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Helgoe J, Davy SK, Weis VM, Rodriguez-Lanetty M. Triggers, cascades, and endpoints: connecting the dots of coral bleaching mechanisms. Biol Rev Camb Philos Soc 2024; 99:715-752. [PMID: 38217089 DOI: 10.1111/brv.13042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/15/2024]
Abstract
The intracellular coral-dinoflagellate symbiosis is the engine that underpins the success of coral reefs, one of the most diverse ecosystems on the planet. However, the breakdown of the symbiosis and the loss of the microalgal symbiont (i.e. coral bleaching) due to environmental changes are resulting in the rapid degradation of coral reefs globally. There is an urgent need to understand the cellular physiology of coral bleaching at the mechanistic level to help develop solutions to mitigate the coral reef crisis. Here, at an unprecedented scope, we present novel models that integrate putative mechanisms of coral bleaching within a common framework according to the triggers (initiators of bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, e.g. photoinhibition, unfolded protein response, nitric oxide), and endpoints (mechanisms of symbiont loss, e.g. apoptosis, necrosis, exocytosis/vomocytosis). The models are supported by direct evidence from cnidarian systems, and indirectly through comparative evolutionary analyses from non-cnidarian systems. With this approach, new putative mechanisms have been established within and between cascades initiated by different bleaching triggers. In particular, the models provide new insights into the poorly understood connections between bleaching cascades and endpoints and highlight the role of a new mechanism of symbiont loss, i.e. 'symbiolysosomal digestion', which is different from symbiophagy. This review also increases the approachability of bleaching physiology for specialists and non-specialists by mapping the vast landscape of bleaching mechanisms in an atlas of comprehensible and detailed mechanistic models. We then discuss major knowledge gaps and how future research may improve the understanding of the connections between the diverse cascade of cellular pathways and the mechanisms of symbiont loss (endpoints).
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Affiliation(s)
- Joshua Helgoe
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 2701 SW Campus Way, 2403 Cordley Hall, Corvallis, OR, USA
| | - Mauricio Rodriguez-Lanetty
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
- Department of Biological Sciences, Biomolecular Sciences Institute, Florida International University, 11200 SW 8th Street, Miami, FL, USA
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2
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Doering T, Tandon K, Topa SH, Pidot SJ, Blackall LL, van Oppen MJH. Genomic exploration of coral-associated bacteria: identifying probiotic candidates to increase coral bleaching resilience in Galaxea fascicularis. MICROBIOME 2023; 11:185. [PMID: 37596630 PMCID: PMC10439622 DOI: 10.1186/s40168-023-01622-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/14/2023] [Indexed: 08/20/2023]
Abstract
BACKGROUND Reef-building corals are acutely threatened by ocean warming, calling for active interventions to reduce coral bleaching and mortality. Corals associate with a wide diversity of bacteria which can influence coral health, but knowledge of specific functions that may be beneficial for corals under thermal stress is scant. Under the oxidative stress theory of coral bleaching, bacteria that scavenge reactive oxygen (ROS) or nitrogen species (RNS) are expected to enhance coral thermal resilience. Further, bacterial carbon export might substitute the carbon supply from algal photosymbionts, enhance thermal resilience and facilitate bleaching recovery. To identify probiotic bacterial candidates, we sequenced the genomes of 82 pure-cultured bacteria that were isolated from the emerging coral model Galaxea fascicularis. RESULTS Genomic analyses showed bacterial isolates were affiliated with 37 genera. Isolates such as Ruegeria, Muricauda and Roseovarius were found to encode genes for the synthesis of the antioxidants mannitol, glutathione, dimethylsulfide, dimethylsulfoniopropionate, zeaxanthin and/or β-carotene. Genes involved in RNS-scavenging were found in many G. fascicularis-associated bacteria, which represents a novel finding for several genera (including Pseudophaeobacter). Transporters that are suggested to export carbon (semiSWEET) were detected in seven isolates, including Pseudovibrio and Roseibium. Further, a range of bacterial strains, including strains of Roseibium and Roseovarius, revealed genomic features that may enhance colonisation and association of bacteria with the coral host, such as secretion systems and eukaryote-like repeat proteins. CONCLUSIONS Our work provides an in-depth genomic analysis of the functional potential of G. fascicularis-associated bacteria and identifies novel combinations of traits that may enhance the coral's ability to withstand coral bleaching. Identifying and characterising bacteria that are beneficial for corals is critical for the development of effective probiotics that boost coral climate resilience. Video Abstract.
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Affiliation(s)
- Talisa Doering
- School of BioSciences, The University of Melbourne, Parkville, VIC Australia
| | - Kshitij Tandon
- School of BioSciences, The University of Melbourne, Parkville, VIC Australia
| | - Sanjida H. Topa
- School of BioSciences, The University of Melbourne, Parkville, VIC Australia
| | - Sacha J. Pidot
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, VIC Australia
| | - Linda L. Blackall
- School of BioSciences, The University of Melbourne, Parkville, VIC Australia
| | - Madeleine J. H. van Oppen
- School of BioSciences, The University of Melbourne, Parkville, VIC Australia
- Australian Institute of Marine Science, Townsville, QLD Australia
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3
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Doering T, Maire J, Chan WY, Perez-Gonzalez A, Meyers L, Sakamoto R, Buthgamuwa I, Blackall LL, van Oppen MJH. Comparing the Role of ROS and RNS in the Thermal Stress Response of Two Cnidarian Models, Exaiptasia diaphana and Galaxea fascicularis. Antioxidants (Basel) 2023; 12:antiox12051057. [PMID: 37237923 DOI: 10.3390/antiox12051057] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/24/2023] [Accepted: 04/29/2023] [Indexed: 05/28/2023] Open
Abstract
Coral reefs are threatened by climate change, because it causes increasingly frequent and severe summer heatwaves, resulting in mass coral bleaching and mortality. Coral bleaching is believed to be driven by an excess production of reactive oxygen (ROS) and nitrogen species (RNS), yet their relative roles during thermal stress remain understudied. Here, we measured ROS and RNS net production, as well as activities of key enzymes involved in ROS scavenging (superoxide dismutase and catalase) and RNS synthesis (nitric oxide synthase) and linked these metrics to physiological measurements of cnidarian holobiont health during thermal stress. We did this for both an established cnidarian model, the sea anemone Exaiptasia diaphana, and an emerging scleractinian model, the coral Galaxea fascicularis, both from the Great Barrier Reef (GBR). Increased ROS production was observed during thermal stress in both species, but it was more apparent in G. fascicularis, which also showed higher levels of physiological stress. RNS did not change in thermally stressed G. fascicularis and decreased in E. diaphana. Our findings in combination with variable ROS levels in previous studies on GBR-sourced E. diaphana suggest G. fascicularis is a more suitable model to study the cellular mechanisms of coral bleaching.
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Affiliation(s)
- Talisa Doering
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Justin Maire
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Wing Yan Chan
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Alexis Perez-Gonzalez
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute of Infection and Immunity, Parkville, VIC 3010, Australia
- Melbourne Cytometry Platform, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Luka Meyers
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Rumi Sakamoto
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Isini Buthgamuwa
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Linda L Blackall
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia
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Mashini AG, Oakley CA, Beepat SS, Peng L, Grossman AR, Weis VM, Davy SK. The Influence of Symbiosis on the Proteome of the Exaiptasia Endosymbiont Breviolum minutum. Microorganisms 2023; 11:292. [PMID: 36838257 PMCID: PMC9967746 DOI: 10.3390/microorganisms11020292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/13/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
The cellular mechanisms responsible for the regulation of nutrient exchange, immune response, and symbiont population growth in the cnidarian-dinoflagellate symbiosis are poorly resolved. Here, we employed liquid chromatography-mass spectrometry to elucidate proteomic changes associated with symbiosis in Breviolum minutum, a native symbiont of the sea anemone Exaiptasia diaphana ('Aiptasia'). We manipulated nutrients available to the algae in culture and to the holobiont in hospite (i.e., in symbiosis) and then monitored the impacts of our treatments on host-endosymbiont interactions. Both the symbiotic and nutritional states had significant impacts on the B. minutum proteome. B. minutum in hospite showed an increased abundance of proteins involved in phosphoinositol metabolism (e.g., glycerophosphoinositol permease 1 and phosphatidylinositol phosphatase) relative to the free-living alga, potentially reflecting inter-partner signalling that promotes the stability of the symbiosis. Proteins potentially involved in concentrating and fixing inorganic carbon (e.g., carbonic anhydrase, V-type ATPase) and in the assimilation of nitrogen (e.g., glutamine synthase) were more abundant in free-living B. minutum than in hospite, possibly due to host-facilitated access to inorganic carbon and nitrogen limitation by the host when in hospite. Photosystem proteins increased in abundance at high nutrient levels irrespective of the symbiotic state, as did proteins involved in antioxidant defences (e.g., superoxide dismutase, glutathione s-transferase). Proteins involved in iron metabolism were also affected by the nutritional state, with an increased iron demand and uptake under low nutrient treatments. These results detail the changes in symbiont physiology in response to the host microenvironment and nutrient availability and indicate potential symbiont-driven mechanisms that regulate the cnidarian-dinoflagellate symbiosis.
