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Deore P, Tsang Min Ching SJ, Nitschke MR, Rudd D, Brumley DR, Hinde E, Blackall LL, van Oppen MJH. Unique photosynthetic strategies employed by closely related Breviolum minutum strains under rapid short-term cumulative heat stress. J Exp Bot 2024:erae170. [PMID: 38636949 DOI: 10.1093/jxb/erae170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Indexed: 04/20/2024]
Abstract
The thermal tolerance of symbiodiniacean photo-endosymbionts largely underpins the thermal bleaching resilience of their cnidarian hosts such as corals and the coral model, Exaiptasia diaphana. While variation in thermal tolerance between species is well documented, variation between conspecific strains is understudied. We compared the thermal tolerance of three closely related strains of Breviolum minutum represented by two internal transcribed spacer region 2 profiles (one strain B1-B1o-B1g-B1p and the other two strains B1-B1a-B1b-1g) and differences in photochemical and non-photochemical quenching, de-epoxidation state of photopigments, and accumulation of reactive oxygen species under rapid short-term cumulative temperature stress (26-40°C). We found that B. minutum strains employ distinct photoprotective strategies, resulting in different upper thermal tolerances. We provide evidence for previously unknown interdependencies between thermal tolerance traits and photoprotective mechanisms which include a delicate balancing of excitation energy and its dissipation through fast relaxing and state transition components of non-photochemical quenching. The more thermally tolerant B. minutum strain (B1-B1o-B1g-B1p) exhibited an enhanced de-epoxidation that is strongly linked to the thylakoid membrane melting point and possibly membrane rigidification minimising oxidative damage. This study provides an in-depth understanding of photoprotective mechanisms underpinning thermal tolerance in closely related strains of B. minutum.
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Affiliation(s)
- Pranali Deore
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | | | - Matthew R Nitschke
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington 6102, New Zealand
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Douglas R Brumley
- School of Mathematics and Statistics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Elizabeth Hinde
- School of Physics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
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2
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Garcias-Bonet N, Roik A, Tierney B, García FC, Villela HDM, Dungan AM, Quigley KM, Sweet M, Berg G, Gram L, Bourne DG, Ushijima B, Sogin M, Hoj L, Duarte G, Hirt H, Smalla K, Rosado AS, Carvalho S, Thurber RV, Ziegler M, Mason CE, van Oppen MJH, Voolstra CR, Peixoto RS. Horizon scanning the application of probiotics for wildlife. Trends Microbiol 2024; 32:252-269. [PMID: 37758552 DOI: 10.1016/j.tim.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023]
Abstract
The provision of probiotics benefits the health of a wide range of organisms, from humans to animals and plants. Probiotics can enhance stress resilience of endangered organisms, many of which are critically threatened by anthropogenic impacts. The use of so-called 'probiotics for wildlife' is a nascent application, and the field needs to reflect on standards for its development, testing, validation, risk assessment, and deployment. Here, we identify the main challenges of this emerging intervention and provide a roadmap to validate the effectiveness of wildlife probiotics. We cover the essential use of inert negative controls in trials and the investigation of the probiotic mechanisms of action. We also suggest alternative microbial therapies that could be tested in parallel with the probiotic application. Our recommendations align approaches used for humans, aquaculture, and plants to the emerging concept and use of probiotics for wildlife.
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Affiliation(s)
- Neus Garcias-Bonet
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Anna Roik
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Oldenburg, Germany; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Bremerhaven, Germany
| | - Braden Tierney
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Francisca C García
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Helena D M Villela
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Ashley M Dungan
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Kate M Quigley
- Minderoo Foundation, Perth, WA, Australia; James Cook University, Townsville, Australia
| | - Michael Sweet
- Aquatic Research Facility, Nature-based Solutions Research Centre, University of Derby, Derby, UK
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria; University of Potsdam and Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB), Potsdam, Germany
| | - Lone Gram
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs., Lyngby, Denmark
| | - David G Bourne
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Blake Ushijima
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Maggie Sogin
- Molecular Cell Biology, University of California, Merced, CA, USA
| | - Lone Hoj
- Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Gustavo Duarte
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia; IMPG, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Heribert Hirt
- Center for Desert Agriculture (CDA), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | | | - Alexandre S Rosado
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia; Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Susana Carvalho
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | | | - Maren Ziegler
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA; WorldQuant Initiative on Quantitative Prediction, Weill Cornell Medicine, New York, NY, USA
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia; Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville, QLD 4810, Australia
| | | | - Raquel S Peixoto
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia; Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
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3
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Maire J, Tsang Min Ching SJ, Damjanovic K, Epstein HE, Judd LM, Blackall LL, van Oppen MJH. Tissue-associated and vertically transmitted bacterial symbiont in the coral Pocillopora acuta. ISME J 2024; 18:wrad027. [PMID: 38365239 PMCID: PMC10833068 DOI: 10.1093/ismejo/wrad027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/07/2023] [Accepted: 12/09/2023] [Indexed: 02/18/2024]
Abstract
Coral microhabitats are colonized by a myriad of microorganisms, including diverse bacteria which are essential for host functioning and survival. However, the location, transmission, and functions of individual bacterial species living inside the coral tissues remain poorly studied. Here, we show that a previously undescribed bacterial symbiont of the coral Pocillopora acuta forms cell-associated microbial aggregates (CAMAs) within the mesenterial filaments. CAMAs were found in both adults and larval offspring, suggesting vertical transmission. In situ laser capture microdissection of CAMAs followed by 16S rRNA gene amplicon sequencing and shotgun metagenomics produced a near complete metagenome-assembled genome. We subsequently cultured the CAMA bacteria from Pocillopora acuta colonies, and sequenced and assembled their genomes. Phylogenetic analyses showed that the CAMA bacteria belong to an undescribed Endozoicomonadaceae genus and species, which we propose to name Candidatus Sororendozoicomonas aggregata gen. nov sp. nov. Metabolic pathway reconstruction from its genome sequence suggests this species can synthesize most amino acids, several B vitamins, and antioxidants, and participate in carbon cycling and prey digestion, which may be beneficial to its coral hosts. This study provides detailed insights into a new member of the widespread Endozoicomonadaceae family, thereby improving our understanding of coral holobiont functioning. Vertically transmitted, tissue-associated bacteria, such as Sororendozoicomonas aggregata may be key candidates for the development of microbiome manipulation approaches with long-term positive effects on the coral host.
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Affiliation(s)
- Justin Maire
- School of BioSciences, The University of Melbourne, Parkville, 3010 VIC, Australia
| | | | - Katarina Damjanovic
- School of BioSciences, The University of Melbourne, Parkville, 3010 VIC, Australia
- Australian Institute of Marine Science, PMB No 3, Townsville, 4810 QLD, Australia
| | - Hannah E Epstein
- Australian Institute of Marine Science, PMB No 3, Townsville, 4810 QLD, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, 4811 QLD, Australia
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, United Kingdom
| | - Louise M Judd
- Doherty Applied Microbial Genomics, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, 3010 VIC, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Parkville, 3010 VIC, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville, 3010 VIC, Australia
- Australian Institute of Marine Science, PMB No 3, Townsville, 4810 QLD, Australia
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Maire J, Collingro A, Horn M, van Oppen MJH. Chlamydiae in corals: shared functional potential despite broad taxonomic diversity. ISME Commun 2024; 4:ycae054. [PMID: 38707840 PMCID: PMC11070183 DOI: 10.1093/ismeco/ycae054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/15/2024] [Accepted: 04/09/2024] [Indexed: 05/07/2024]
Abstract
Cnidarians, such as corals and sea anemones, associate with a wide range of bacteria that have essential functions, including nutrient cycling and the production of antimicrobial compounds. Within cnidarians, bacteria can colonize all microhabitats including the tissues. Among them are obligate intracellular bacteria of the phylum Chlamydiota (chlamydiae) whose impact on cnidarian hosts and holobionts, especially corals, remain unknown. Here, we conducted a meta-analysis of previously published 16S rRNA gene metabarcoding data from cnidarians (e.g. coral, jellyfish, and anemones), eight metagenome-assembled genomes (MAGs) of coral-associated chlamydiae, and one MAG of jellyfish-associated chlamydiae to decipher their diversity and functional potential. While the metabarcoding dataset showed an enormous diversity of cnidarian-associated chlamydiae, six out of nine MAGs were affiliated with the Simkaniaceae family. The other three MAGs were assigned to the Parasimkaniaceae, Rhabdochlamydiaceae, and Anoxychlamydiaceae, respectively. All MAGs lacked the genes necessary for an independent existence, lacking any nucleotide or vitamin and most amino acid biosynthesis pathways. Hallmark chlamydial genes, such as a type III secretion system, nucleotide transporters, and genes for host interaction, were encoded in all MAGs. Together these observations suggest an obligate intracellular lifestyle of coral-associated chlamydiae. No unique genes were found in coral-associated chlamydiae, suggesting a lack of host specificity. Additional studies are needed to understand how chlamydiae interact with their coral host, and other microbes in coral holobionts. This first study of the diversity and functional potential of coral-associated chlamydiae improves our understanding of both the coral microbiome and the chlamydial lifestyle and host range.
