1
|
Morla J, Salin K, Lassus R, Favre-Marinet J, Sentis A, Daufresne M. Multigenerational exposure to temperature influences mitochondrial oxygen fluxes in the Medaka fish (Oryzias latipes). Acta Physiol (Oxf) 2024; 240:e14194. [PMID: 38924292 DOI: 10.1111/apha.14194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 05/08/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024]
Abstract
AIM Thermal sensitivity of cellular metabolism is crucial for animal physiology and survival under climate change. Despite recent efforts, effects of multigenerational exposure to temperature on the metabolic functioning remain poorly understood. We aimed at determining whether multigenerational exposure to temperature modulate the mitochondrial respiratory response of Medaka fish. METHODS We conducted a multigenerational exposure with Medaka fish reared multiple generations at 20 and 30°C (COLD and WARM fish, respectively). We then measured the oxygen consumption of tail muscle at two assay temperatures (20 and 30°C). Mitochondrial function was determined as the respiration supporting ATP synthesis (OXPHOS) and the respiration required to offset proton leak (LEAK(Omy)) in a full factorial design (COLD-20°C; COLD-30°C; WARM-20°C; WARM-30°C). RESULTS We found that higher OXPHOS and LEAK fluxes at 30°C compared to 20°C assay temperature. At each assay temperature, WARM fish had lower tissue oxygen fluxes than COLD fish. Interestingly, we did not find significant differences in respiratory flux when mitochondria were assessed at the rearing temperature of the fish (i.e., COLD-20°C vs. WARM -30°C). CONCLUSION The lower OXPHOS and LEAK capacities in warm fish are likely the result of the multigenerational exposure to warm temperature. This is consistent with a modulatory response of mitochondrial capacity to compensate for potential detrimental effects of warming on metabolism. Finally, the absence of significant differences in respiratory fluxes between COLD-20°C and WARM-30°C fish likely reflects an optimal respiration flux when organisms adapt to their thermal conditions.
Collapse
Affiliation(s)
- Julie Morla
- INRAE, Aix-Marseille University, UMR RECOVER, Aix-en-Provence, France
| | - Karine Salin
- Départment of Environment and Resources, IFREMER, Unité de Physiologie Fonctionnelle des Organismes Marins-LEMAR UMR 6530, BP70, Plouzané, France
| | - Rémy Lassus
- INRAE, Aix-Marseille University, UMR RECOVER, Aix-en-Provence, France
| | | | - Arnaud Sentis
- INRAE, Aix-Marseille University, UMR RECOVER, Aix-en-Provence, France
| | - Martin Daufresne
- INRAE, Aix-Marseille University, UMR RECOVER, Aix-en-Provence, France
| |
Collapse
|
2
|
Borowiec BG, Firth BL, Craig PM. Oxygen consumption rate during recovery from loss of equilibrium induced by warming, hypoxia, or exhaustive exercise in rainbow darter (Etheostoma caeruleum). JOURNAL OF FISH BIOLOGY 2024; 105:23-33. [PMID: 38599790 DOI: 10.1111/jfb.15756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 03/03/2024] [Accepted: 04/01/2024] [Indexed: 04/12/2024]
Abstract
Animals routinely encounter environmental (e.g., high temperatures and hypoxia) as well as physiological perturbations (e.g., exercise and digestion) that may threaten homeostasis. However, comparing the relative threat or "disruptiveness" imposed by different stressors is difficult, as stressors vary in their mechanisms, effects, and timescales. We exploited the fact that several acute stressors can induce the loss of equilibrium (LOE) in fish to (i) compare the metabolic recovery profiles of three environmentally relevant stressors and (ii) test the concept that LOE could be used as a physiological calibration for the intensity of different stressors. We focused on Etheostoma caeruleum, a species that routinely copes with environmental fluctuations in temperature and oxygen and that relies on burst swimming to relocate and avoid predators, as our model. Using stop-flow (intermittent) respirometry, we tracked the oxygen consumption rate (MO2) as E. caeruleum recovered from LOE induced by hypoxia (PO2 at LOE), warming (critical thermal maximum, CTmax), or exhaustive exercise. Regardless of the stressor used, E. caeruleum recovered rapidly, returning to routine MO2 within ~3 h. Fish recovering from hypoxia and warming had similar maximum MO2, aerobic scopes, recovery time, and total excess post-hypoxia or post-warming oxygen consumption. Though exhaustive exercise induced a greater maximum MO2 and corresponding higher aerobic scope than warming or hypoxia, its recovery profile was otherwise similar to the other stressors, suggesting that "calibration" to a physiological state such as LOE may be a viable conceptual approach for investigators interested in questions related to multiple stressors, cross tolerance, and how animals cope with challenges to homeostasis.
Collapse
Affiliation(s)
| | - Britney L Firth
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Paul M Craig
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
3
|
Makri V, Giantsis IA, Nathanailides C, Feidantsis K, Antonopoulou E, Theodorou JA, Michaelidis B. Seasonal energy investment and metabolic patterns in a farmed fish. J Therm Biol 2024; 123:103894. [PMID: 38879912 DOI: 10.1016/j.jtherbio.2024.103894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 06/09/2024] [Accepted: 06/11/2024] [Indexed: 06/18/2024]
Abstract
The present research focuses on the seasonal changes in the energy content and metabolic patterns of red porgy (Pagrus pagrus) sampled in a fish farm in North Evoikos Gulf (Greece). The study was designed in an effort to evaluate the influence of seasonality in several physiological feauteres of high commercial importance that may affect feed intake and growth. We determined glycogen, lipids and proteins levels, and cellular energy allocation (CEA) as a valuable marker of exposure to stress, which integrates available energy (Ea) and energy consumption (Ec). Metabolic patterns and aerobic oxidation potential were based on the determination of glucose transporter (GLU), carnitine transporter (CTP), L-lactate dehydrogenase (L-LDH), citrate synthase (CS), cytochrome C oxidase subunit IV isoform 1 (COX1) and 3-hydroxyacyl CoA dehydrogenase (HOAD) relative gene expression. To integrate metabolic patterns and gene expression, L-LDH, CS, COX and HOAD activities were also determined. For further estimation of biological stores oxidized during seasonal acclimatization, we determined the blood levels of glucose, lipids and lactate. The results indicated seasonal changes in energy content, different patterns in gene expression and reorganization of metabolic patterns during cool acclimatization with increased lipid oxidation. During warm acclimatization, however, energy consumption was mostly based on carbohydrates oxidation. The decrease of Ec and COX1 activity in the warm exposed heart seem to be consistent with the OCLTT hypothesis, suggesting that the heart may be one of the first organs to be limited during seasonal warming. Overall, this study has profiled changes in energetics and metabolic patterns occurring at annual temperatures at which P. pagrus is currently farmed, suggesting that this species is living at the upper edge of their thermal window, at least during summer.
Collapse
Affiliation(s)
- Vasiliki Makri
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, Thessaloniki, GR-54124, Greece
| | - Ioannis A Giantsis
- Department of Animal Science, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, GR-54124, Thessaloniki, Greece
| | | | | | - Efthimia Antonopoulou
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, Thessaloniki, GR-54124, Greece
| | - John A Theodorou
- Department of Fisheries & Aquaculture, University of Patras, GR-26504, Mesolonghi, Greece
| | - Basile Michaelidis
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, Thessaloniki, GR-54124, Greece.
| |
Collapse
|
4
|
Blanchard A, Aminot M, Gould N, Léger A, Pichaud N. Flies on the rise: acclimation effect on mitochondrial oxidation capacity at normal and high temperatures in Drosophila melanogaster. J Exp Biol 2024; 227:jeb247706. [PMID: 38841909 DOI: 10.1242/jeb.247706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 05/28/2024] [Indexed: 06/07/2024]
Abstract
Increased average temperatures and extreme thermal events (such as heatwaves) brought forth by climate change impose important constraints on aerobic metabolism. Notably, mitochondrial metabolism, which is affected by both long- and short-term temperature changes, has been put forward as an important determinant for thermal tolerance of organisms. This study examined the influence of phenotypic plasticity on metabolic and physiological parameters in Drosophila melanogaster and the link between mitochondrial function and their upper thermal limits. We showed that D. melanogaster acclimated to 15°C have a 0.65°C lower critical thermal maximum (CTmax) compared with those acclimated to 24°C. Drosophila melanogaster acclimated to 15°C exhibited a higher proportion of shorter saturated and monounsaturated fatty acids, concomitant with lower proportions of polyunsaturated fatty acids. No mitochondrial quantitative changes (fractional area and number) were detected between acclimation groups, but changes of mitochondrial oxidation capacities were observed. Specifically, in both 15°C- and 24°C-acclimated flies, complex I-induced respiration was increased when measured between 15 and 24°C, but drastically declined when measured at 40°C. When succinate and glycerol-3-phosphate were added, this decrease was however compensated for in flies acclimated to 24°C, suggesting an important impact of acclimation on mitochondrial function related to thermal tolerance. Our study reveals that the use of oxidative substrates at high temperatures is influenced by acclimation temperature and strongly related to upper thermal tolerance as a difference of 0.65°C in CTmax translates into significant mitochondrial changes.
Collapse
Affiliation(s)
- Arianne Blanchard
- New Brunswick Centre for Precision Medicine, Moncton, NB E1C8X3, Canada
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada
| | - Mélanie Aminot
- New Brunswick Centre for Precision Medicine, Moncton, NB E1C8X3, Canada
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada
| | - Nathalie Gould
- New Brunswick Centre for Precision Medicine, Moncton, NB E1C8X3, Canada
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada
| | - Adèle Léger
- New Brunswick Centre for Precision Medicine, Moncton, NB E1C8X3, Canada
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada
| | - Nicolas Pichaud
- New Brunswick Centre for Precision Medicine, Moncton, NB E1C8X3, Canada
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada
| |
Collapse
|
5
|
Zhan L, He J, Meng S, Guo Z, Chen Y, Storey KB, Zhang J, Yu D. Mitochondrial Protein-Coding Gene Expression in the Lizard Sphenomorphus incognitus (Squamata:Scincidae) Responding to Different Temperature Stresses. Animals (Basel) 2024; 14:1671. [PMID: 38891717 PMCID: PMC11170996 DOI: 10.3390/ani14111671] [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: 05/06/2024] [Revised: 05/25/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
In the context of global warming, the frequency of severe weather occurrences, such as unexpected cold spells and heat waves, will grow, as well as the intensity of these natural disasters. Lizards, as a large group of reptiles, are ectothermic. Their body temperatures are predominantly regulated by their environment and temperature variations directly impact their behavior and physiological activities. Frequent cold periods and heat waves can affect their biochemistry and physiology, and often their ability to maintain their body temperature. Mitochondria, as the center of energy metabolism, are crucial for maintaining body temperature, regulating metabolic rate, and preventing cellular oxidative damage. Here, we used RT-qPCR technology to investigate the expression patterns and their differences for the 13 mitochondrial PCGs in Sphenomorphus incognitus (Squamata:Scincidae), also known as the brown forest skink, under extreme temperature stress at 4 °C, 8 °C, 34 °C, and 38 °C for 24 h, compared to the control group at 25 °C. In southern China, for lizards, 4 °C is close to lethal, and 8 °C induces hibernation, while 34/38 °C is considered hot and environmentally realistic. Results showed that at a low temperature of 4 °C for 24 h, transcript levels of ATP8, ND1, ND4, COI, and ND4L significantly decreased, to values of 0.52 ± 0.08, 0.65 ± 0.04, 0.68 ± 0.10, 0.28 ± 0.02, and 0.35 ± 0.02, respectively, compared with controls. By contrast, transcript levels of COIII exhibited a significant increase, with a mean value of 1.86 ± 0.21. However, exposure to 8 °C for 24 h did not lead to an increase in transcript levels. Indeed, transcript levels of ATP6, ATP8, ND1, ND3, and ND4 were significantly downregulated, to 0.48 ± 0.11, 0.68 ± 0.07, 0.41 ± 0.08, 0.54 ± 0.10, and 0.52 ± 0.07, respectively, as compared with controls. Exposure to a hot environment of 34 °C for 24 h led to an increase in transcript levels of COI, COII, COIII, ND3, ND5, CYTB, and ATP6, with values that were 3.3 ± 0.24, 2.0 ± 0.2, 2.70 ± 1.06, 1.57 ± 0,08, 1.47 ± 0.13, 1.39 ± 0.56, and 1.86 ± 0.12, respectively, over controls. By contrast, ND4L exhibited a significant decrease (to 0.31 ± 0.01) compared with controls. When exposed to 38 °C, the transcript levels of the 13 PCGs significantly increased, ranging from a 2.04 ± 0.23 increase in ND1 to a 6.30 ± 0.96 rise in ND6. Under two different levels of cold and heat stress, the expression patterns of mitochondrial genes in S. incognitus vary, possibly associated with different strategies employed by this species in response to low and high temperatures, allowing for rapid compensatory adjustments in mitochondrial electron transport chain proteins in response to temperature changes. Furthermore, this underscores once again the significant role of mitochondrial function in determining thermal plasticity in reptiles.
