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Tignat-Perrier R, van de Water JAJM, Allemand D, Ferrier-Pagès C. Holobiont responses of mesophotic precious red coral Corallium rubrum to thermal anomalies. ENVIRONMENTAL MICROBIOME 2023; 18:70. [PMID: 37580830 PMCID: PMC10424431 DOI: 10.1186/s40793-023-00525-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 07/31/2023] [Indexed: 08/16/2023]
Abstract
Marine heat waves (MHWs) have increased in frequency and intensity worldwide, causing mass mortality of benthic organisms and loss of biodiversity in shallow waters. The Mediterranean Sea is no exception, with shallow populations of habitat-forming octocorals facing the threat of local extinction. The mesophotic zone, which is less affected by MHWs, may be of ecological importance in conservation strategies for these species. However, our understanding of the response of mesophotic octocoral holobionts to changes in seawater temperature remains limited. To address this knowledge gap, we conducted a study on an iconic Mediterranean octocoral, the red coral Corallium rubrum sampled at 60 m depth and 15 °C. We exposed the colonies to temperatures they occasionally experience (18 °C) and temperatures that could occur at the end of the century if global warming continues (21 °C). We also tested their response to extremely cold and warm temperatures (12 °C and 24 °C). Our results show a high tolerance of C. rubrum to a two-month long exposure to temperatures ranging from 12 to 21 °C as no colony showed signs of tissue loss, reduced feeding ability, stress-induced gene expression, or disruption of host-bacterial symbioses. At 24 °C, however, we measured a sharp decrease in the relative abundance of Spirochaetaceae, which are the predominant bacterial symbionts under healthy conditions, along with a relative increase in Vibrionaceae. Tissue loss and overexpression of the tumor necrosis factor receptor 1 gene were also observed after two weeks of exposure. In light of ongoing global warming, our study helps predict the consequences of MHWs on mesophotic coralligenous reefs and the biodiversity that depends on them.
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Affiliation(s)
- Romie Tignat-Perrier
- Unité de Recherche sur la Biologie des Coraux Précieux CSM-CHANEL, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Principality of Monaco.
- Coral Ecophysiology Laboratory, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Principality of Monaco.
| | - Jeroen A J M van de Water
- Unité de Recherche sur la Biologie des Coraux Précieux CSM-CHANEL, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Principality of Monaco
- Coral Ecophysiology Laboratory, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Principality of Monaco
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research, Korringaweg 7, 4401 NT, Yerseke, The Netherlands
| | - Denis Allemand
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Principality of Monaco
| | - Christine Ferrier-Pagès
- Coral Ecophysiology Laboratory, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Principality of Monaco
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Mayfield AB. Multi-macromolecular Extraction from Endosymbiotic Anthozoans. Methods Mol Biol 2023; 2625:17-56. [PMID: 36653630 DOI: 10.1007/978-1-0716-2966-6_3] [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] [Indexed: 06/17/2023]
Abstract
Obligately symbiotic associations between reef-building corals (anthozoan cnidarians) and photosynthetically active dinoflagellates of the family Symbiodiniaceae comprise the functional basis of all coral reef ecosystems. Given the existential threats of global climate change toward these thermo-sensitive entities, there is an urgent need to better understand the physiological implications of changes in the abiotic milieu of scleractinian corals and their mutualistic algal endosymbionts. Although initially slow to leverage the immense breakthroughs in molecular biotechnology that have benefited humankind, coral biologists are making up for lost time in exploiting an array of ever-advancing molecular tools for answering key questions pertaining to the survival of corals in an ever-changing world. In order to comprehensively characterize the multi-omic landscape of the coral holobiont-the cnidarian host, its intracellular dinoflagellates, and a plethora of other microbial constituents-I introduce a series of protocols herein that yield large quantities of high-quality RNA, DNA, protein, lipids, and polar metabolites from a diverse array of reef corals and endosymbiotic sea anemones. Although numerous published articles in the invertebrate zoology field feature protocols that lead to sufficiently high yield of intact host coral macromolecules, through using the approach outlined herein one may simultaneously acquire a rich, multi-compartmental biochemical pool that truly reflects the complex and dynamic nature of these animal-plant chimeras.
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3
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Nitschke MR, Rosset SL, Oakley CA, Gardner SG, Camp EF, Suggett DJ, Davy SK. The diversity and ecology of Symbiodiniaceae: A traits-based review. ADVANCES IN MARINE BIOLOGY 2022; 92:55-127. [PMID: 36208879 DOI: 10.1016/bs.amb.2022.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Among the most successful microeukaryotes to form mutualisms with animals are dinoflagellates in the family Symbiodiniaceae. These photosynthetic symbioses drive significant primary production and are responsible for the formation of coral reef ecosystems but are particularly sensitive when environmental conditions become extreme. Annual episodes of widespread coral bleaching (disassociation of the mutualistic partnership) and mortality are forecasted from the year 2060 under current trends of ocean warming. However, host cnidarians and dinoflagellate symbionts display exceptional genetic and functional diversity, and meaningful predictions of the future that embrace this biological complexity are difficult to make. A recent move to trait-based biology (and an understanding of how traits are shaped by the environment) has been adopted to move past this problem. The aim of this review is to: (1) provide an overview of the major cnidarian lineages that are symbiotic with Symbiodiniaceae; (2) summarise the symbiodiniacean genera associated with cnidarians with reference to recent changes in taxonomy and systematics; (3) examine the knowledge gaps in Symbiodiniaceae life history from a trait-based perspective; (4) review Symbiodiniaceae trait variation along three abiotic gradients (light, nutrients, and temperature); and (5) provide recommendations for future research of Symbiodiniaceae traits. We anticipate that a detailed understanding of traits will further reveal basic knowledge of the evolution and functional diversity of these mutualisms, as well as enhance future efforts to model stability and change in ecosystems dependent on cnidarian-dinoflagellate organisms.
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Affiliation(s)
- Matthew R Nitschke
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand; Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia.
| | - Sabrina L Rosset
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Stephanie G Gardner
- Center for Marine Science and Innovation, University of New South Wales Sydney, Kensington, NSW, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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4
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Machine-Learning-Based Proteomic Predictive Modeling with Thermally-Challenged Caribbean Reef Corals. DIVERSITY 2022. [DOI: 10.3390/d14010033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coral health is currently diagnosed retroactively; colonies are deemed “stressed” upon succumbing to bleaching or disease. Ideally, health inferences would instead be made on a pre-death timescale that would enable, for instance, environmental mitigation that could promote coral resilience. To this end, diverse Caribbean coral (Orbicella faveolata) genotypes of varying resilience to high temperatures along the Florida Reef Tract were exposed herein to elevated temperatures in the laboratory, and a proteomic analysis was taken with a subset of 20 samples via iTRAQ labeling followed by nano-liquid chromatography + mass spectrometry; 46 host coral and 40 Symbiodiniaceae dinoflagellate proteins passed all stringent quality control criteria, and the partial proteomes of biopsies of (1) healthy controls, (2) sub-lethally stressed samples, and (3) actively bleaching corals differed significantly from one another. The proteomic data were then used to train predictive models of coral colony bleaching susceptibility, and both generalized regression and machine-learning-based neural networks were capable of accurately forecasting the bleaching susceptibility of coral samples based on their protein signatures. Successful future testing of the predictive power of these models in situ could establish the capacity to proactively monitor coral health.
