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Dellaert Z, Putnam HM. Reconciling the variability in the biological response of marine invertebrates to climate change. J Exp Biol 2023; 226:jeb245834. [PMID: 37655544 DOI: 10.1242/jeb.245834] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
As climate change increases the rate of environmental change and the frequency and intensity of disturbance events, selective forces intensify. However, given the complicated interplay between plasticity and selection for ecological - and thus evolutionary - outcomes, understanding the proximate signals, molecular mechanisms and the role of environmental history becomes increasingly critical for eco-evolutionary forecasting. To enhance the accuracy of our forecasting, we must characterize environmental signals at a level of resolution that is relevant to the organism, such as the microhabitat it inhabits and its intracellular conditions, while also quantifying the biological responses to these signals in the appropriate cells and tissues. In this Commentary, we provide historical context to some of the long-standing challenges in global change biology that constrain our capacity for eco-evolutionary forecasting using reef-building corals as a focal model. We then describe examples of mismatches between the scales of external signals relative to the sensors and signal transduction cascades that initiate and maintain cellular responses. Studying cellular responses at this scale is crucial because these responses are the basis of acclimation to changing environmental conditions and the potential for environmental 'memory' of prior or historical conditions through molecular mechanisms. To challenge the field, we outline some unresolved questions and suggest approaches to align experimental work with an organism's perception of the environment; these aspects are discussed with respect to human interventions.
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Affiliation(s)
- Zoe Dellaert
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Rd, Kingston, RI 02881, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Rd, Kingston, RI 02881, USA
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2
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Edmunds PJ, Johnson KW, Burgess SC. Branching coral morphology affects physiological performance in the absence of colony integration. Biol Lett 2022; 18:20220414. [PMID: 36475423 PMCID: PMC9727676 DOI: 10.1098/rsbl.2022.0414] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
For nearly 50 years, analyses of coral physiology have used small coral fragments (nubbins) to make inferences about larger colonies. However, scaling in corals shows that linear extrapolations from nubbins to whole colonies can be misleading, because polyps in nubbins are divorced of their morphologically complex and physiologically integrated corallum. We tested for the effects of integration among branches in determining size-dependent calcification of the coral Pocillopora spp. under elevated PCO2. Area-normalized net calcification was compared between branches (nubbins), aggregates of nubbins (complex morphologies without integration) and whole colonies (physiologically integrated) at 400 versus approximately 1000 µatm PCO2. Net calcification was unaffected by PCO2, but differed among colony types. Single nubbins grew faster than whole colonies, but when aggregated, nubbins changed calcification to match whole colonies even though they lacked integration among branches. Corallum morphology causes the phenotype of branching corals to differ from the summation of their branches.
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Affiliation(s)
- Peter J. Edmunds
- Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA
| | - Kelly W. Johnson
- Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA,Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| | - Scott C. Burgess
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA
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Majerova E, Carey FC, Drury C, Gates RD. Preconditioning improves bleaching tolerance in the reef-building coral Pocillopora acuta through modulations in the programmed cell death pathways. Mol Ecol 2021; 30:3560-3574. [PMID: 34008873 DOI: 10.1111/mec.15988] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 12/25/2022]
Abstract
Reef-building corals rely on intracellular algal symbionts to meet energetic demands. Increasing extreme weather driven by climate change often leads to disruption of this symbiosis and to coral death. Corals can better withstand stress after previous exposure to sublethal conditions, but the mechanisms for this resilience remain unclear. Here, we show that a three-day thermal preconditioning increases tolerance of acute heat stress through modulations in cell death pathways in the stony coral Pocillopora acuta. In preconditioned corals, the ratio of pro-survival (pa-Bcl-2 and pa-BI-1) to pro-death (pa-BAK and pa-BAX) gene expression increased and the corals underwent significantly less bleaching. When treated with Bcl-2 inhibitor, corals lost the improved thermal tolerance, suggesting an important role of programmed cell death in coral bleaching and acclimatization. During heat stress, the activity of acid phosphatase increased but caspase-3 did not, suggesting the involvement of autophagy/symbiophagy rather than apoptosis in this process. A similar shift in gene expression also occurs in thermally stressed corals that have been exposed to naturally higher temperatures during summer thermal maxima in Kāne'ohe Bay, Hawai'i, suggesting that corals can increase their resilience to realistic warming events during high-risk periods through alterations in cell signalling. These data suggest that programmed cell death pathways underly coral acclimatization and resilience and may be important for coral reef conservation and management.
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Affiliation(s)
- Eva Majerova
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Fiona C Carey
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Crawford Drury
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
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Huffmyer AS, Johnson CJ, Epps AM, Lemus JD, Gates RD. Feeding and thermal conditioning enhance coral temperature tolerance in juvenile Pocillopora acuta. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210644. [PMID: 34084554 PMCID: PMC8150050 DOI: 10.1098/rsos.210644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/06/2021] [Indexed: 05/13/2023]
Abstract
Scleractinian corals form the foundation of coral reefs by acquiring autotrophic nutrition from photosynthetic endosymbionts (Symbiodiniaceae) and use feeding to obtain additional nutrition, especially when the symbiosis is compromised (i.e. bleaching). Juvenile corals are vulnerable to stress due to low energetic reserves and high demand for growth, which is compounded when additional stressors occur. Therefore, conditions that favour energy acquisition and storage may enhance survival under stressful conditions. To investigate the influence of feeding on thermal tolerance, we exposed Pocillopora acuta juveniles to temperature (ambient, 27.4°C versus cool, 25.9°C) and feeding treatments (fed versus unfed) for 30 days post-settlement and monitored growth and physiology, followed by tracking survival under thermal stress. Feeding increased growth and resulted in thicker tissues and elevated symbiont fluorescence. Under high-temperature stress (31-60 days post-settlement; ca 30.1°C), corals that were fed and previously exposed to cool temperature had 33% higher survival than other treatment groups. These corals demonstrated reduced symbiont fluorescence, which may have provided protective effects under thermal stress. These results highlight that the impacts of feeding on coral physiology and stress tolerance are dependent on temperature and as oceans continue to warm, early life stages may experience shifts in feeding strategies to survive.