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Affiliation(s)
| | - Clinton A. Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Sandeep S. Beepat
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Lifeng Peng
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Arthur R. Grossman
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Simon K. Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
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5
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Moroz LL, Mukherjee K, Romanova DY. Nitric oxide signaling in ctenophores. Front Neurosci 2023; 17:1125433. [PMID: 37034176 PMCID: PMC10073611 DOI: 10.3389/fnins.2023.1125433] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Nitric oxide (NO) is one of the most ancient and versatile signal molecules across all domains of life. NO signaling might also play an essential role in the origin of animal organization. Yet, practically nothing is known about the distribution and functions of NO-dependent signaling pathways in representatives of early branching metazoans such as Ctenophora. Here, we explore the presence and organization of NO signaling components using Mnemiopsis and kin as essential reference species. We show that NO synthase (NOS) is present in at least eight ctenophore species, including Euplokamis and Coeloplana, representing the most basal ctenophore lineages. However, NOS could be secondarily lost in many other ctenophores, including Pleurobrachia and Beroe. In Mnemiopsis leidyi, NOS is present both in adult tissues and differentially expressed in later embryonic stages suggesting the involvement of NO in developmental mechanisms. Ctenophores also possess soluble guanylyl cyclases as potential NO receptors with weak but differential expression across tissues. Combined, these data indicate that the canonical NO-cGMP signaling pathways existed in the common ancestor of animals and could be involved in the control of morphogenesis, cilia activities, feeding and different behaviors.
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Affiliation(s)
- Leonid L. Moroz
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- The Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, United States
- *Correspondence: Leonid L. Moroz, ; orcid.org/0000-0002-1333-3176
| | - Krishanu Mukherjee
- The Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, United States
| | - Daria Y. Romanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia
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Al-Hammady MA, Silva TF, Hussein HN, Saxena G, Modolo LV, Belasy MB, Westphal H, Farag MA. How do algae endosymbionts mediate for their coral host fitness under heat stress? A comprehensive mechanistic overview. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Yuyama I, Higuchi T, Mezaki T, Tashiro H, Ikeo K. Metatranscriptomic Analysis of Corals Inoculated With Tolerant and Non-Tolerant Symbiont Exposed to High Temperature and Light Stress. Front Physiol 2022; 13:806171. [PMID: 35480050 PMCID: PMC9037784 DOI: 10.3389/fphys.2022.806171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/17/2022] [Indexed: 11/13/2022] Open
Abstract
Algal symbionts of corals can influence host stress resistance; for example, in the Pacific Ocean, whereas Cladocopium (C-type) is generally dominant in corals, Durusdinium (D-type) is found in more heat-resistant corals. Thus, the presence of D-type symbiont likely increases coral heat tolerance, and this symbiotic relationship potentially provides a hint to increase the stress tolerance of coral–algal symbioses. In this study, transcriptome profiles of Cladocopium- and Durusdinium-harboring Acropora solitaryensis (C-coral and D-coral, respectively) and algal photosystem functioning (Fv/Fm) under bleaching conditions (high temperature and light stress) were compared. Stress treatment caused algal photoinhibition that the Fv/Fm value of Symbiodiniaceae was immediately reduced. The transcriptome analysis of corals revealed that genes involved in the following processes were detected: endoplasmic reticulum (ER) stress, mitophagy, apoptosis, endocytosis, metabolic processes (acetyl-CoA, chitin metabolic processes, etc.), and the PI3K-AKT pathway were upregulated, while DNA replication and the calcium signaling pathway were downregulated in both C- and D-corals. These results suggest that unrepaired DNA and protein damages were accumulated in corals under high temperature and light stress. Additionally, some differentially expressed genes (DEGs) were specific to C- or D-corals, which includes genes involved in transient receptor potential (TRP) channels and vitamin B metabolic processes. Algal transcriptome analysis showed the increased expression of gene encoding photosystem and molecular chaperone especially in D-type symbiont. The transcriptome data imply a possible difference in the stress reactions on C-type and D-type symbionts. The results reveal the basic process of coral heat/light stress response and symbiont-type-specific coral transcriptional responses, which provides a perspective on the mechanisms that cause differences in coral stress tolerance.
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Affiliation(s)
- Ikuko Yuyama
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
- *Correspondence: Ikuko Yuyama
| | - Tomihiko Higuchi
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
| | - Takuma Mezaki
- Kuroshio Biological Research Foundation, Otsuki, Japan
| | - Hisako Tashiro
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Japan
| | - Kazuho Ikeo
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Japan
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8
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Bleaching physiology: who's the 'weakest link' - host vs. symbiont? Emerg Top Life Sci 2022; 6:17-32. [PMID: 35179208 DOI: 10.1042/etls20210228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/20/2022] [Accepted: 02/01/2022] [Indexed: 11/17/2022]
Abstract
Environmental stress, such as an increase in the sea surface temperature, triggers coral bleaching, a profound dysfunction of the mutualist symbiosis between the host cnidarians and their photosynthetic dinoflagellates of the Family Symbiodiniaceae. Because of climate change, mass coral bleaching events will increase in frequency and severity in the future, threatening the persistence of this iconic marine ecosystem at global scale. Strategies adapted to coral reefs preservation and restoration may stem from the identification of the succession of events and of the different molecular and cellular contributors to the bleaching phenomenon. To date, studies aiming to decipher the cellular cascade leading to temperature-related bleaching, emphasized the involvement of reactive species originating from compromised bioenergetic pathways (e.g. cellular respiration and photosynthesis). These molecules are responsible for damage to various cellular components causing the dysregulation of cellular homeostasis and the breakdown of symbiosis. In this review, we synthesize the current knowledge available in the literature on the cellular mechanisms caused by thermal stress, which can initiate or participate in the cell cascade leading to the loss of symbionts, with a particular emphasis on the role of each partner in the initiating processes.
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da Silva Fonseca J, de Barros Marangoni LF, Marques JA, Bianchini A. Elevated Temperature and Exposure to Copper Leads to Changes in the Antioxidant Defense System of the Reef-Building Coral Mussismilia harttii. Front Physiol 2021; 12:804678. [PMID: 35002777 PMCID: PMC8734030 DOI: 10.3389/fphys.2021.804678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/01/2021] [Indexed: 11/17/2022] Open
Abstract
The frequency and severity of coral bleaching events have increased in recent years. Global warming and contamination are primarily responsible for triggering these responses in corals. Thus, the objective of this study was to evaluate the isolated and combined effects of elevated temperature and exposure to copper (Cu) on responses of the antioxidant defense system of coral Mussismilia harttii. In a marine mesocosm, fragments of the coral were exposed to three temperatures (25.0, 26.6, and 27.3°C) and three concentrations of Cu (2.9, 5.4, and 8.6 μg/L) for up to 12 days. Levels of reduced glutathione (GSH) and the activity of enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutamate cysteine ligase (GCL), were evaluated on the corals and symbionts. The short exposure to isolated and combined stressors caused a reduction in GSH levels and inhibition of the activity of antioxidant enzymes. After prolonged exposure, the combination of stressors continued to reduce GSH levels and SOD, CAT, and GCL activity in symbionts and GST activity in host corals. GCL activity was the parameter most affected by stressors, remaining inhibited after 12-days exposure. Interesting that long-term exposure to stressors stimulated antioxidant defense proteins in M. harttii, demonstrating a counteracting response that may beneficiate the oxidative state. These results, combined with other studies already published suggest that the antioxidant system should be further studied in order to understand the mechanisms of tolerance of South Atlantic reefs.
