day or as a function of thermal microhabitat, despite changes in body temperature up to 24°C within 8 h. Membrane fluidities of a diverse group of snails collected from high, middle, and low vertical regions of the intertidal zone varied among species but did not correlate with thermal microhabitat. Our data suggest intertidal gastropod snails do not exhibit homeoviscous adaptation of gill and mantle membranes. We discuss possible alternatives for how these organisms counter thermal excursions characteristic of the marine intertidal zone.
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Affiliation(s)
- Amber Rais
- Hopkins Marine Station, Stanford University, Oceanview Blvd., Pacific Grove, CA 93950 USA
| | - Nathan Miller
- Romberg Tiburon Center, San Francisco State University, 3150 Paradise Dr, Tiburon, CA 94920 USA
| | - Jonathon H. Stillman
- Romberg Tiburon Center, San Francisco State University, 3150 Paradise Dr, Tiburon, CA 94920 USA
- Department of Integrative Biology, University of California Berkeley, 3060 Valley Life Sciences, Bldg #3140, Berkeley, CA 94720-2140 USA
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Hofmann GE, Todgham AE. Living in the now: physiological mechanisms to tolerate a rapidly changing environment. Annu Rev Physiol 2010; 72:127-45. [PMID: 20148670 DOI: 10.1146/annurev-physiol-021909-135900] [Citation(s) in RCA: 301] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rising atmospheric carbon dioxide has resulted in scientific projections of changes in global temperatures, climate in general, and surface seawater chemistry. Although the consequences to ecosystems and communities of metazoans are only beginning to be revealed, a key to forecasting expected changes in animal communities is an understanding of species' vulnerability to a changing environment. For example, environmental stressors may affect a particular species by driving that organism outside a tolerance window, by altering the costs of metabolic processes under the new conditions, or by changing patterns of development and reproduction. Implicit in all these examples is the foundational understanding of physiological mechanisms and how a particular environmental driver (e.g., temperature and ocean acidification) will be transduced through the animal to alter tolerances and performance. In this review, we highlight examples of mechanisms, focusing on those underlying physiological plasticity, that operate in contemporary organisms as a means to consider physiological responses that are available to organisms in the future.
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Affiliation(s)
- Gretchen E Hofmann
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106-9620, USA.
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Šamajová P, Gvoždík L. Inaccurate or disparate temperature cues? Seasonal acclimation of terrestrial and aquatic locomotor capacity in newts. Funct Ecol 2010. [DOI: 10.1111/j.1365-2435.2010.01720.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Toyoda T, Hiramatsu Y, Sasaki T, Nakaoka Y. Thermo-sensitive response based on the membrane fluidity adaptation in Paramecium multimicronucleatum. J Exp Biol 2009; 212:2767-72. [DOI: 10.1242/jeb.031278] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Relationships between the thermo-sensitive response and membrane lipid fluidity were studied using a ciliated protozoan, Paramecium multimicronucleatum. Paramecium elicits a transient membrane depolarization in response to a cooling stimulus (temperature drop). The depolarization amplitude was largest when the cooling stimulus was started from the culture temperature, whilst when cooling started at a temperature more than 5°C higher or lower than the culture temperature, only a small depolarization was induced. Therefore, the cooling-induced response was dependent on the culture temperature and its sensitivity to the cooling stimulus was highest at the culture temperature. Membrane fluidity measurements of living cells using the fluorescent dye 6-lauroyl-2-dimethylaminonaphthalene (laurdan) showed that the fluidity measured at the culture temperature was almost constant irrespective of the temperature at which the cells had been cultured and adapted, which is consistent with homeoviscous adaptation. The constant fluidity at the culture temperature quickly decreased within a few seconds of application of the cooling stimulus, and the decreased fluidity gradually readapted to a constant level at the decreased temperature within 1 h. When the constant fluidity at culture temperature was modified by the addition of procaine or benzyl alcohol, the cooling-induced depolarization was completely abolished. These results suggest the possibility that the adaptation of fluidity to a constant level and its quick decrease below the constant level activate cooling-sensitive channels to elicit the transient depolarization.