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Affiliation(s)
- Ariana S. Huffmyer
- Hawai‘i Institute of Marine Biology, University of Hawai‘i at Mānoa, Kāne‘ohe, HI 96744, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Colton J. Johnson
- Hawai‘i Institute of Marine Biology, University of Hawai‘i at Mānoa, Kāne‘ohe, HI 96744, USA
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Ashleigh M. Epps
- Hawai‘i Institute of Marine Biology, University of Hawai‘i at Mānoa, Kāne‘ohe, HI 96744, USA
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX 78412, USA
| | - Judith D. Lemus
- Hawai‘i Institute of Marine Biology, University of Hawai‘i at Mānoa, Kāne‘ohe, HI 96744, USA
| | - Ruth D. Gates
- Hawai‘i Institute of Marine Biology, University of Hawai‘i at Mānoa, Kāne‘ohe, HI 96744, USA
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Roger LM, Reich HG, Lawrence E, Li S, Vizgaudis W, Brenner N, Kumar L, Klein-Seetharaman J, Yang J, Putnam HM, Lewinski NA. Applying model approaches in non-model systems: A review and case study on coral cell culture. PLoS One 2021; 16:e0248953. [PMID: 33831033 PMCID: PMC8031391 DOI: 10.1371/journal.pone.0248953] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/09/2021] [Indexed: 12/19/2022] Open
Abstract
Model systems approaches search for commonality in patterns underlying biological diversity and complexity led by common evolutionary paths. The success of the approach does not rest on the species chosen but on the scalability of the model and methods used to develop the model and engage research. Fine-tuning approaches to improve coral cell cultures will provide a robust platform for studying symbiosis breakdown, the calcification mechanism and its disruption, protein interactions, micronutrient transport/exchange, and the toxicity of nanoparticles, among other key biological aspects, with the added advantage of minimizing the ethical conundrum of repeated testing on ecologically threatened organisms. The work presented here aimed to lay the foundation towards development of effective methods to sort and culture reef-building coral cells with the ultimate goal of obtaining immortal cell lines for the study of bleaching, disease and toxicity at the cellular and polyp levels. To achieve this objective, the team conducted a thorough review and tested the available methods (i.e. cell dissociation, isolation, sorting, attachment and proliferation). The most effective and reproducible techniques were combined to consolidate culture methods and generate uncontaminated coral cell cultures for ~7 days (10 days maximum). The tests were conducted on scleractinian corals Pocillopora acuta of the same genotype to harmonize results and reduce variation linked to genetic diversity. The development of cell separation and identification methods in conjunction with further investigations into coral cell-type specific metabolic requirements will allow us to tailor growth media for optimized monocultures as a tool for studying essential reef-building coral traits such as symbiosis, wound healing and calcification at multiple scales.
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Affiliation(s)
- Liza M. Roger
- Life Science and Engineering, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail: ,
| | - Hannah G. Reich
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Evan Lawrence
- Life Science and Engineering, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Shuaifeng Li
- Aeronautics and Astronautics, University of Washington, Seattle, Washington, United States of America
| | - Whitney Vizgaudis
- Department of Chemistry, Colorado School of Mines, Golden, Colorado, United States of America
| | - Nathan Brenner
- Department of Chemistry, Colorado School of Mines, Golden, Colorado, United States of America
| | - Lokender Kumar
- Department of Chemistry, Colorado School of Mines, Golden, Colorado, United States of America
| | | | - Jinkyu Yang
- Aeronautics and Astronautics, University of Washington, Seattle, Washington, United States of America
| | - Hollie M. Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Nastassja A. Lewinski
- Life Science and Engineering, Virginia Commonwealth University, Richmond, Virginia, United States of America
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Edmunds PJ, Putnam HM. Science-based approach to using growth rate to assess coral performance and restoration outcomes. Biol Lett 2020; 16:20200227. [PMID: 32673540 DOI: 10.1098/rsbl.2020.0227] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
One response to the coral reef crisis has been human intervention to enhance selection on the fittest corals through cultivation. This requires genotypes to be identified for intervention, with a primary basis for this choice being growth: corals that quickly grow on contemporary reefs might be future winners. To test for temporal stability of growth as a predictor of future performance, genotypes of the coral Porites spp. were grown in common gardens in Mo'orea, French Polynesia. Growth was measured every two to four months throughout 2018, and each period was used as a predictor of growth over the subsequent period. Area-normalized growth explained less than 29% of the variance in subsequent growth, but for biomass-normalized growth this increased to 45-60%, and was highest when summer growth was used to predict autumn growth. The capacity of initial growth to predict future performance is dependent on the units of measurement and the time of year in which it is measured. The final choice of traits to quantify performance must be informed through consideration of the species and the normalization that best capture the information inherent in the biological processes mediating variation in traits values.
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Affiliation(s)
- Peter J Edmunds
- Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA
| | - Hollie M Putnam
- Department of Biological Science, University of Rhode Island, 120 Flagg Road, Kingston, RI 02881, USA
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