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Affiliation(s)
- Justin Maire
- School of BioSciences, The University of Melbourne, Parkville 3010, VIC, Australia
| | - Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna 1030, Austria
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna 1030, Austria
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville 3010, VIC, Australia
- Australian Institute of Marine Science, PMB No 3, Townsville 4810, QLD, Australia
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Maire J, Philip GK, Livingston J, Judd LM, Blackall LL, van Oppen MJH. Functional potential and evolutionary response to long-term heat selection of bacterial associates of coral photosymbionts. mSystems 2023; 8:e0086023. [PMID: 37909753 PMCID: PMC10746172 DOI: 10.1128/msystems.00860-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Symbiotic microorganisms are crucial for the survival of corals and their resistance to coral bleaching in the face of climate change. However, the impact of microbe-microbe interactions on coral functioning is mostly unknown but could be essential factors for coral adaption to future climates. Here, we investigated interactions between cultured dinoflagellates of the Symbiodiniaceae family, essential photosymbionts of corals, and associated bacteria. By assessing the genomic potential of 49 bacteria, we found that they are likely beneficial for Symbiodiniaceae, through the production of B vitamins and antioxidants. Additionally, bacterial genes involved in host-symbiont interactions, such as secretion systems, accumulated mutations following long-term exposure to heat, suggesting symbiotic interactions may change under climate change. This highlights the importance of microbe-microbe interactions in coral functioning.
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Affiliation(s)
- Justin Maire
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Gayle K. Philip
- Melbourne Bioinformatics, The University of Melbourne, Parkville, Victoria, Australia
| | - Jadzia Livingston
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Louise M. Judd
- Doherty Applied Microbial Genomics, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, Victoria, Australia
| | - Linda L. Blackall
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Madeleine J. H. van Oppen
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
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Chan WY, Meyers L, Rudd D, Topa SH, van Oppen MJH. Heat-evolved algal symbionts enhance bleaching tolerance of adult corals without trade-off against growth. Glob Chang Biol 2023; 29:6945-6968. [PMID: 37913765 DOI: 10.1111/gcb.16987] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 09/11/2023] [Accepted: 10/01/2023] [Indexed: 11/03/2023]
Abstract
Ocean warming has caused coral mass bleaching and mortality worldwide and the persistence of symbiotic reef-building corals requires rapid acclimation or adaptation. Experimental evolution of the coral's microalgal symbionts followed by their introduction into coral is one potential method to enhance coral thermotolerance. Heat-evolved microalgal symbionts of the generalist species, Cladocopium proliferum (strain SS8), were exposed to elevated temperature (31°C) for ~10 years, and were introduced into four genotypes of chemically bleached adult fragments of the scleractinian coral, Galaxea fascicularis. Two of the four coral genotypes acquired SS8. The new symbionts persisted for the 5 months of the experiment and enhanced adult coral thermotolerance, compared with corals that were inoculated with the wild-type C. proliferum strain. Thermotolerance of SS8-corals was similar to that of coral fragments from the same colony hosting the homologous symbiont, Durusdinium sp., which is naturally heat tolerant. However, SS8-coral fragments exhibited faster growth and recovered cell density and photochemical efficiency more quickly following chemical bleaching and inoculation under ambient temperature relative to Durusdinium-corals. Mass spectrometry imaging suggests that algal pigments involved in photobiology and oxidative stress were the greatest contributors to the thermotolerance differences between coral hosting heat-evolved versus wild-type C. proliferum. These pigments may have increased photoprotection in the heat-evolved symbionts. This is the first laboratory study to show that thermotolerance of adult corals (G. fascicularis) can be enhanced via the uptake of exogenously supplied, heat-evolved symbionts, without a trade-off against growth under ambient temperature. Importantly, heat-evolved C. proliferum remained in the corals in moderate abundance 2 years after first inoculation, suggesting long-term stability of this novel symbiosis and potential long-term benefits to coral thermotolerance.
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Affiliation(s)
- Wing Yan Chan
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Luka Meyers
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - David Rudd
- Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
- Melbourne Centre for Nanofabrication, Clayton, Victoria, Australia
| | - Sanjida H Topa
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
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Maire J, Deore P, Jameson VJ, Sakkas M, Perez-Gonzalez A, Blackall LL, van Oppen MJH. Assessing the contribution of bacteria to the heat tolerance of experimentally evolved coral photosymbionts. Environ Microbiol 2023; 25:3298-3318. [PMID: 37849020 DOI: 10.1111/1462-2920.16521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 09/28/2023] [Indexed: 10/19/2023]
Abstract
Coral reefs are extremely vulnerable to ocean warming, which triggers coral bleaching-the loss of endosymbiotic microalgae (Symbiodiniaceae) from coral tissues, often leading to death. To enhance coral climate resilience, the symbiont, Cladocopium proliferum was experimentally evolved for >10 years under elevated temperatures resulting in increased heat tolerance. Bacterial 16S rRNA gene metabarcoding showed the composition of intra- and extracellular bacterial communities of heat-evolved strains was significantly different from that of wild-type strains, suggesting bacteria responded to elevated temperatures, and may even play a role in C. proliferum thermal tolerance. To assess whether microbiome transplantation could enhance heat tolerance of the sensitive wild-type C. proliferum, we transplanted bacterial communities from heat-evolved to the wild-type strain and subjected it to acute heat stress. Microbiome transplantation resulted in the incorporation of only 30 low-abundance strains into the microbiome of wild-type cultures, while the relative abundance of 14 pre-existing strains doubled in inoculated versus uninoculated samples. Inoculation with either wild-type or heat-evolved bacterial communities boosted C. proliferum growth, although no difference in heat tolerance was observed between the two inoculation treatments. This study provides evidence that Symbiodiniaceae-associated bacterial communities respond to heat selection and may contribute to coral adaptation to climate change.
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Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Pranali Deore
- School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Vanta J Jameson
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute of Infection and Immunity, Parkville, Victoria, Australia
- Melbourne Cytometry Platform, The University of Melbourne, Parkville, Victoria, Australia
| | - Magdaline Sakkas
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute of Infection and Immunity, Parkville, Victoria, Australia
- Melbourne Cytometry Platform, The University of Melbourne, Parkville, Victoria, Australia
| | - Alexis Perez-Gonzalez
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute of Infection and Immunity, Parkville, Victoria, Australia
- Melbourne Cytometry Platform, The University of Melbourne, Parkville, Victoria, Australia
| | - Linda L Blackall
- School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
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Scharfenstein HJ, Alvarez‐Roa C, Peplow LM, Buerger P, Chan WY, van Oppen MJH. Chemical mutagenesis and thermal selection of coral photosymbionts induce adaptation to heat stress with trait trade-offs. Evol Appl 2023; 16:1549-1567. [PMID: 37752965 PMCID: PMC10519419 DOI: 10.1111/eva.13586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 08/02/2023] [Accepted: 08/02/2023] [Indexed: 09/28/2023] Open
Abstract
Despite the relevance of heat-evolved microalgal endosymbionts to coral reef restoration, to date, few Symbiodiniaceae strains have been thermally enhanced via experimental evolution. Here, we investigated whether the thermal tolerance of Symbiodiniaceae can be increased through chemical mutagenesis followed by thermal selection. Strains of Durusdinium trenchii, Fugacium kawagutii and Symbiodinium pilosum were exposed to ethyl methanesulfonate to induce random mutagenesis, and then underwent thermal selection at high temperature (31/33°C). After 4.6-5 years of experimental evolution, the in vitro thermal tolerance of these strains was assessed via reciprocal transplant experiments to ambient (27°C) and elevated (31/35°C) temperatures. Growth, photosynthetic efficiency, oxidative stress and nutrient use were measured to compare thermal tolerance between strains. Heat-evolved D. trenchii, F. kawagutii and S. pilosum strains all exhibited increased photosynthetic efficiency under thermal stress. However, trade-offs in growth rates were observed for the heat-evolved D. trenchii lineage at both ambient and elevated temperatures. Reduced phosphate and nitrate uptake rates in F. kawagutii and S. pilosum heat-evolved lineages, respectively, suggest alterations in nutrition resource usage and allocation processes may have occurred. Increased phosphate uptake rates of the heat-evolved D. trenchii strain indicate that experimental evolution resulted in further trade-offs in this species. These findings deepen our understanding of the physiological responses of Symbiodiniaceae cultures to thermal selection and their capacity to adapt to elevated temperatures. The new heat-evolved Symbiodiniaceae developed here may be beneficial for coral reef restoration efforts if their enhanced thermal tolerance can be conferred in hospite.