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5
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Thummasan M, Casareto BE, Ramphul C, Suzuki T, Toyoda K, Suzuki Y. Physiological responses (Hsps 60 and 32, caspase 3, H 2O 2 scavenging, and photosynthetic activity) of the coral Pocillopora damicornis under thermal and high nitrate stresses. MARINE POLLUTION BULLETIN 2021; 171:112737. [PMID: 34298325 DOI: 10.1016/j.marpolbul.2021.112737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/22/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
This study explored the physiological responses of the coral Pocillopora damicornis to high nitrate concentrations and thermal stresses. The expression of heat shock proteins Hsp60 and Hsp32, Symbiodiniaceae density, Chl a concentration, Fv/Fm, H2O2 scavenging, and caspase 3 activity varied during 60 h incubations at 28 °C or 32 °C, ambient or high nitrate (~10 μM) concentrations, and their combinations. In combined stresses, corals showed a rapid and high oxidation level negatively affecting the Symbiodiniaceae density and Chl a concentration at 12 h, followed by caspase 3 and Hsps upregulations that induced apoptosis, bleaching and tissue detachment. Corals under thermal stress showed the highest oxidation and upregulation of Hsps and caspase 3 resulting in coral discoloration. High nitrate treatment alone did not seriously affect the coral function. Results showed that combined stress treatment severely affected coral physiology and, judging from the condition of detached tissues, these corals might have lower chances to recover.
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Affiliation(s)
- Montaphat Thummasan
- Environmental and Energy System, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Beatriz Estela Casareto
- Environmental and Energy System, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
| | - Chitra Ramphul
- Environmental and Energy System, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Toshiyuki Suzuki
- Environmental and Energy System, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
| | - Keita Toyoda
- Environmental and Energy System, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
| | - Yoshimi Suzuki
- Environmental and Energy System, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
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Grottoli AG, Toonen RJ, Woesik R, Vega Thurber R, Warner ME, McLachlan RH, Price JT, Bahr KD, Baums IB, Castillo KD, Coffroth MA, Cunning R, Dobson KL, Donahue MJ, Hench JL, Iglesias‐Prieto R, Kemp DW, Kenkel CD, Kline DI, Kuffner IB, Matthews JL, Mayfield AB, Padilla‐Gamiño JL, Palumbi S, Voolstra CR, Weis VM, Wu HC. Increasing comparability among coral bleaching experiments. ECOLOGICAL APPLICATIONS 2021; 31:e02262. [PMID: 33222325 PMCID: PMC8243963 DOI: 10.1002/eap.2262] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 09/09/2020] [Indexed: 05/14/2023]
Affiliation(s)
- A. G. Grottoli
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - R. J. Toonen
- Hawaiʻi Institute of Marine Biology University of Hawaiʻi at Mānoa Kāneʻohe Hawaii96744USA
| | - R. Woesik
- Department of Ocean Engineering and Marine Sciences Florida Institute of Technology Melbourne Florida32901USA
| | - R. Vega Thurber
- Department of Microbiology Oregon State University Corvallis Oregon97331USA
| | - M. E. Warner
- School of Marine Science and Policy University of Delaware Lewes Delaware19958USA
| | - R. H. McLachlan
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - J. T. Price
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - K. D. Bahr
- Department of Life Sciences Texas A&M University–Corpus Christi Corpus Christi Texas78412USA
| | - I. B. Baums
- Department of Biology Pennsylvania State University University Park Pennsylvania16802USA
| | - K. D. Castillo
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill North Carolina27599USA
| | - M. A. Coffroth
- Department of Geology State University of New York at Buffalo Buffalo New York14260USA
| | - R. Cunning
- Daniel P. Hearther Center for Conservation and Research John G. Shedd Aquarium Chicago Illinois60605USA
| | - K. L. Dobson
- School of Earth Sciences The Ohio State University Columbus Ohio43210USA
| | - M. J. Donahue
- Hawaiʻi Institute of Marine Biology University of Hawaiʻi at Mānoa Kāneʻohe Hawaii96744USA
| | - J. L. Hench
- Nicholas School of the Environment Duke University Beaufort North Carolina28516USA
| | - R. Iglesias‐Prieto
- Department of Biology Pennsylvania State University University Park Pennsylvania16802USA
| | - D. W. Kemp
- Department of Biology University of Alabama at Birmingham Birmingham Alabama35233USA
| | - C. D. Kenkel
- Department of Biological Sciences University of Southern California Los Angeles California90089USA
| | - D. I. Kline
- Smithsonian Tropical Research Institute Washington D.C.20013USA
| | - I. B. Kuffner
- St Petersburg Coastal & Marine Science Center United States Geological Survey St Petersburg Florida33701USA
| | - J. L. Matthews
- Faculty of Science Climate Change Cluster University of Technology Sydney Broadway, Sydney New South Wales2007Australia
| | - A. B. Mayfield
- Oceanographic and Meteorological Laboratory Atlantic National Oceanic and Atmospheric Administration Miami Florida33149USA
- Cooperative Institute for Marine & Atmospheric Studies University of Miami Miami Florida33149USA
| | - J. L. Padilla‐Gamiño
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington98117USA
| | - S. Palumbi
- Hopkins Marine Station Stanford University Pacific Grove California93950USA
| | - C. R. Voolstra
- Department of Biology University of Konstanz Konstanz78457Germany
| | - V. M. Weis
- Department of Integrative Biology Oregon State University Corvallis Oregon97331USA
| | - H. C. Wu
- Leibniz Centre for Tropical Marine Research Bremen28359Germany
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7
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Louis YD, Bhagooli R, Seveso D, Maggioni D, Galli P, Vai M, Dyall SD. Local acclimatisation-driven differential gene and protein expression patterns of Hsp70 in Acropora muricata: Implications for coral tolerance to bleaching. Mol Ecol 2020; 29:4382-4394. [PMID: 32967057 DOI: 10.1111/mec.15642] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 08/22/2020] [Accepted: 08/25/2020] [Indexed: 01/15/2023]
Abstract
Corals show spatial acclimatisation to local environment conditions. However, the various cellular mechanisms involved in local acclimatisation and variable bleaching patterns in corals remain to be thoroughly understood. In this study, the modulation of a protein implicated in cellular heat stress tolerance, the heat shock protein 70, was compared at both gene (hsp70) and protein (Hsp70) expression level in bleaching tolerant near-coast Acropora muricata colonies and bleaching susceptible reef colonies, in the lagoon of Belle Mare (Mauritius). The relative Hsp70 levels varied significantly between colonies from the two different locations, colonies having different health conditions and the year of collection. Before the bleaching event of 2016, near-coast colonies had higher basal levels of both Hsp70 gene and protein compared to reef colonies. During the bleaching event, the near-coast colonies did not bleach and had significantly higher relative levels of both Hsp70 gene and protein compared to bleached reef colonies. No significant genetic differentiation between the two studied coral populations was observed and all the colonies analysed were associated with Symbiodiniaceae of the genus Symbiodinium (Clade A) irrespective of location and sampling period. These findings provide further evidence of the involvement of Hsp70 in conferring bleaching tolerance to corals. Moreover, the consistent expression differences of Hsp70 gene and protein between the near-coast and reef coral populations in a natural setting indicate that the modulation of this Hsp is involved in local acclimatisation of corals to their environments.