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Affiliation(s)
- Taichi Toyoda
- Biophysical Dynamics Laboratories, Graduate School of Frontier Bioscience,Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Yoshinori Hiramatsu
- Division of Biophysical Engineering, Graduate School of Engineering Science,Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Toshiaki Sasaki
- Biophysical Dynamics Laboratories, Graduate School of Frontier Bioscience,Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Yasuo Nakaoka
- Biophysical Dynamics Laboratories, Graduate School of Frontier Bioscience,Osaka University, Toyonaka, Osaka 560-8531, Japan
- Division of Biophysical Engineering, Graduate School of Engineering Science,Osaka University, Toyonaka, Osaka 560-8531, Japan
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Pernet F, Tremblay R, Comeau L, Guderley H. Temperature adaptation in two bivalve species from different thermal habitats: energetics and remodelling of membrane lipids. J Exp Biol 2007; 210:2999-3014. [PMID: 17704075 DOI: 10.1242/jeb.006007] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
We compared lipid dynamics and the physiological responses of blue mussels Mytilus edulis, a cold-adapted species, and oysters Crassostrea virginica, a warmer-water species, during simulated overwintering and passage to spring conditions. To simulate overwintering, animals were held at 0°C, 4°C and 9°C for 3 months and then gradually brought to and maintained at 20°C for 5 weeks to simulate spring–summer conditions. Changes in lipid class and fatty acid composition were related to clearance rate and oxygen consumption.
We found major differences between species in triglyceride (TAG) metabolism during overwintering. Mussels used digestive gland TAG stores for energy metabolism or reproductive processes during the winter, whereas oysters did not accumulate large TAG stores prior to overwintering. Mussel TAG contained high levels of 20:5n-3 compared to levels in oysters and in the diet. This may help to counteract the effect of low temperature by reducing the melting point of TAG and thus increasing the availability of storage fats at low temperature. Mussels seemed better able to mobilise 20:5n-3 and 18:4n-3 than other fatty acids.
We also found that both bivalves underwent a major remodelling of membrane phospholipids. The unsaturation index decreased in the gills and digestive glands of both species during the early stages of warming, principally due to decreases in 22:6n-3 and 20:5n-3. In digestive glands, the unsaturation index did not increase with decreasing temperature beyond a threshold attained at 9°C whereas a perfect negative relationship was observed in gills, as predicted by homeoviscous adaptation. The presence of digestive enzymes and acids in the digestive gland microenvironment may lead to specific requirements for membrane stability. That oysters had lower metabolic rates than mussels coincides with a lower unsaturation index of their lipids, as predicted by Hulbert's theory of membranes as metabolic pacemakers. Both species showed increased 20:4n-6 levels in their tissues as temperature rose,suggesting an increasing availability of this fatty acid for eicosanoid biosynthesis during stress responses.
The contrast between the species in TAG dynamics and the similarity of their phospholipid remodelling emphasises the essential functional role of membrane phospholipid structure and the contrasting use of TAG by oysters and mussels during overwintering.
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Affiliation(s)
- Fabrice Pernet
- Institut de Recherche sur les Zones Côtières, 232B rue de l'Eglise, Shippagan, Nouveau-Brunswick, E8S 1J2, Canada.
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Pernet F, Tremblay R, Gionet C, Landry T. Lipid remodeling in wild and selectively bred hard clams at low temperatures in relation to genetic and physiological parameters. ACTA ACUST UNITED AC 2007; 209:4663-75. [PMID: 17114400 DOI: 10.1242/jeb.02581] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A temperature decrease usually induces an ordering effect in membrane phospholipids, which can lead to membrane dysfunction. Poikilotherms inhabiting eurythermal environments typically counteract this temperature effect by remodeling membrane lipids as stipulated in the homeoviscous adaptation theory (HVA). Hard clams, Mercenaria mercenaria, can suffer high overwintering mortalities in the Gulf of St Lawrence, Canada. The selectively bred M. mercenaria var. notata can have higher overwintering mortalities than the wild species, thus suggesting that the two varieties have different degrees of adaptation to low temperatures. The objective of this study was to investigate the changes in lipid composition of soft tissues in wild and selected hard clams in relation to their metabolic and genetic characteristics. Clams were placed at the northern limit of their distribution from August 2003 to May 2004; they were exposed to a gradual temperature decrease and then maintained at <0 degrees C for 3.5 months. This study is the first to report a major remodeling of lipids in this species as predicted by HVA; this remodeling involved a sequential response of the phospholipid to sterol ratio as well as in levels of 22:6n-3 and non-methylene interrupted dienoic fatty acids. Hard clams showed an increase in 20:5n-3 as temperature decreased, but this was not maintained during overwintering, which suggests that 20:5n-3 may have been used for eicosanoid biosynthesis as a stress response to environmental conditions. Selectively bred hard clams were characterized by a higher metabolic demand and a deviation from Hardy-Weinberg equilibrium at several genetic loci due to a deficit in heterozygote frequency compared with wild clams, which is believed to impose additional stress and render these animals more vulnerable to overwintering mortality. Finally, an intriguing finding is that the lower metabolic requirements of wild animals coincide with a lower unsaturation index of their lipids, as predicted by Hulbert's theory of membranes as pacemakers of metabolism.