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Affiliation(s)
- Hugo J. Scharfenstein
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
- Australian Institute of Marine ScienceTownsvilleQueenslandAustralia
| | | | - Lesa M. Peplow
- Australian Institute of Marine ScienceTownsvilleQueenslandAustralia
| | - Patrick Buerger
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
- Applied BioSciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Wing Yan Chan
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Madeleine J. H. van Oppen
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
- Australian Institute of Marine ScienceTownsvilleQueenslandAustralia
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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10
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Butler CC, Turnham KE, Lewis AM, Nitschke MR, Warner ME, Kemp DW, Hoegh-Guldberg O, Fitt WK, van Oppen MJH, LaJeunesse TC. Formal recognition of host-generalist species of dinoflagellate (Cladocopium, Symbiodiniaceae) mutualistic with Indo-Pacific reef corals. J Phycol 2023; 59:698-711. [PMID: 37126002 DOI: 10.1111/jpy.13340] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 03/30/2023] [Accepted: 03/30/2023] [Indexed: 06/01/2023]
Abstract
The existence of widespread species with the capacity to endure diverse, or variable, environments are of importance to ecological and genetic research, and conservation. Such "ecological generalists" are more likely to have key adaptations that allow them to better tolerate the physiological challenges of rapid climate change. Reef-building corals are dependent on endosymbiotic dinoflagellates (Family: Symbiodiniaceae) for their survival and growth. While these symbionts are biologically diverse, certain genetic types appear to have broad geographic distributions and are mutualistic with various host species from multiple genera and families in the order Scleractinia that must acquire their symbionts through horizontal transmission. Despite the considerable ecological importance of putative host-generalist symbionts, they lack formal species descriptions. In this study, we used molecular, ecological, and morphological evidence to verify the existence of five new host-generalist species in the symbiodiniacean genus Cladocopium. Their geographic distribution and prevalence among host communities corresponds to prevailing environmental conditions at both regional and local scales. The influence that each species has on host physiology may partially explain regional differences in thermal sensitivities among coral communities. The potential increased prevalence of a generalist species that endures environmental instability is a consequential ecological response to warming oceans. Large-scale shifts in symbiont dominance could ensure reef coral persistence and productivity in the near term. Ultimately, these formal designations should advance scientific communication and generate informed research questions on the physiology and ecology of coral-dinoflagellate mutualisms.
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Affiliation(s)
- Caleb C Butler
- Penn State University, University Park, Pennsylvania, USA
| | - Kira E Turnham
- Penn State University, University Park, Pennsylvania, USA
| | - Allison M Lewis
- Penn State University, University Park, Pennsylvania, USA
- Lawrence Berkeley National Laboratory, Berkely, California, USA
| | - Matthew R Nitschke
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | | | | | | | | | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
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11
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Maire J, Tandon K, Collingro A, van de Meene A, Damjanovic K, Gotze CR, Stephenson S, Philip GK, Horn M, Cantin NE, Blackall LL, van Oppen MJH. Colocalization and potential interactions of Endozoicomonas and chlamydiae in microbial aggregates of the coral Pocillopora acuta. Sci Adv 2023; 9:eadg0773. [PMID: 37196086 DOI: 10.1126/sciadv.adg0773] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 04/13/2023] [Indexed: 05/19/2023]
Abstract
Corals are associated with a variety of bacteria, which occur in the surface mucus layer, gastrovascular cavity, skeleton, and tissues. Some tissue-associated bacteria form clusters, termed cell-associated microbial aggregates (CAMAs), which are poorly studied. Here, we provide a comprehensive characterization of CAMAs in the coral Pocillopora acuta. Combining imaging techniques, laser capture microdissection, and amplicon and metagenome sequencing, we show that (i) CAMAs are located in the tentacle tips and may be intracellular; (ii) CAMAs contain Endozoicomonas (Gammaproteobacteria) and Simkania (Chlamydiota) bacteria; (iii) Endozoicomonas may provide vitamins to its host and use secretion systems and/or pili for colonization and aggregation; (iv) Endozoicomonas and Simkania occur in distinct, but adjacent, CAMAs; and (v) Simkania may receive acetate and heme from neighboring Endozoicomonas. Our study provides detailed insight into coral endosymbionts, thereby improving our understanding of coral physiology and health and providing important knowledge for coral reef conservation in the climate change era.
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Affiliation(s)
- Justin Maire
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Kshitij Tandon
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna 1030, Austria
| | - Allison van de Meene
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Katarina Damjanovic
- Australian Institute of Marine Science, PMB No 3, Townsville, QLD 4810, Australia
| | - Cecilie Ravn Gotze
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Australian Institute of Marine Science, PMB No 3, Townsville, QLD 4810, Australia
| | - Sophie Stephenson
- Australian Institute of Marine Science, PMB No 3, Townsville, QLD 4810, Australia
| | - Gayle K Philip
- Melbourne Bioinformatics, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna 1030, Austria
| | - Neal E Cantin
- Australian Institute of Marine Science, PMB No 3, Townsville, QLD 4810, 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, PMB No 3, Townsville, QLD 4810, Australia
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12
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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Doering T, Maire J, van Oppen MJH, Blackall LL. Advancing coral microbiome manipulation to build long-term climate resilience. Microbiol Aust 2023. [DOI: 10.1071/ma23009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023] Open
Abstract
Coral reefs house one-third of all marine species and are of high cultural and socioeconomic importance. However, coral reefs are under dire threat from climate change and other anthropogenic stressors. Climate change is causing coral bleaching, the breakdown of the symbiosis between the coral host and its algal symbionts, often resulting in coral mortality and the deterioration of these valuable ecosystems. While it is essential to counteract the root causes of climate change, it remains urgent to develop coral restoration and conservation methods that will buy time for coral reefs. The manipulation of the bacterial microbiome that is associated with corals has been suggested as one intervention to improve coral climate resilience. Early coral microbiome-manipulation studies, which are aimed at enhancing bleaching tolerance, have shown promising results, but the inoculated bacteria did generally not persist within the coral microbiome. Here, we highlight the importance of long-term incorporation of bacterial inocula into the microbiome of target corals, as repeated inoculations will be too costly and not feasible on large reef systems like the Great Barrier Reef. Therefore, coral microbiome-manipulation studies need to prioritise approaches that can provide sustained coral climate resilience.
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14
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Maor-Landaw K, Eisenhut M, Tortorelli G, van de Meene A, Kurz S, Segal G, van Oppen MJH, Weber APM, McFadden GI. A candidate transporter allowing symbiotic dinoflagellates to feed their coral hosts. ISME Commun 2023; 3:7. [PMID: 36709382 PMCID: PMC9884229 DOI: 10.1038/s43705-023-00218-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/10/2023] [Accepted: 01/18/2023] [Indexed: 01/30/2023]
Abstract
The symbiotic partnership between corals and dinoflagellate algae is crucial to coral reefs. Corals provide their algal symbionts with shelter, carbon dioxide and nitrogen. In exchange, the symbiotic algae supply their animal hosts with fixed carbon in the form of glucose. But how glucose is transferred from the algal symbiont to the animal host is unknown. We reasoned that a transporter resident in the dinoflagellate cell membrane would facilitate outward transfer of glucose to the surrounding host animal tissue. We identified a candidate transporter in the cnidarian symbiont dinoflagellate Breviolum minutum that belongs to the ubiquitous family of facilitative sugar uniporters known as SWEETs (sugars will eventually be exported transporters). Previous gene expression analyses had shown that BmSWEET1 is upregulated when the algae are living symbiotically in a cnidarian host by comparison to the free-living state [1, 2]. We used immunofluorescence microscopy to localise BmSWEET1 in the dinoflagellate cell membrane. Substrate preference assays in a yeast surrogate transport system showed that BmSWEET1 transports glucose. Quantitative microscopy showed that symbiotic B. minutum cells have significantly more BmSWEET1 protein than free-living cells of the same strain, consistent with export during symbiosis but not during the free-living, planktonic phase. Thus, BmSWEET1 is in the right place, at the right time, and has the right substrate to be the transporter with which symbiotic dinoflagellate algae feed their animal hosts to power coral reefs.