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Affiliation(s)
- Yohan Didier Louis
- Department of Biosciences and Ocean Studies, Faculty of Science, University of Mauritius, Réduit, Republic of Mauritius
| | - Ranjeet Bhagooli
- Department of Biosciences and Ocean Studies, Faculty of Science, University of Mauritius, Réduit, Republic of Mauritius.,The Biodiversity and Environmental Institute, Réduit, Republic of Mauritius.,Institute of Oceanography and Environment (INOS), University Malaysia Terengganu, Kuala Terengganu, Terengganu, Malaysia.,Pole of Research Excellence in Sustainable Marine Biodiversity, University of Mauritius, Réduit, Mauritius
| | - Davide Seveso
- Department of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Milan, Italy.,MaRHE Center (Marine Research and High Education Centre), Faafu Atoll, Magoodhoo, Faafu, Republic of Maldives
| | - Davide Maggioni
- Department of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Milan, Italy.,MaRHE Center (Marine Research and High Education Centre), Faafu Atoll, Magoodhoo, Faafu, Republic of Maldives
| | - Paolo Galli
- Department of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Milan, Italy.,MaRHE Center (Marine Research and High Education Centre), Faafu Atoll, Magoodhoo, Faafu, Republic of Maldives
| | - Marina Vai
- Department of Biotechnologies and Biosciences, University of Milano - Bicocca, Milan, Italy
| | - Sabrina Devi Dyall
- Department of Biosciences and Ocean Studies, Faculty of Science, University of Mauritius, Réduit, Republic of Mauritius.,Pole of Research Excellence in Molecular Life Sciences, University of Mauritius, Réduit, Republic of Mauritius
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8
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Mayfield AB. Proteomic Signatures of Corals from Thermodynamic Reefs. Microorganisms 2020; 8:microorganisms8081171. [PMID: 32752238 PMCID: PMC7465421 DOI: 10.3390/microorganisms8081171] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/30/2020] [Accepted: 07/31/2020] [Indexed: 12/30/2022] Open
Abstract
Unlike most parts of the world, coral reefs of Taiwan’s deep south have generally been spared from climate change-induced degradation. This has been linked to the oceanographically unique nature of Nanwan Bay, where intense upwelling occurs. Specifically, large-amplitude internal waves cause shifts in temperature of 6–9 °C over the course of several hours, and the resident corals not only thrive under such conditions, but they have also been shown to withstand multi-month laboratory incubations at experimentally elevated temperatures. To gain insight into the sub-cellular basis of acclimation to upwelling, proteins isolated from reef corals (Seriatopora hystrix) featured in laboratory-based reciprocal transplant studies in which corals from upwelling and non-upwelling control reefs (<20 km away) were exposed to stable or variable temperature regimes were analyzed via label-based proteomics (iTRAQ). Corals exposed to their “native” temperature conditions for seven days (1) demonstrated highest growth rates and (2) were most distinct from one another with respect to their protein signatures. The latter observation was driven by the fact that two Symbiodiniaceae lipid trafficking proteins, sec1a and sec34, were marginally up-regulated in corals exposed to their native temperature conditions. Alongside the marked degree of proteomic “site fidelity” documented, this dataset sheds light on the molecular mechanisms underlying acclimatization to thermodynamically extreme conditions in situ.
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Affiliation(s)
- Anderson B. Mayfield
- Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, 4301 Rickenbacker Causeway, Miami, FL 33149, USA; or ; Tel.: +1-337-501-1976
- Cooperative Institutes for Marine and Atmospheric Studies, University of Miami, 4300 Rickenbacker Causeway, Miami, FL 33149, USA
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Abstract
Herein we propose an ambitious confrontation of the current coral reef crisis through the establishment of a "Coral Hospital." In an analogous manner to a human hospital, "sick" corals will first be diagnosed either in situ or in the hospital's diagnostic "clinic" such that the root cause of illness can be discerned (e.g., disease, high temperatures, or pollutant stress). Then, corals will be "treated" (when necessary) and allowed to "convalesce" in precisely controlled coral husbandry facilities. Upon "rehabilitation," the recovered corals will be returned to their home reef (if this reef was not found to have degraded), or, alternatively, to a site featuring oceanographic conditions favoring a high level of health, as determined by husbandry experiments performed in other hospital "wards." When possible, diagnostic data from the sick corals (i.e., the underlying cause of sickness) will be used to guide environmental remediation schemes aimed at promoting coral resilience in the ocean. If the home reef improves to an appreciable extent during the time the corals are "hospitalized," these corals could be replanted there upon rehabilitation. Regardless of the site of outplanting, recuperated corals will be monitored over time to validate the "quality of care" in the hospital. In the event that the home reefs suffer to such an extent that environmental mitigation is no longer possible, coral gametes will be collected and cryopreserved such that they may be fertilized, reared in officinarum, and later reseeded once/if global marine conditions again permit coral survival.
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Affiliation(s)
- Anderson B Mayfield
- 1Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Checheng, Taiwan
| | - Sujune Tsai
- 2Department of Post-Modern Agriculture, Ming-Dao University, Beidou, Taiwan
| | - Chiahsin Lin
- 1Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Checheng, Taiwan.,3Graduate Institute of Marine Biology, National Dong-Hwa University, Checheng, Taiwan
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10
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Morse D, Tse SPK, Lo SCL. Exploring dinoflagellate biology with high-throughput proteomics. HARMFUL ALGAE 2018; 75:16-26. [PMID: 29778222 DOI: 10.1016/j.hal.2018.03.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 06/08/2023]
Abstract
Dinoflagellates are notorious for their ability to form the harmful algal blooms known as "red tides," yet the mechanisms underlying bloom formation remain poorly understood. Despite recent advances in nucleic acid sequencing, which have generated transcriptomes from a wide range of species exposed to a variety of different conditions, measuring changes in RNA levels have not generally produced great insight into dinoflagellate cell biology or environmental physiology, nor do we have a thorough grasp on the molecular events underpinning bloom formation. Not only is the transcriptomic response of dinoflagellates to environmental change generally muted, but there is a markedly low degree of congruency between mRNA expression and protein expression in dinoflagellates. Herein we discuss the application of high-throughput proteomics to the study of dinoflagellate biology. By profiling the cellular protein complement (the proteome) instead of mRNA (the transcriptome), the biomolecular events that underlie the changes of phenotypes can be more readily evaluated, as proteins directly determine the structure and the function of the cell. Recent advances in proteomics have seen this technique become a high-throughput method that is now able to provide a perspective different from the more commonly employed nucleic acid sequencing. We suggest that the time is ripe to exploit these new technologies in addressing the many mysteries of dinoflagellate biology, such as how the symbiotic dinoflagellate inhabiting reef corals acclimate to increases in temperature, as well as how harmful algal blooms are initiated at the sub-cellular level. Furthermore, as dinoflagellates are not the only eukaryotes that demonstrate muted transcriptional responses, the techniques addressed within this review are amenable to a wide array of organisms.
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Affiliation(s)
- David Morse
- Institut de Recherche en biologie Végétale, Département de Sciences Biologiques, Université de Montréal, Canada.
| | - Sirius P K Tse
- Shenzhen Key Laboratory of Food Biological Safety Control, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
| | - Samuel C L Lo
- Shenzhen Key Laboratory of Food Biological Safety Control, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
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11
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Mayfield AB, Chen YJ, Lu CY, Chen CS. The proteomic response of the reef coral Pocillopora acuta to experimentally elevated temperatures. PLoS One 2018; 13:e0192001. [PMID: 29385204 PMCID: PMC5792016 DOI: 10.1371/journal.pone.0192001] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/15/2018] [Indexed: 12/12/2022] Open
Abstract
Although most reef-building corals live near the upper threshold of their thermotolerance, some scleractinians are resilient to temperature increases. For instance, Pocillopora acuta specimens from an upwelling habitat in Southern Taiwan survived a nine-month experimental exposure to 30°C, a temperature hypothesized to induce stress. To gain a greater understanding of the molecular pathways underlying such high-temperature acclimation, the protein profiles of experimental controls incubated at 27°C were compared to those of conspecific P. acuta specimens exposed to 30°C for two, four, or eight weeks, and differentially concentrated proteins (DCPs) were removed from the gels and sequenced with mass spectrometry. Sixty unique DCPs were uncovered across both eukaryotic compartments of the P. acuta-dinoflagellate (genus Symbiodinium) mutualism, and Symbiodinium were more responsive to high temperature at the protein-level than the coral hosts in which they resided at the two-week sampling time. Furthermore, proteins involved in the stress response were more likely to be documented at different cellular concentrations across temperature treatments in Symbiodinium, whereas the temperature-sensitive host coral proteome featured numerous proteins involved in cytoskeletal structure, immunity, and metabolism. These proteome-scale data suggest that the coral host and its intracellular dinoflagellates have differing strategies for acclimating to elevated temperatures.