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Affiliation(s)
- Juliana da Silva Fonseca
- Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil
| | - Laura Fernandes de Barros Marangoni
- Programa de Pós-Graduação em Oceanografia Biológica, Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Brazil
- Instituto Coral Vivo, Santa Cruz Cabrália, Brazil
- Smithsonian Tropical Research Institute, Ciudad de Panamá, Panama
| | - Joseane Aparecida Marques
- Programa de Pós-Graduação em Oceanografia Biológica, Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Brazil
- Instituto Coral Vivo, Santa Cruz Cabrália, Brazil
| | - Adalto Bianchini
- Instituto Coral Vivo, Santa Cruz Cabrália, Brazil
- Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil
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10
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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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11
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Rosset SL, Oakley CA, Ferrier-Pagès C, Suggett DJ, Weis VM, Davy SK. The Molecular Language of the Cnidarian-Dinoflagellate Symbiosis. Trends Microbiol 2020; 29:320-333. [PMID: 33041180 DOI: 10.1016/j.tim.2020.08.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/21/2020] [Accepted: 08/27/2020] [Indexed: 12/18/2022]
Abstract
The cnidarian-dinoflagellate symbiosis is of huge importance as it underpins the success of coral reefs, yet we know very little about how the host cnidarian and its dinoflagellate endosymbionts communicate with each other to form a functionally integrated unit. Here, we review the current knowledge of interpartner molecular signaling in this symbiosis, with an emphasis on lipids, glycans, reactive species, biogenic volatiles, and noncoding RNA. We draw upon evidence of these compounds from recent omics-based studies of cnidarian-dinoflagellate symbiosis and discuss the signaling roles that they play in other, better-studied symbioses. We then consider how improved knowledge of interpartner signaling might be used to develop solutions to the coral reef crisis by, for example, engineering more thermally resistant corals.
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Affiliation(s)
- Sabrina L Rosset
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | | | - David J Suggett
- University of Technology Sydney, Climate Change Cluster, Faculty of Science, PO Box 123, Broadway NSW 2007, Australia
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand.
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A Review: The Role of Reactive Oxygen Species in Mass Coral Bleaching. PHOTOSYNTHESIS IN ALGAE: BIOCHEMICAL AND PHYSIOLOGICAL MECHANISMS 2020. [DOI: 10.1007/978-3-030-33397-3_17] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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Marangoni LFDB, Mies M, Güth AZ, Banha TNS, Inague A, Fonseca JDS, Dalmolin C, Faria SC, Ferrier-Pagès C, Bianchini A. Peroxynitrite Generation and Increased Heterotrophic Capacity Are Linked to the Disruption of the Coral-Dinoflagellate Symbiosis in a Scleractinian and Hydrocoral Species. Microorganisms 2019; 7:microorganisms7100426. [PMID: 31600926 PMCID: PMC6843776 DOI: 10.3390/microorganisms7100426] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 01/08/2023] Open
Abstract
Ocean warming is one of the greatest global threats to coral reef ecosystems; it leads to the disruption of the coral–dinoflagellate symbiosis (bleaching) and to nutrient starvation, because corals mostly rely on autotrophy (i.e., the supply of photosynthates from the dinoflagellate symbionts) for their energy requirements. Although coral bleaching has been well studied, the early warning signs of bleaching, as well as the capacity of corals to shift from autotrophy to heterotrophy, are still under investigation. In this study, we evaluated the bleaching occurrence of the scleractinian coral Mussismillia harttii and the hydrocoral Millepora alcicornis during a natural thermal stress event, under the 2015–2016 El Niño influence in three reef sites of the South Atlantic. We focused on the link between peroxynitrite (ONOO−) generation and coral bleaching, as ONOO− has been very poorly investigated in corals and never during a natural bleaching event. We also investigated the natural trophic plasticity of the two corals through the use of new lipid biomarkers. The results obtained first demonstrate that ONOO− is linked to the onset and intensity of bleaching in both scleractinian corals and hydrocorals. Indeed, ONOO− concentrations were correlated with bleaching intensity, with the highest levels preceding the highest bleaching intensity. The time lag between bleaching and ONOO− peak was, however, species-specific. In addition, we observed that elevated temperatures forced heterotrophy in scleractinian corals, as Mu. harttii presented high heterotrophic activity 15 to 30 days prior bleaching occurrence. On the contrary, a lower heterotrophic activity was monitored for the hydrocoral Mi. alicornis, which also experienced higher bleaching levels compared to Mu. hartii. Overall, we showed that the levels of ONOO− in coral tissue, combined to the heterotrophic capacity, are two good proxies explaining the intensity of coral bleaching.
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Affiliation(s)
- Laura Fernandes de Barros Marangoni
- Pós-Graduação em Oceanografia Biológica, Oceanographic Institute, Federal University of Rio Grande, Av. Itália, Km 8, Rio Grande, RS 96203-900, Brazil;
- Coral Vivo Institute, Rua dos Coqueiros, Parque Yaya, Santa Cruz Cabrália, BA 45.807-000, Brazil;
- Centre Scientifique de Monaco, Marine Department, 8 Quai Antoine 1er, MC-98000, Monaco;
- Correspondence: or
| | - Miguel Mies
- Coral Vivo Institute, Rua dos Coqueiros, Parque Yaya, Santa Cruz Cabrália, BA 45.807-000, Brazil;
- Oceanographic Institute, University of São Paulo. Praça do Oceanográfico, 191-05508-120 São Paulo, SP, Brazil; (A.Z.G.); (T.N.S.B.)
| | - Arthur Z. Güth
- Oceanographic Institute, University of São Paulo. Praça do Oceanográfico, 191-05508-120 São Paulo, SP, Brazil; (A.Z.G.); (T.N.S.B.)
| | - Thomás N. S. Banha
- Oceanographic Institute, University of São Paulo. Praça do Oceanográfico, 191-05508-120 São Paulo, SP, Brazil; (A.Z.G.); (T.N.S.B.)
| | - Alex Inague
- Chemistry Institute, University of São Paulo. Av Prof Lineu Prestes, 748-05508-000 São Paulo, SP, Brazil;
| | - Juliana da Silva Fonseca
- Pós-Graduação em Ciências Fisiológicas, Biological Science Institute, Federal University of Rio Grande, Av. Itália, Km 8, Rio Grande, RS 96203-900, Brazil (C.D.)
| | - Camila Dalmolin
- Pós-Graduação em Ciências Fisiológicas, Biological Science Institute, Federal University of Rio Grande, Av. Itália, Km 8, Rio Grande, RS 96203-900, Brazil (C.D.)
| | - Samuel Coelho Faria
- Institute of Biosciences, University of São Paulo. São Paulo, SP 05508-090, Brazil;
- Bermuda Institute of Ocean Sciences, St. George’s GE01, Bermuda
| | | | - Adalto Bianchini
- Pós-Graduação em Oceanografia Biológica, Oceanographic Institute, Federal University of Rio Grande, Av. Itália, Km 8, Rio Grande, RS 96203-900, Brazil;
- Coral Vivo Institute, Rua dos Coqueiros, Parque Yaya, Santa Cruz Cabrália, BA 45.807-000, Brazil;
- Pós-Graduação em Ciências Fisiológicas, Biological Science Institute, Federal University of Rio Grande, Av. Itália, Km 8, Rio Grande, RS 96203-900, Brazil (C.D.)