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Affiliation(s)
- Keren Maor-Landaw
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
- Department of Marine Biology, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Marion Eisenhut
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, Universitätsstraße 1, D-40225, Düsseldorf, Germany
- Computational Biology, Faculty of Biology, CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Giada Tortorelli
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
- Coral Resilience Lab, Hawai'i Institute of Marine Biology, Kāne'ohe, HI, USA
| | | | - Samantha Kurz
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, Universitätsstraße 1, D-40225, Düsseldorf, Germany
| | - Gabriela Segal
- Biological Optical Microscopy Platform, 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
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, Universitätsstraße 1, D-40225, Düsseldorf, Germany
| | - Geoffrey I McFadden
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia.
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15
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van Oppen MJH, Raina JB. Coral holobiont research needs spatial analyses at the microbial scale. Environ Microbiol 2023; 25:179-183. [PMID: 36209397 PMCID: PMC10100515 DOI: 10.1111/1462-2920.16237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 10/01/2022] [Indexed: 01/21/2023]
Affiliation(s)
- Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia.,School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Jean-Baptiste Raina
- Climate Change Cluster (C3), University of Technology Sydney, Sydney, New South Wales, Australia
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16
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McLeod IM, Hein MY, Babcock R, Bay L, Bourne DG, Cook N, Doropoulos C, Gibbs M, Harrison P, Lockie S, van Oppen MJH, Mattocks N, Page CA, Randall CJ, Smith A, Smith HA, Suggett DJ, Taylor B, Vella KJ, Wachenfeld D, Boström-Einarsson L. Coral restoration and adaptation in Australia: The first five years. PLoS One 2022; 17:e0273325. [PMID: 36449458 PMCID: PMC9710771 DOI: 10.1371/journal.pone.0273325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
While coral reefs in Australia have historically been a showcase of conventional management informed by research, recent declines in coral cover have triggered efforts to innovate and integrate intervention and restoration actions into management frameworks. Here we outline the multi-faceted intervention approaches that have developed in Australia since 2017, from newly implemented in-water programs, research to enhance coral resilience and investigations into socio-economic perspectives on restoration goals. We describe in-water projects using coral gardening, substrate stabilisation, coral repositioning, macro-algae removal, and larval-based restoration techniques. Three areas of research focus are also presented to illustrate the breadth of Australian research on coral restoration, (1) the transdisciplinary Reef Restoration and Adaptation Program (RRAP), one of the world's largest research and development programs focused on coral reefs, (2) interventions to enhance coral performance under climate change, and (3) research into socio-cultural perspectives. Together, these projects and the recent research focus reflect an increasing urgency for action to confront the coral reef crisis, develop new and additional tools to manage coral reefs, and the consequent increase in funding opportunities and management appetite for implementation. The rapid progress in trialling and deploying coral restoration in Australia builds on decades of overseas experience, and advances in research and development are showing positive signs that coral restoration can be a valuable tool to improve resilience at local scales (i.e., high early survival rates across a variety of methods and coral species, strong community engagement with local stakeholders). RRAP is focused on creating interventions to help coral reefs at multiple scales, from micro scales (i.e., interventions targeting small areas within a specific reef site) to large scales (i.e., interventions targeting core ecosystem function and social-economic values at multiple select sites across the Great Barrier Reef) to resist, adapt to and recover from the impacts of climate change. None of these interventions aim to single-handedly restore the entirety of the Great Barrier Reef, nor do they negate the importance of urgent climate change mitigation action.
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Affiliation(s)
- Ian M. McLeod
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Margaux Y. Hein
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- MER Research and Consulting, The Office, Monaco, Monaco
- * E-mail:
| | - Russ Babcock
- CSIRO Oceans & Atmosphere, St Lucia, Queensland, Australia
| | - Line Bay
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - David G. Bourne
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- College of Science and Engineering, James Cook University, Townsville, Australia
| | - Nathan Cook
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Reef Ecologic, Townsville, Queensland, Australia
| | | | - Mark Gibbs
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Peter Harrison
- Marine Ecology Research Centre, Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Stewart Lockie
- The Cairns Institute, James Cook University, Cairns, Queensland, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - Neil Mattocks
- Great Barrier Reef Marine Park Authority, Townsville, Queensland, Australia
| | - Cathie A. Page
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Carly J. Randall
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Adam Smith
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Reef Ecologic, Townsville, Queensland, Australia
| | - Hillary A. Smith
- College of Science and Engineering, James Cook University, Townsville, Australia
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Randwick, New South Wales, Australia
| | - David J. Suggett
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Bruce Taylor
- Land & Water, Commonwealth Scientific and Industrial Research Organisation, Dutton Park, Queensland, Australia
| | - Karen J. Vella
- School of Architecture and Built Environment, Queensland University of Technology, Brisbane, Australia
| | - David Wachenfeld
- Great Barrier Reef Marine Park Authority, Townsville, Queensland, Australia
| | - Lisa Boström-Einarsson
- TropWATER (Centre for Tropical Water and Aquatic Ecosystem Research), James Cook University, Townsville, Queensland, Australia
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, United Kingdom
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17
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Abstract
The rapid growth in genomic techniques provides the potential to transform how we protect, manage, and conserve marine life. Further, solutions to boost the resilience of marine species to climate change and other disturbances that characterize the Anthropocene require transformative approaches, made more effective if guided by genomic data. Although genetic techniques have been employed in marine conservation for decades and the availability of genomic data is rapidly expanding, widespread application still lags behind other data types. This Essay reviews how genetics and genomics have been utilized in management initiatives for ocean conservation and restoration, highlights success stories, and presents a pathway forward to enhance the uptake of genomic data for protecting our oceans.
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Affiliation(s)
- Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Melinda A. Coleman
- Department of Primary Industries, NSW Fisheries, National Marine Science Centre, Coffs Harbour, New South Wales, Australia
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18
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Salazar OR, N. Arun P, Cui G, Bay LK, van Oppen MJH, Webster NS, Aranda M. The coral Acropora loripes genome reveals an alternative pathway for cysteine biosynthesis in animals. Sci Adv 2022; 8:eabq0304. [PMID: 36149959 PMCID: PMC9506716 DOI: 10.1126/sciadv.abq0304] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/10/2022] [Indexed: 05/28/2023]
Abstract
The metabolic capabilities of animals have been derived from well-studied model organisms and are generally considered to be well understood. In animals, cysteine is an important amino acid thought to be exclusively synthesized through the transsulfuration pathway. Corals of the genus Acropora have lost cystathionine β-synthase, a key enzyme of the transsulfuration pathway, and it was proposed that Acropora relies on the symbiosis with dinoflagellates of the family Symbiodiniaceae for the acquisition of cysteine. Here, we identify the existence of an alternative pathway for cysteine biosynthesis in animals through the analysis of the genome of the coral Acropora loripes. We demonstrate that these coral proteins are functional and synthesize cysteine in vivo, exhibiting previously unrecognized metabolic capabilities of animals. This pathway is also present in most animals but absent in mammals, arthropods, and nematodes, precisely the groups where most of the animal model organisms belong to, highlighting the risks of generalizing findings from model organisms.
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Affiliation(s)
- Octavio R. Salazar
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Prasanna N. Arun
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Guoxin Cui
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Line K. Bay
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Division of Research and Innovation, James Cook University, Townsville, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Nicole S. Webster
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- Australian Centre for Ecogenomics, University of Queensland, St Lucia, Australia
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, Australia
| | - Manuel Aranda
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
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19
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Chen Y, Shah S, Dougan KE, van Oppen MJH, Bhattacharya D, Chan CX. Improved Cladocopium goreaui Genome Assembly Reveals Features of a Facultative Coral Symbiont and the Complex Evolutionary History of Dinoflagellate Genes. Microorganisms 2022; 10:microorganisms10081662. [PMID: 36014080 PMCID: PMC9412976 DOI: 10.3390/microorganisms10081662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022] Open
Abstract
Dinoflagellates of the family Symbiodiniaceae are crucial photosymbionts in corals and other marine organisms. Of these, Cladocopium goreaui is one of the most dominant symbiont species in the Indo-Pacific. Here, we present an improved genome assembly of C. goreaui combining new long-read sequence data with previously generated short-read data. Incorporating new full-length transcripts to guide gene prediction, the C. goreaui genome (1.2 Gb) exhibits a high extent of completeness (82.4% based on BUSCO protein recovery) and better resolution of repetitive sequence regions; 45,322 gene models were predicted, and 327 putative, topologically associated domains of the chromosomes were identified. Comparison with other Symbiodiniaceae genomes revealed a prevalence of repeats and duplicated genes in C. goreaui, and lineage-specific genes indicating functional innovation. Incorporating 2,841,408 protein sequences from 96 taxonomically diverse eukaryotes and representative prokaryotes in a phylogenomic approach, we assessed the evolutionary history of C. goreaui genes. Of the 5246 phylogenetic trees inferred from homologous protein sets containing two or more phyla, 35–36% have putatively originated via horizontal gene transfer (HGT), predominantly (19–23%) via an ancestral Archaeplastida lineage implicated in the endosymbiotic origin of plastids: 10–11% are of green algal origin, including genes encoding photosynthetic functions. Our results demonstrate the utility of long-read sequence data in resolving structural features of a dinoflagellate genome, and highlight how genetic transfer has shaped genome evolution of a facultative symbiont, and more broadly of dinoflagellates.