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Affiliation(s)
- Anderson B. Mayfield
- Khaled bin Sultan Living Oceans Foundation, Annapolis, MD, United States of America
- Taiwan Coral Research Center, Checheng, Pingtung, Taiwan
- * E-mail:
| | - Yi-Jyun Chen
- Taiwan Coral Research Center, Checheng, Pingtung, Taiwan
| | - Chi-Yu Lu
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Center for Research Resources and Development, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chii-Shiarng Chen
- Taiwan Coral Research Center, Checheng, Pingtung, Taiwan
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan
- Graduate Institute of Marine Biotechnology, National Dong-Hwa University, Checheng, Pingtung, Taiwan
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12
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Mayfield AB, Chen YJ, Lu CY, Chen CS. Exploring the Environmental Physiology of the Indo-Pacific Reef Coral <em>Seriatopora hystrix</em> with Differential Proteomics. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/ojms.2018.82012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Mayfield AB, Wang YB, Chen CS, Chen SH, Lin CY. Dual-compartmental transcriptomic + proteomic analysis of a marine endosymbiosis exposed to environmental change. Mol Ecol 2017; 25:5944-5958. [PMID: 27778414 DOI: 10.1111/mec.13896] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 12/24/2022]
Abstract
As significant anthropogenic pressures are putting undue stress on the world's oceans, there has been a concerted effort to understand how marine organisms respond to environmental change. Transcriptomic approaches, in particular, have been readily employed to document the mRNA-level response of a plethora of marine invertebrates exposed to an array of simulated stress scenarios, with the tacit and untested assumption being that the respective proteins show a corresponding trend. To better understand the degree of congruency between mRNA and protein expression in an endosymbiotic marine invertebrate, mRNAs and proteins were sequenced from the same samples of the common, Indo-Pacific coral Seriatopora hystrix exposed to stable or upwelling-simulating conditions for 1 week. Of the 167 proteins downregulated at variable temperature, only two were associated with mRNAs that were also differentially expressed between treatments. Of the 378 differentially expressed genes, none were associated with a differentially expressed protein. Collectively, these results highlight the inherent risk of inferring cellular behaviour based on mRNA expression data alone and challenge the current, mRNA-focused approach taken by most marine and many molecular biologists.
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Affiliation(s)
- Anderson B Mayfield
- National Museum of Marine Biology and Aquarium, 2 Houwan Road, Checheng, Pingtung, 944, Taiwan.,Living Oceans Foundation, 130 Severn Avenue, Annapolis, MD, 21403, USA
| | - Yu-Bin Wang
- Graduate Institute of Zoology, National Taiwan University, No. 1, Sec. 4 Roosevelt Road, Taipei, 106, Taiwan.,Institute of Information Sciences, Academia Sinica, 128 Academia Road, Sec. 2, Nangang, Taipei, 115, Taiwan
| | - Chii-Shiarng Chen
- National Museum of Marine Biology and Aquarium, 2 Houwan Road, Checheng, Pingtung, 944, Taiwan.,Taiwan Coral Research Center, 2 Houwan Road, Checheng, Pingtung, 944, Taiwan.,Graduate Institute of Marine Biotechnology, National Dong-Hwa University, 2 Houwan Road, Checheng, Pingtung, 944, Taiwan.,Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, 70 Lianhai Road, Kaohsiung, 80424, Taiwan
| | - Shu-Hwa Chen
- Institute of Information Sciences, Academia Sinica, 128 Academia Road, Sec. 2, Nangang, Taipei, 115, Taiwan
| | - Chung-Yen Lin
- Institute of Information Sciences, Academia Sinica, 128 Academia Road, Sec. 2, Nangang, Taipei, 115, Taiwan.,Institute of Fisheries Science, National Taiwan University, No. 1, Sec. 4 Roosevelt Road, Taipei, 106, Taiwan.,Institute of Population Health Sciences, National Health Research Institutes, 5 Keyan Road, Zhunan, Miaoli, 350, Taiwan
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14
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Mayfield AB, Chen CS, Dempsey AC. Biomarker profiling in reef corals of Tonga's Ha'apai and Vava'u archipelagos. PLoS One 2017; 12:e0185857. [PMID: 29091723 PMCID: PMC5665425 DOI: 10.1371/journal.pone.0185857] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 09/20/2017] [Indexed: 01/04/2023] Open
Abstract
Given the significant threats towards Earth's coral reefs, there is an urgent need to document the current physiological condition of the resident organisms, particularly the reef-building scleractinians themselves. Unfortunately, most of the planet's reefs are understudied, and some have yet to be seen. For instance, the Kingdom of Tonga possesses an extensive reef system, with thousands of hectares of unobserved reefs; little is known about their ecology, nor is there any information on the health of the resident corals. Given such knowledge deficiencies, 59 reefs across three Tongan archipelagos were surveyed herein, and pocilloporid corals were sampled from approximately half of these surveyed sites; 10 molecular-scale response variable were assessed in 88 of the sampled colonies, and 12 colonies were found to be outliers based on employment of a multivariate statistics-based aberrancy detection system. These outliers differed from the statistically normally behaving colonies in having not only higher RNA/DNA ratios but also elevated expression levels of three genes: 1) Symbiodinium zinc-induced facilitator-like 1-like, 2) host coral copper-zinc superoxide dismutase, and 3) host green fluorescent protein-like chromoprotein. Outliers were also characterized by significantly higher variation amongst the molecular response variables assessed, and the response variables that contributed most significantly to colonies being delineated as outliers differed between the two predominant reef coral species sampled, Pocillopora damicornis and P. acuta. These closely related species also displayed dissimilar temporal fluctuation patterns in their molecular physiologies, an observation that may have been driven by differences in their feeding strategies. Future works should attempt to determine whether corals displaying statistically aberrant molecular physiology, such as the 12 Tongan outliers identified herein, are indeed characterized by a diminished capacity for acclimating to the rapid changes in their abiotic milieu occurring as a result of global climate change.