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Affiliation(s)
- Fabrice Pernet
- Institut de Recherche sur les Zones Côtières, 232B rue de l'Eglise, Shippagan, Nouveau-Brunswick, E8S 1J2, Canada.
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Change in lipid composition in eastern oyster (Crassostrea virginica Gmelin) exposed to constant or fluctuating temperature regimes. Comp Biochem Physiol B Biochem Mol Biol 2007; 147:557-65. [PMID: 17468027 DOI: 10.1016/j.cbpb.2007.03.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 03/15/2007] [Accepted: 03/16/2007] [Indexed: 11/24/2022]
Abstract
A temperature decrease usually induces an ordering effect in membrane phospholipids that can lead to membrane dysfunction. Ectotherms typically counteract this temperature effect by remodeling membrane lipids as stipulated in the homeoviscous adaptation theory (HVA). Previous studies mostly focused on the remodeling of membrane lipids during long-term acclimatization or acclimation at constant temperature regimes, whereas in nature, many organisms experience variations in temperature on a daily basis and must react to this changing thermal environment. The objective of this study was to examine the composition of membrane lipids in oysters subjected to long-term acclimation at constant temperatures (12 or 25 degrees C) or to environmentally realistic daily fluctuations in temperature between 12 and 25 degrees C for 7 d. The lipid composition of gill in oysters subjected to long-term acclimation at a constant temperature or to daily temperature fluctuations varied in a way consistent with HVA: oysters adjusted their phospholipid to sterol ratio in response to long-term acclimation to a constant temperature but not to daily temperature fluctuations. In contrast, the unsaturation index of polar lipids in oysters varied in response to both long-term acclimation to a constant temperature and to daily temperature fluctuations, mainly due to changes in 22:6n-3 and 20:5n-3. The 20:4n-6 levels in oyster gills increased as temperature rose, suggesting an increasing availability of this fatty acid for eicosanoid biosynthesis during stress responses.
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Sasaki T, Konoha Y, Toyoda T, Yasaka Y, Przybos E, Nakaoka Y. Correlation between thermotolerance and membrane properties in Paramecium aurelia. ACTA ACUST UNITED AC 2006; 209:3580-6. [PMID: 16943498 DOI: 10.1242/jeb.02426] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The relationship between thermotolerance and membrane properties was studied by using a ciliated protozoan, Paramecium aurelia. P. aurelia is a complex of sibling species termed ;syngens' whose cell morphology appear similar on microscopic examination. From the comparison of tolerance to increasing temperature among 14 syngens of P. aurelia, we selected syngens 2 and 3 as low thermotolerant examples, and syngens 8 and 10 as high thermotolerant examples. The membrane resistance of high thermotolerant syngens measured by injection of a constant inward current was greater than that of low thermotolerant syngens. Membrane fluidity measurements of living cells using the fluorescent dye, 6-lauroyl-2-dimethylaminonaphtalene (laurdan) showed that the fluidity at the cultured temperature was decreased in high thermotolerant syngens compared to that of low thermotolerant syngens. However, when the temperature was increased to the killing temperature of each syngens, the fluidity was increased to almost the same level irrespective of syngen. Furthermore, analysis of fatty acids extracted from whole cells showed that the ratios of unsaturated to saturated fatty acids was smaller in high thermotolerant syngens than in low thermotolerant syngens. These results suggest that the thermotolerance of P. aurelia syngens is determined by the membrane fluidity which is related to the fatty acids composition.