Collapse
Affiliation(s)
- Lemei Zhan
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China; (L.Z.)
| | - Jingyi He
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China; (L.Z.)
| | - Siqi Meng
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China; (L.Z.)
| | - Zhiqiang Guo
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China; (L.Z.)
| | - Yuxin Chen
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China; (L.Z.)
| | - Kenneth B. Storey
- Department of Biology, Carleton University, Ottawa, ON K1S5B6, Canada;
| | - Jiayong Zhang
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China; (L.Z.)
| | - Danna Yu
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China; (L.Z.)
- Key Lab of Wildlife Biotechnology, Conservation and Utilization of Zhejiang Province, Zhejiang Normal University, Jinhua 321004, China
| |
Collapse
|
6
|
Sadler DE, Watts PC, Uusi-Heikkilä S. Directional selection, not the direction of selection, affects telomere length and copy number at ribosomal RNA loci. Sci Rep 2024; 14:12162. [PMID: 38802448 PMCID: PMC11130246 DOI: 10.1038/s41598-024-63030-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 05/23/2024] [Indexed: 05/29/2024] Open
Abstract
Many fisheries exert directional selection on traits such as body size and growth rate. Whether directional selection impacts regions of the genome associated with traits related to growth is unknown. To address this issue, we characterised copy number variation in three regions of the genome associated with cell division, (1) telomeric DNA, (2) loci transcribed as ribosomal RNA (rDNA), and (3) mitochondrial DNA (mtDNA), in three selection lines of zebrafish reared at three temperatures (22 °C, 28 °C, and 34 °C). Selection lines differed in (1) the direction of selection (two lines experienced directional selection for large or small body size) and (2) whether they experienced any directional selection itself. Lines that had experienced directional selection were smaller, had lower growth rate, shorter telomeres, and lower rDNA copy number than the line that experiencing no directional selection. Neither telomere length nor rDNA copy number were affected by temperature. In contrast, mtDNA content increased at elevated temperature but did not differ among selection lines. Though directional selection impacts rDNA and telomere length, direction of such selection did not matter, whereas mtDNA acts as a stress marker for temperature. Future work should examine the consequences of these genomic changes in natural fish stocks.
Collapse
Affiliation(s)
- Daniel E Sadler
- Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland.
| | - Phillip C Watts
- Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland
| | - Silva Uusi-Heikkilä
- Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland
| |
Collapse
|
7
|
Montgomery DW, Finlay J, Simpson SD, Engelhard GH, Birchenough SNR, Wilson RW. Respiratory acidosis and O 2 supply capacity do not affect the acute temperature tolerance of rainbow trout ( Oncorhynchus mykiss). CONSERVATION PHYSIOLOGY 2024; 12:coae026. [PMID: 38779432 PMCID: PMC11109029 DOI: 10.1093/conphys/coae026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/06/2024] [Accepted: 04/15/2024] [Indexed: 05/25/2024]
Abstract
The mechanisms that determine the temperature tolerances of fish are poorly understood, creating barriers to disentangle how additional environmental challenges-such as CO2-induced aquatic acidification and fluctuating oxygen availability-may exacerbate vulnerability to a warming climate and extreme heat events. Here, we explored whether two acute exposures (~0.5 hours or ~72 hours) to increased CO2 impact acute temperature tolerance limits in a freshwater fish, rainbow trout (Oncorhynchus mykiss). We separated the potential effects of acute high CO2 exposure on critical thermal maximum (CTmax), caused via either respiratory acidosis (reduced internal pH) or O2 supply capacity (aerobic scope), by exposing rainbow trout to ~1 kPa CO2 (~1% or 10 000 μatm) in combination with normoxia or hyperoxia (~21 or 42 kPa O2, respectively). In normoxia, acute exposure to high CO2 caused a large acidosis in trout (blood pH decreased by 0.43 units), while a combination of hyperoxia and ~1 kPa CO2 increased the aerobic scope of trout by 28%. Despite large changes in blood pH and aerobic scope between treatments, we observed no impacts on the CTmax of trout. Our results suggest that the mechanisms that determine the maximum temperature tolerance of trout are independent of blood acid-base balance or the capacity to deliver O2 to tissues.
Collapse
Affiliation(s)
| | - Jennifer Finlay
- Biosciences, Stocker Road, University of Exeter, Exeter, EX4 4QD, UK
| | - Stephen D Simpson
- Biosciences, Stocker Road, University of Exeter, Exeter, EX4 4QD, UK
| | - Georg H Engelhard
- International Marine Climate Change Centre (iMC3), Centre for Environment, Fisheries & Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT, UK
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Silvana N R Birchenough
- International Marine Climate Change Centre (iMC3), Centre for Environment, Fisheries & Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT, UK
| | - Rod W Wilson
- Biosciences, Stocker Road, University of Exeter, Exeter, EX4 4QD, UK
| |
Collapse
|
8
|
Léger A, Cormier SB, Blanchard A, Menail HA, Pichaud N. Investigating the thermal sensitivity of key enzymes involved in the energetic metabolism of three insect species. J Exp Biol 2024; 227:jeb247221. [PMID: 38680096 DOI: 10.1242/jeb.247221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 04/16/2024] [Indexed: 05/01/2024]
Abstract
The metabolic responses of insects to high temperatures have been linked to their mitochondrial substrate oxidation capacity. However, the mechanism behind this mitochondrial flexibility is not well understood. Here, we used three insect species with different thermal tolerances (the honey bee, Apis mellifera; the fruit fly, Drosophila melanogaster; and the potato beetle, Leptinotarsa decemlineata) to characterize the thermal sensitivity of different metabolic enzymes. Specifically, we measured activity of enzymes involved in glycolysis (hexokinase, HK; pyruvate kinase, PK; and lactate dehydrogenase, LDH), pyruvate oxidation and the tricarboxylic acid cycle (pyruvate dehydrogenase, PDH; citrate synthase, CS; malate dehydrogenase, MDH; and aspartate aminotransferase, AAT), and the electron transport system (Complex I, CI; Complex II, CII; mitochondrial glycerol-3-phosphate dehydrogenase, mG3PDH; proline dehydrogenase, ProDH; and Complex IV, CIV), as well as that of ATP synthase (CV) at 18, 24, 30, 36, 42 and 45°C. Our results show that at high temperature, all three species have significantly increased activity of enzymes linked to FADH2 oxidation, specifically CII and mG3PDH. In fruit flies and honey bees, this coincides with a significant decrease of PDH and CS activity, respectively, that would limit NADH production. This is in line with the switch from NADH-linked substrates to FADH2-linked substrates previously observed with mitochondrial oxygen consumption. Thus, we demonstrate that even though the three insect species have a different metabolic regulation, a similar response to high temperature involving CII and mG3PDH is observed, denoting the importance of these proteins for thermal tolerance in insects.
Collapse
Affiliation(s)
- Adèle Léger
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, CanadaE1A 3E9
- New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, CanadaE1C 8X3
| | - Simon B Cormier
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, CanadaE1A 3E9
- New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, CanadaE1C 8X3
| | - Arianne Blanchard
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, CanadaE1A 3E9
- New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, CanadaE1C 8X3
| | - Hichem A Menail
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, CanadaE1A 3E9
- New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, CanadaE1C 8X3
| | - Nicolas Pichaud
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, CanadaE1A 3E9
- New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, CanadaE1C 8X3
| |
Collapse
|
9
|
Iverson ENK. Conservation Mitonuclear Replacement: Facilitated mitochondrial adaptation for a changing world. Evol Appl 2024; 17:e13642. [PMID: 38468713 PMCID: PMC10925831 DOI: 10.1111/eva.13642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/29/2023] [Accepted: 01/03/2024] [Indexed: 03/13/2024] Open
Abstract
Most species will not be able to migrate fast enough to cope with climate change, nor evolve quickly enough with current levels of genetic variation. Exacerbating the problem are anthropogenic influences on adaptive potential, including the prevention of gene flow through habitat fragmentation and the erosion of genetic diversity in small, bottlenecked populations. Facilitated adaptation, or assisted evolution, offers a way to augment adaptive genetic variation via artificial selection, induced hybridization, or genetic engineering. One key source of genetic variation, particularly for climatic adaptation, are the core metabolic genes encoded by the mitochondrial genome. These genes influence environmental tolerance to heat, drought, and hypoxia, but must interact intimately and co-evolve with a suite of important nuclear genes. These coadapted mitonuclear genes form some of the important reproductive barriers between species. Mitochondrial genomes can and do introgress between species in an adaptive manner, and they may co-introgress with nuclear genes important for maintaining mitonuclear compatibility. Managers should consider the relevance of mitonuclear genetic variability in conservation decision-making, including as a tool for facilitating adaptation. I propose a novel technique dubbed Conservation Mitonuclear Replacement (CmNR), which entails replacing the core metabolic machinery of a threatened species-the mitochondrial genome and key nuclear loci-with those from a closely related species or a divergent population, which may be better-adapted to climatic changes or carry a lower genetic load. The most feasible route to CmNR is to combine CRISPR-based nuclear genetic editing with mitochondrial replacement and assisted reproductive technologies. This method preserves much of an organism's phenotype and could allow populations to persist in the wild when no other suitable conservation options exist. The technique could be particularly important on mountaintops, where rising temperatures threaten an alarming number of species with almost certain extinction in the next century.
Collapse
Affiliation(s)
- Erik N. K. Iverson
- Department of Integrative BiologyThe University of Texas at AustinAustinTexasUSA
| |
Collapse
|
10
|
Gunderson AR. Disentangling physiological and physical explanations for body size-dependent thermal tolerance. J Exp Biol 2024; 227:jeb245645. [PMID: 38426549 DOI: 10.1242/jeb.245645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
The effects of climate change are often body size dependent. One contributing factor could be size-dependent thermal tolerance (SDTT), the propensity for heat and cold tolerance to vary with body size among species and among individuals within species. SDTT is hypothesized to be caused by size differences in the temperature dependence of underlying physiological processes that operate at the cellular and organ/system level (physiological SDTT). However, temperature-dependent physiology need not change with body size for SDTT to be observed. SDTT can also arise because of physical differences that affect the relative body temperature dynamics of large and small organisms (physical SDTT). In this Commentary, I outline how physical SDTT occurs, its mechanistic differences from physiological SDTT, and how physical and physiological SDTT make different predictions about organismal responses to thermal variation. I then describe how physical SDTT can influence the outcome of thermal tolerance experiments, present an experimental framework for disentangling physical and physiological SDTT, and provide examples of tests for physiological SDTT that control for physical effects using data from Anolis lizards. Finally, I discuss how physical SDTT can affect organisms in natural environments and influence their vulnerability to anthropogenic warming. Differentiating between physiological and physical SDTT is important because it has implications for how we design and interpret thermal tolerance experiments and our fundamental understanding of thermal ecology and thermal adaptation.
Collapse
Affiliation(s)
- Alex R Gunderson
- Department of Ecology & Evolutionary Biology, Tulane University, 6823 St Charles Avenue, Lindy Boggs Building Room 400, New Orleans, LA 70118-5698, USA
| |
Collapse
|
11
|
Thoral E, García-Díaz CC, Persson E, Chamkha I, Elmér E, Ruuskanen S, Nord A. The relationship between mitochondrial respiration, resting metabolic rate and blood cell count in great tits. Biol Open 2024; 13:bio060302. [PMID: 38385271 PMCID: PMC10958200 DOI: 10.1242/bio.060302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 02/19/2024] [Indexed: 02/23/2024] Open
Abstract
Although mitochondrial respiration is believed to explain a substantial part of the variation in resting metabolic rate (RMR), few studies have empirically studied the relationship between organismal and cellular metabolism. We therefore investigated the relationship between RMR and mitochondrial respiration of permeabilized blood cells in wild great tits (Parus major L.). We also studied the correlation between mitochondrial respiration traits and blood cell count, as normalizing mitochondrial respiration by the cell count is a method commonly used to study blood metabolism. In contrast to previous studies, our results show that there was no relationship between RMR and mitochondrial respiration in intact blood cells (i.e. with the ROUTINE respiration). However, when cells were permeabilized and interrelation re-assessed under saturating substrate availability, we found that RMR was positively related to phosphorylating respiration rates through complexes I and II (i.e. OXPHOS respiration) and to the mitochondrial efficiency to produce energy (i.e. net phosphorylation efficiency), though variation explained by the models was low (i.e. linear model: R2=0.14 to 0.21). However, unlike studies in mammals, LEAK respiration without [i.e. L(n)] and with [i.e. L(Omy)] adenylates was not significantly related to RMR. These results suggest that phosphorylating respiration in blood cells can potentially be used to predict RMR in wild birds, but that this relationship may have to be addressed in standardized conditions (permeabilized cells) and that the prediction risks being imprecise. We also showed that, in our conditions, there was no relationship between any mitochondrial respiration trait and blood cell count. Hence, we caution against normalising respiration rates using this parameter as is sometimes done. Future work should address the functional explanations for the observed relationships, and determine why these appear labile across space, time, taxon, and physiological state.