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Affiliation(s)
- Anderson B. Mayfield
- National Museum of Marine Biology and Aquarium, Checheng, Pingtung, Taiwan
- Khaled bin Sultan Living Oceans Foundation, Annapolis, Maryland, United States of America
- Taiwan Coral Research Center, Checheng, Pingtung, Taiwan
- * E-mail:
| | - Chii-Shiarng Chen
- National Museum of Marine Biology and Aquarium, Checheng, Pingtung, Taiwan
- Taiwan Coral Research Center, Checheng, Pingtung, Taiwan
- Graduate Institute of Marine Biotechnology, National Dong-Hwa University, Checheng, Pingtung, Taiwan
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Alexandra C. Dempsey
- Khaled bin Sultan Living Oceans Foundation, Annapolis, Maryland, United States of America
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15
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Bonesso JL, Leggat W, Ainsworth TD. Exposure to elevated sea-surface temperatures below the bleaching threshold impairs coral recovery and regeneration following injury. PeerJ 2017; 5:e3719. [PMID: 28828283 PMCID: PMC5564385 DOI: 10.7717/peerj.3719] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 07/29/2017] [Indexed: 12/28/2022] Open
Abstract
Elevated sea surface temperatures (SSTs) are linked to an increase in the frequency and severity of bleaching events due to temperatures exceeding corals’ upper thermal limits. The temperatures at which a breakdown of the coral-Symbiodinium endosymbiosis (coral bleaching) occurs are referred to as the upper thermal limits for the coral species. This breakdown of the endosymbiosis results in a reduction of corals’ nutritional uptake, growth, and tissue integrity. Periods of elevated sea surface temperature, thermal stress and coral bleaching are also linked to increased disease susceptibility and an increased frequency of storms which cause injury and physical damage to corals. Herein we aimed to determine the capacity of corals to regenerate and recover from injuries (removal of apical tips) sustained during periods of elevated sea surface temperatures which result in coral stress responses, but which do not result in coral bleaching (i.e., sub-bleaching thermal stress events). In this study, exposure of the species Acropora aspera to an elevated SST of 32 °C (2 °C below the bleaching threshold, 34 °C) was found to result in reduced fluorescence of green fluorescent protein (GFP), reduced skeletal calcification and a lack of branch regrowth at the site of injury, compared to corals maintained under ambient SST conditions (26 °C). Corals maintained under normal, ambient, sea surface temperatures expressed high GFP fluorescence at the injury site, underwent a rapid regeneration of the coral branch apical tip within 12 days of sustaining injury, and showed extensive regrowth of the coral skeleton. Taken together, our results have demonstrated that periods of sustained increased sea surface temperatures, below the corals’ bleaching threshold but above long-term summertime averages, impair coral recovery from damage, regardless of the onset or occurrence of coral bleaching.
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Affiliation(s)
- Joshua Louis Bonesso
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia
| | - William Leggat
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia.,ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
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16
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Mayfield AB, Chen CS, Dempsey AC. Identifying corals displaying aberrant behavior in Fiji's Lau Archipelago. PLoS One 2017; 12:e0177267. [PMID: 28542245 PMCID: PMC5443480 DOI: 10.1371/journal.pone.0177267] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/25/2017] [Indexed: 12/04/2022] Open
Abstract
Given the numerous threats against Earth’s coral reefs, there is an urgent need to develop means of assessing reef coral health on a proactive timescale. Molecular biomarkers may prove useful in this endeavor because their expression should theoretically undergo changes prior to visible signs of health decline, such as the breakdown of the coral-dinoflagellate (genus Symbiodinium) endosymbiosis. Herein 13 molecular- and physiological-scale biomarkers spanning both eukaryotic compartments of the anthozoan-Symbiodinium mutualism were assessed across 70 pocilloporid coral colonies sampled from reefs of Fiji’s easternmost province, Lau. Eleven colonies were identified as outliers upon employment of a detection method based partially on the Mahalanobis distance; these corals were hypothesized to have been displaying aberrant sub-cellular behavior with respect to their gene expression signatures, as they were characterized not only by lower Symbiodinium densities, but also by higher levels of expression of several stress-targeted genes. Although these findings could suggest that the sampled colonies were physiologically compromised at the time of sampling, further studies are warranted to state conclusively whether these 11 scleractinian coral colonies are more stress-prone than nearby conspecifics that demonstrated statistically normal phenotypes.
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Affiliation(s)
- Anderson B. Mayfield
- National Museum of Marine Biology and Aquarium, Checheng, Pingtung, Taiwan
- Khaled bin Sultan Living Oceans Foundation, Annapolis, MD, United States of America
- Taiwan Coral Research Center, Checheng, Pingtung, Taiwan
- * E-mail:
| | - Chii-Shiarng Chen
- National Museum of Marine Biology and Aquarium, Checheng, Pingtung, Taiwan
- Taiwan Coral Research Center, Checheng, Pingtung, Taiwan
- Graduate Institute of Marine Biotechnology, National Dong Hwa University, Checheng, Pingtung, Taiwan
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Alexandra C. Dempsey
- Khaled bin Sultan Living Oceans Foundation, Annapolis, MD, United States of America
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17
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Salas BH, Haslun JA, Strychar KB, Ostrom PH, Cervino JM. Site-specific variation in gene expression from Symbiodinium spp. associated with offshore and inshore Porites astreoides in the lower Florida Keys is lost with bleaching and disease stress. PLoS One 2017; 12:e0173350. [PMID: 28355291 PMCID: PMC5371298 DOI: 10.1371/journal.pone.0173350] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 02/20/2017] [Indexed: 11/18/2022] Open
Abstract
Scleractinian coral are experiencing unprecedented rates of mortality due to increases in sea surface temperatures in response to global climate change. Some coral species however, survive high temperature events due to a reduced susceptibility to bleaching. We investigated the relationship between bleaching susceptibility and expression of five metabolically related genes of Symbiodinium spp. from the coral Porites astreoides originating from an inshore and offshore reef in the Florida Keys. The acclimatization potential of Symbiodinium spp. to changing temperature regimes was also measured via a two-year reciprocal transplant between the sites. Offshore coral fragments displayed significantly higher expression in Symbiodinium spp. genes PCNA, SCP2, G3PDH, PCP and psaE than their inshore counterparts (p<0.05), a pattern consistent with increased bleaching susceptibility in offshore corals. Additionally, gene expression patterns in Symbiodinium spp. from site of origin were conserved throughout the two-year reciprocal transplant, indicating acclimatization did not occur within this multi-season time frame. Further, laboratory experiments were used to investigate the influence of acute high temperature (32°C for eight hours) and disease (lipopolysaccharide of Serratia marcescens) on the five metabolically related symbiont genes from the same offshore and inshore P. astreoides fragments. Gene expression did not differ between reef fragments, or as a consequence of acute exposure to heat or heat and disease, contrasting to results found in the field. Gene expression reported here indicates functional variation in populations of Symbiodinium spp. associated with P. astreoides in the Florida Keys, and is likely a result of localized adaptation. However, gene expression patterns observed in the lab imply that functional variation in zooxanthellae observed under conditions of chronic moderate stress is lost under the acute extreme conditions studied here.
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Affiliation(s)
- Briana Hauff Salas
- University of Texas School of Medicine, San Antonio, TX, United States of America
| | - Joshua A Haslun
- Michigan State University, Department of Integrative Biology, East Lansing, MI, United States of America
| | - Kevin B Strychar
- Annis Water Resources Institute-Grand Valley State University, Muskegon, MI, United States of America
| | - Peggy H Ostrom
- Michigan State University, Department of Integrative Biology, East Lansing, MI, United States of America
| | - James M Cervino
- Woods Hole Oceanographic Institute, Department of Marine Chemistry & Geochemistry, Woods Hole, MA, United States of America
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18
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Uncovering Spatio-Temporal and Treatment-Derived Differences in the Molecular Physiology of a Model Coral-Dinoflagellate Mutualism with Multivariate Statistical Approaches. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2016. [DOI: 10.3390/jmse4030063] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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19
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Seveso D, Montano S, Strona G, Orlandi I, Galli P, Vai M. Hsp60 expression profiles in the reef-building coral Seriatopora caliendrum subjected to heat and cold shock regimes. MARINE ENVIRONMENTAL RESEARCH 2016; 119:1-11. [PMID: 27183199 DOI: 10.1016/j.marenvres.2016.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/02/2016] [Accepted: 05/07/2016] [Indexed: 06/05/2023]
Abstract
Climate changes have increased the intensity/frequency of extreme thermal events, which represent serious threats to the health of reef-building corals. Since the vulnerability of corals exposed to thermal stresses are related to their ability to regulate Heat shock proteins (Hsps), we have analyzed together the time related expression profiles of the mitochondrial Hsp60 and the associated changes in tissue pigmentation in Seriatopora caliendrum subjected to 48 h of heat and cold treatments characterized by moderate (±2 °C) and severe (±6 °C) shocks. For the first time, an Hsp60 response was observed in a scleractinian coral exposed to cold stresses. Furthermore, the Hsp60 modulations and the changes in the tissue coloration were found to be specific for each treatment. A strong down-regulation at the end of the treatments was observed following both the severe shocks, but only the severe heat stress led to bleaching in concert with the lowest levels of Hsp60, suggesting that a severe heat shock can be more deleterious than an exposure to a severe cold temperature. On the contrary, a moderate cold stress seems to be more harmful than a moderate temperature increase, which could allow coral acclimation. Our results can provide a potential framework for understanding the physiological tolerance of corals under possible future climate changes.