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Affiliation(s)
- Toshiaki Sasaki
- Biophysical Dynamics Laboratories, Graduate School of Frontier Bioscience, Osaka University, Toyonaka, Osaka 560-8531, Japan
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40
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Teranishi KS, Stillman JH. A cDNA microarray analysis of the response to heat stress in hepatopancreas tissue of the porcelain crab Petrolisthes cinctipes. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2006; 2:53-62. [PMID: 20483278 DOI: 10.1016/j.cbd.2006.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 11/20/2006] [Accepted: 11/20/2006] [Indexed: 10/23/2022]
Abstract
Intertidal zone organisms experience thermal stress during periods of low tide, and much work has shown that induction of heat shock proteins and ubiquitination occurs in response to this stress. However, less is known of other cellular pathways that are regulated following thermal stress in these organisms. Here, we used a functional genomics approach to identify genes that were up- and downregulated following heat stress in the intertidal porcelain crab, Petrolisthes cinctipes using custom cDNA microarrays made from 13,824 cloned P. cinctipes ESTs representing 6717 unique consensus sequences. Statistically significant differences in gene expression between heat stressed and control groups were determined with R/maanova. Genes upregulated following heat stress were involved with protein folding, protein degradation, protein synthesis and gluconeogenesis, suggesting that heat stress accelerated protein turnover. Genes downregulated following heat stress were involved with detoxification, oxygen transport, oxidative phosphorylation, and lipid metabolism, suggesting that the animals were avoiding the generation of reactive oxygen species. ESTs matching hypothetical proteins and ESTs that had no GenBank match were also found to have been both upregulated and downregulated following heat stress, suggesting that novel genes may be involved in the heat stress response.
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Affiliation(s)
- Kristen S Teranishi
- Romberg Tiburon Center, San Francisco State University, 3152 Paradise Drive, Tiburon, CA 94920, USA
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41
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Williams EE, Anderson MJ, Miller TJ, Smith SD. The lipid composition of hypodermal membranes from the blue crab (Callinectes sapidus) changes during the molt cycle and alters hypodermal calcium permeability. Comp Biochem Physiol B Biochem Mol Biol 2004; 137:235-45. [PMID: 14990220 DOI: 10.1016/j.cbpc.2003.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2003] [Revised: 11/18/2003] [Accepted: 11/18/2003] [Indexed: 11/15/2022]
Abstract
Crustaceans are covered by a cuticle that does not grow. In order for an individual to grow, the cuticle must periodically be shed (ecdysis). Replacement of the old cuticle with a new one depends on processes that require precise timing and control, yet the nature and location of these controls remain unclear. A candidate site for them is within the hypodermal microvilli. These cellular structures extend through pore canals deep into the acellular cuticular matrix. Changes in the lipid composition of hypodermal microvilli could modulate water and ion fluxes and enzyme activities during critical stages of the molt cycle; however, the lipid composition of these structures has not been assessed during the molt cycle. Data presented here show that phospholipids isolated from hypodermal microvilli of Callinectes sapidus initially have elevated levels of n-6 fatty acids that decline steadily beginning just after ecdysis. Experiments with liposomes reveal that n-6 fatty acids decrease the calcium permeability of membranes, suggesting that the initially elevated levels in the cuticle may function to reduce calcium flux from the cuticle into the hypodermis. In addition, the ratio of cholesterol to phospholipid and the proportion of oleic acid in membrane phospholipids are maximal at 6 h post-ecdysis. It is known that changes in cholesterol and oleic acid content alter membrane permeability to water. It is, therefore possible that water flux through hypodermal membranes is also modulated in the early post-molt cuticle. Changes in microvillar lipid composition might serve importantly to control biomineralization in the post-ecdysal cuticle.
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Affiliation(s)
- E Eugene Williams
- Department of Biological Sciences, Salisbury University, Salisbury, MD, 21801 USA.
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42
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Leary SC, Lyons CN, Rosenberger AG, Ballantyne JS, Stillman J, Moyes CD. Fiber-type differences in muscle mitochondrial profiles. Am J Physiol Regul Integr Comp Physiol 2003; 285:R817-26. [PMID: 12947029 DOI: 10.1152/ajpregu.00058.2003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although striated muscles differ in mitochondrial content, the extent of fiber-type specific mitochondrial specializations is not well known. To address this issue, we compared mitochondrial structural and functional properties in red muscle (RM), white muscle (WM), and cardiac muscle of rainbow trout. Overall preservation of the basic relationships between oxidative phosphorylation complexes among fiber types was confirmed by kinetic analyses, immunoblotting of native holoproteins, and spectroscopic measurements of cytochrome content. Fiber-type differences in mitochondrial properties were apparent when parameters were expressed per milligram mitochondrial protein. However, the differences diminished when expressed relative to cytochrome oxidase (COX), possibly a more meaningful denominator than mitochondrial protein. Expressed relative to COX, there were no differences in oxidative phosphorylation enzyme activities, pyruvate-based respiratory rates, H2O2 production, or state 4 proton leak respiration. These data suggest most mitochondrial qualitative properties are conserved across fiber types. However, there remained modest differences ( approximately 50%) in stoichiometries of selected enzymes of the Krebs cycle, beta-oxidation, and antioxidant enzymes. There were clear differences in membrane fluidity (RM > cardiac, WM) and proton conductance (H+/min/mV/U COX: WM > RM > cardiac). The pronounced differences in mitochondrial content between fiber types could be attributed to a combination of differences in myonuclear domain and modest effects on the expression of nuclear- and mitochondrially encoded respiratory genes. Collectively, these studies suggest constitutive pathways that transcend fiber types are primarily responsible for determining most quantitative and qualitative properties of mitochondria.