Collapse
Affiliation(s)
- Elisa Thoral
- Lund University, Department of Biology, Section for Evolutionary Ecology, Sölvegatan 37, SE-223 62 Lund, Sweden
| | - Carmen C. García-Díaz
- Lund University, Department of Biology, Section for Evolutionary Ecology, Sölvegatan 37, SE-223 62 Lund, Sweden
| | - Elin Persson
- Lund University, Department of Biology, Section for Evolutionary Ecology, Sölvegatan 37, SE-223 62 Lund, Sweden
| | - Imen Chamkha
- Lund University, Department of Clinical Sciences, Mitochondrial Medicine, Sölvegatan 17, SE-221 84, Lund, Sweden
| | - Eskil Elmér
- Lund University, Department of Clinical Sciences, Mitochondrial Medicine, Sölvegatan 17, SE-221 84, Lund, Sweden
| | - Suvi Ruuskanen
- Department of Biological and Environmental Science, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Andreas Nord
- Lund University, Department of Biology, Section for Evolutionary Ecology, Sölvegatan 37, SE-223 62 Lund, Sweden
| |
Collapse
|
12
|
Štětina T, Koštál V. Extracellular freezing induces a permeability transition in the inner membrane of muscle mitochondria of freeze-sensitive but not freeze-tolerant Chymomyza costata larvae. Front Physiol 2024; 15:1358190. [PMID: 38384799 PMCID: PMC10880108 DOI: 10.3389/fphys.2024.1358190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/29/2024] [Indexed: 02/23/2024] Open
Abstract
Background: Many insect species have evolved the ability to survive extracellular freezing. The search for the underlying principles of their natural freeze tolerance remains hampered by our poor understanding of the mechanistic nature of freezing damage itself. Objectives: Here, in search of potential primary cellular targets of freezing damage, we compared mitochondrial responses (changes in morphology and physical integrity, respiratory chain protein functionality, and mitochondrial inner membrane (IMM) permeability) in freeze-sensitive vs. freeze-tolerant phenotypes of the larvae of the drosophilid fly, Chymomyza costata. Methods: Larvae were exposed to freezing stress at -30°C for 1 h, which is invariably lethal for the freeze-sensitive phenotype but readily survived by the freeze-tolerant phenotype. Immediately after melting, the metabolic activity of muscle cells was assessed by the Alamar Blue assay, the morphology of muscle mitochondria was examined by transmission electron microscopy, and the functionality of the oxidative phosphorylation system was measured by Oxygraph-2K microrespirometry. Results: The muscle mitochondria of freeze-tolerant phenotype larvae remained morphologically and functionally intact after freezing stress. In contrast, most mitochondria of the freeze-sensitive phenotype were swollen, their matrix was diluted and enlarged in volume, and the structure of the IMM cristae was lost. Despite this morphological damage, the electron transfer chain proteins remained partially functional in lethally frozen larvae, still exhibiting strong responses to specific respiratory substrates and transferring electrons to oxygen. However, the coupling of electron transfer to ATP synthesis was severely impaired. Based on these results, we formulated a hypothesis linking the observed mitochondrial swelling to a sudden loss of barrier function of the IMM.
Collapse
Affiliation(s)
| | - Vladimír Koštál
- Institute of Entomology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czechia
| |
Collapse
|
13
|
Dallas JW, Kazarina A, Lee STM, Warne RW. Cross-species gut microbiota transplantation predictably affects host heat tolerance. J Exp Biol 2024; 227:jeb246735. [PMID: 38073469 PMCID: PMC10906491 DOI: 10.1242/jeb.246735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/29/2023] [Indexed: 01/11/2024]
Abstract
The gut microbiome is known to influence and have regulatory effects in diverse physiological functions of host animals, but only recently has the relationship between host thermal biology and gut microbiota been explored. Here, we examined how early-life manipulations of the gut microbiota in larval amphibians influenced their critical thermal maximum (CTmax) at different acclimation temperatures. We stripped the resident microbiome from egg masses of wild-caught wood frogs (Lithobates sylvaticus) via an antibiotic wash, and then inoculated the eggs with pond water (control), no inoculation, or the intestinal microbiota of another species that has a wider thermal tolerance - green frogs (Lithobates clamitans). We predicted that this cross-species transplant would increase the CTmax of the recipient wood frog larvae relative to the other treatments. In line with this prediction, green frog microbiome-recipient larvae had the highest CTmax while those with no inoculum had the lowest CTmax. Both the microbiome treatment and acclimation temperature significantly influenced the larval gut microbiota communities and α-diversity indices. Green frog microbiome-inoculated larvae were enriched in Rikenellaceae relative to the other treatments, which produce short-chain fatty acids and could contribute to greater energy availability and enhanced heat tolerance. Larvae that received no inoculation had a higher relative abundance of potentially pathogenic Aeromonas spp., which negatively affects host health and performance. Our results are the first to show that cross-species gut microbiota transplants alter heat tolerance in a predictable manner. This finding has repercussions for the conservation of species that are threatened by climate change and demonstrates a need to further explore the mechanisms by which the gut microbiota modulate host thermal tolerance.
Collapse
Affiliation(s)
- Jason W. Dallas
- Southern Illinois University,School of Biological Sciences, 1125 Lincoln Dr., Carbondale, IL 62901-6501, USA
| | - Anna Kazarina
- Kansas State University, Division of Biology, 1717 Claflin Rd, Manhattan, KS 66506, USA
| | - Sonny T. M. Lee
- Kansas State University, Division of Biology, 1717 Claflin Rd, Manhattan, KS 66506, USA
| | - Robin W. Warne
- Southern Illinois University,School of Biological Sciences, 1125 Lincoln Dr., Carbondale, IL 62901-6501, USA
| |
Collapse
|
14
|
Kayhani K, Barreto FS. Disproportionate role of nuclear-encoded proteins in organismal and mitochondrial thermal performance in a copepod. J Exp Biol 2023; 226:jeb246085. [PMID: 37947077 DOI: 10.1242/jeb.246085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 10/30/2023] [Indexed: 11/12/2023]
Abstract
Determining the mechanisms by which organisms evolve thermal tolerance is crucial to predicting how populations may respond to changes in local temperature regimes. Although evidence of relationships between mitochondrial background and thermal adaptation have been found, the presence of both nuclear-encoded and mitochondrial DNA (mtDNA)-encoded proteins warrants experiments aimed at parsing out the relative role of each genome in thermal adaptation. We investigated the relative role of mtDNA-encoded products in thermal tolerance between two divergent populations of Tigriopus californicus using first-generation (F1) hybrids that vary in maternally inherited mtDNA but are heterozygous for population-specific alleles across nuclear loci. We tested two measures of thermal tolerance, (1) survivorship to acute thermal stress and (2) thermal stability of mitochondrial performance in Complex I-fueled ATP synthesis, both across a range of increasing temperatures. We found that the southern population (San Diego, CA, USA) outperformed the northern population (Strawberry Hill, OR, USA) in survivorship, and that both reciprocal F1 hybrid crosses had intermediate survival. Mitochondria from the San Diego population displayed greater stability in ATP synthesis with increasing temperatures compared with those from Strawberry Hill. Interestingly, hybrids from both cross directions had synthesis profiles that were very similar to that of Strawberry Hill. Taken together, these results suggest that the relative role of the mtDNA in these phenotypes is negligible compared with that of elements encoded by nuclear DNA in this system.
Collapse
Affiliation(s)
- Kamron Kayhani
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Felipe S Barreto
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| |
Collapse
|
15
|
Sapozhnikova YP, Koroleva AG, Yakhnenko VM, Volkova AA, Avezova TN, Glyzina OY, Sakirko MV, Tolstikova LI, Sukhanova LV. Thermal Preconditioning Alters the Stability of Hump-Snout Whitefish ( Coregonus fluviatilis) and Its Hybrid Form, Showing Potential for Aquaculture. BIOLOGY 2023; 12:1348. [PMID: 37887058 PMCID: PMC10603914 DOI: 10.3390/biology12101348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/28/2023]
Abstract
One of the little-studied ways that climate warming or temperature increases in aquaculture could affect aquatic animals is through accelerated aging. This study is dedicated to understanding the principles of molecular and cellular aging in the target tissues of juvenile whitefishes (Yenisei hump-snout whitefish and its hybrid) under the influence of acute heat stress (up to 26 °C), and the effects of thermal preconditioning as pre-adaptation. Non-adapted stressed hump-snout whitefish showed a higher induction threshold for functionally active mitochondria in the blood and a decrease in telomerase activity in the liver after heat shock exposure as a long-term compensatory response to prevent telomere shortening. However, we observed heat-induced telomere shortening in non-adapted hybrids, which can be explained by a decrease in mitochondrial membrane stability and a gradual increase in energy demand, leading to a decrease in protective telomerase activity. The pre-adapted groups of hump-snout whitefish and hybrids showed a long-term or delayed response of telomerase activity to heat shock, which served as a therapeutic mechanism against telomere shortening. We concluded that the telomerase and telomere responses to thermal stress demonstrate plasticity of tolerance limits and greater stability in hump-snout whitefish compared with hybrids.
Collapse
Affiliation(s)
- Yulia P. Sapozhnikova
- Limnological Institute Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya, 664033 Irkutsk, Russia; (V.M.Y.); (A.A.V.); (T.N.A.); (O.Y.G.); (M.V.S.); (L.I.T.); (L.V.S.)
| | - Anastasia G. Koroleva
- Limnological Institute Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya, 664033 Irkutsk, Russia; (V.M.Y.); (A.A.V.); (T.N.A.); (O.Y.G.); (M.V.S.); (L.I.T.); (L.V.S.)
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Roussel D, Janillon S, Teulier L, Pichaud N. Succinate oxidation rescues mitochondrial ATP synthesis at high temperature in Drosophila melanogaster. FEBS Lett 2023; 597:2221-2229. [PMID: 37463836 DOI: 10.1002/1873-3468.14701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/05/2023] [Accepted: 07/03/2023] [Indexed: 07/20/2023]
Abstract
Decreased NADH-induced and increased reduced FADH2 -induced respiration rates at high temperatures are associated with thermal tolerance in Drosophila. Here, we determined whether this change was associated with adjustments of adenosine triphosphate (ATP) production rate and coupling efficiency (ATP/O) in Drosophila melanogaster. We show that decreased pyruvate + malate oxidation at 35°C is associated with a collapse of ATP synthesis and a drop in ATP/O ratio. However, adding succinate triggered a full compensation of both oxygen consumption and ATP synthesis rates at this high temperature. Addition of glycerol-3-phosphate (G3P) led to a huge increase in respiration with no further advantage in terms of ATP production. We conclude that succinate is the only alternative substrate able to compensate both oxygen consumption and ATP production rates during oxidative phosphorylation at high temperature, which has important implications for thermal adaptation.
Collapse
Affiliation(s)
- Damien Roussel
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, Villeurbanne, France
| | - Sonia Janillon
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR 5558 LBBE, Villeurbanne, France
| | - Loïc Teulier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, Villeurbanne, France
| | - Nicolas Pichaud
- Department of Chemistry and Biochemistry, Université de Moncton, New Brunswick, Canada
| |
Collapse
|
17
|
Lagarde H, Lallias D, Patrice P, Dehaullon A, Prchal M, François Y, D'Ambrosio J, Segret E, Acin-Perez A, Cachelou F, Haffray P, Dupont-Nivet M, Phocas F. Genetic architecture of acute hyperthermia resistance in juvenile rainbow trout (Oncorhynchus mykiss) and genetic correlations with production traits. Genet Sel Evol 2023; 55:39. [PMID: 37308823 DOI: 10.1186/s12711-023-00811-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 05/11/2023] [Indexed: 06/14/2023] Open
Abstract
BACKGROUND Selective breeding is a promising solution to reduce the vulnerability of fish farms to heat waves, which are predicted to increase in intensity and frequency. However, limited information about the genetic architecture of acute hyperthermia resistance in fish is available. Two batches of sibs from a rainbow trout commercial line were produced: the first (N = 1382) was phenotyped for acute hyperthermia resistance at nine months of age and the second (N = 1506) was phenotyped for main production traits (growth, body length, muscle fat content and carcass yield) at 20 months of age. Fish were genotyped on a 57 K single nucleotide polymorphism (SNP) array and their genotypes were imputed to high-density based on the parent's genotypes from a 665 K SNP array. RESULTS The heritability estimate of resistance to acute hyperthermia was 0.29 ± 0.05, confirming the potential of selective breeding for this trait. Since genetic correlations of acute hyperthermia resistance with the main production traits near harvest age were all close to zero, selecting for acute hyperthermia resistance should not impact the main production traits, and vice-versa. A genome-wide association study revealed that resistance to acute hyperthermia is a highly polygenic trait, with six quantitative trait loci (QTL) detected, but explaining less than 5% of the genetic variance. Two of these QTL, including the most significant one, may explain differences in acute hyperthermia resistance across INRAE isogenic lines of rainbow trout. Differences in mean acute hyperthermia resistance phenotypes between homozygotes at the most significant SNP was 69% of the phenotypic standard deviation, showing promising potential for marker-assisted selection. We identified 89 candidate genes within the QTL regions, among which the most convincing functional candidates are dnajc7, hsp70b, nkiras2, cdk12, phb, fkbp10, ddx5, cygb1, enpp7, pdhx and acly. CONCLUSIONS This study provides valuable insight into the genetic architecture of acute hyperthermia resistance in juvenile rainbow trout. We show that the selection potential for this trait is substantial and selection for this trait should not be too detrimental to improvement of other traits of interest. Identified functional candidate genes provide new knowledge on the physiological mechanisms involved in acute hyperthermia resistance, such as protein chaperoning, oxidative stress response, homeostasis maintenance and cell survival.