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Affiliation(s)
- Davide Seveso
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives.
| | - Simone Montano
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives
| | - Giovanni Strona
- European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, I-21027, Ispra, Italy
| | - Ivan Orlandi
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Paolo Galli
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives
| | - Marina Vai
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
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20
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Morphological Variability and Distinct Protein Profiles of Cultured and Endosymbiotic Symbiodinium cells Isolated from Exaiptasia pulchella. Sci Rep 2015; 5:15353. [PMID: 26481560 PMCID: PMC4611179 DOI: 10.1038/srep15353] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 08/05/2015] [Indexed: 01/10/2023] Open
Abstract
Symbiodinium is a dinoflagellate that plays an important role in the physiology of the symbiotic relationships of Cnidarians such as corals and sea anemones. However, it is very difficult to cultivate free-living dinoflagellates after being isolated from the host, as they are very sensitive to environmental changes. How these symbiont cells are supported by the host tissue is still unclear. This study investigated the characteristics of Symbiodinium cells, particularly with respect to the morphological variability and distinct protein profiles of both cultured and endosymbiotic Symbiodinium which were freshly isolated from Exaiptasia pulchella. The response of the cellular morphology of freshly isolated Symbiodinium cells kept under a 12 h L:12 h D cycle to different temperatures was measured. Cellular proliferation was investigated by measuring the growth pattern of Symbiodinium cells, the results of which indicated that the growth was significantly reduced in response to the extreme temperatures. Proteomic analysis of freshly isolated Symbiodinium cells revealed twelve novel proteins that putatively included transcription translation factors, photosystem proteins, and proteins associated with energy and lipid metabolism, as well as defense response. The results of this study will bring more understandings to the mechanisms governing the endosymbiotic relationship between the cnidarians and dinoflagellates.
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21
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Krueger T, Fisher PL, Becker S, Pontasch S, Dove S, Hoegh-Guldberg O, Leggat W, Davy SK. Transcriptomic characterization of the enzymatic antioxidants FeSOD, MnSOD, APX and KatG in the dinoflagellate genus Symbiodinium. BMC Evol Biol 2015; 15:48. [PMID: 25887897 PMCID: PMC4416395 DOI: 10.1186/s12862-015-0326-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 02/24/2015] [Indexed: 11/26/2022] Open
Abstract
Background The diversity of the symbiotic dinoflagellate Symbiodinium sp., as assessed by genetic markers, is well established. To what extent this diversity is reflected on the amino acid level of functional genes such as enzymatic antioxidants that play an important role in thermal stress tolerance of the coral-Symbiodinium symbiosis is, however, unknown. Here we present a predicted structural analysis and phylogenetic characterization of the enzymatic antioxidant repertoire of the genus Symbiodinium. We also report gene expression and enzymatic activity under short-term thermal stress in Symbiodinium of the B1 genotype. Results Based on eight different ITS2 types, covering six clades, multiple protein isoforms for three of the four investigated antioxidants (ascorbate peroxidase [APX], catalase peroxidase [KatG], manganese superoxide dismutase [MnSOD]) are present in the genus Symbiodinium. Amino acid sequences of both SOD metalloforms (Fe/Mn), as well as KatG, exhibited a number of prokaryotic characteristics that were also supported by the protein phylogeny. In contrast to the bacterial form, KatG in Symbiodinium is characterized by extended functionally important loops and a shortened C-terminal domain. Intercladal sequence variations were found to be much higher in both peroxidases, compared to SODs. For APX, these variable residues involve binding sites for substrates and cofactors, and might therefore differentially affect the catalytic properties of this enzyme between clades. While expression of antioxidant genes was successfully measured in Symbiodinium B1, it was not possible to assess the link between gene expression and protein activity due to high variability in expression between replicates, and little response in their enzymatic activity over the three-day experimental period. Conclusions The genus Symbiodinium has a diverse enzymatic antioxidant repertoire that has similarities to prokaryotes, potentially as a result of horizontal gene transfer or events of secondary endosymbiosis. Different degrees of sequence evolution between SODs and peroxidases might be the result of potential selective pressure on the conserved molecular function of SODs as the first line of defence. In contrast, genetic redundancy of hydrogen peroxide scavenging enzymes might permit the observed variations in peroxidase sequences. Our data and successful measurement of antioxidant gene expression in Symbiodinium will serve as basis for further studies of coral health. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0326-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Thomas Krueger
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand. .,Laboratory for Biological Geochemistry, ENAC, École polytechnique fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland.
| | - Paul L Fisher
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand. .,School of Civil Engineering, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Susanne Becker
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand.
| | - Stefanie Pontasch
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand.
| | - Sophie Dove
- School of Biological Sciences & ARC Centre of Excellence for Coral Reef Studies, University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Ove Hoegh-Guldberg
- Global Change Institute, University of Queensland, Brisbane, QLD 4072, Australia.
| | - William Leggat
- Comparative Genomics Centre, School of Pharmacy and Molecular Sciences & ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand.
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Mayfield AB, Wang YB, Chen CS, Lin CY, Chen SH. Compartment-specific transcriptomics in a reef-building coral exposed to elevated temperatures. Mol Ecol 2015; 23:5816-30. [PMID: 25354956 PMCID: PMC4265203 DOI: 10.1111/mec.12982] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 12/27/2022]
Abstract
Although rising ocean temperatures threaten scleractinian corals and the reefs they construct, certain reef corals can acclimate to elevated temperatures to which they are rarely exposed in situ. Specimens of the model Indo-Pacific reef coral Pocillopora damicornis collected from upwelling reefs of Southern Taiwan were previously found to have survived a 36-week exposure to 30°C, a temperature they encounter infrequently and one that can elicit the breakdown of the coral–dinoflagellate (genus Symbiodinium) endosymbiosis in many corals of the Pacific Ocean. To gain insight into the subcellular pathways utilized by both the coral hosts and their mutualistic Symbiodinium populations to acclimate to this temperature, mRNAs from both control (27°C) and high (30°C)-temperature samples were sequenced on an Illumina platform and assembled into a 236 435-contig transcriptome. These P. damicornis specimens were found to be ∼60% anthozoan and 40% microbe (Symbiodinium, other eukaryotic microbes, and bacteria), from an mRNA-perspective. Furthermore, a significantly higher proportion of genes from the Symbiodinium compartment were differentially expressed after two weeks of exposure. Specifically, at elevated temperatures, Symbiodinium populations residing within the coral gastrodermal tissues were more likely to up-regulate the expression of genes encoding proteins involved in metabolism than their coral hosts. Collectively, these transcriptome-scale data suggest that the two members of this endosymbiosis have distinct strategies for acclimating to elevated temperatures that are expected to characterize many of Earth's coral reefs in the coming decades.