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Affiliation(s)
- Yibi Chen
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Sarah Shah
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Katherine E. Dougan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Madeleine J. H. van Oppen
- School of Bioscience, The University of Melbourne, Parkville, VIC 3010, Australia
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Cheong Xin Chan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Correspondence:
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20
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Tsang Min Ching SJ, Chan WY, Perez-Gonzalez A, Hillyer KE, Buerger P, van Oppen MJH. Colonization and metabolite profiles of homologous, heterologous and experimentally evolved algal symbionts in the sea anemone Exaiptasia diaphana. ISME Commun 2022; 2:30. [PMID: 37938648 PMCID: PMC9723793 DOI: 10.1038/s43705-022-00114-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/17/2022] [Accepted: 03/01/2022] [Indexed: 07/30/2023]
Abstract
The sea anemone, Exaiptasia diaphana, is a model of coral-dinoflagellate (Symbiodiniaceae) symbiosis. However, little is known of its potential to form symbiosis with Cladocopium-a key Indo-Pacific algal symbiont of scleractinian corals, nor the host nutritional consequences of such an association. Aposymbiotic anemones were inoculated with homologous algal symbionts, Breviolum minutum, and seven heterologous strains of Cladocopium C1acro (wild-type and heat-evolved) under ambient conditions. Despite lower initial algal cell density, Cladocopium C1acro-anemeones achieved similar cell densities as B. minutum-anemones by week 77. Wild-type and heat-evolved Cladocopium C1acro showed similar colonization patterns. Targeted LC-MS-based metabolomics revealed that almost all significantly different metabolites in the host and Symbiodiniaceae fractions were due to differences between Cladocopium C1acro and B. minutum, with little difference between heat-evolved and wild-type Cladocopium C1acro at week 9. The algal fraction of Cladocopium C1acro-anemones was enriched in metabolites related to nitrogen storage, while the host fraction of B. minutum-anemones was enriched in sugar-related metabolites. Compared to B. minutum, Cladocopium C1acro is likely slightly less nutritionally beneficial to the host under ambient conditions, but more capable of maintaining its own growth when host nitrogen supply is limited. Our findings demonstrate the value of E. diaphana to study experimentally evolved Cladocopium.
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Affiliation(s)
| | - Wing Yan Chan
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia.
| | - Alexis Perez-Gonzalez
- Melbourne Cytometry Platform, University of Melbourne, Parkville, VIC, Australia
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute of Infection and Immunity, Parkville, VIC, Australia
| | | | - Patrick Buerger
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
- Applied Biosciences, Macquarie University, North Ryde, NSW, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
- Australian Institute of Marine Science, Townsville, QLD, Australia
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21
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Matsuda SB, Chakravarti LJ, Cunning R, Huffmyer AS, Nelson CE, Gates RD, van Oppen MJH. Temperature-mediated acquisition of rare heterologous symbionts promotes survival of coral larvae under ocean warming. Glob Chang Biol 2022; 28:2006-2025. [PMID: 34957651 PMCID: PMC9303745 DOI: 10.1111/gcb.16057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Reef-building corals form nutritional symbioses with endosymbiotic dinoflagellates (Symbiodiniaceae), a relationship that facilitates the ecological success of coral reefs. These symbionts are mostly acquired anew each generation from the environment during early life stages ("horizontal transmission"). Symbiodiniaceae species exhibit trait variation that directly impacts the health and performance of the coral host under ocean warming. Here, we test the capacity for larvae of a horizontally transmitting coral, Acropora tenuis, to establish symbioses with Symbiodiniaceae species in four genera that have varying thermal thresholds (the common symbiont genera, Cladocopium and Durusdinium, and the less common Fugacium and Gerakladium). Over a 2-week period in January 2018, a series of both no-choice and four-way choice experiments were conducted at three temperatures (27, 30, and 31°C). Symbiont acquisition success and cell proliferation were measured in individual larvae. Larvae successfully acquired and maintained symbionts of all four genera in no-choice experiments, and >80% of larvae were infected with at least three genera when offered a four-way choice. Unexpectedly, Gerakladium symbionts increased in dominance over time, and at high temperatures outcompeted Durusdinium, which is regarded as thermally tolerant. Although Fugacium displayed the highest thermal tolerance in culture and reached similar cell densities to the other three symbionts at 31°C, it remained a background symbiont in choice experiments, suggesting host preference for other symbiont species. Larval survivorship at 1 week was highest in larvae associated with Gerakladium and Fugacium symbionts at 27 and 30°C, however at 31°C, mortality was similar for all treatments. We hypothesize that symbionts that are currently rare in corals (e.g., Gerakladium) may become more common and widespread in early life stages under climate warming. Uptake of such symbionts may function as a survival strategy in the wild, and has implications for reef restoration practices that use sexually produced coral stock.
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Affiliation(s)
- Shayle B. Matsuda
- Hawai‘i Institute of Marine BiologyUniversity of Hawai‘i at MānoaKāne‘oheHawai‘iUSA
| | | | - Ross Cunning
- Daniel P. Haerther Center for Conservation and ResearchJohn G. Shedd AquariumChicagoIllinoisUSA
| | - Ariana S. Huffmyer
- Department of Biological SciencesUniversity of Rhode IslandKingstonRhode IslandUSA
| | - Craig E. Nelson
- Daniel K. Inouye Center for Microbial Oceanography: Research and EducationDepartment of Oceanography and Sea Grant College ProgramUniversity of Hawai‘i at MānoaHonoluluHawai‘iUSA
| | - Ruth D. Gates
- Hawai‘i Institute of Marine BiologyUniversity of Hawai‘i at MānoaKāne‘oheHawai‘iUSA
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine ScienceTownsvilleQueenslandAustralia
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
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22
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Scharfenstein HJ, Chan WY, Buerger P, Humphrey C, van Oppen MJH. Evidence for de novo acquisition of microalgal symbionts by bleached adult corals. ISME J 2022; 16:1676-1679. [PMID: 35132118 PMCID: PMC9122906 DOI: 10.1038/s41396-022-01203-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 11/18/2022]
Abstract
Early life stages of most coral species acquire microalgal endosymbionts (Symbiodiniaceae) from the environment, but whether exogenous symbiont uptake is possible in the adult life stage is unclear. Deep sequencing of the Symbiodiniaceae ITS2 genetic marker has revealed novel symbionts in adult corals following bleaching; however these strains may have already been present at densities below detection limits. To test whether acquisition of symbionts from the environment occurs, we subjected adult fragments of corals (six species in four families) to a chemical bleaching treatment (menthol and DCMU). The treatment reduced the native microalgal symbiont abundance to below 2% of their starting densities. The bleached corals were then inoculated with a cultured Cladocopium C1acro strain. Genotyping of the Symbiodiniaceae communities before bleaching and after reinoculation showed that fragments of all six coral species acquired the Cladocopium C1acro strain used for inoculation. Our results provide strong evidence for the uptake of Symbiodiniaceae from the environment by adult corals. We also demonstrate the feasibility of chemical bleaching followed by reinoculation to manipulate the Symbiodiniaceae communities of adult corals, providing an innovative approach to establish new symbioses between adult corals and heat-evolved microalgal symbionts, which could prove highly relevant to coral reef restoration efforts.