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14
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Dias M, Ferreira A, Gouveia R, Madeira C, Jogee N, Cabral H, Diniz M, Vinagre C. Long-term exposure to increasing temperatures on scleractinian coral fragments reveals oxidative stress. MARINE ENVIRONMENTAL RESEARCH 2019; 150:104758. [PMID: 31301459 DOI: 10.1016/j.marenvres.2019.104758] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/16/2019] [Accepted: 07/07/2019] [Indexed: 06/10/2023]
Abstract
Global warming is leading to increases in tropical storms' frequency and intensity, allowing fragmentation of reef-forming coral species, but also to coral bleaching and mortality. The first level of organism's response to an environmental perturbation occurs at the cellular level. This study investigated the long-term oxidative stress on fragments of nine Indo-Pacific reef-forming coral species exposed for 60 days to increasing temperatures (30 °C and 32 °C) and compared results with control temperature (26 °C). Coral overall condition (appearance), lipid peroxidation (LPO), catalase activity (CAT), and glutathione S-transferase (GST) were assessed. The species Turbinaria reniformis, Galaxea fascicularis, and Psammocora contigua were the most resistant to heat stress, presenting no oxidative damage at 30 °C. Unlike G. fasciularis, both T. reniformis and P. contigua showed no evidence of oxidative damage at 32 °C. All remaining species' fragments died at 32 °C. Stylophora pistillata and Pocillopora damicornis were the most susceptible species to heat stress, not resisting at 30 °C.
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Affiliation(s)
- Marta Dias
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisboa, Portugal.
| | - Ana Ferreira
- Oceanário de Lisboa, Esplanada D. Carlos I, 1990-005, Lisboa, Portugal
| | - Raúl Gouveia
- Oceanário de Lisboa, Esplanada D. Carlos I, 1990-005, Lisboa, Portugal
| | - Carolina Madeira
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal
| | - Nadia Jogee
- The School of Geosciences, The University of Edinburgh, The Grant Institute, James Hutton Road, King's Buildings, Edinburgh, EH9 3FE, UK
| | - Henrique Cabral
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisboa, Portugal; Irstea, UR EABX, 50, Avenue de Verdun, 33612, Cestas, France
| | - Mário Diniz
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal
| | - Catarina Vinagre
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisboa, Portugal
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15
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Ishii Y, Maruyama S, Takahashi H, Aihara Y, Yamaguchi T, Yamaguchi K, Shigenobu S, Kawata M, Ueno N, Minagawa J. Global Shifts in Gene Expression Profiles Accompanied with Environmental Changes in Cnidarian-Dinoflagellate Endosymbiosis. G3 (BETHESDA, MD.) 2019; 9:2337-2347. [PMID: 31097480 PMCID: PMC6643889 DOI: 10.1534/g3.118.201012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 05/15/2019] [Indexed: 12/13/2022]
Abstract
Stable endosymbiotic relationships between cnidarian animals and dinoflagellate algae are vital for sustaining coral reef ecosystems. Recent studies have shown that elevated seawater temperatures can cause the collapse of their endosymbiosis, known as 'bleaching', and result in mass mortality. However, the molecular interplay between temperature responses and symbiotic states still remains unclear. To identify candidate genes relevant to the symbiotic stability, we performed transcriptomic analyses under multiple conditions using the symbiotic and apo-symbiotic (symbiont free) Exaiptasia diaphana, an emerging model sea anemone. Gene expression patterns showed that large parts of differentially expressed genes in response to heat stress were specific to the symbiotic state, suggesting that the host sea anemone could react to environmental changes in a symbiotic state-dependent manner. Comparative analysis of expression profiles under multiple conditions highlighted candidate genes potentially important in the symbiotic state transition under heat-induced bleaching. Many of these genes were functionally associated with carbohydrate and protein metabolisms in lysosomes. Symbiont algal genes differentially expressed in hospite encode proteins related to heat shock response, calcium signaling, organellar protein transport, and sugar metabolism. Our data suggest that heat stress alters gene expression in both the hosts and symbionts. In particular, heat stress may affect the lysosome-mediated degradation and transportation of substrates such as carbohydrates through the symbiosome (phagosome-derived organelle harboring symbiont) membrane, which potentially might attenuate the stability of symbiosis and lead to bleaching-associated symbiotic state transition.
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Affiliation(s)
- Yuu Ishii
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | | | - Hiroki Takahashi
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Yusuke Aihara
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Takeshi Yamaguchi
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Katsushi Yamaguchi
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Shuji Shigenobu
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Masakado Kawata
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Naoto Ueno
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Jun Minagawa
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Aichi, Japan
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16
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Santolini J, Wootton SA, Jackson AA, Feelisch M. The Redox architecture of physiological function. CURRENT OPINION IN PHYSIOLOGY 2019; 9:34-47. [PMID: 31417975 PMCID: PMC6686734 DOI: 10.1016/j.cophys.2019.04.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The ability of organisms to accommodate variations in metabolic need and environmental conditions is essential for their survival. However, an explanation is lacking as to how the necessary accommodations in response to these challenges are organized and coordinated from (sub)cellular to higher-level physiological functions, especially in mammals. We propose that the chemistry that enables coordination and synchronization of these processes dates to the origins of Life. We offer a conceptual framework based upon the nature of electron exchange (Redox) processes that co-evolved with biological complexification, giving rise to a multi-layered system in which intra/intercellular and inter-organ exchange processes essential to sensing and adaptation stay fully synchronized. Our analysis explains why Redox is both the lingua franca and the mechanism that enable integration by connecting the various elements of regulatory processes. We here define these interactions across levels of organization as the 'Redox Interactome'. This framework provides novel insight into the chemical and biological basis of Redox signalling and may explain the recent convergence of metabolism, bioenergetics, and inflammation as well as the relationship between Redox stress and human disease.
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Affiliation(s)
- Jerome Santolini
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Universite Paris-Saclay, F-91198, Gif-sur-Yvette Cedex, France
| | - Stephen A Wootton
- Human Nutrition, University of Southampton and University Hospital Southampton, Tremona Road, Southampton, SO16 6YD, UK
| | - Alan A Jackson
- Human Nutrition, University of Southampton and University Hospital Southampton, Tremona Road, Southampton, SO16 6YD, UK
| | - Martin Feelisch
- Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, NIHR Southampton Biomedical Research Centre, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK
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17
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Lin MF, Takahashi S, Forêt S, Davy SK, Miller DJ. Transcriptomic analyses highlight the likely metabolic consequences of colonization of a cnidarian host by native or non-native Symbiodinium species. Biol Open 2019; 8:bio.038281. [PMID: 30814067 PMCID: PMC6451341 DOI: 10.1242/bio.038281] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Reef-building corals and some other cnidarians form symbiotic relationships with members of the dinoflagellate family Symbiodinaceae. As Symbiodinaceae is a highly diverse taxon, the physiological interactions between its members and their hosts are assumed to differ between associations. The presence of different symbiont types is known to affect expression levels of specific host genes, but knowledge of the effects on the transcriptome more broadly remains limited. In the present study, transcriptome profiling was conducted on the tropical corallimorpharian, Ricordea yuma, following the establishment of symbiosis with either the ‘homologous’ symbiont Symbiodinium goreaui (also known as Cladocopium goreaui; ITS2 type C1) or ‘heterologous’ symbionts (predominantly S. trenchii, which is also known as Durusdinium trenchii; ITS2 type D1a) isolated from a different corallimorpharian host (Rhodactis indosinensis). Transcriptomic analyses showed that genes encoding host glycogen biosynthesis pathway components are more highly induced during colonization by the homologous symbiont than by the heterologous symbiont. Similar patterns were also observed for several other genes thought to facilitate symbiotic nutrient exchange, including those involved in lipid translocation/storage and metabolite transport. The gene expression results presented here imply that colonization by homologous or heterologous Symbiodinium types may have very different metabolic consequences for the Ricordea host, supporting the notion that even though some cnidarians may be able to form novel symbioses after bleaching, the metabolic performance of these may be compromised. This article has an associated First Person interview with the first author of the paper. Summary: Colonization by the homologous symbiont, Symbiodinium goreaui, resulted in greater glycogen synthesis and ammonium assimilation capacity in the host than when it was colonized by a heterologous symbiont (S. trenchii).