Collapse
Affiliation(s)
- Henri Lagarde
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350, Jouy-en-Josas, France
| | - Delphine Lallias
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350, Jouy-en-Josas, France
| | - Pierre Patrice
- SYSAAF, French Poultry, Aquaculture and Insect Breeders Association, 35042, Rennes, France
| | - Audrey Dehaullon
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350, Jouy-en-Josas, France
| | - Martin Prchal
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České Budějovice, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Yoannah François
- SYSAAF, French Poultry, Aquaculture and Insect Breeders Association, 35042, Rennes, France
| | - Jonathan D'Ambrosio
- SYSAAF, French Poultry, Aquaculture and Insect Breeders Association, 35042, Rennes, France
| | - Emilien Segret
- Viviers de Sarrance, Pisciculture Labedan, 64490, Sarrance, France
| | - Ana Acin-Perez
- Viviers de Sarrance, Pisciculture Labedan, 64490, Sarrance, France
| | | | - Pierrick Haffray
- SYSAAF, French Poultry, Aquaculture and Insect Breeders Association, 35042, Rennes, France
| | | | - Florence Phocas
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350, Jouy-en-Josas, France.
| |
Collapse
|
18
|
Dallas JW, Warne RW. Ranavirus infection does not reduce heat tolerance in a larval amphibian. J Therm Biol 2023; 114:103584. [PMID: 37209633 DOI: 10.1016/j.jtherbio.2023.103584] [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: 02/26/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/22/2023]
Abstract
Extreme heat events and emerging infectious diseases negatively impact wildlife populations, but the interacting effects of infection and host heat tolerance remain understudied. The few studies covering this subject have demonstrated that pathogens lower the heat tolerance of their hosts, which places infected hosts at a greater risk experiencing lethal heat stress. Here, we studied how ranavirus infection influenced heat tolerance in larval wood frogs (Lithobates sylvaticus). In line with similar studies, we predicted the elevated costs of ranavirus infection would lower heat tolerance, measured as critical thermal maximum (CTmax), compared to uninfected controls. Ranavirus infection did not reduce CTmax and there was a positive relationship between CTmax and viral loads. Our results demonstrate that ranavirus-infected wood frog larvae had no loss in heat tolerance compared to uninfected larvae, even at viral loads associated with high mortality rates, which contradicts the common pattern for other pathogenic infections in ectotherms. Larval anurans may prioritize maintenance of their CTmax when infected with ranavirus to promote selection of warmer temperatures during behavioral fever that can improve pathogen clearance. Our study represents the first to examine the effect of ranavirus infection on host heat tolerance, and because no decline in CTmax was observed, this suggests that infected hosts would not be under greater risk of heat stress.
Collapse
Affiliation(s)
- Jason W Dallas
- School of Biological Sciences, Southern Illinois University Carbondale, 1125 Lincoln Street, Carbondale, IL, 62901, USA.
| | - Robin W Warne
- School of Biological Sciences, Southern Illinois University Carbondale, 1125 Lincoln Street, Carbondale, IL, 62901, USA
| |
Collapse
|
19
|
Jiménez AG, Nash-Braun E. Enzymatic responses reveal different physiological strategies employed by eurytolerant fish during extreme hot and cold cycling acclimation temperatures. J Therm Biol 2023; 114:103578. [PMID: 37344032 DOI: 10.1016/j.jtherbio.2023.103578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/13/2023] [Accepted: 04/16/2023] [Indexed: 06/23/2023]
Abstract
Heat waves and cold snaps are projected to rise in magnitude, duration, interval, and harshness in the coming years. The current literature examining thermal impacts on the physiology of organisms rarely uses chronic, variable thermal acclimations despite the fact that climate change predictions project a more variable environment. If we are to determine species' susceptibility to climate change, chronic and variable lab acclimations should be prioritized. Here, we acclimated the eurytolerant sheepshead minnow (Cyprinodon variegatus) to two extreme cycling thermal regimes: one warm [resting 27 °C with a spike to 33 °C for 8 h daily], one cold [resting 6.5 °C with a spike to 12 °C for 8 h daily], and three chronically stable conditions (10, 22, and 30 °C) for comparison. We measured enzymatic antioxidants (catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)), total antioxidant capacity, lipid peroxidation (LPO) damage, and citrate synthase (CS) activity in white epaxial muscle. Of particular note, we found significant increases in log CAT activity and SOD concentration in the warm cycling temperatures, and significant increases in GPx activity in the cold cycling temperatures. We found no significant accumulation of LPO damage in any of our thermal acclimation treatments. Thus, sheepshead minnows demonstrate two particularly different mechanisms towards dealing with thermal variation in low and high temperatures. The enzymatic differences between low and high cycling temperatures may define pathways of eurytolerant organisms and how they may survive predicted variability in thermal regimes.
Collapse
Affiliation(s)
- Ana Gabriela Jiménez
- Colgate University, Department of Biology, 13 Oak Dr., Hamilton, NY, 133546, USA.
| | - Evan Nash-Braun
- Colgate University, Department of Biology, 13 Oak Dr., Hamilton, NY, 133546, USA
| |
Collapse
|
20
|
Sokolova IM. Ectotherm mitochondrial economy and responses to global warming. Acta Physiol (Oxf) 2023; 237:e13950. [PMID: 36790303 DOI: 10.1111/apha.13950] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/24/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023]
Abstract
Temperature is a key abiotic factor affecting ecology, biogeography, and evolution of species. Alterations of energy metabolism play an important role in adaptations and plastic responses to temperature shifts on different time scales. Mitochondrial metabolism affects cellular bioenergetics and redox balance making these organelles an important determinant of organismal performances such as growth, locomotion, or development. Here I analyze the impacts of environmental temperature on the mitochondrial functions (including oxidative phosphorylation, proton leak, production of reactive oxygen species(ROS), and ATP synthesis) of ectotherms and discuss the mechanisms underlying negative shifts in the mitochondrial energy economy caused by supraoptimal temperatures. Owing to the differences in the thermal sensitivity of different mitochondrial processes, elevated temperatures (beyond the species- and population-specific optimal range) cause reallocation of the electron flux and the protonmotive force (Δp) in a way that decreases ATP synthesis efficiency, elevates the relative cost of the mitochondrial maintenance, causes excessive production of ROS and raises energy cost for antioxidant defense. These shifts in the mitochondrial energy economy might have negative consequences for the organismal fitness traits such as the thermal tolerance or growth. Correlation between the thermal sensitivity indices of the mitochondria and the whole organism indicate that these traits experience similar selective pressures but further investigations are needed to establish whether there is a cause-effect relationship between the mitochondrial failure and loss of organismal performance during temperature change.
Collapse
Affiliation(s)
- Inna M Sokolova
- Department of Marine Biology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
- Department of Maritime Systems, Interdisciplinary Faculty, University of Rostock, Rostock, Germany
| |
Collapse
|
21
|
Horne LM, DeVries DR, Wright R, Irwin E, Staton BA, Abdelrahman HA, Stoeckel JA. Thermal performance of the electron transport system Complex III in seven Alabama fishes. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:153-162. [PMID: 36285344 DOI: 10.1002/jez.2667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 07/13/2022] [Accepted: 09/23/2022] [Indexed: 11/06/2022]
Abstract
Management of fish populations for conservation in thermally variable systems requires an understanding of the fish's underlying physiology and responses to thermal stress. Physiological research at the organismal level provides information on the overall effects of stressors such as extreme temperature fluctuations. While experiments with whole organisms provide information as to the overall effects of temperature fluctuations, biochemical assays of thermal stress provide direct results of exposure that are both sensitive and specific. Electron transport system (ETS; Complex III) assays quantify a rate-limiting step of respiratory enzymes. Parameters that can be estimated via this approach include optimum thermal temperature (Topt ) and optimal breadth of thermal performance (Tbreadth ), which can both be related to organismal-level temperature thresholds. We exposed enzymes of seven fish species (native fish chosen to represent a typical community in Alabama streams) to temperatures in the range 11-44°C. The resultant enzymatic thermal performance curves showed that Topt , the lower temperature for enzyme optimal thermal performance (Tlow ), the upper temperature for enzyme optimal thermal performance (Tup ), and Tbreadth differed among species. Relationships between enzymatic activity and temperature for all fish followed a pattern of steadily increasing enzyme activity to Topt before gradually decreasing with increasing temperature. A comparison of our enzyme optimum and upper-temperature limit results versus published critical thermal maxima values supports that ETS Complex III assays may be useful for assessing organismal-level thermal tolerance.
Collapse
Affiliation(s)
- Lindsay M Horne
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, Alabama, USA.,Department of Biology, School of Mathematics and Sciences, Lincoln Memorial University, Tennessee, Harrogate, USA
| | - Dennis R DeVries
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, Alabama, USA
| | - Russell Wright
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, Alabama, USA
| | - Elise Irwin
- U.S. Geological Survey, Cooperative Fish and Wildlife Research Units, Auburn, Alabama, USA
| | | | - Hisham A Abdelrahman
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, Alabama, USA.,Department of Veterinary Hygiene and Management, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - James A Stoeckel
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, Alabama, USA
| |
Collapse
|
22
|
Pacheco-Fuentes H, Ton R, Griffith SC. Short- and long-term consequences of heat exposure on mitochondrial metabolism in zebra finches (Taeniopygia castanotis). Oecologia 2023; 201:637-648. [PMID: 36894790 PMCID: PMC10038956 DOI: 10.1007/s00442-023-05344-7] [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: 09/20/2022] [Accepted: 02/20/2023] [Indexed: 03/11/2023]
Abstract
Understanding the consequences of heat exposure on mitochondrial function is crucial as mitochondria lie at the core of metabolic processes, also affecting population dynamics. In adults, mitochondrial metabolism varies with temperature but can also depend on thermal conditions experienced during development. We exposed zebra finches to two alternative heat treatments during early development: "constant", maintained birds at ambient 35 °C from parental pair formation to fledglings' independence, while "periodic" heated broods at 40 °C, 6 h daily at nestling stage. Two years later, we acclimated birds from both experiments at 25 °C for 21 days, before exposing them to artificial heat (40 °C, 5 h daily for 10 days). After both conditions, we measured red blood cells' mitochondrial metabolism using a high-resolution respirometer. We found significantly decreased mitochondrial metabolism for Routine, Oxidative Phosphorylation (OxPhos) and Electron Transport System maximum capacity (ETS) after the heat treatments. In addition, the birds exposed to "constant" heat in early life showed lower oxygen consumption at the Proton Leak (Leak) stage after the heat treatment as adults. Females showed higher mitochondrial respiration for Routine, ETS and Leak independent of the treatments, while this pattern was reversed for OxPhos coupling efficiency (OxCE). Our results show that short-term acclimation involved reduced mitochondrial respiration, and that the reaction of adult birds to heat depends on the intensity, pattern and duration of temperature conditions experienced at early-life stages. Our study provides insight into the complexity underlying variation in mitochondrial metabolism and raises questions on the adaptive value of long-lasting physiological adjustments triggered by the early-life thermal environment.
Collapse
Affiliation(s)
| | - Riccardo Ton
- School of Natural Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Simon C Griffith
- School of Natural Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| |
Collapse
|
23
|
Healy TM, Burton RS. Loss of mitochondrial performance at high temperatures is correlated with upper thermal tolerance among populations of an intertidal copepod. Comp Biochem Physiol B Biochem Mol Biol 2023; 266:110836. [PMID: 36801253 DOI: 10.1016/j.cbpb.2023.110836] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/24/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023]
Abstract
Environmental temperatures have pervasive effects on the performance and tolerance of ectothermic organisms, and thermal tolerance limits likely play key roles underlying biogeographic ranges and responses to environmental change. Mitochondria are central to metabolic processes in eukaryotic cells, and these metabolic functions are thermally sensitive; however, potential relationships between mitochondrial function, thermal tolerance limits and local thermal adaptation in general remain unresolved. Loss of ATP synthesis capacity at high temperatures has recently been suggested as a mechanistic link between mitochondrial function and upper thermal tolerance limits. Here we use a common-garden experiment with seven locally adapted populations of intertidal copepods (Tigriopus californicus), spanning approximately 21.5° latitude, to assess genetically based variation in the thermal performance curves of maximal ATP synthesis rates in isolated mitochondria. These thermal performance curves displayed substantial variation among populations with higher ATP synthesis rates at lower temperatures (20-25 °C) in northern populations than in southern populations. In contrast, mitochondria from southern populations maintained ATP synthesis rates at higher temperatures than the temperatures that caused loss of ATP synthesis capacity in mitochondria from northern populations. Additionally, there was a tight correlation between the thermal limits of ATP synthesis and previously determined variation in upper thermal tolerance limits among populations. This suggests that mitochondria may play an important role in latitudinal thermal adaptation in T. californicus, and supports the hypothesis that loss of mitochondrial performance at high temperatures is linked to whole-organism thermal tolerance limits in this ectotherm.