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Affiliation(s)
- Hugo J Scharfenstein
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia. .,Australian Institute of Marine Science, Townsville, QLD, Australia.
| | - Wing Yan Chan
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Patrick Buerger
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.,Applied BioSciences, Macquarie University, Sydney, NSW, Australia
| | - Craig Humphrey
- Australian Institute of Marine Science, Townsville, QLD, 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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23
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Dungan AM, Hartman LM, Blackall LL, van Oppen MJH. Exploring microbiome engineering as a strategy for improved thermal tolerance in Exaiptasia diaphana. J Appl Microbiol 2022; 132:2940-2956. [PMID: 35104027 PMCID: PMC9303619 DOI: 10.1111/jam.15465] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/08/2021] [Accepted: 01/24/2022] [Indexed: 11/28/2022]
Abstract
Aims Fourteen percent of all living coral, equivalent to more than all the coral on the Great Barrier Reef, has died in the past decade as a result of climate change‐driven bleaching. Inspired by the ‘oxidative stress theory of coral bleaching’, we investigated whether a bacterial consortium designed to scavenge free radicals could integrate into the host microbiome and improve thermal tolerance of the coral model, Exaiptasia diaphana. Methods and Results E. diaphana anemones were inoculated with a consortium of high free radical scavenging (FRS) bacteria, a consortium of congeneric low FRS bacteria, or sterile seawater as a control, then exposed to elevated temperature. Increases in the relative abundance of Labrenzia during the first 2 weeks following the last inoculation provided evidence for temporary inoculum integration into the E. diaphana microbiome. Initial uptake of other consortium members was inconsistent, and these bacteria did not persist either in E. diaphana’s microbiome over time. Given their non‐integration into the host microbiome, the ability of the FRS consortium to mitigate thermal stress could not be assessed. Importantly, there were no physiological impacts (negative or positive) of the bacterial inoculations on the holobiont. Conclusions The introduced bacteria were not maintained in the anemone microbiome over time, thus, their protective effect is unknown. Achieving long‐term integration of bacteria into cnidarian microbiomes remains a research priority. Significance and Impact of the Study Microbiome engineering strategies to mitigate coral bleaching may assist coral reefs in their persistence until climate change has been curbed. This study provides insights that will inform microbiome manipulation approaches in coral bleaching mitigation research.
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Affiliation(s)
- Ashley M Dungan
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Leon M Hartman
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia.,Swinburne University of Technology, Hawthorn, VIC, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia.,Australian Institute of Marine Science, Townsville, Australia
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24
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Hartman LM, Blackall LL, van Oppen MJH. Antibiotics reduce bacterial load in Exaiptasia diaphana, but biofilms hinder its development as a gnotobiotic coral model. Access Microbiol 2022; 4:000314. [PMID: 35252752 PMCID: PMC8895603 DOI: 10.1099/acmi.0.000314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 12/07/2021] [Indexed: 12/02/2022] Open
Abstract
Coral reefs are declining due to anthropogenic disturbances, including climate change. Therefore, improving our understanding of coral ecosystems is vital, and the influence of bacteria on coral health has attracted particular interest. However, a gnotobiotic coral model that could enhance studies of coral–bacteria interactions is absent. To address this gap, we tested the ability of treatment with seven antibiotics for 3 weeks to deplete bacteria in Exaiptasia diaphana, a sea anemone widely used as a coral model. Digital droplet PCR (ddPCR) targeting anemone Ef1-α and bacterial 16S rRNA genes was used to quantify bacterial load, which was found to decrease six-fold. However, metabarcoding of bacterial 16S rRNA genes showed that alpha and beta diversity of the anemone-associated bacterial communities increased significantly. Therefore, gnotobiotic E. diaphana with simplified, uniform bacterial communities were not generated, with biofilm formation in the culture vessels most likely impeding efforts to eliminate bacteria. Despite this outcome, our work will inform future efforts to create a much needed gnotobiotic coral model.
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Affiliation(s)
- Leon M. Hartman
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Swinburne University of Technology, Hawthorn, VIC, Australia
- Monash University, Clayton, VIC, Australia
| | - Linda L. Blackall
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville, QLD, Australia
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
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25
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Deore P, Wanigasuriya I, Tsang Min Ching SJ, Brumley DR, van Oppen MJH, Blackall LL, Hinde E. Fluorescence lifetime imaging microscopy (FLIM): a non-traditional approach to study host-microbial symbioses. Microbiol Aust 2022. [DOI: 10.1071/ma22008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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26
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Bairos-Novak KR, Hoogenboom MO, van Oppen MJH, Connolly SR. Coral adaptation to climate change: Meta-analysis reveals high heritability across multiple traits. Glob Chang Biol 2021; 27:5694-5710. [PMID: 34482591 DOI: 10.1111/gcb.15829] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/23/2021] [Accepted: 07/25/2021] [Indexed: 06/13/2023]
Abstract
Anthropogenic climate change is a rapidly intensifying selection pressure on biodiversity across the globe and, particularly, on the world's coral reefs. The rate of adaptation to climate change is proportional to the amount of phenotypic variation that can be inherited by subsequent generations (i.e., narrow-sense heritability, h2 ). Thus, traits that have higher heritability (e.g., h2 > 0.5) are likely to adapt to future conditions faster than traits with lower heritability (e.g., h2 < 0.1). Here, we synthesize 95 heritability estimates across 19 species of reef-building corals. Our meta-analysis reveals low heritability (h2 < 0.25) of gene expression metrics, intermediate heritability (h2 = 0.25-0.50) of photochemistry, growth, and bleaching, and high heritability (h2 > 0.50) for metrics related to survival and immune responses. Some of these values are higher than typically observed in other taxa, such as survival and growth, while others were more comparable, such as gene expression and photochemistry. There was no detectable effect of temperature on heritability, but narrow-sense heritability estimates were generally lower than broad-sense estimates, indicative of significant non-additive genetic variation across traits. Trait heritability also varied depending on coral life stage, with bleaching and growth in juveniles generally having lower heritability compared to bleaching and growth in larvae and adults. These differences may be the result of previous stabilizing selection on juveniles or may be due to constrained evolution resulting from genetic trade-offs or genetic correlations between growth and thermotolerance. While we find no evidence that heritability decreases under temperature stress, explicit tests of the heritability of thermal tolerance itself-such as coral thermal reaction norm shape-are lacking. Nevertheless, our findings overall reveal high trait heritability for the majority of coral traits, suggesting corals may have a greater potential to adapt to climate change than has been assumed in recent evolutionary models.
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Affiliation(s)
- Kevin R Bairos-Novak
- College of Science and Engineering and ARCCOE for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | - Mia O Hoogenboom
- College of Science and Engineering and ARCCOE for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Sean R Connolly
- College of Science and Engineering and ARCCOE for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
- Smithsonian Tropical Research Institute, Panama City, Panama
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27
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Maire J, Blackall LL, van Oppen MJH. Intracellular Bacterial Symbionts in Corals: Challenges and Future Directions. Microorganisms 2021; 9:2209. [PMID: 34835335 PMCID: PMC8619543 DOI: 10.3390/microorganisms9112209] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 02/07/2023] Open
Abstract
Corals are the main primary producers of coral reefs and build the three-dimensional reef structure that provides habitat to more than 25% of all marine eukaryotes. They harbor a complex consortium of microorganisms, including bacteria, archaea, fungi, viruses, and protists, which they rely on for their survival. The symbiosis between corals and bacteria is poorly studied, and their symbiotic relationships with intracellular bacteria are only just beginning to be acknowledged. In this review, we emphasize the importance of characterizing intracellular bacteria associated with corals and explore how successful approaches used to study such microorganisms in other systems could be adapted for research on corals. We propose a framework for the description, identification, and functional characterization of coral-associated intracellular bacterial symbionts. Finally, we highlight the possible value of intracellular bacteria in microbiome manipulation and mitigating coral bleaching.
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Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
| | - Linda L. Blackall
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
| | - Madeleine J. H. van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia
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28
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Tortorelli G, Oakley CA, Davy SK, van Oppen MJH, McFadden GI. Cell wall proteomic analysis of the cnidarian photosymbionts Breviolum minutum and Cladocopium goreaui. J Eukaryot Microbiol 2021; 69:e12870. [PMID: 34448326 PMCID: PMC9293036 DOI: 10.1111/jeu.12870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The algal cell wall is an important cellular component that functions in defense, nutrient utilization, signaling, adhesion, and cell–cell recognition—processes important in the cnidarian–dinoflagellate symbiosis. The cell wall of symbiodiniacean dinoflagellates is not well characterized. Here, we present a method to isolate cell walls of Symbiodiniaceae and prepare cell‐wall‐enriched samples for proteomic analysis. Label‐free liquid chromatography–electrospray ionization tandem mass spectrometry was used to explore the surface proteome of two Symbiodiniaceae species from the Great Barrier Reef: Breviolum minutum and Cladocopium goreaui. Transporters, hydrolases, translocases, and proteins involved in cell‐adhesion and protein–protein interactions were identified, but the majority of cell wall proteins had no homologues in public databases. We propose roles for some of these proteins in the cnidarian–dinoflagellate symbiosis. This work provides the first proteomics investigation of cell wall proteins in the Symbiodiniaceae and represents a basis for future explorations of the roles of cell wall proteins in Symbiodiniaceae and other dinoflagellates.