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Affiliation(s)
- Mei-Fang Lin
- Molecular and Cell Biology, James Cook University, Townsville, QLD 4811, Australia.,ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.,Evolutionary Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan
| | - Shunichi Takahashi
- Division of Environmental Photobiology, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki 444-8585, Japan
| | - Sylvain Forêt
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.,Ecology and Evolution, Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington 6140, New Zealand
| | - David J Miller
- Molecular and Cell Biology, James Cook University, Townsville, QLD 4811, Australia .,ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
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18
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Mansfield KM, Gilmore TD. Innate immunity and cnidarian-Symbiodiniaceae mutualism. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 90:199-209. [PMID: 30268783 DOI: 10.1016/j.dci.2018.09.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
The phylum Cnidaria (sea anemones, corals, hydra, jellyfish) is one the most distantly related animal phyla to humans, and yet cnidarians harbor many of the same cellular pathways involved in innate immunity in mammals. In addition to its role in pathogen recognition, the innate immune system has a role in managing beneficial microbes and supporting mutualistic microbial symbioses. Some corals and sea anemones undergo mutualistic symbioses with photosynthetic algae in the family Symbiodiniaceae. These symbioses can be disrupted by anthropogenic disturbances of ocean environments, which can have devastating consequences for the health of coral reef ecosystems. Several studies of cnidarian-Symbiodiniaceae symbiosis have implicated proteins in the host immune system as playing a role in both symbiont tolerance and loss of symbiosis (i.e., bleaching). In this review, we critically evaluate current knowledge about the role of host immunity in the regulation of symbiosis in cnidarians.
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Affiliation(s)
| | - Thomas D Gilmore
- Department of Biology, Boston University, Boston, MA, 02215, USA.
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19
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Abstract
Climate change is killing coral at an unprecedented rate. As immune systems promote homeostasis and survival of adverse conditions I propose we explore coral health in the context of holobiont immunity. Caroline Palmer proposes the concept of coral holobiont damage thresholds to stimulate research into coral health and immunity as tropical reefs are increasingly threatened by climate change. This framework may be used to develop targeted approaches to coral reef restoration, management and conservation.
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20
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21
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Yu X, Huang B, Zhou Z, Tang J, Yu Y. Involvement of caspase3 in the acute stress response to high temperature and elevated ammonium in stony coral Pocillopora damicornis. Gene 2017; 637:108-114. [DOI: 10.1016/j.gene.2017.09.040] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 09/14/2017] [Accepted: 09/19/2017] [Indexed: 12/29/2022]
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22
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Bellis ES, Denver DR. Natural Variation in Responses to Acute Heat and Cold Stress in a Sea Anemone Model System for Coral Bleaching. THE BIOLOGICAL BULLETIN 2017; 233:168-181. [PMID: 29373064 DOI: 10.1086/694890] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Rising ocean temperatures disrupt the symbiosis between corals and their microalgae, accelerating global decline of coral reef ecosystems. Because of the difficulty of performing laboratory experiments with corals, the sea anemone Aiptasia has emerged as an important model system for molecular studies of coral bleaching and symbiosis. Here, we investigate natural variation in bleaching responses among different genetic lineages of Aiptasia. Both heat- and cold-induced paths to symbiosis breakdown were analyzed. Significant genetic variation in response to acute heat stress was observed, with severe bleaching of two Aiptasia strains from Hawaii but minimal bleaching of strains from the U.S. South Atlantic, including the strain used to generate the Aiptasia reference genome. Both strains from Hawaii hosted Symbiodinium type B1, whereas strains from the U.S. South Atlantic hosted type A4 or B2. In contrast to the results from exposures to acute heat stress, negligible variation was observed in response to a pulsed cold shock despite moderate bleaching across all strains. These results support our hypothesis that bleaching responses to distinct stressors are independent. Our findings emphasize the role of stress regime when predicting adaptive responses of symbiotic cnidarians to changing climates, because genetic variation may exist for some forms of stress-induced bleaching but not others.
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23
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Marcelino VR, Morrow KM, Oppen MJH, Bourne DG, Verbruggen H. Diversity and stability of coral endolithic microbial communities at a naturally high
p
CO
2
reef. Mol Ecol 2017; 26:5344-5357. [DOI: 10.1111/mec.14268] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 12/15/2022]
Affiliation(s)
| | - Kathleen M. Morrow
- Department of Molecular, Cellular and Biomedical Sciences University of New Hampshire Durham NH USA
- Australian Institute of Marine Science Townsville Qld Australia
| | - Madeleine J. H. Oppen
- School of Biosciences University of Melbourne Melbourne Vic. Australia
- Australian Institute of Marine Science Townsville Qld Australia
| | - David G. Bourne
- Australian Institute of Marine Science Townsville Qld Australia
- College of Science and Engineering James Cook University Townville Qld Australia
| | - Heroen Verbruggen
- School of Biosciences University of Melbourne Melbourne Vic. Australia
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24
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Zhou Z, Zhang G, Chen G, Ni X, Guo L, Yu X, Xiao C, Xu Y, Shi X, Huang B. Elevated ammonium reduces the negative effect of heat stress on the stony coral Pocillopora damicornis. MARINE POLLUTION BULLETIN 2017; 118:319-327. [PMID: 28302358 DOI: 10.1016/j.marpolbul.2017.03.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/01/2017] [Accepted: 03/09/2017] [Indexed: 06/06/2023]
Abstract
Climate change and environmental pollution have been threatening the survival of corals. In the present study, whole transcriptomes of the coral Pocillopora damicornis were sequenced under high temperature and elevated ammonium. After reads mapping and abundance estimation, differentially expressed genes were obtained in the Control/Heat, Control/Heat_NH4 and Heat/Heat_NH4 comparisons. Five overrepresented GO terms centering the tumor necrosis factor signaling pathway were noted for significantly upregulated genes in the Control/Heat and Control/Heat_NH4 comparisons. In addition, five GO terms related to apoptosis and cell death were overrepresented for significantly upregulated genes in the Control/Heat comparison but not in the Control/Heat_NH4 comparison. The expression level of 112 genes in these GO terms increased significantly in the Heat group, but only 44 genes showed the increase trend in the Heat_NH4 group. These results collectively suggested that elevated ammonium could reduce the negative effect of heat stress on the coral P. damicornis.
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Affiliation(s)
- Zhi Zhou
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China.
| | - Guoqing Zhang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - Guangmei Chen
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - Xingzhen Ni
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - Liping Guo
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China; Beijing Normal University, Beijing 100875, China.
| | - Xiaopeng Yu
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - Chunlin Xiao
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - Yanlai Xu
- Qingdao First Sanitarium of Jinan Military Region, Qingdao 266071, China
| | | | - Bo Huang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
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25
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Oakley CA, Durand E, Wilkinson SP, Peng L, Weis VM, Grossman AR, Davy SK. Thermal Shock Induces Host Proteostasis Disruption and Endoplasmic Reticulum Stress in the Model Symbiotic Cnidarian Aiptasia. J Proteome Res 2017; 16:2121-2134. [PMID: 28474894 DOI: 10.1021/acs.jproteome.6b00797] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Coral bleaching has devastating effects on coral survival and reef ecosystem function, but many of the fundamental cellular effects of thermal stress on cnidarian physiology are unclear. We used label-free liquid chromatography-tandem mass spectrometry to compare the effects of rapidly (33.5 °C, 24 h) and gradually (30 and 33.5 °C, 12 days) elevated temperatures on the proteome of the model symbiotic anemone Aiptasia. We identified 2133 proteins in Aiptasia, 136 of which were differentially abundant between treatments. Thermal shock, but not acclimation, resulted in significant abundance changes in 104 proteins, including those involved in protein folding and synthesis, redox homeostasis, and central metabolism. Nineteen abundant structural proteins showed particularly reduced abundance, demonstrating proteostasis disruption and potential protein synthesis inhibition. Heat shock induced antioxidant mechanisms and proteins involved in stabilizing nascent proteins, preventing protein aggregation and degrading damaged proteins, which is indicative of endoplasmic reticulum stress. Host proteostasis disruption occurred before either bleaching or symbiont photoinhibition was detected, suggesting host-derived reactive oxygen species production as the proximate cause of thermal damage. The pronounced abundance changes in endoplasmic reticulum proteins associated with proteostasis and protein turnover indicate that these processes are essential in the cellular response of symbiotic cnidarians to severe thermal stress.