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Affiliation(s)
- Anderson B Mayfield
- National Museum of Marine Biology and Aquarium, 2 Houwan Rd., Checheng, Pingtung, 944, Taiwan; Living Oceans Foundation, 8181 Professional Place, Suite 215, Landover, MD, 20785, USA
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23
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Rosic N, Kaniewska P, Chan CKK, Ling EYS, Edwards D, Dove S, Hoegh-Guldberg O. Early transcriptional changes in the reef-building coral Acropora aspera in response to thermal and nutrient stress. BMC Genomics 2014; 15:1052. [PMID: 25467196 PMCID: PMC4301396 DOI: 10.1186/1471-2164-15-1052] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 11/12/2014] [Indexed: 11/10/2022] Open
Abstract
Background Changes to the environment as a result of human activities can result in a range of impacts on reef building corals that include coral bleaching (reduced concentrations of algal symbionts), decreased coral growth and calcification, and increased incidence of diseases and mortality. Understanding how elevated temperatures and nutrient concentration affect early transcriptional changes in corals and their algal endosymbionts is critically important for evaluating the responses of coral reefs to global changes happening in the environment. Here, we investigated the expression of genes in colonies of the reef-building coral Acropora aspera exposed to short-term sub-lethal levels of thermal (+6°C) and nutrient stress (ammonium-enrichment: 20 μM). Results The RNA-Seq data provided hundreds of differentially expressed genes (DEGs) corresponding to various stress regimes, with 115 up- and 78 down-regulated genes common to all stress regimes. A list of DEGs included up-regulated coral genes like cytochrome c oxidase and NADH-ubiquinone oxidoreductase and up-regulated photosynthetic genes of algal origin, whereas coral GFP-like fluorescent chromoprotein and sodium/potassium-transporting ATPase showed reduced transcript levels. Taxonomic analyses of the coral holobiont disclosed the dominant presence of transcripts from coral (~70%) and Symbiodinium (~10-12%), as well as ~15-20% of unknown sequences which lacked sequence identity to known genes. Gene ontology analyses revealed enriched pathways, which led to changes in the dynamics of protein networks affecting growth, cellular processes, and energy requirement. Conclusions In corals with preserved symbiont physiological performance (based on Fv/Fm, photo-pigment and symbiont density), transcriptomic changes and DEGs provided important insight into early stages of the stress response in the coral holobiont. Although there were no signs of coral bleaching after exposure to short-term thermal and nutrient stress conditions, we managed to detect oxidative stress and apoptotic changes on a molecular level and provide a list of prospective stress biomarkers for both partners in symbiosis. Consequently, our findings are important for understanding and anticipating impacts of anthropogenic global climate change on coral reefs. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1052) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nedeljka Rosic
- School of Biological Sciences, The University of Queensland, Brisbane Qld 4072, Australia.
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24
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Cellular membrane accommodation to thermal oscillations in the coral Seriatopora caliendrum. PLoS One 2014; 9:e105345. [PMID: 25140803 PMCID: PMC4139334 DOI: 10.1371/journal.pone.0105345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/21/2014] [Indexed: 11/19/2022] Open
Abstract
In the present study, the membrane lipid composition of corals from a region with tidally induced upwelling was investigated. The coral community is subject to strong temperature oscillations yet flourishes as a result of adaptation. Glycerophosphocholine profiling of the dominant pocilloporid coral, Seriatopora caliendrum, was performed using a validated method. The coral inhabiting the upwelling region shows a definite shift in the ratio of lipid molecular species, covering several subclasses. Mainly, the coral possesses a higher percentage of saturated, monounsaturated and polyunsaturated plasmanylcholines and a lower percentage of polyunsaturated phosphatidylcholines. Higher levels of lyso-plasmanylcholines containing saturated or monounsaturated fatty acid chains were also revealed in coral tissue at the distal portion of the branch. Based on the physicochemical properties of these lipids, we proposed mechanisms for handling cellular membrane perturbations, such as tension, induced by thermal oscillation to determine how coral cells are able to spontaneously maintain their physiological functions, in both molecular and physical terms. Interestingly, the biochemical and biophysical properties of these lipids also have beneficial effects on the resistance, maintenance, and growth of the corals. The results of this study suggest that lipid metabolic adjustment is a major factor in the adaption of S. caliendrum in upwelling regions.
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Mayfield AB, Hsiao YY, Chen HK, Chen CS. Rubisco expression in the dinoflagellate Symbiodinium sp. is influenced by both photoperiod and endosymbiotic lifestyle. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2014; 16:371-384. [PMID: 24449387 DOI: 10.1007/s10126-014-9558-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 10/10/2013] [Indexed: 06/03/2023]
Abstract
Although the importance of anthozoan-dinoflagellate (genus Symbiodinium) endosymbioses in the establishment of coral reef ecosystems is evident, little is known about the molecular regulation of photosynthesis in the intra-gastrodermal symbiont communities, particularly with respect to the rate-limiting Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). In this study, we analyzed rubisco mRNA (rbcL) and protein (RBCL) concentrations over the diel cycle in both cultured and endosymbiotic Symbiodinium samples. In the former, rbcL expression increased upon illumination and decreased during the dark, a pattern that was upheld under continual dark incubation. A different trend in rbcL expression was observed in endosymbiotic Symbiodinium residing within sea anemone (Aiptasia pulchella) tissues, in which illumination gradually led to decreased rbcL mRNA expression. Unexpectedly, RBCL protein expression did not vary over time within anemone tissues, and in neither cultured nor endosymbiotic samples was a correlation between gene and protein expression documented. It appears, then, that photoperiod, lifestyle, and posttranscriptional regulation are all important drivers of RBCL expression in this ecologically important dinoflagellate.
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Affiliation(s)
- Anderson B Mayfield
- Taiwan Coral Research Center (TCRC), National Museum of Marine Biology and Aquarium, 2 Houwan Rd., Checheng, Pingtung 944, Taiwan, Republic of China
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Seveso D, Montano S, Strona G, Orlandi I, Galli P, Vai M. The susceptibility of corals to thermal stress by analyzing Hsp60 expression. MARINE ENVIRONMENTAL RESEARCH 2014; 99:69-75. [PMID: 24999860 DOI: 10.1016/j.marenvres.2014.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/23/2014] [Accepted: 06/13/2014] [Indexed: 06/03/2023]
Abstract
Due to the increasing frequency and severity of the coral bleaching events in the context of global warming, there is an urgent need to improve our understanding of the susceptibility of corals to thermal stresses, particularly at the sub-cellular level. In this context, we examined the modulation of the polyp mitochondrial Hsp60 in three scleractinian coral species (Seriatopora hystrix, Montipora monasteriata and Acropora echinata) under simulated heat shock bleaching at 34 °C during a time course of 36 h. All three species displayed a similar initial increase of Hsp60 level which accompanies the increasing paleness of coral tissue. Afterwards, each of them showed a specific pattern of Hsp60 down-regulation which can be indicative of a different threshold of resistance, although it proceeded in synchrony with the complete bleaching of tissues. The finely branched S. hystrix was the species most susceptible to heat stress while the plating M. monasteriata was the most tolerant one, as its Hsp60 down-regulation was less rapid than the branching corals. On the whole, the Hsp60 modulation appears useful for providing information about the susceptibility of the different coral taxa to environmental disturbances.