Collapse
Affiliation(s)
- Timothy M Healy
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive #0202, La Jolla, CA, USA.
| | - Ronald S Burton
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive #0202, La Jolla, CA, USA
| |
Collapse
|
24
|
Wang Y, Wang HM, Zhou Y, Hu LH, Wan JM, Yang JH, Niu HB, Hong XP, Hu P, Chen LB, Hu P, Chen LB. Dusp1 regulates thermal tolerance limits in zebrafish by maintaining mitochondrial integrity. Zool Res 2023; 44:126-141. [PMID: 36419379 PMCID: PMC9841188 DOI: 10.24272/j.issn.2095-8137.2022.397] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Temperature tolerance restricts the distribution of a species. However, the molecular and cellular mechanisms that set the thermal tolerance limits of an organism are poorly understood. Here, we report on the function of dual-specificity phosphatase 1 (DUSP1) in thermal tolerance regulation. Notably, we found that dusp1 -/- zebrafish grew normally but survived within a narrowed temperature range. The higher susceptibility of these mutant fish to both cold and heat challenges was attributed to accelerated cell death caused by aggravated mitochondrial dysfunction and over-production of reactive oxygen species in the gills. The DUSP1-MAPK-DRP1 axis was identified as a key pathway regulating these processes in both fish and human cells. These observations suggest that DUSP1 may play a role in maintaining mitochondrial integrity and redox homeostasis. We therefore propose that maintenance of cellular redox homeostasis may be a key mechanism for coping with cellular thermal stress and that the interplay between signaling pathways regulating redox homeostasis in the most thermosensitive tissue (i.e., gills) may play an important role in setting the thermal tolerance limit of zebrafish.
Collapse
Affiliation(s)
- Ying Wang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Hua-Min Wang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Yan Zhou
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Ling-Hong Hu
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Jing-Ming Wan
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Ji-Hui Yang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Hong-Bo Niu
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Xiu-Ping Hong
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Peng Hu
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China
| | - Liang-Biao Chen
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 200120, China,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 200120, China,Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 200120, China,E-mail:
| | | | | | | | | | | | | |
Collapse
|
25
|
Friesen CR, Wapstra E, Olsson M. Of telomeres and temperature: Measuring thermal effects on telomeres in ectothermic animals. Mol Ecol 2022; 31:6069-6086. [PMID: 34448287 DOI: 10.1111/mec.16154] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/20/2021] [Accepted: 08/23/2021] [Indexed: 01/31/2023]
Abstract
Ectotherms are classic models for understanding life-history tradeoffs, including the reproduction-somatic maintenance tradeoffs that may be reflected in telomere length and their dynamics. Importantly, life-history traits of ectotherms are tightly linked to their thermal environment, with diverse or synergistic mechanistic explanations underpinning the variation. Telomere dynamics potentially provide a mechanistic link that can be used to monitor thermal effects on individuals in response to climatic perturbations. Growth rate, age and developmental stage are all affected by temperature, which interacts with telomere dynamics in complex and intriguing ways. The physiological processes underpinning telomere dynamics can be visualized and understood using thermal performance curves (TPCs). TPCs reflect the evolutionary history and the thermal environment during an individual's ontogeny. Telomere maintenance should be enhanced at or near the thermal performance optimum of a species, population and individual. The thermal sensitivity of telomere dynamics should reflect the interacting TPCs of the processes underlying them. The key processes directly underpinning telomere dynamics are mitochondrial function (reactive oxygen production), antioxidant activity, telomerase activity and telomere endcap protein status. We argue that identifying TPCs for these processes will significantly help design robust, repeatable experiments and field studies of telomere dynamics in ectotherms. Conceptually, TPCs are a valuable framework to predict and interpret taxon- and population-specific telomere dynamics across thermal regimes. The literature of thermal effects on telomeres in ectotherms is sparse and mostly limited to vertebrates, but our conclusions and recommendations are relevant across ectothermic animals.
Collapse
Affiliation(s)
- Christopher R Friesen
- School of Earth, Atmospheric and Life Sciences, The University of Wollongong, Wollongong, New South Wales, Australia.,School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Erik Wapstra
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Mats Olsson
- School of Earth, Atmospheric and Life Sciences, The University of Wollongong, Wollongong, New South Wales, Australia.,Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
26
|
Cortese D, Crespel A, Mills SC, Norin T, Killen SS, Beldade R. Adaptive effects of parental and developmental environments on offspring survival, growth and phenotype. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Daphne Cortese
- PSL Université Paris: EPHE‐UPVD‐CNRS USR 3278 CRIOBE Moorea Papetoai French Polynesia
- School of Biodiversity, One Health and Veterinary Medicine University of Glasgow Glasgow UK
| | - Amélie Crespel
- School of Biodiversity, One Health and Veterinary Medicine University of Glasgow Glasgow UK
- Department of Biology University of Turku Turku Finland
| | - Suzanne C. Mills
- PSL Université Paris: EPHE‐UPVD‐CNRS USR 3278 CRIOBE Moorea Papetoai French Polynesia
- Laboratoire d'Excellence “CORAIL” France
| | - Tommy Norin
- School of Biodiversity, One Health and Veterinary Medicine University of Glasgow Glasgow UK
- DTU Aqua: National Institute of Aquatic Resources Technical University of Denmark Kgs. Lyngby Denmark
| | - Shaun S. Killen
- School of Biodiversity, One Health and Veterinary Medicine University of Glasgow Glasgow UK
| | - Ricardo Beldade
- PSL Université Paris: EPHE‐UPVD‐CNRS USR 3278 CRIOBE Moorea Papetoai French Polynesia
- Estación Costera de Investigaciones Marinas and Center for Advanced Studies in Ecology and Biodiversity, Las Cruces Pontificia Universidad Católica de Chile Santiago Chile
| |
Collapse
|
27
|
Ørsted M, Jørgensen LB, Overgaard J. Finding the right thermal limit: a framework to reconcile ecological, physiological and methodological aspects of CTmax in ectotherms. J Exp Biol 2022; 225:277015. [DOI: 10.1242/jeb.244514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
ABSTRACT
Upper thermal limits (CTmax) are frequently used to parameterize the fundamental niche of ectothermic animals and to infer biogeographical distribution limits under current and future climate scenarios. However, there is considerable debate associated with the methodological, ecological and physiological definitions of CTmax. The recent (re)introduction of the thermal death time (TDT) model has reconciled some of these issues and now offers a solid mathematical foundation to model CTmax by considering both intensity and duration of thermal stress. Nevertheless, the physiological origin and boundaries of this temperature–duration model remain unexplored. Supported by empirical data, we here outline a reconciling framework that integrates the TDT model, which operates at stressful temperatures, with the classic thermal performance curve (TPC) that typically describes biological functions at permissive temperatures. Further, we discuss how the TDT model is founded on a balance between disruptive and regenerative biological processes that ultimately defines a critical boundary temperature (Tc) separating the TDT and TPC models. Collectively, this framework allows inclusion of both repair and accumulation of heat stress, and therefore also offers a consistent conceptual approach to understand the impact of high temperature under fluctuating thermal conditions. Further, this reconciling framework allows improved experimental designs to understand the physiological underpinnings and ecological consequences of ectotherm heat tolerance.
Collapse
Affiliation(s)
- Michael Ørsted
- Aarhus University Section for Zoophysiology, Department of Biology , , 8000 Aarhus C , Denmark
| | | | - Johannes Overgaard
- Aarhus University Section for Zoophysiology, Department of Biology , , 8000 Aarhus C , Denmark
| |
Collapse
|
28
|
Experimental evolution reveals the synergistic genomic mechanisms of adaptation to ocean warming and acidification in a marine copepod. Proc Natl Acad Sci U S A 2022; 119:e2201521119. [PMID: 36095205 PMCID: PMC9499500 DOI: 10.1073/pnas.2201521119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Metazoan adaptation to global change relies on selection of standing genetic variation. Determining the extent to which this variation exists in natural populations, particularly for responses to simultaneous stressors, is essential to make accurate predictions for persistence in future conditions. Here, we identified the genetic variation enabling the copepod Acartia tonsa to adapt to experimental ocean warming, acidification, and combined ocean warming and acidification (OWA) over 25 generations of continual selection. Replicate populations showed a consistent polygenic response to each condition, targeting an array of adaptive mechanisms including cellular homeostasis, development, and stress response. We used a genome-wide covariance approach to partition the allelic changes into three categories: selection, drift and replicate-specific selection, and laboratory adaptation responses. The majority of allele frequency change in warming (57%) and OWA (63%) was driven by shared selection pressures across replicates, but this effect was weaker under acidification alone (20%). OWA and warming shared 37% of their response to selection but OWA and acidification shared just 1%, indicating that warming is the dominant driver of selection in OWA. Despite the dominance of warming, the interaction with acidification was still critical as the OWA selection response was highly synergistic with 47% of the allelic selection response unique from either individual treatment. These results disentangle how genomic targets of selection differ between single and multiple stressors and demonstrate the complexity that nonadditive multiple stressors will contribute to predictions of adaptation to complex environmental shifts caused by global change.
Collapse
|
29
|
Meza-Buendia AK, Aparicio-Trejo OE, Díaz F, Caamal-Monsreal C, Pedraza-Chaverri J, Álvarez-Delgado C, Paschke K, Rosas C. High resolution respirometry of isolated mitochondria from adult Octopus maya (Class: Cephalopoda) systemic heart. PLoS One 2022; 17:e0273554. [PMID: 36037204 PMCID: PMC9423623 DOI: 10.1371/journal.pone.0273554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 08/11/2022] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial respirometry is key to understand how environmental factors model energetic cellular process. In the case of ectotherms, thermal tolerance has been hypothesized to be intimately linked with mitochondria capability to produce enough adenosine triphosphate (ATP) to respond to the energetic demands of animals in high temperatures. In a recent study made in Octopus maya was proposed the hypothesis postulating that high temperatures could restrain female reproduction due to the limited capacity of the animals’ heart to sustain oxygen flow to the body, affecting in this manner energy production in the rest of the organs, including the ovarium Meza-Buendia AK et al. (2021). Unfortunately, until now, no reports have shown temperature effects and other environmental variables on cephalopod mitochondria activity because of the lack of a method to evaluate mitochondrial respiratory parameters in those species’ groups. In this sense and for the first time, this study developed a method to obtain mitochondrial respirometry data of adult Octopus maya’s heart. This protocol illustrates a step-by-step procedure to get high yield and functional mitochondria of cephalopod heart and procedure for determining the corresponding respiratory parameters. The procedure described in this paper takes approximately 3 to 4 hours from isolation of intact mitochondria to measurement of mitochondrial oxygen consumption.
Collapse
Affiliation(s)
- Ana Karen Meza-Buendia
- Laboratorio de Ecofisiología de Organismos Acuáticos, Departamento de Biotecnología Marina, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Baja California, México
| | - Omar Emiliano Aparicio-Trejo
- Departamento de Fisiopatología Cardio-Renal, Instituto Nacional de Cardiología “Ignacio Chávez”, Mexico City, Mexico
| | - Fernando Díaz
- Laboratorio de Ecofisiología de Organismos Acuáticos, Departamento de Biotecnología Marina, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Baja California, México
| | - Claudia Caamal-Monsreal
- Unidad Multidisciplinaria de Docencia e Investigación, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sisal, Mexico
- Laboratorio de Resilencia Costera LANRESC, CONACYT, Sisal, Mexico
| | - José Pedraza-Chaverri
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Carolina Álvarez-Delgado
- Departamento de Innovación Biomédica, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Baja California, Mexico
| | - Kurt Paschke
- Instituto de Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
- Centro FONDAP de Investigación de AltasLatitudes (IDEAL), Punta Arenas, Chile
| | - Carlos Rosas
- Unidad Multidisciplinaria de Docencia e Investigación, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sisal, Mexico
- Laboratorio de Resilencia Costera LANRESC, CONACYT, Sisal, Mexico
- * E-mail:
| |
Collapse
|
30
|
Rees BB, Reemeyer JE, Irving BA. Interindividual variation in maximum aerobic metabolism varies with gill morphology and myocardial bioenergetics. J Exp Biol 2022; 225:275636. [DOI: 10.1242/jeb.243680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 05/27/2022] [Indexed: 11/20/2022]
Abstract
This study asked whether interindividual variation in maximum and standard aerobic metabolic rates of the Gulf killifish, Fundulus grandis, correlate with gill morphology and cardiac mitochondrial bioenergetics, traits reflecting critical steps in the O2 transport cascade from the environment to the tissues. Maximum metabolic rate (MMR) was positively related to body mass, total gill filament length, and myocardial oxygen consumption during maximum oxidative phosphorylation (multiple R2=0.836). Standard metabolic rate (SMR) was positively related to body mass, total gill filament length, and myocardial oxygen consumption during maximum electron transport system activity (multiple R2=0.717). After controlling for body mass, individuals with longer gill filaments, summed over all gill arches, or greater cardiac respiratory capacity had higher whole-animal metabolic rates. The overall model fit and the explanatory power of individual predictor variables were better for MMR than for SMR, suggesting that gill morphology and myocardial bioenergetics are more important in determining active rather than resting metabolism. After accounting for body mass, heart ventricle mass was not related to variation in MMR or SMR, indicating that the quality of the heart (i.e., the capacity for mitochondrial metabolism) was more influential than heart size. Finally, the myocardial oxygen consumption required to offset the dissipation of the transmembrane proton gradient in the absence of ATP synthesis was not correlated with either MMR or SMR. The results support the idea that interindividual variation in aerobic metabolism, particularly maximum metabolic rate, is associated with variation in specific steps in the O2 transport cascade.