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Affiliation(s)
- Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington , Wellington 6012, New Zealand
| | - Elysanne Durand
- Department of Ecology and Environmental Sciences, Université Pierre et Marie Curie , Paris 75005, France
| | - Shaun P Wilkinson
- School of Biological Sciences, Victoria University of Wellington , Wellington 6012, New Zealand
| | - Lifeng Peng
- School of Biological Sciences, Victoria University of Wellington , Wellington 6012, New Zealand
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University , Corvallis, Oregon 97331, United States
| | - Arthur R Grossman
- Department of Plant Biology, The Carnegie Institution for Science , Stanford, California 94305, United States
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington , Wellington 6012, New Zealand
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26
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Yuan C, Zhou Z, Zhang Y, Chen G, Yu X, Ni X, Tang J, Huang B. Effects of elevated ammonium on the transcriptome of the stony coral Pocillopora damicornis. MARINE POLLUTION BULLETIN 2017; 114:46-52. [PMID: 27567199 DOI: 10.1016/j.marpolbul.2016.08.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/25/2016] [Accepted: 08/17/2016] [Indexed: 06/06/2023]
Abstract
The survival of corals worldwide has been seriously threatened by eutrophication events concomitant with the increase in ocean pollution. In the present study, whole transcriptomes of the stony coral Pocillopora damicornis exposed to elevated ammonium were sequenced. A total of 121,366,983 pair-end reads were obtained, and 209,337 genes were assembled, including 42,399 coral-derived and 54,874 zooxanthella-derived genes. Further, a comparison of the control versus stress group revealed 6572 differentially expressed genes. For 1015 significantly upregulated genes, 24 GO terms were overrepresented, among which 3 terms related to apoptosis and cell death induction included one caspase, five bcl-2-like proteins, and two tumor necrosis factor receptor superfamily member genes. For 5557 significantly downregulated genes, the top 10 overrepresented terms were related to metabolism and signal transduction. These results indicate that apoptosis and cell death could be induced under elevated ammonium, suggesting that metabolic regulation and signal transduction might be involved in the reconstruction of the coral-zooxanthellae symbiotic balance in the stony coral P. damicornis.
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Affiliation(s)
- Chao Yuan
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China
| | - Zhi Zhou
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China.
| | - Yidan Zhang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China
| | - Guangmei Chen
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China
| | - Xiaopeng Yu
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China
| | - Xingzhen Ni
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China
| | - Jia Tang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China
| | - Bo Huang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan, People's Republic of China.
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27
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Kitchen SA, Weis VM. The sphingosine rheostat is involved in the cnidarian heat stress response but not necessarily in bleaching. J Exp Biol 2017; 220:1709-1720. [DOI: 10.1242/jeb.153858] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 02/16/2017] [Indexed: 12/17/2022]
Abstract
Sphingolipids play important roles in mitigating cellular heat and oxidative stress by altering membrane fluidity, receptor clustering and gene expression. Accumulation of signaling sphingolipids that comprise the sphingosine rheostat, pro-apoptotic sphingosine (Sph) and pro-survival sphingosine-1-phosphate (S1P), is key to determining cell fate. Reef-building corals and other symbiotic cnidarians living in shallow tropical waters can experience elevated seawater temperature and high UV irradiance, two stressors that are increasing in frequency and severity with climate change. In symbiotic cnidarians, these stressors disrupt the photosynthetic machinery of the endosymbiont and ultimately result in the collapse of the partnership (dysbiosis), known as cnidarian bleaching. In a previous study, exogenously applied sphingolipids altered heat-induced bleaching in the symbiotic anemone Aiptasia pallida, but endogenous regulation of these lipids is unknown. Here, we characterized the role of the rheostat in the cnidarian heat stress response (HSR) and in dysbiosis. Gene expression of rheostat enzymes sphingosine kinase (AP-SPHK) and S1P phosphatase (AP-SGPP), and concentrations of sphingolipids were quantified from anemones incubated at elevated temperatures. We observed a biphasic HSR in A. pallida. At early exposure, rheostat gene expression and lipid levels were suppressed while gene expression of a heat stress biomarker increased and 40% of symbionts were lost. After longer incubations at the highest temperature, AP-SGPP and then Sph levels both increased. These results indicate that the sphingosine rheostat in A. pallida does not participate in initiation of dysbiosis, but instead functions in the chronic response to prolonged heat stress that promotes host survival.
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Affiliation(s)
- Sheila A. Kitchen
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA
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28
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Hawkins TD, Warner ME. Warm preconditioning protects against acute heat-induced respiratory dysfunction and delays bleaching in a symbiotic sea anemone. ACTA ACUST UNITED AC 2016; 220:969-983. [PMID: 27980125 DOI: 10.1242/jeb.150391] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 12/08/2016] [Indexed: 12/18/2022]
Abstract
Preconditioning to non-stressful warming can protect some symbiotic cnidarians against the high temperature-induced collapse of their mutualistic endosymbiosis with photosynthetic dinoflagellates (Symbiodinium spp.), a process known as bleaching. Here, we sought to determine whether such preconditioning is underpinned by differential regulation of aerobic respiration. We quantified in vivo metabolism and mitochondrial respiratory enzyme activity in the naturally symbiotic sea anemone Exaiptasia pallida preconditioned to 30°C for >7 weeks as well as anemones kept at 26°C. Preconditioning resulted in increased Symbiodinium photosynthetic activity and holobiont (host+symbiont) respiration rates. Biomass-normalised activities of host respiratory enzymes [citrate synthase and the mitochondrial electron transport chain (mETC) complexes I and IV] were higher in preconditioned animals, suggesting that increased holobiont respiration may have been due to host mitochondrial biogenesis and/or enlargement. Subsequent acute heating of preconditioned and 'thermally naive' animals to 33°C induced dramatic increases in host mETC complex I and Symbiodinium mETC complex II activities only in thermally naive E. pallida These changes were not reflected in the activities of other respiratory enzymes. Furthermore, bleaching in preconditioned E. pallida (defined as the significant loss of symbionts) was delayed by several days relative to the thermally naive group. These findings suggest that changes to mitochondrial biogenesis and/or function in symbiotic cnidarians during warm preconditioning might play a protective role during periods of exposure to stressful heating.