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Affiliation(s)
- Giada Tortorelli
- School of Biosciences, The University of Melbourne, Melbourne, Vic, Australia
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Kelburn, New Zealand
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Kelburn, New Zealand
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, Vic, Australia.,Australian Institute of Marine Science, Townsville, Qld, Australia
| | - Geoffrey I McFadden
- School of Biosciences, The University of Melbourne, Melbourne, Vic, Australia
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29
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Maire J, van Oppen MJH. A role for bacterial experimental evolution in coral bleaching mitigation? Trends Microbiol 2021; 30:217-228. [PMID: 34429226 DOI: 10.1016/j.tim.2021.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 12/13/2022]
Abstract
Coral reefs are rapidly declining because of widespread mass coral bleaching causing extensive coral mortality. Elevated seawater temperatures are the main drivers of coral bleaching, and climate change is increasing the frequency and severity of destructive marine heatwaves. Efforts to enhance coral thermal bleaching tolerance can be targeted at the coral host or at coral-associated microorganisms (e.g., dinoflagellate endosymbionts and bacteria). The literature on experimental evolution of bacteria suggests that it has value as a tool to increase coral climate resilience. We provide a workflow on how to experimentally evolve coral-associated bacteria to confer thermal tolerance to coral hosts and emphasize the value of implementing this approach in coral reef conservation and restoration efforts.
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Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia; Australian Institute of Marine Science, Townsville, QLD, Australia
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30
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Tortorelli G, Rautengarten C, Bacic A, Segal G, Ebert B, Davy SK, van Oppen MJH, McFadden GI. Cell surface carbohydrates of symbiotic dinoflagellates and their role in the establishment of cnidarian-dinoflagellate symbiosis. ISME J 2021; 16:190-199. [PMID: 34285364 PMCID: PMC8290866 DOI: 10.1038/s41396-021-01059-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 01/05/2023]
Abstract
Symbiodiniaceae algae are often photosymbionts of reef-building corals. The establishment of their symbiosis resembles a microbial infection where eukaryotic pattern recognition receptors (e.g. lectins) are thought to recognize a specific range of taxon-specific microbial-associated molecular patterns (e.g. glycans). The present study used the sea anemone, Exaiptasia diaphana and three species of Symbiodiniaceae (the homologous Breviolum minutum, the heterologous-compatible Cladocopium goreaui and the heterologous-incompatible Fugacium kawagutii) to compare the surface glycomes of three symbionts and explore the role of glycan–lectin interactions in host–symbiont recognition and establishment of symbiosis. We identified the nucleotide sugars of the algal cells, then examined glycans on the cell wall of the three symbiont species with monosaccharide analysis, lectin array technology and fluorescence microscopy of the algal cell decorated with fluorescently tagged lectins. Armed with this inventory of possible glycan moieties, we then assayed the ability of the three Symbiodiniaceae to colonize aposymbiotic E. diaphana after modifying the surface of one of the two partners. The Symbiodiniaceae cell-surface glycome varies among algal species. Trypsin treatment of the alga changed the rate of B. minutum and C. goreaui uptake, suggesting that a protein-based moiety is an essential part of compatible symbiont recognition. Our data strongly support the importance of D-galactose (in particular β-D-galactose) residues in the establishment of the cnidarian–dinoflagellate symbiosis, and we propose a potential involvement of L-fucose, D-xylose and D-galacturonic acid in the early steps of this mutualism.
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Affiliation(s)
- Giada Tortorelli
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia.
| | | | - Antony Bacic
- Department of Animal, Plant & Soil Sciences, La Trobe Institute for Agriculture and Food, La Trobe University, Bundoora, VIC, Australia
| | - Gabriela Segal
- Biological Optical Microscopy Platform, The University of Melbourne, Parkville, VIC, Australia
| | - Berit Ebert
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia.,Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Geoffrey I McFadden
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
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31
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Dungan AM, Bulach D, Lin H, van Oppen MJH, Blackall LL. Development of a free radical scavenging bacterial consortium to mitigate oxidative stress in cnidarians. Microb Biotechnol 2021; 14:2025-2040. [PMID: 34259383 PMCID: PMC8449677 DOI: 10.1111/1751-7915.13877] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 06/13/2021] [Indexed: 12/19/2022] Open
Abstract
Corals are colonized by symbiotic microorganisms that profoundly influence the animal’s health. One noted symbiont is a single‐celled alga (in the dinoflagellate family Symbiodiniaceae), which provides the coral with most of its fixed carbon. Thermal stress increases the production of reactive oxygen species (ROS) by Symbiodiniaceae during photosynthesis. ROS can both damage the algal symbiont’s photosynthetic machinery and inhibit its repair, causing a positive feedback loop for the toxic accumulation of ROS. If not scavenged by the antioxidant network, excess ROS may trigger a signaling cascade ending with the coral host and algal symbiont disassociating in a process known as bleaching. We use Exaiptasia diaphana as a model for corals and constructed a consortium comprised of E. diaphana–associated bacteria capable of neutralizing ROS. We identified six strains with high free radical scavenging (FRS) ability belonging to the families Alteromonadaceae, Rhodobacteraceae, Flavobacteriaceae and Micrococcaceae. In parallel, we established a consortium of low FRS isolates consisting of genetically related strains. Bacterial whole genome sequences were used to identify key pathways that are known to influence ROS.
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Affiliation(s)
- Ashley M Dungan
- School of Biosciences, The University of Melbourne, Melbourne, Vic., Australia
| | - Dieter Bulach
- Melbourne Bioinformatics, The University of Melbourne, Melbourne, Vic., Australia
| | - Heyu Lin
- School of Earth Sciences, The University of Melbourne, Melbourne, Vic., Australia
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, Vic., Australia.,Australian Institute of Marine Science, Townsville, Qld, Australia
| | - Linda L Blackall
- School of Biosciences, The University of Melbourne, Melbourne, Vic., Australia
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32
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Maire J, Girvan SK, Barkla SE, Perez-Gonzalez A, Suggett DJ, Blackall LL, van Oppen MJH. Correction to: Intracellular bacteria are common and taxonomically diverse in cultured and in hospite algal endosymbionts of coral reefs. ISME J 2021; 15:2168-2170. [PMID: 33854192 PMCID: PMC8245416 DOI: 10.1038/s41396-021-00970-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.
| | - Sam K Girvan
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Sophie E Barkla
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Alexis Perez-Gonzalez
- Melbourne Cytometry Platform, Melbourne Dental School, The University of Melbourne, Melbourne, VIC, Australia
| | - David J Suggett
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Linda L Blackall
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia
- Australian Institute of Marine Science, Townsville, QLD, Australia
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Maire J, Blackall LL, van Oppen MJH. Microbiome characterization of defensive tissues in the model anemone Exaiptasia diaphana. BMC Microbiol 2021; 21:152. [PMID: 34020587 PMCID: PMC8140459 DOI: 10.1186/s12866-021-02211-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/29/2021] [Indexed: 01/04/2023] Open
Abstract
Background Coral reefs are among the most diverse and productive ecosystems on Earth. This success relies on the coral’s association with a wide range of microorganisms, including dinoflagellates of the family Symbiodiniaceae that provide coral hosts with most of their organic carbon requirements. While bacterial associates have long been overlooked, research on these microorganisms is gaining traction, and deciphering bacterial identity and function is greatly enhancing our understanding of cnidarian biology. Here, we investigated bacterial communities in defensive tissues (acontia) of the coral model, the sea anemone Exaiptasia diaphana. Acontia are internal filaments that are ejected upon detection of an external threat and release toxins to repel predators. Results Using culturing techniques and 16S rRNA gene metabarcoding we identified bacterial communities associated with acontia of four Great Barrier Reef-sourced E. diaphana genotypes. We show that bacterial communities are similar across genotypes, and dominated by Alteromonadaceae, Vibrionaceae, Rhodobacteraceae, and Saprospiraceae. By analyzing abundant amplicon sequence variants (ASVs) from metabarcoding data from acontia and comparing these to data from whole anemones, we identified five potentially important bacterial genera of the acontia microbiome: Vibrio, Sulfitobacter, Marivita, Alteromonas, and Lewinella. The role of these bacteria within the acontia remains uninvestigated but could entail assistance in defense processes such as toxin production. Conclusions This study provides insight into potential bacterial involvement in cnidarian defense tissues and highlights the need to study bacterial communities in individual compartments within a holobiont. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02211-4.