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Affiliation(s)
- S C Leary
- Department of Biology, Queen's University, Kingston, Ontario, Canada K7L 3N6
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43
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Hall JM, Parrish CC, Thompson RJ. Eicosapentaenoic acid regulates scallop (Placopecten magellanicus) membrane fluidity in response to cold. THE BIOLOGICAL BULLETIN 2002; 202:201-203. [PMID: 12086990 DOI: 10.2307/1543469] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- Jonathon M Hall
- Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, Canada A1C 5S7
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Williams EE, Stewart BS, Beuchat CA, Somero GN, Hazel JR. Hydrostatic-pressure and temperature effects on the molecular order of erythrocyte membranes from deep-, shallow-, and non-diving mammals. CAN J ZOOL 2001. [DOI: 10.1139/z01-047] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Little is known about the cellular mechanisms involved in the tolerance of deep-diving marine mammals to hydrostatic pressures that cause serious pathologies when experienced by other mammals. We compared fatty-acid composition, cholesterol content, and the effects of pressure on the molecular order of erythrocyte membranes from deep-, shallow-, and non-diving mammals to determine how these properties may be related to diving performance. Erythrocytes were collected from two deep-diving phocid pinnipeds (northern elephant seal (Mirounga angustirostris) and harbor seal (Phoca vitulina)), a relatively shallow-diving otariid pinniped (northern fur seal (Callorhinus ursinus)), and several nondiving terrestrial mammals (dog (Canis familiaris), horse (Equus caballus), and cow (Bos taurus)). Fatty-acid composition clearly distinguished the phocids from the other species. The monoene content of erythrocyte membranes was substantially lower (3 vs.»20%), whereas the lipid unsaturation indices, the ratio of α- to γ-linolenic acids, and the proportions of long-chain polyunsaturated fatty acids were substantially higher in the phocids. The cell-membrane cholesterol content was also significantly lower in erythrocytes from the deep-diving phocids (cholesterol:phospholipid ratios 0.20.3) than from most other mammals (1.0). Membranes from the phocids were more ordered than those from the shallow- and non-divers, and were also more sensitive to changes in pressure and temperature. The physiological significance of these differences in cell-membrane structure, which affect the order and sensitivity of cell membranes to hydrostatic pressure, is unknown, but they may be important adaptations that allow repeated and prolonged exposure to great hydrostatic pressure.
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Fudge DS, Stevens ED, Ballantyne JS. No evidence for homeoviscous adaptation in a heterothermic tissue: tuna heat exchangers. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:R818-23. [PMID: 9728080 DOI: 10.1152/ajpregu.1998.275.3.r818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many poikilotherms are known to adjust the membrane composition of their cells in response to a temperature change so that membrane fluidity, and therefore function, is conserved. Such compensatory changes in membrane composition are considered "homeoviscous adaptations." In this study, we examined a heterothermic tissue, the visceral rete mirabile of the bluefin tuna, for evidence of homeoviscous adaptation. We measured the proportions of phospholipid fatty acids and phospholipid head groups as a function of position along the rete thermal gradient, which has been estimated to be approximately 10 degrees C. We found no effect of position along the rete on the composition of either phospholipid fatty acids or head groups. Our results were unexpected in light of our previous demonstration of compensation of metabolic enzyme activity in the same tissue. The lack of evidence for a homeoviscous response may be due to the fluctuating nature of the thermal gradient along the visceral retia; i.e., membranes may be adapted to a eurythermal existence rather than being fine-tuned to a particular temperature.
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Affiliation(s)
- D S Fudge
- Department of Zoology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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