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Affiliation(s)
- Thomas D Hawkins
- School of Marine Science and Policy, College of Earth, Ocean and Environment, University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA
| | - Mark E Warner
- School of Marine Science and Policy, College of Earth, Ocean and Environment, University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA
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29
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Hawkins TD, Hagemeyer JCG, Warner ME. Temperature moderates the infectiousness of two conspecific
Symbiodinium
strains isolated from the same host population. Environ Microbiol 2016; 18:5204-5217. [DOI: 10.1111/1462-2920.13535] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 08/15/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Thomas D. Hawkins
- School of Marine Science and Policy, College of Earth, Ocean and EnvironmentUniversity of DelawareLewes Delaware, USA
| | - Julia. C. G. Hagemeyer
- School of Marine Science and Policy, College of Earth, Ocean and EnvironmentUniversity of DelawareLewes Delaware, USA
| | - Mark E. Warner
- School of Marine Science and Policy, College of Earth, Ocean and EnvironmentUniversity of DelawareLewes Delaware, USA
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30
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Bhattacharya D, Agrawal S, Aranda M, Baumgarten S, Belcaid M, Drake JL, Erwin D, Foret S, Gates RD, Gruber DF, Kamel B, Lesser MP, Levy O, Liew YJ, MacManes M, Mass T, Medina M, Mehr S, Meyer E, Price DC, Putnam HM, Qiu H, Shinzato C, Shoguchi E, Stokes AJ, Tambutté S, Tchernov D, Voolstra CR, Wagner N, Walker CW, Weber AP, Weis V, Zelzion E, Zoccola D, Falkowski PG. Comparative genomics explains the evolutionary success of reef-forming corals. eLife 2016; 5. [PMID: 27218454 PMCID: PMC4878875 DOI: 10.7554/elife.13288] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/20/2016] [Indexed: 12/30/2022] Open
Abstract
Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years. DOI:http://dx.doi.org/10.7554/eLife.13288.001 For millions of years, reef-building stony corals have created extensive habitats for numerous marine plants and animals in shallow tropical seas. Stony corals consist of many small, tentacled animals called polyps. These polyps secrete a mineral called aragonite to create the reef – an external ‘skeleton’ that supports and protects the corals. Photosynthesizing algae live inside the cells of stony corals, and each species depends on the other to survive. The algae produce the coral’s main source of food, although they also produce some waste products that can harm the coral if they build up inside cells. If the oceans become warmer and more acidic, the coral are more likely to become stressed and expel the algae from their cells in a process known as coral bleaching. This makes the coral more likely to die or become diseased. Corals have survived previous periods of ocean warming, although it is not known how they evolved to do so. The evolutionary history of an organism can be traced by studying its genome – its complete set of DNA – and the RNA molecules encoded by these genes. Bhattacharya et al. performed this analysis for twenty stony coral species, and compared the resulting genome and RNA sequences with the genomes of other related marine organisms, such as sea anemones and sponges. In particular, Bhattacharya et al. examined “ortholog” groups of genes, which are present in different species and evolved from a common ancestral gene. This analysis identified the genes in the corals that encode the proteins responsible for constructing the aragonite skeleton. The coral genome also encodes a network of environmental sensors that coordinate how the polyps respond to temperature, light and acidity. Bhattacharya et al. also uncovered a variety of stress-related pathways, including those that detoxify the polyps of the damaging molecules generated by algae, and the pathways that enable the polyps to adapt to environmental stress. Many of these genes were recruited from other species in a process known as horizontal gene transfer. The oceans are expected to become warmer and more acidic in the coming centuries. Provided that humans do not physically destroy the corals’ habitats, the evidence found by Bhattacharya et al. suggests that the genome of the corals contains the diversity that will allow them to adapt to these new conditions. DOI:http://dx.doi.org/10.7554/eLife.13288.002
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Affiliation(s)
- Debashish Bhattacharya
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, United States.,Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, United States
| | - Shobhit Agrawal
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Manuel Aranda
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Sebastian Baumgarten
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Mahdi Belcaid
- Hawaii Institute of Marine Biology, Kaneohe, United States
| | - Jeana L Drake
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, United States
| | - Douglas Erwin
- Smithsonian Institution, National Museum of Natural History, Washington, United States
| | - Sylvian Foret
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia.,Research School of Biology, Australian National University, Canberra, Australia
| | - Ruth D Gates
- Hawaii Institute of Marine Biology, Kaneohe, United States
| | - David F Gruber
- American Museum of Natural History, Sackler Institute for Comparative Genomics, New York, United States.,Department of Natural Sciences, City University of New York, Baruch College and The Graduate Center, New York, United States
| | - Bishoy Kamel
- Department of Biology, Mueller Lab, Penn State University, University Park, United States
| | - Michael P Lesser
- School of Marine Science and Ocean Engineering, University of New Hampshire, Durham, United States
| | - Oren Levy
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gam, Israel
| | - Yi Jin Liew
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Matthew MacManes
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, United States
| | - Tali Mass
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, United States.,Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Israel
| | - Monica Medina
- Department of Biology, Mueller Lab, Penn State University, University Park, United States
| | - Shaadi Mehr
- American Museum of Natural History, Sackler Institute for Comparative Genomics, New York, United States.,Biological Science Department, State University of New York, College at Old Westbury, New York, United States
| | - Eli Meyer
- Department of Integrative Biology, Oregon State University, Corvallis, United States
| | - Dana C Price
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, United States
| | | | - Huan Qiu
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, United States
| | - Chuya Shinzato
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Alexander J Stokes
- Laboratory of Experimental Medicine and Department of Cell and Molecular Biology, John A. Burns School of Medicine, Honolulu, United States.,Chaminade University, Honolulu, United States
| | | | - Dan Tchernov
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Israel
| | - Christian R Voolstra
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Nicole Wagner
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, United States
| | - Charles W Walker
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, United States
| | - Andreas Pm Weber
- Institute of Plant Biochemistry, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Virginia Weis
- Department of Integrative Biology, Oregon State University, Corvallis, United States
| | - Ehud Zelzion
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, United States
| | | | - Paul G Falkowski
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, United States.,Department of Earth and Planetary Sciences, Rutgers University, New Jersey, United States
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31
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Bieri T, Onishi M, Xiang T, Grossman AR, Pringle JR. Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching. PLoS One 2016; 11:e0152693. [PMID: 27119147 PMCID: PMC4847765 DOI: 10.1371/journal.pone.0152693] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 03/17/2016] [Indexed: 12/15/2022] Open
Abstract
When exposed to stress such as high seawater temperature, corals and other cnidarians can bleach due to loss of symbiotic algae from the host tissue and/or loss of pigments from the algae. Although the environmental conditions that trigger bleaching are reasonably well known, its cellular and molecular mechanisms are not well understood. Previous studies have reported the occurrence of at least four different cellular mechanisms for the loss of symbiotic algae from the host tissue: in situ degradation of algae, exocytic release of algae from the host, detachment of host cells containing algae, and death of host cells containing algae. The relative contributions of these several mechanisms to bleaching remain unclear, and it is also not known whether these relative contributions change in animals subjected to different types and/or durations of stresses. In this study, we used a clonal population of the small sea anemone Aiptasia, exposed individuals to various precisely controlled stress conditions, and quantitatively assessed the several possible bleaching mechanisms in parallel. Under all stress conditions tested, except for acute cold shock at 4°C, expulsion of intact algae from the host cells appeared to be by far the predominant mechanism of bleaching. During acute cold shock, in situ degradation of algae and host-cell detachment also became quantitatively significant, and the algae released under these conditions appeared to be severely damaged.
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Affiliation(s)
- Tamaki Bieri
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Masayuki Onishi
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Tingting Xiang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California, United States of America
| | - Arthur R. Grossman
- Department of Biology, Stanford University, Stanford, California, United States of America
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California, United States of America
| | - John R Pringle
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
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32
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Hawkins TD, Hagemeyer JCG, Hoadley KD, Marsh AG, Warner ME. Partitioning of Respiration in an Animal-Algal Symbiosis: Implications for Different Aerobic Capacity between Symbiodinium spp. Front Physiol 2016; 7:128. [PMID: 27148067 PMCID: PMC4834350 DOI: 10.3389/fphys.2016.00128] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/22/2016] [Indexed: 11/29/2022] Open
Abstract
Cnidarian-dinoflagellate symbioses are ecologically important and the subject of much investigation. However, our understanding of critical aspects of symbiosis physiology, such as the partitioning of total respiration between the host and symbiont, remains incomplete. Specifically, we know little about how the relationship between host and symbiont respiration varies between different holobionts (host-symbiont combinations). We applied molecular and biochemical techniques to investigate aerobic respiratory capacity in naturally symbiotic Exaiptasia pallida sea anemones, alongside animals infected with either homologous ITS2-type A4 Symbiodinium or a heterologous isolate of Symbiodinium minutum (ITS2-type B1). In naturally symbiotic anemones, host, symbiont, and total holobiont mitochondrial citrate synthase (CS) enzyme activity, but not host mitochondrial copy number, were reliable predictors of holobiont respiration. There was a positive association between symbiont density and host CS specific activity (mg protein−1), and a negative correlation between host- and symbiont CS specific activities. Notably, partitioning of total CS activity between host and symbiont in this natural E. pallida population was significantly different to the host/symbiont biomass ratio. In re-infected anemones, we found significant between-holobiont differences in the CS specific activity of the algal symbionts. Furthermore, the relationship between the partitioning of total CS activity and the host/symbiont biomass ratio differed between holobionts. These data have broad implications for our understanding of cnidarian-algal symbiosis. Specifically, the long-held assumption of equivalency between symbiont/host biomass and respiration ratios can result in significant overestimation of symbiont respiration and potentially erroneous conclusions regarding the percentage of carbon translocated to the host. The interspecific variability in symbiont aerobic capacity provides further evidence for distinct physiological differences that should be accounted for when studying diverse host-symbiont combinations.