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Affiliation(s)
- Davide Seveso
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives.
| | - Simone Montano
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives
| | - Giovanni Strona
- European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, I-21027 Ispra, Italy
| | - Ivan Orlandi
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Paolo Galli
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives
| | - Marina Vai
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
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Mayfield AB, Chen MN, Meng PJ, Lin HJ, Chen CS, Liu PJ. The physiological response of the reef coral Pocillopora damicornis to elevated temperature: results from coral reef mesocosm experiments in Southern Taiwan. MARINE ENVIRONMENTAL RESEARCH 2013; 86:1-11. [PMID: 23453047 DOI: 10.1016/j.marenvres.2013.01.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 01/17/2013] [Accepted: 01/17/2013] [Indexed: 06/01/2023]
Abstract
Given the threat of climate change towards scleractinian corals, there is an urgent need to understand their physiological mechanisms of acclimation to increasing temperatures. To gain insight into this process, two mesocosm-based experiments were conducted in Southern Taiwan with the model reef-building coral Pocillopora damicornis. In the first study, temperature was gradually elevated to 32 °C, though reduced to ambient levels at night, in order to simulate a temperature profile that can characterize intertidal reefs of Southern Taiwan. All corals acclimated to such conditions over the course of the month-long experiment, as evidenced by a variety of physiological and sub-cellular responses. In the second experiment, corals were exposed continually to 31.5 °C for two weeks, and, in contrast to results from the first study, the majority of the corals died, revealing that prolonged exposure to this temperature is lethal for this dominant reef builder of many regions of the Pacific Ocean.
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Granados-Cifuentes C, Bellantuono AJ, Ridgway T, Hoegh-Guldberg O, Rodriguez-Lanetty M. High natural gene expression variation in the reef-building coral Acropora millepora: potential for acclimative and adaptive plasticity. BMC Genomics 2013; 14:228. [PMID: 23565725 PMCID: PMC3630057 DOI: 10.1186/1471-2164-14-228] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 02/27/2013] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Ecosystems worldwide are suffering the consequences of anthropogenic impact. The diverse ecosystem of coral reefs, for example, are globally threatened by increases in sea surface temperatures due to global warming. Studies to date have focused on determining genetic diversity, the sequence variability of genes in a species, as a proxy to estimate and predict the potential adaptive response of coral populations to environmental changes linked to climate changes. However, the examination of natural gene expression variation has received less attention. This variation has been implicated as an important factor in evolutionary processes, upon which natural selection can act. RESULTS We acclimatized coral nubbins from six colonies of the reef-building coral Acropora millepora to a common garden in Heron Island (Great Barrier Reef, GBR) for a period of four weeks to remove any site-specific environmental effects on the physiology of the coral nubbins. By using a cDNA microarray platform, we detected a high level of gene expression variation, with 17% (488) of the unigenes differentially expressed across coral nubbins of the six colonies (jsFDR-corrected, p < 0.01). Among the main categories of biological processes found differentially expressed were transport, translation, response to stimulus, oxidation-reduction processes, and apoptosis. We found that the transcriptional profiles did not correspond to the genotype of the colony characterized using either an intron of the carbonic anhydrase gene or microsatellite loci markers. CONCLUSION Our results provide evidence of the high inter-colony variation in A. millepora at the transcriptomic level grown under a common garden and without a correspondence with genotypic identity. This finding brings to our attention the importance of taking into account natural variation between reef corals when assessing experimental gene expression differences. The high transcriptional variation detected in this study is interpreted and discussed within the context of adaptive potential and phenotypic plasticity of reef corals. Whether this variation will allow coral reefs to survive to current challenges remains unknown.
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Affiliation(s)
- Camila Granados-Cifuentes
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Anthony J Bellantuono
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Tyrone Ridgway
- Oceanica Consulting Pty Ltd, PO Box 462, Wembley, WA, 6913, Australia
- The Oceans Institute, University of Western Australia, Crawley, WA, 6009, Australia
| | - Ove Hoegh-Guldberg
- ARC Centre of Excellence for Coral Reef Studies and Coral Genomics Group, School of Pharmacy and Molecular Sciences, James Cook University, Townsville, QLD, Australia
- Global Change Institute, The University of Queensland, St Lucia, QLD, Australia
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Bellantuono AJ, Granados-Cifuentes C, Miller DJ, Hoegh-Guldberg O, Rodriguez-Lanetty M. Coral thermal tolerance: tuning gene expression to resist thermal stress. PLoS One 2012; 7:e50685. [PMID: 23226355 PMCID: PMC3511300 DOI: 10.1371/journal.pone.0050685] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/26/2012] [Indexed: 11/18/2022] Open
Abstract
The acclimatization capacity of corals is a critical consideration in the persistence of coral reefs under stresses imposed by global climate change. The stress history of corals plays a role in subsequent response to heat stress, but the transcriptomic changes associated with these plastic changes have not been previously explored. In order to identify host transcriptomic changes associated with acquired thermal tolerance in the scleractinian coral Acropora millepora, corals preconditioned to a sub-lethal temperature of 3°C below bleaching threshold temperature were compared to both non-preconditioned corals and untreated controls using a cDNA microarray platform. After eight days of hyperthermal challenge, conditions under which non-preconditioned corals bleached and preconditioned corals (thermal-tolerant) maintained Symbiodinium density, a clear differentiation in the transcriptional profiles was revealed among the condition examined. Among these changes, nine differentially expressed genes separated preconditioned corals from non-preconditioned corals, with 42 genes differentially expressed between control and preconditioned treatments, and 70 genes between non-preconditioned corals and controls. Differentially expressed genes included components of an apoptotic signaling cascade, which suggest the inhibition of apoptosis in preconditioned corals. Additionally, lectins and genes involved in response to oxidative stress were also detected. One dominant pattern was the apparent tuning of gene expression observed between preconditioned and non-preconditioned treatments; that is, differences in expression magnitude were more apparent than differences in the identity of genes differentially expressed. Our work revealed a transcriptomic signature underlying the tolerance associated with coral thermal history, and suggests that understanding the molecular mechanisms behind physiological acclimatization would be critical for the modeling of reefs in impending climate change scenarios.
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Affiliation(s)
- Anthony J Bellantuono
- Department of Biological Sciences, Florida International University, Miami, Florida, United States of America
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Mayfield AB, Chan PH, Putnam HM, Chen CS, Fan TY. The effects of a variable temperature regime on the physiology of the reef-building coral Seriatopora hystrix: results from a laboratory-based reciprocal transplant. ACTA ACUST UNITED AC 2012; 215:4183-95. [PMID: 22933614 DOI: 10.1242/jeb.071688] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
To understand the effects of global climate change on reef-building corals, a thorough investigation of their physiological mechanisms of acclimatization is warranted. However, static temperature manipulations may underestimate the thermal complexity of the reefs in which many corals live. For instance, corals of Houbihu, Taiwan, experience changes in temperature of up to 10°C over the course of a day during spring-tide upwelling events. To better understand the phenotypic plasticity of these corals, a laboratory-based experiment was conducted whereby specimens of Seriatopora hystrix from an upwelling reef (Houbihu) and conspecifics from a non-upwelling reef (Houwan) were exposed to both a stable seawater temperature (26°C) regime and a regime characterized by a 6°C fluctuation (23-29°C) over a 12 h period for 7 days. A suite of physiological and molecular parameters was measured in samples of both treatments, as well as in experimental controls, to determine site of origin (SO) and temperature treatment (TT) responses. Only chlorophyll a (chl a) concentration and growth demonstrated the hypothesized trend of higher levels when exposed to a TT that mimicked SO conditions. In contrast, chl a, maximum dark-adapted quantum yield of photosystem II (F(v)/F(m)), and Symbiodinium ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL), photosystem I (psI, subunit III) and phosphoglycolate phosphatase (pgpase) mRNA expression demonstrated significant TT effects. Specifically, levels of these response variables were higher in samples exposed to a variable temperature regime, suggesting that S. hystrix may acclimate to fluctuating temperatures by increasing its capacity for photosynthesis.
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Affiliation(s)
- Anderson B Mayfield
- National Museum of Marine Biology and Aquarium, Checheng, Pingtung, Taiwan, ROC.
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