Collapse
Affiliation(s)
- Bernard B. Rees
- 1 Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148, USA
| | - Jessica E. Reemeyer
- 2 Department of Biology, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Brian A. Irving
- 3 School of Kinesiology, Louisiana State University, Baton Rouge, LA 70803, USA
- 4 Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA 70808, USA
| |
Collapse
|
31
|
Menail HA, Cormier SB, Ben Youssef M, Jørgensen LB, Vickruck JL, Morin P, Boudreau LH, Pichaud N. Flexible Thermal Sensitivity of Mitochondrial Oxygen Consumption and Substrate Oxidation in Flying Insect Species. Front Physiol 2022; 13:897174. [PMID: 35547573 PMCID: PMC9081799 DOI: 10.3389/fphys.2022.897174] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/06/2022] [Indexed: 12/26/2022] Open
Abstract
Mitochondria have been suggested to be paramount for temperature adaptation in insects. Considering the large range of environments colonized by this taxon, we hypothesized that species surviving large temperature changes would be those with the most flexible mitochondria. We thus investigated the responses of mitochondrial oxidative phosphorylation (OXPHOS) to temperature in three flying insects: the honeybee (Apis mellifera carnica), the fruit fly (Drosophila melanogaster) and the Colorado potato beetle (Leptinotarsa decemlineata). Specifically, we measured oxygen consumption in permeabilized flight muscles of these species at 6, 12, 18, 24, 30, 36, 42 and 45°C, sequentially using complex I substrates, proline, succinate, and glycerol-3-phosphate (G3P). Complex I respiration rates (CI-OXPHOS) were very sensitive to temperature in honeybees and fruit flies with high oxygen consumption at mid-range temperatures but a sharp decline at high temperatures. Proline oxidation triggers a major increase in respiration only in potato beetles, following the same pattern as CI-OXPHOS for honeybees and fruit flies. Moreover, both succinate and G3P oxidation allowed an important increase in respiration at high temperatures in honeybees and fruit flies (and to a lesser extent in potato beetles). However, when reaching 45°C, this G3P-induced respiration rate dropped dramatically in fruit flies. These results demonstrate that mitochondrial functions are more resilient to high temperatures in honeybees compared to fruit flies. They also indicate an important but species-specific mitochondrial flexibility for substrate oxidation to sustain high oxygen consumption levels at high temperatures and suggest previously unknown adaptive mechanisms of flying insects’ mitochondria to temperature.
Collapse
Affiliation(s)
- Hichem A Menail
- New Brunswick Centre for Precision Medicine, Moncton, NB, Canada.,Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| | - Simon B Cormier
- New Brunswick Centre for Precision Medicine, Moncton, NB, Canada.,Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| | - Mariem Ben Youssef
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| | | | - Jess L Vickruck
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, NB, Canada
| | - Pier Morin
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| | - Luc H Boudreau
- New Brunswick Centre for Precision Medicine, Moncton, NB, Canada.,Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| | - Nicolas Pichaud
- New Brunswick Centre for Precision Medicine, Moncton, NB, Canada.,Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| |
Collapse
|
32
|
Blewett TA, Binning SA, Weinrauch AM, Ivy CM, Rossi GS, Borowiec BG, Lau GY, Overduin SL, Aragao I, Norin T. Physiological and behavioural strategies of aquatic animals living in fluctuating environments. J Exp Biol 2022; 225:275292. [PMID: 35511083 DOI: 10.1242/jeb.242503] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Shallow or near-shore environments, such as ponds, estuaries and intertidal zones, are among the most physiologically challenging of all aquatic settings. Animals inhabiting these environments experience conditions that fluctuate markedly over relatively short temporal and spatial scales. Living in these habitats requires the ability to tolerate the physiological disturbances incurred by these environmental fluctuations. This tolerance is achieved through a suite of physiological and behavioural responses that allow animals to maintain homeostasis, including the ability to dynamically modulate their physiology through reversible phenotypic plasticity. However, maintaining the plasticity to adjust to some stresses in a dynamic environment may trade off with the capacity to deal with other stressors. This paper will explore studies on select fishes and invertebrates exposed to fluctuations in dissolved oxygen, salinity and pH. We assess the physiological mechanisms these species employ to achieve homeostasis, with a focus on the plasticity of their responses, and consider the resulting physiological trade-offs in function. Finally, we discuss additional factors that may influence organismal responses to fluctuating environments, such as the presence of multiple stressors, including parasites. We echo recent calls from experimental biologists to consider physiological responses to life in naturally fluctuating environments, not only because they are interesting in their own right but also because they can reveal mechanisms that may be crucial for living with increasing environmental instability as a consequence of climate change.
Collapse
Affiliation(s)
- Tamzin A Blewett
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, T6G 2E9
| | - Sandra A Binning
- Département de Sciences Biologiques, Université de Montréal, Montréal, QC, Canada, H2V 0B3
| | - Alyssa M Weinrauch
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2
| | - Catherine M Ivy
- Department of Biology, Western University, London, ON, Canada, N6A 5B7
| | - Giulia S Rossi
- Department of Biological Science, University of Toronto, Scarborough, ON, Canada, M1C 1A4
| | - Brittney G Borowiec
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada, N2L 3C5
| | - Gigi Y Lau
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Sienna L Overduin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, T6G 2E9
| | - Isabel Aragao
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, T6G 2E9
| | - Tommy Norin
- DTU Aqua: National Institute of Aquatic Resources, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| |
Collapse
|
33
|
Borowiec BG, Birceanu O, Wilson JM, McDonald AE, Wilkie MP. Niclosamide Is a Much More Potent Toxicant of Mitochondrial Respiration than TFM in the Invasive Sea Lamprey ( Petromyzon marinus). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:4970-4979. [PMID: 35363472 DOI: 10.1021/acs.est.1c07117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Invasive sea lampreys in the Laurentian Great Lakes are controlled by applying TFM (3-trifluoromethyl-4-nitrophenol) and niclosamide to streams infested with their larvae. Both agents uncouple oxidative phosphorylation in the mitochondria, but TFM specifically targets lampreys, which have a lower capacity to detoxify the lampricide. Niclosamide lacks specificity and is more potent than TFM. However, its greater potency is poorly understood. We tested the hypothesis that niclosamide is a stronger uncoupler of mitochondrial oxidative phosphorylation than TFM by measuring oxygen consumption rates in isolated liver mitochondria exposed to physiologically relevant concentrations of TFM, niclosamide, or their mixture (100 TFM:1 niclosamide) at environmentally relevant temperatures (7, 13, and 25 °C). Niclosamide increased State 4 respiration and decreased the respiratory control ratio (RCR) at much lower concentrations than TFM. Calculations of the relative EC50 values, the amount of TFM or niclosamide required to decrease the RCR by 50%, indicated that niclosamide was 40-60 times more potent than TFM. Warmer temperature did not appear to decrease the sensitivity of mitochondria to niclosamide or TFM, as observed in the intact sea lamprey exposed to TFM in warmer waters. We conclude that the extreme sensitivity of mitochondria to niclosamide contributes to its greater in vivo toxicity in the whole animal.
Collapse
Affiliation(s)
- Brittney G Borowiec
- Department of Biology, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario N2L 3C5, Canada
| | - Oana Birceanu
- Department of Biology, McMaster University, 1280 Main Street W., Hamilton, Ontario L8S 4K1, Canada
- Department of Physiology and Pharmacology, Western University, 1151 Richmond Street, London, Ontario N6A 5C1, Canada
| | - Jonathan M Wilson
- Department of Biology, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario N2L 3C5, Canada
| | - Allison E McDonald
- Department of Biology, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario N2L 3C5, Canada
| | - Michael P Wilkie
- Department of Biology, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario N2L 3C5, Canada
| |
Collapse
|
34
|
Lemieux H, Blier PU. Exploring Thermal Sensitivities and Adaptations of Oxidative Phosphorylation Pathways. Metabolites 2022; 12:metabo12040360. [PMID: 35448547 PMCID: PMC9025460 DOI: 10.3390/metabo12040360] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 12/20/2022] Open
Abstract
Temperature shifts are a major challenge to animals; they drive adaptations in organisms and species, and affect all physiological functions in ectothermic organisms. Understanding the origin and mechanisms of these adaptations is critical for determining whether ectothermic organisms will be able to survive when faced with global climate change. Mitochondrial oxidative phosphorylation is thought to be an important metabolic player in this regard, since the capacity of the mitochondria to produce energy greatly varies according to temperature. However, organism survival and fitness depend not only on how much energy is produced, but, more precisely, on how oxidative phosphorylation is affected and which step of the process dictates thermal sensitivity. These questions need to be addressed from a new perspective involving a complex view of mitochondrial oxidative phosphorylation and its related pathways. In this review, we examine the effect of temperature on the commonly measured pathways, but mainly focus on the potential impact of lesser-studied pathways and related steps, including the electron-transferring flavoprotein pathway, glycerophosphate dehydrogenase, dihydroorotate dehydrogenase, choline dehydrogenase, proline dehydrogenase, and sulfide:quinone oxidoreductase. Our objective is to reveal new avenues of research that can address the impact of temperature on oxidative phosphorylation in all its complexity to better portray the limitations and the potential adaptations of aerobic metabolism.
Collapse
Affiliation(s)
- Hélène Lemieux
- Faculty Saint-Jean, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6C 4G9, Canada
- Correspondence: (H.L.); (P.U.B.)
| | - Pierre U. Blier
- Department Biologie, Université du Québec à Rimouski, Rimouski, QC G5L 3A1, Canada
- Correspondence: (H.L.); (P.U.B.)
| |
Collapse
|
35
|
Brennan RS, deMayo JA, Dam HG, Finiguerra MB, Baumann H, Pespeni MH. Loss of transcriptional plasticity but sustained adaptive capacity after adaptation to global change conditions in a marine copepod. Nat Commun 2022; 13:1147. [PMID: 35241657 PMCID: PMC8894427 DOI: 10.1038/s41467-022-28742-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 02/04/2022] [Indexed: 12/04/2022] Open
Abstract
Adaptive evolution and phenotypic plasticity will fuel resilience in the geologically unprecedented warming and acidification of the earth’s oceans, however, we have much to learn about the interactions and costs of these mechanisms of resilience. Here, using 20 generations of experimental evolution followed by three generations of reciprocal transplants, we investigated the relationship between adaptation and plasticity in the marine copepod, Acartia tonsa, in future global change conditions (high temperature and high CO2). We found parallel adaptation to global change conditions in genes related to stress response, gene expression regulation, actin regulation, developmental processes, and energy production. However, reciprocal transplantation showed that adaptation resulted in a loss of transcriptional plasticity, reduced fecundity, and reduced population growth when global change-adapted animals were returned to ambient conditions or reared in low food conditions. However, after three successive transplant generations, global change-adapted animals were able to match the ambient-adaptive transcriptional profile. Concurrent changes in allele frequencies and erosion of nucleotide diversity suggest that this recovery occurred via adaptation back to ancestral conditions. These results demonstrate that while plasticity facilitated initial survival in global change conditions, it eroded after 20 generations as populations adapted, limiting resilience to new stressors and previously benign environments. Rapid adaptation will facilitate species resilience under global climate change, but its effects on plasticity are less commonly investigated. This study shows that 20 generations of experimental adaptation in a marine copepod drives a rapid loss of plasticity that carries costs and might have impacts on future resilience to environmental change.
Collapse
Affiliation(s)
- Reid S Brennan
- Department of Biology, University of Vermont, Burlington, VT, USA. .,Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
| | - James A deMayo
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA.,Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
| | - Hans G Dam
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA
| | - Michael B Finiguerra
- Department of Ecology and Evolutionary Biology, University of Connecticut, Groton, CT, USA
| | - Hannes Baumann
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA
| | | |
Collapse
|
36
|
Holden KG, Hedrick AR, Gangloff EJ, Hall SJ, Bronikowski AM. Temperature-dependence of metabolism and fuel selection from cells to whole organisms. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:199-205. [PMID: 34855309 DOI: 10.1002/jez.2564] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
Temperature affects nearly every aspect of how organisms interact with and are constrained by their environment. Measures of organismal energetics, such as metabolic rate, are highly temperature-dependent and governed through temperature effects on rates of biochemical reactions. Characterizing the relationships among levels of biological organization can lend insight into how temperature affects whole-organism function. We tested the temperature dependence of cellular oxygen consumption and its relationship to whole-animal metabolic rate in garter snakes (Thamnophis elegans). Additionally, we tested whether thermal responses were linked to shifts in the fuel source oxidized to support metabolism with the use of carbon stable isotopes. Our results demonstrate temperature dependence of metabolic rates across levels of biological organization. Cellular (basal, adenosine triphosphate-linked) and whole-animal rates of respiration increased with temperature but were not correlated within or among individuals, suggesting that variation in whole-animal metabolic rates is not due simply to variation at the cellular level, but rather other interacting factors across scales of biological organization. Counter to trends observed during fasting, elevated temperature did not alter fuel selection (i.e., natural-abundance stable carbon isotope composition in breath, δ13 Cbreath ). This consistency suggests the maintenance and oxidation of a single fuel source supporting metabolism across a broad range of metabolic demands.