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Affiliation(s)
- Thomas D Hawkins
- College of Earth, Ocean and Environment, School of Marine Science and Policy, University of Delaware Lewes, DE, USA
| | - Julia C G Hagemeyer
- College of Earth, Ocean and Environment, School of Marine Science and Policy, University of Delaware Lewes, DE, USA
| | - Kenneth D Hoadley
- College of Earth, Ocean and Environment, School of Marine Science and Policy, University of Delaware Lewes, DE, USA
| | - Adam G Marsh
- College of Earth, Ocean and Environment, School of Marine Science and Policy, University of Delaware Lewes, DE, USA
| | - Mark E Warner
- College of Earth, Ocean and Environment, School of Marine Science and Policy, University of Delaware Lewes, DE, USA
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33
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Malafoglia V, Traversetti L, Del Grosso F, Scalici M, Lauro F, Russo V, Persichini T, Salvemini D, Mollace V, Fini M, Raffaeli W, Muscoli C, Colasanti M. Transient Receptor Potential Melastatin-3 (TRPM3) Mediates Nociceptive-Like Responses in Hydra vulgaris. PLoS One 2016; 11:e0151386. [PMID: 26974325 PMCID: PMC4790967 DOI: 10.1371/journal.pone.0151386] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/27/2016] [Indexed: 12/19/2022] Open
Abstract
The ability of mammals to feel noxious stimuli lies in a heterogeneous group of primary somatosensory neurons termed nociceptors, which express specific membrane receptors, such as the Transient Receptor Potential (TRP) family. Here, we show that one of the most important nociceptive-like pathways is conserved in the freshwater coelenterate Hydra vulgaris, the most primitive organism possessing a nervous system. In particular, we found that H. vulgaris expresses TRPM3, a nociceptor calcium channel involved in the detection of noxious heat in mammals. Furthermore, we detected that both heat shock and TRPM3 specific agonist (i.e., pregnenolone sulfate) induce the modulation of the heat shock protein 70 (HSP70) and the nitric oxide synthase (NOS), two genes activated by TRP-mediated heat painful stimuli in mammals. As expected, these effects are inhibited by a TRPM3 antagonist (i.e., mefenamic acid). Interestingly, the TRPM3 agonist and heat shock also induce the expression of nuclear transcription erythroid 2-related factor (Nrf2) and superoxide dismutase (SOD), known markers of oxidative stress; noteworthy gene expression was also inhibited by the TRPM3 antagonist. As a whole, our results demonstrate the presence of conserved molecular oxidative/nociceptive-like pathways at the primordial level of the animal kingdom.
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Affiliation(s)
- Valentina Malafoglia
- Department of Science, University of Roma Tre, Rome, Italy
- Institute for Research on Pain, ISAL-Foundation, Torre Pedrera (RN), Italy
- IRCCS San Raffaele Pisana, Rome, Italy
| | | | | | | | | | - Valeria Russo
- Department of Science, University of Roma Tre, Rome, Italy
| | | | - Daniela Salvemini
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St Louis, United States of America
| | - Vincenzo Mollace
- IRC-FSH, Department of Health Science, University of ‘Magna Graecia’, Catanzaro, Italy
| | | | - William Raffaeli
- Institute for Research on Pain, ISAL-Foundation, Torre Pedrera (RN), Italy
| | - Carolina Muscoli
- IRC-FSH, Department of Health Science, University of ‘Magna Graecia’, Catanzaro, Italy
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34
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Krueger T, Hawkins TD, Becker S, Pontasch S, Dove S, Hoegh-Guldberg O, Leggat W, Fisher PL, Davy SK. Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress. Comp Biochem Physiol A Mol Integr Physiol 2015; 190:15-25. [DOI: 10.1016/j.cbpa.2015.08.012] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 08/13/2015] [Accepted: 08/19/2015] [Indexed: 12/29/2022]
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35
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Nitric oxide in marine photosynthetic organisms. Nitric Oxide 2015; 47:34-9. [PMID: 25795592 DOI: 10.1016/j.niox.2015.03.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 12/22/2022]
Abstract
Nitric oxide is a versatile and powerful signaling molecule in plants. However, most of our understanding stems from studies on terrestrial plants and very little is known about marine autotrophs. This review summarizes current knowledge about the source of nitric oxide synthesis in marine photosynthetic organisms and its role in various physiological processes under normal and stress conditions. The interactions of nitric oxide with other stress signals and cross talk among secondary messengers are also highlighted.
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36
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Fujise L, Yamashita H, Suzuki G, Sasaki K, Liao LM, Koike K. Moderate Thermal Stress Causes Active and Immediate Expulsion of Photosynthetically Damaged Zooxanthellae (Symbiodinium) from Corals. PLoS One 2014; 9:e114321. [PMID: 25493938 PMCID: PMC4262390 DOI: 10.1371/journal.pone.0114321] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 11/05/2014] [Indexed: 11/18/2022] Open
Abstract
The foundation of coral reef biology is the symbiosis between corals and zooxanthellae (dinoflagellate genus Symbiodinium). Recently, coral bleaching, which often results in mass mortality of corals and the collapse of coral reef ecosystems, has become an important issue around the world as coral reefs decrease in number year after year. To understand the mechanisms underlying coral bleaching, we maintained two species of scleractinian corals (Acroporidae) in aquaria under non-thermal stress (27°C) and moderate thermal stress conditions (30°C), and we compared the numbers and conditions of the expelled Symbiodinium from these corals. Under non-thermal stress conditions corals actively expel a degraded form of Symbiodinium, which are thought to be digested by their host coral. This response was also observed at 30°C. However, while the expulsion rates of Symbiodinium cells remained constant, the proportion of degraded cells significantly increased at 30°C. This result indicates that corals more actively digest and expel damaged Symbiodinium under thermal stress conditions, likely as a mechanism for coping with environmental change. However, the increase in digested Symbiodinium expulsion under thermal stress may not fully keep up with accumulation of the damaged cells. There are more photosynthetically damaged Symbiodinium upon prolonged exposure to thermal stress, and corals release them without digestion to prevent their accumulation. This response may be an adaptive strategy to moderate stress to ensure survival, but the accumulation of damaged Symbiodinium, which causes subsequent coral deterioration, may occur when the response cannot cope with the magnitude or duration of environmental stress, and this might be a possible mechanism underlying coral bleaching during prolonged moderate thermal stress.
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Affiliation(s)
- Lisa Fujise
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Hiroshi Yamashita
- Research Center for Subtropical Fisheries, Seikai National Fisheries Research Institute, Fisheries Research Agency, Ishigaki, Okinawa, Japan
| | - Go Suzuki
- Research Center for Subtropical Fisheries, Seikai National Fisheries Research Institute, Fisheries Research Agency, Ishigaki, Okinawa, Japan
| | - Kengo Sasaki
- Western Region Industrial Research Center, Higashi-Hiroshima, Hiroshima, Japan
| | - Lawrence M. Liao
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Kazuhiko Koike
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
- * E-mail:
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37
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Cunning R, Baker AC. Not just who, but how many: the importance of partner abundance in reef coral symbioses. Front Microbiol 2014; 5:400. [PMID: 25136339 PMCID: PMC4120693 DOI: 10.3389/fmicb.2014.00400] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 07/16/2014] [Indexed: 11/18/2022] Open
Abstract
The performance and function of reef corals depends on the genetic identity of their symbiotic algal partners, with some symbionts providing greater benefits (e.g., photosynthate, thermotolerance) than others. However, these interaction outcomes may also depend on partner abundance, with differences in the total number of symbionts changing the net benefit to the coral host, depending on the particular environmental conditions. We suggest that symbiont abundance is a fundamental aspect of the dynamic interface between reef corals and the abiotic environment that ultimately determines the benefits, costs, and functional responses of these symbioses. This density-dependent framework suggests that corals may regulate the size of their symbiont pool to match microhabitat-specific optima, which may contribute to the high spatiotemporal variability in symbiont abundance observed within and among colonies and reefs. Differences in symbiont standing stock may subsequently explain variation in energetics, growth, reproduction, and stress susceptibility, and may mediate the impacts of environmental change on these outcomes. However, the importance of symbiont abundance has received relatively little recognition, possibly because commonly-used metrics based on surface area (e.g., symbiont cells cm-2) may be only weakly linked to biological phenomena and are difficult to compare across studies. We suggest that normalizing symbionts to biological host parameters, such as units of protein or numbers of host cells, will more clearly elucidate the functional role of symbiont abundance in reef coral symbioses. In this article, we generate testable hypotheses regarding the importance of symbiont abundance by first discussing different metrics and their potential links to symbiosis performance and breakdown, and then describing how natural variability and dynamics of symbiont communities may help explain ecological patterns on coral reefs and predict responses to environmental change.
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Affiliation(s)
- Ross Cunning
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
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