Collapse
Affiliation(s)
- Kaitlyn G Holden
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Ashley R Hedrick
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Eric J Gangloff
- Department of Zoology, Ohio Wesleyan University, Delaware, Ohio, USA
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| |
Collapse
|
37
|
Loughland I, Lau GY, Jolly J, Seebacher F. Rates of warming impact oxidative stress in zebrafish (Danio rerio). J Exp Biol 2022; 225:274436. [PMID: 35179603 DOI: 10.1242/jeb.243740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/10/2022] [Indexed: 11/20/2022]
Abstract
Potentially negative effects of thermal variation on physiological functions may be modulated by compensatory responses, but their efficacy depends on the timescale of phenotypic adjustment relative to the rate of temperature change. Increasing temperatures in particular can affect mitochondrial bioenergetics and rates of reactive oxygen species (ROS) production. Our aim was to test whether different rates of temperature increase impact mitochondrial bioenergetics and modulate oxidative stress. We exposed zebrafish (Danio rerio) to warming from 20 to 28°C over 3, 6, 24, or 48 h, and compared these to a control group that was kept at constant 20°C. Fish exposed to the fastest (3 h) and slowest (48 h) rates of warming had significantly higher rates of H2O2 production relative to the control treatment, and the proportion of O2 converted to H2O2 (H2O2/O2 ratio) was significantly greater in these groups. However, ROS production was not paralleled by differences in mitochondrial substrate oxidation rates, leak respiration rates, or coupling (respiratory control ratios). Increased rates of ROS production did not lead to damage of proteins or membranes, which may be explained by a moderate increase in catalase activity at the fastest, but not the slowest rate of warming. The increase in ROS production at the slowest rate of heating indicates that even seemingly benign environments may be stressful. Understanding how animals respond to different rates of temperature change is important, because the rate determines the time period for phenotypic adjustments and it also alters the environmental thermal signal that triggers compensatory pathways.
Collapse
Affiliation(s)
- Isabella Loughland
- School of Life and Environmental Sciences A08, University of Sydney, NSW 2006, Australia
| | - Gigi Y Lau
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Blindernveien 31, Postbox 1066, Blindern, Oslo NO-0316, Norway
| | - Jordan Jolly
- School of Life and Environmental Sciences A08, University of Sydney, NSW 2006, Australia
| | - Frank Seebacher
- School of Life and Environmental Sciences A08, University of Sydney, NSW 2006, Australia
| |
Collapse
|
38
|
Lamptey DI, Sparks RW, De Oca RM, Skolik R, Menze MA, Martinez E. Seasonal changes in mitochondrial bioenergetics and physiological performance of the bluegill sunfish, Lepomis macrochirus, from a shallow, Midwest river. J Therm Biol 2022; 104:103186. [DOI: 10.1016/j.jtherbio.2021.103186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/24/2021] [Accepted: 12/31/2021] [Indexed: 11/16/2022]
|
39
|
Gómez Alés R, Acosta JC, Astudillo V, Córdoba M. Season-sex interaction induces changes in the ecophysiological traits of a lizard in a high altitude cold desert, Puna region. J Therm Biol 2022; 103:103152. [PMID: 35027202 DOI: 10.1016/j.jtherbio.2021.103152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/11/2021] [Accepted: 11/30/2021] [Indexed: 10/19/2022]
Abstract
Functional traits are those characteristics of organisms that influence the ability of a species to develop in a habitat and persist in the face of environmental changes. The traits are often affected by a multiplicity of species-dependent and external factors. Our objective was to investigate thermal biology of Liolaemus ruibali in a high altitude cold desert at the arid Puna region, Argentina. We address the following question: do sex and seasonal variations in environmental temperature induce changes in the ecophysiological traits? We measured and compared the operative temperatures between fall and spring; and between sexes and seasons, we compared the ecophysiological traits of lizards, microenvironmental temperatures and thermoregulatory behavior. Air and operative temperatures were different between seasons. We found an effect of season-sex interaction on field body temperatures, preferred temperatures, panting threshold and thermal quality. The voluntary and critical temperatures presented seasonal variation in relation to changes in environmental temperatures, suggesting thermal acclimatization. We note behavioral changes between seasons, with the substrate being the main resource for gaining heat in spring. We conclude that Liolaemus ruibali is an efficient thermoregulator; it is a eurythermic lizard and presents phenotypic plasticity in different ecophysiological and behavioral traits induced by sex and seasonality. In addition, we predict that this population could buffer the effects of projected global warming scenarios.
Collapse
Affiliation(s)
- Rodrigo Gómez Alés
- DIBIOVA (Gabinete Diversidad y Biología de Vertebrados del Árido), Departamento de Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, Av. Ignacio de la Roza 590 (O), Rivadavia, J5402DCS, San Juan, Argentina; CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), San Juan, Argentina.
| | - Juan Carlos Acosta
- DIBIOVA (Gabinete Diversidad y Biología de Vertebrados del Árido), Departamento de Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, Av. Ignacio de la Roza 590 (O), Rivadavia, J5402DCS, San Juan, Argentina
| | - Vanesa Astudillo
- DIBIOVA (Gabinete Diversidad y Biología de Vertebrados del Árido), Departamento de Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, Av. Ignacio de la Roza 590 (O), Rivadavia, J5402DCS, San Juan, Argentina; CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), San Juan, Argentina
| | - Mariela Córdoba
- DIBIOVA (Gabinete Diversidad y Biología de Vertebrados del Árido), Departamento de Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, Av. Ignacio de la Roza 590 (O), Rivadavia, J5402DCS, San Juan, Argentina; CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), San Juan, Argentina
| |
Collapse
|
40
|
Denny MW, Dowd WW. Elevated Salinity Rapidly Confers Cross-Tolerance to High Temperature in a Splash-Pool Copepod. Integr Org Biol 2022; 4:obac037. [PMID: 36003414 PMCID: PMC9394168 DOI: 10.1093/iob/obac037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/07/2022] [Accepted: 08/04/2022] [Indexed: 12/11/2022] Open
Abstract
Accurate forecasting of organismal responses to climate change requires a deep mechanistic understanding of how physiology responds to present-day variation in the physical environment. However, the road to physiological enlightenment is fraught with complications: predictable environmental fluctuations of any single factor are often accompanied by substantial stochastic variation and rare extreme events, and several factors may interact to affect physiology. Lacking sufficient knowledge of temporal patterns of co-variation in multiple environmental stressors, biologists struggle to design and implement realistic and relevant laboratory experiments. In this study, we directly address these issues, using measurements of the thermal tolerance of freshly collected animals and long-term field records of environmental conditions to explore how the splash-pool copepod Tigriopus californicus adjusts its physiology as its environment changes. Salinity and daily maximum temperature-two dominant environmental stressors experienced by T. californicus-are extraordinarily variable and unpredictable more than 2-3 days in advance. However, they substantially co-vary such that when temperature is high salinity is also likely to be high. Copepods appear to take advantage of this correlation: median lethal temperature of field-collected copepods increases by 7.5°C over a roughly 120 parts-per-thousand range of ambient salinity. Complementary laboratory experiments show that exposure to a single sublethal thermal event or to an abrupt shift in salinity also elicits rapid augmentation of heat tolerance via physiological plasticity, although the effect of salinity dwarfs that of temperature. These results suggest that T. californicus's physiology keeps pace with the rapid, unpredictable fluctuations of its hypervariable physical environment by responding to the cues provided by recent sublethal stress and, more importantly, by leveraging the mechanistic cross-talk between responses to salinity and heat stress.
Collapse
Affiliation(s)
| | - W Wesley Dowd
- School of Biological Sciences, Washington State University, 100 Dairy Road, Eastlick G81, Pullman, WA99164, USA
| |
Collapse
|
41
|
Hardison EA, Kraskura K, Van Wert J, Nguyen T, Eliason EJ. Diet mediates thermal performance traits: implications for marine ectotherms. J Exp Biol 2021; 224:272691. [PMID: 34647599 DOI: 10.1242/jeb.242846] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/01/2021] [Indexed: 11/20/2022]
Abstract
Thermal acclimation is a key process enabling ectotherms to cope with temperature change. To undergo a successful acclimation response, ectotherms require energy and nutritional building blocks obtained from their diet. However, diet is often overlooked as a factor that can alter acclimation responses. Using a temperate omnivorous fish, opaleye (Girella nigricans), as a model system, we tested the hypotheses that (1) diet can impact the magnitude of thermal acclimation responses and (2) traits vary in their sensitivity to both temperature acclimation and diet. We fed opaleye a simple omnivorous diet (ad libitum Artemia sp. and Ulva sp.) or a carnivorous diet (ad libitum Artemia sp.) at two ecologically relevant temperatures (12 and 20°C) and measured a suite of whole-animal (growth, sprint speed, metabolism), organ (cardiac thermal tolerance) and cellular-level traits (oxidative stress, glycolytic capacity). When opaleye were offered two diet options compared with one, they had reduced cardiovascular thermal performance and higher standard metabolic rate under conditions representative of the maximal seasonal temperature the population experiences (20°C). Further, sprint speed and absolute aerobic scope were insensitive to diet and temperature, while growth was highly sensitive to temperature but not diet, and standard metabolic rate and maximum heart rate were sensitive to both diet and temperature. Our results reveal that diet influences thermal performance in trait-specific ways, which could create diet trade-offs for generalist ectotherms living in thermally variable environments. Ectotherms that alter their diet may be able to regulate their performance at different environmental temperatures.
Collapse
Affiliation(s)
- Emily A Hardison
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Krista Kraskura
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Jacey Van Wert
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Tina Nguyen
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Erika J Eliason
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| |
Collapse
|
42
|
Ritchie DJ, Friesen CR. Invited review: Thermal effects on oxidative stress in vertebrate ectotherms. Comp Biochem Physiol A Mol Integr Physiol 2021; 263:111082. [PMID: 34571153 DOI: 10.1016/j.cbpa.2021.111082] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/07/2021] [Accepted: 09/16/2021] [Indexed: 10/20/2022]
Abstract
Human-induced climate change is occurring rapidly. Ectothermic organisms are particularly vulnerable to these temperature changes due to their reliance on environmental temperature. The extent of ectothermic thermal adaptation and plasticity in the literature is well documented; however, the role of oxidative stress in these processes needs more attention. Oxidative stress occurs when reactive oxygen species, generated mainly through aerobic respiration, overwhelm antioxidant defences and damage crucial biomolecules. The effects of oxidative damage include the alteration of life-history traits and reductions in whole-organism fitness. Here we review the literature addressing experimental temperature effects on oxidative stress in vertebrate ectotherms. Acute and acclimation temperature treatments produce distinctly different results and highlight the role of phylogeny and thermal adaptation in shaping oxidative stress responses. Acute treatments on organisms adapted to stable environments generally produced significant oxidative stress responses, whilst organisms adapted to variable conditions exhibited capacity to cope with temperature changes and mitigate oxidative stress. In acclimation treatments, the temperature treatments higher than optimal temperatures tended to produce significantly less oxidative stress than lower temperatures in reptiles, whilst in some eurythermal fish species, no oxidative stress response was observed. These results highlight the importance of phylogeny and adaptation to past environmental conditions for temperature-dependent oxidative stress responses. We conclude with recommendations on experimental procedures to investigate these phenomena with reference to thermal plasticity, adaptation and biogeographic variation that provide the most significant benefits to adaptable populations. These results have potential conservation ramifications as they may shed light on the physiological effects of temperature alterations in some vertebrate ectotherms.
Collapse
Affiliation(s)
- Daniel J Ritchie
- School of Earth, Atmospheric and Life Sciences, The University of Wollongong, 2522 Wollongong, New South Wales, Australia
| | - Christopher R Friesen
- School of Earth, Atmospheric and Life Sciences, The University of Wollongong, 2522 Wollongong, New South Wales, Australia; School of Life and Environmental Sciences, University of Sydney, Heydon-Laurence Bldg A08, Science Road, Sydney, NSW 2006, Australia.
| |
Collapse
|
43
|
Hraoui G, Breton S, Miron G, Boudreau LH, Hunter-Manseau F, Pichaud N. Mitochondrial responses towards intermittent heat shocks in the eastern oyster, Crassostrea virginica. J Exp Biol 2021; 224:272029. [PMID: 34401903 DOI: 10.1242/jeb.242745] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/10/2021] [Indexed: 12/12/2022]
Abstract
Frequent heat waves caused by climate change can give rise to physiological stress in many animals, particularly in sessile ectotherms such as bivalves. Most studies characterizing thermal stress in bivalves focus on evaluating the responses to a single stress event. This does not accurately reflect the reality faced by bivalves, which are often subject to intermittent heat waves. Here, we investigated the effect of intermittent heat stress on mitochondrial functions of the eastern oyster, Crassostrea virginica, which play a key role in setting the thermal tolerance of ectotherms. Specifically, we measured changes in mitochondrial oxygen consumption and H2O2 emission rates before, during and after intermittent 7.5°C heat shocks in oysters acclimated to 15 and 22.5°C. Our results showed that oxygen consumption was impaired following the first heat shock at both acclimation temperatures. After the second heat shock, results for oysters acclimated to 15°C indicated a return to normal. However, oysters acclimated to 22.5°C struggled more with the compounding effects of intermittent heat shocks as denoted by an increased contribution of FAD-linked substrates to mitochondrial respiration as well as high levels of H2O2 emission rates. However, both acclimated populations showed signs of potential recovery 10 days after the second heat shock, reflecting a surprising resilience to heat waves by C. virginica. Thus, this study highlights the important role of acclimation in the oyster's capacity to weather intermittent heat shock.
Collapse
Affiliation(s)
- Georges Hraoui
- Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, QC, Canada, H2X 1Y4.,Département de Sciences Biologiques, Université de Montréal, Montréal, QC, Canada, H2V 0B3
| | - Sophie Breton
- Département de Sciences Biologiques, Université de Montréal, Montréal, QC, Canada, H2V 0B3
| | - Gilles Miron
- Department of Biology, Université de Moncton, Moncton, NB, Canada, E1A 3E9
| | - Luc H Boudreau
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada, E1A 3E9.,New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, Canada, E1C 8X3
| | - Florence Hunter-Manseau
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada, E1A 3E9.,New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, Canada, E1C 8X3
| | - Nicolas Pichaud
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada, E1A 3E9.,New Brunswick Centre for Precision Medicine (NBCPM), Moncton, NB, Canada, E1C 8X3
| |
Collapse
|
44
|
de Melo Teixeira M, Lang BF, Matute DR, Stajich JE, Barker BM. Mitochondrial genomes of the human pathogens Coccidioides immitis and Coccidioides posadasii. G3 (BETHESDA, MD.) 2021; 11:jkab132. [PMID: 33871031 PMCID: PMC8496281 DOI: 10.1093/g3journal/jkab132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/25/2021] [Indexed: 12/25/2022]
Abstract
Fungal mitochondrial genomes encode genes involved in crucial cellular processes, such as oxidative phosphorylation and mitochondrial translation, and the molecule has been used as a molecular marker for population genetics studies. Coccidioides immitis and C. posadasii are endemic fungal pathogens that cause coccidioidomycosis in arid regions across both American continents. To date, approximately 150 Coccidioides isolates have been sequenced to infer patterns of variation in nuclear genomes. However, less attention has been given to the mitochondrial genomes of Coccidioides. In this report, we describe the assembly and annotation of mitochondrial reference genomes for two representative strains of C. posadasii and C. immitis, as well as assess population variation among 77 selected genomes. The sizes of the circular-mapping molecules are 68.2 Kb in C. immitis and 75.1 Kb in C. posadasii. We identify 14 mitochondrial protein-coding genes common to most fungal mitochondria, which are largely syntenic across different populations and species of Coccidioides. Both Coccidioides species are characterized by a large number of group I and II introns, harboring twice the number of elements as compared to closely related Onygenales. The introns contain complete or truncated ORFs with high similarity to homing endonucleases of the LAGLIDADG and GIY-YIG families. Phylogenetic comparisons of mitochondrial and nuclear genomes show extensive phylogenetic discordance suggesting that the evolution of the two types of genetic material is not identical. This work represents the first assessment of mitochondrial genomes among isolates of both species of Coccidioides, and provides a foundation for future functional work.
Collapse
Affiliation(s)
- Marcus de Melo Teixeira
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA
- Faculty of Medicine, University of Brasília-DF, Brasília, Federal District 70910-3300, Brazil
| | - B Franz Lang
- Robert Cedergren Centre for Bioinformatics and Génomiques, Département de Biochimie, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - Daniel R Matute
- Biology Department, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jason E Stajich
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA
| | - Bridget M Barker
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA
| |
Collapse
|
45
|
Treatment with ascorbic acid normalizes the aerobic capacity, antioxidant defence, and cell death pathways in thermally stressed Mytilus galloprovincialis. Comp Biochem Physiol B Biochem Mol Biol 2021; 255:110611. [PMID: 33965617 DOI: 10.1016/j.cbpb.2021.110611] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 04/24/2021] [Accepted: 05/04/2021] [Indexed: 12/20/2022]
Abstract
Considering temperature's upcoming increase due to climate change, combined with the fact that Mediterranean mussels Mytilus galloprovincialis (Lamarck, 1819) live at their upper limits [critical temperatures (Tc) beyond 25 °C], we cannot be sure of this species' sustainable future in the Mediterranean Sea. Deviation from optimum temperatures leads to cellular damage due to oxidative stress. Although ascorbic acid (AA) is a major scavenger of reactive oxygen species (ROS), its capacity to minimize oxidative stress effects is scarcely studied in aquatic organisms. Thus, treatment with 5 mM and 10 mM AA of thermally stressed molluscs had been employed in order to examine its antioxidant capacity. While 5 mM had no effect, 10 mM normalized COX1 and ND2 relative mRNA levels, and superoxide dismutase (SOD), catalase, and glutathione reductase (GR) enzymatic activity levels in both examined tissues: posterior adductor muscle (PAM) and mantle. ATP levels, probably providing the adequate energy for antioxidant defence in thermally stressed mussels, is also normalized under 10 mM AA treatment. Moreover, autophagic indicators such as LC3 II/I and SQSTM1/p62 levels are normalized, indicating autophagy amelioration. Apoptosis also seems to be inhibited since both Bax/Bcl-2 and cleaved caspase substrate levels decrease with 10 mM AA treatment. Therefore, treatment of mussels with AA seems to produce threshold effects, although the precise underlying mechanisms must be elucidated in future studies. These findings show that treatment of mussels with effective antioxidants can be useful as a strategic approach for the reduction of the deleterious effects on mussels' summer mortality in aquaculture zones.
Collapse
|
46
|
Michaelsen J, Fago A, Bundgaard A. High temperature impairs mitochondrial function in rainbow trout cardiac mitochondria. J Exp Biol 2021; 224:jeb.242382. [DOI: 10.1242/jeb.242382] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 03/18/2021] [Indexed: 12/17/2022]
Abstract
ABSTRACT
Mitochondria provide cellular energy through oxidative phosphorylation, and thus temperature-induced constraints on mitochondrial function may be crucial to animal aerobic scope and thermal tolerance. Here, we report the effect of temperature in the range 5–30°C on respiration rates of isolated cardiac mitochondria from rainbow trout (Oncorhynchus mykiss) studied by high-resolution respirometry and spectrophotometric enzyme activity assays. Arrhenius breakpoint temperature analysis indicated that mitochondrial respiration rates under phosphorylating and fully uncoupled conditions increased exponentially up to 20°C, but stopped increasing at higher temperatures. In contrast, respiration rates measured under non-phosphorylating leak conditions continued to increase up to 30°C. The decrease in the ratio between phosphorylating and uncoupled respiration at high temperature indicated that phosphorylation was gradually impaired with increasing temperature, possibly because of the steadily increasing proton leak across the membrane. In addition, we found that complex I (NADH dehydrogenase) activity decreased above 20°C, similarly to mitochondrial respiration, and that complex I was unstable in the presence of detergents, suggesting that it may be particularly sensitive to changes in its interaction with membrane phospholipids. In contrast, complex II (succinate dehydrogenase) maintained activity at temperatures above 20°C, although succinate oxidation was insufficient to compensate for the loss of complex I activity in intact mitochondria. Together, these results indicate that the temperature-induced decrease in cardiac mitochondrial function coincides with the temperature at which trout aerobic scope peaks, and is largely due to impaired phosphorylation and complex I activity.
Collapse
Affiliation(s)
- Jakob Michaelsen
- Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Angela Fago
- Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Amanda Bundgaard
- Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| |
Collapse
|
47
|
Ton R, Stier A, Cooper CE, Griffith SC. Effects of Heat Waves During Post-natal Development on Mitochondrial and Whole Body Physiology: An Experimental Study in Zebra Finches. Front Physiol 2021; 12:661670. [PMID: 33986695 PMCID: PMC8110927 DOI: 10.3389/fphys.2021.661670] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/06/2021] [Indexed: 12/17/2022] Open
Abstract
Human-induced climate change is increasing the frequency, duration, and intensity of heat waves and exposure to these extreme temperatures impacts individual physiology and performance (e.g., metabolism, water balance, and growth). These traits may be susceptible to thermal conditions experienced during embryonic development, but experiments focusing on post-natal development are scant. Documented effects of heat waves on whole-body metabolism may reflect changes in mitochondrial function, but most studies do not measure physiological traits at both the cellular and whole organism levels. Here, we exposed nests of zebra finches to experimentally simulated heat waves for 18 days after hatching and measured body mass, growth rate, whole-body metabolic rate, body temperature, wet thermal conductance, evaporative water loss, and relative water economy of chicks at three ages corresponding to ectothermic (day 5), poikilothermic (day 12), and homoeothermic (day 50) stages. Additionally, we measured mitochondrial bioenergetics of blood cells 80 days post-hatch. While early-life exposure to heat wave conditions did not impact whole body metabolic and hygric physiology, body temperature was lower for birds from heated compared with control nests at both 12 and 50 days of age. There was also an effect of nest heating at the cellular level, with mitochondria from heated birds having higher endogenous and proton-leak related respiration, although oxidative phosphorylation, maximum respiratory capacity, and coupling efficiency were not impacted. Our results suggest that early-life exposure to high ambient temperature induces programming effects on cellular-level and thermal physiology that may not be apparent for whole-animal metabolism.
Collapse
Affiliation(s)
- Riccardo Ton
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Antoine Stier
- Department of Biology, University of Turku, Turku, Finland
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Christine E. Cooper
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
- School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Simon C. Griffith
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| |
Collapse
|
48
|
Jørgensen LB, Overgaard J, Hunter-Manseau F, Pichaud N. Dramatic changes in mitochondrial substrate use at critically high temperatures: a comparative study using Drosophila. J Exp Biol 2021; 224:jeb.240960. [PMID: 33563650 DOI: 10.1242/jeb.240960] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 01/21/2021] [Indexed: 12/17/2022]
Abstract
Ectotherm thermal tolerance is critical to species distribution, but at present the physiological underpinnings of heat tolerance remain poorly understood. Mitochondrial function is perturbed at critically high temperatures in some ectotherms, including insects, suggesting that heat tolerance of these animals is linked to failure of oxidative phosphorylation (OXPHOS) and/or ATP production. To test this hypothesis, we measured mitochondrial oxygen consumption rate in six Drosophila species with different heat tolerance using high-resolution respirometry. Using a substrate-uncoupler-inhibitor titration protocol, we examined specific steps of the electron transport system to study how temperatures below, bracketing and above organismal heat limits affect mitochondrial function and substrate oxidation. At benign temperatures (19 and 30°C), complex I-supported respiration (CI-OXPHOS) was the most significant contributor to maximal OXPHOS. At higher temperatures (34, 38, 42 and 46°C), CI-OXPHOS decreased considerably, ultimately to very low levels at 42 and 46°C. The enzymatic catalytic capacity of complex I was intact across all temperatures and accordingly the decreased CI-OXPHOS is unlikely to be caused directly by hyperthermic denaturation/inactivation of complex I. Despite the reduction in CI-OXPHOS, maximal OXPHOS capacity was maintained in all species, through oxidation of alternative substrates - proline, succinate and, particularly, glycerol-3-phosphate - suggesting important mitochondrial flexibility at temperatures exceeding the organismal heat limit. Interestingly, this failure of CI-OXPHOS and compensatory oxidation of alternative substrates occurred at temperatures that correlated with species heat tolerance, such that heat-tolerant species could defend 'normal' mitochondrial function at higher temperatures than sensitive species. Future studies should investigate why CI-OXPHOS is perturbed and how this potentially affects ATP production rates.
Collapse
Affiliation(s)
| | - Johannes Overgaard
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Florence Hunter-Manseau
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada, E1A 3E9
| | - Nicolas Pichaud
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada, E1A 3E9
| |
Collapse
|
49
|
Lefevre S, Wang T, McKenzie DJ. The role of mechanistic physiology in investigating impacts of global warming on fishes. J Exp Biol 2021; 224:224/Suppl_1/jeb238840. [PMID: 33627469 DOI: 10.1242/jeb.238840] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Warming of aquatic environments as a result of climate change is already having measurable impacts on fishes, manifested as changes in phenology, range shifts and reductions in body size. Understanding the physiological mechanisms underlying these seemingly universal patterns is crucial if we are to reliably predict the fate of fish populations with future warming. This includes an understanding of mechanisms for acute thermal tolerance, as extreme heatwaves may be a major driver of observed effects. The hypothesis of gill oxygen limitation (GOL) is claimed to explain asymptotic fish growth, and why some fish species are decreasing in size with warming; but its underlying assumptions conflict with established knowledge and direct mechanistic evidence is lacking. The hypothesis of oxygen- and capacity-limited thermal tolerance (OCLTT) has stimulated a wave of research into the role of oxygen supply capacity and thermal performance curves for aerobic scope, but results vary greatly between species, indicating that it is unlikely to be a universal mechanism. As thermal performance curves remain important for incorporating physiological tolerance into models, we discuss potentially fruitful alternatives to aerobic scope, notably specific dynamic action and growth rate. We consider the limitations of estimating acute thermal tolerance by a single rapid measure whose mechanism of action is not known. We emphasise the continued importance of experimental physiology, particularly in advancing our understanding of underlying mechanisms, but also the challenge of making this knowledge relevant to the more complex reality.
Collapse
Affiliation(s)
- Sjannie Lefevre
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Tobias Wang
- Department of Biology - Zoophysiology, Aarhus University, 8000 Aarhus C, Denmark
| | - David J McKenzie
- Marine Biodiversity, Exploitation and Conservation (MARBEC), Université de Montpellier, CNRS, Ifremer, IRD, 34000 Montpellier, France
| |
Collapse
|