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Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.
| | - Linda L Blackall
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.,Australian Institute of Marine Science, Townsville, QLD, Australia
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Chan WY, Oakeshott JG, Buerger P, Edwards OR, van Oppen MJH. Adaptive responses of free-living and symbiotic microalgae to simulated future ocean conditions. Glob Chang Biol 2021; 27:1737-1754. [PMID: 33547698 DOI: 10.1111/gcb.15546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 06/12/2023]
Abstract
Marine microalgae are a diverse group of microscopic eukaryotic and prokaryotic organisms capable of photosynthesis. They are important primary producers and carbon sinks but their physiology and persistence are severely affected by global climate change. Powerful experimental evolution technologies are being used to examine the potential of microalgae to respond adaptively to current and predicted future conditions, as well as to develop resources to facilitate species conservation and restoration of ecosystem functions. This review synthesizes findings and insights from experimental evolution studies of marine microalgae in response to elevated temperature and/or pCO2 . Adaptation to these environmental conditions has been observed in many studies of marine dinoflagellates, diatoms and coccolithophores. An enhancement in traits such as growth and photo-physiological performance and an increase in upper thermal limit have been shown to be possible, although the extent and rate of change differ between microalgal taxa. Studies employing multiple monoclonal replicates showed variation in responses among replicates and revealed the stochasticity of mutations. The work to date is already providing valuable information on species' climate sensitivity or resilience to managers and policymakers but extrapolating these insights to ecosystem- and community-level impacts continues to be a challenge. We recommend future work should include in situ experiments, diurnal and seasonal fluctuations, multiple drivers and multiple starting genotypes. Fitness trade-offs, stable versus plastic responses and the genetic bases of the changes also need investigating, and the incorporation of genome resequencing into experimental designs will be invaluable.
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Affiliation(s)
- Wing Yan Chan
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| | - John G Oakeshott
- CSIRO Synthetic Biology Future Science Platform, Land & Water, Canberra, ACT, Australia
- Applied Biosciences, Macquarie University, North Ryde, NSW, Australia
| | - Patrick Buerger
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
- CSIRO Synthetic Biology Future Science Platform, Land & Water, Canberra, ACT, Australia
| | - Owain R Edwards
- CSIRO Synthetic Biology Future Science Platform, Land & Water, Canberra, ACT, Australia
- Applied Biosciences, Macquarie University, North Ryde, NSW, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
- Australian Institute of Marine Science, Townsville, QLD, Australia
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Chan WY, Chung J, Peplow LM, Hoffmann AA, van Oppen MJH. Maternal effects in gene expression of interspecific coral hybrids. Mol Ecol 2020; 30:517-527. [PMID: 33179328 DOI: 10.1111/mec.15727] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 12/24/2022]
Abstract
Maternal effects have been well documented for offspring morphology and life history traits in plants and terrestrial animals, yet little is known about maternal effects in corals. Further, few studies have explored maternal effects in gene expression. In a previous study, F1 interspecific hybrid and purebred larvae of the coral species Acropora tenuis and Acropora loripes were settled and exposed to ambient or elevated temperature and pCO2 conditions for 7 months. At this stage, the hybrid coral recruits from both ocean conditions exhibited strong maternal effects in several fitness traits. We conducted RNA-sequencing on these corals and showed that gene expression of the hybrid Acropora also exhibited clear maternal effects. Only 40 genes were differentially expressed between hybrids and their maternal progenitor. In contrast, ~2000 differentially expressed genes were observed between hybrids and their paternal progenitors, and between the reciprocal F1 hybrids. These results indicate that maternal effects in coral gene expression can be long-lasting. Unlike findings from most short-term stress experiments in corals, no genes were differentially expressed in the hybrid nor purebred offspring after seven months of exposure to elevated temperature and pCO2 conditions.
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Affiliation(s)
- Wing Yan Chan
- Australian Institute of Marine Science, Townsville, QLD, Australia.,School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - Jessica Chung
- Bio21 Institute, University of Melbourne, Parkville, VIC, Australia.,Melbourne Bioinformatics, University of Melbourne, Parkville, VIC, Australia
| | - Lesa M Peplow
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Ary A Hoffmann
- Bio21 Institute, University of Melbourne, Parkville, VIC, Australia
| | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville, QLD, Australia.,School of BioSciences, University of Melbourne, Parkville, VIC, Australia
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Abstract
This review explores how microbial symbioses may have influenced and continue to influence the evolution of reef-building corals (Cnidaria; Scleractinia). The coral holobiont comprises a diverse microbiome including dinoflagellate algae (Dinophyceae; Symbiodiniaceae), bacteria, archaea, fungi and viruses, but here we focus on the Symbiodiniaceae as knowledge of the impact of other microbial symbionts on coral evolution is scant. Symbiosis with Symbiodiniaceae has extended the coral's metabolic capacity through metabolic handoffs and horizontal gene transfer (HGT) and has contributed to the ecological success of these iconic organisms. It necessitated the prior existence or the evolution of a series of adaptations of the host to attract and select the right symbionts, to provide them with a suitable environment and to remove disfunctional symbionts. Signatures of microbial symbiosis in the coral genome include HGT from Symbiodiniaceae and bacteria, gene family expansions, and a broad repertoire of oxidative stress response and innate immunity genes. Symbiosis with Symbiodiniaceae has permitted corals to occupy oligotrophic waters as the algae provide most corals with the majority of their nutrition. However, the coral-Symbiodiniaceae symbiosis is sensitive to climate warming, which disrupts this intimate relationship, causing coral bleaching, mortality and a worldwide decline of coral reefs. This article is part of the theme issue 'The role of the microbiome in host evolution'.
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Affiliation(s)
- Madeleine J. H. van Oppen
- School of BioSciences, The University of Melbourne, Parkville, 3010 Victoria, Australia
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, 4810 Queensland, Australia
| | - Mónica Medina
- Department of Biology, The Pennsylvania State University, 208 Mueller Lab, University Park, PA 16802, USA
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Quigley KM, Bay LK, van Oppen MJH. Genome-wide SNP analysis reveals an increase in adaptive genetic variation through selective breeding of coral. Mol Ecol 2020; 29:2176-2188. [PMID: 32453867 DOI: 10.1111/mec.15482] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 05/13/2020] [Indexed: 12/18/2022]
Abstract
Marine heat waves are increasing in magnitude, duration, and frequency as a result of climate change and are the principal global driver of mortality in reef-building corals. Resilience-based genetic management may increase coral heat tolerance, but it is unclear how temperature responses are regulated at the genome level and thus how corals may adapt to warming naturally or through selective breeding. Here we combine phenotypic, pedigree, and genomic marker data from colonies sourced from a warm reef on the Great Barrier Reef reproductively crossed with conspecific colonies from a cooler reef to produce combinations of warm purebreds and warm-cool hybrid larvae and juveniles. Interpopulation breeding created significantly greater genetic diversity across the coral genome compared to breeding between populations and maintained diversity in key regions associated with heat tolerance and fitness. High-density genome-wide scans of single nucleotide polymorphisms (SNPs) identified alleles significantly associated with larval families reared at 27.5°C (87-2,224 loci), including loci putatively associated with proteins involved in responses to heat stress (cell membrane formation, metabolism, and immune responses). Underlying genetics of these families explained 43% of PCoA multilocus variation in survival, growth, and bleaching responses at 27.5°C and 31°C at the juvenile stage. Genetic marker contribution to total variation in fitness traits (narrow-sense heritability) was high for survival but not for growth and bleaching in juveniles, with heritability of these traits being higher at 31°C relative to 27.5°C. While based on only a limited number of crosses, the mechanistic understanding presented here demonstrates that allele frequencies are affected by one generation of selective breeding, key information for the assessments of genetic intervention feasibility and modelling of reef futures.
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Affiliation(s)
- Kate M Quigley
- Australian Institute of Marine Science, Townsville, Qld, Australia
| | - Line K Bay
- Australian Institute of Marine Science, Townsville, Qld, Australia
| | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville, Qld, Australia.,School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
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Chakravarti LJ, Buerger P, Levin RA, van Oppen MJH. Gene regulation underpinning increased thermal tolerance in a laboratory-evolved coral photosymbiont. Mol Ecol 2020; 29:1684-1703. [PMID: 32268445 DOI: 10.1111/mec.15432] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 03/07/2020] [Accepted: 03/16/2020] [Indexed: 12/12/2022]
Abstract
Small increases in ocean temperature can disrupt the obligate symbiosis between corals and dinoflagellate microalgae, resulting in coral bleaching. Little is known about the genes that drive the physiological and bleaching response of algal symbionts to elevated temperature. Moreover, many studies to-date have compared highly divergent strains, making it challenging to accredit specific genes to contrasting traits. Here, we compare transcriptional responses at ambient (27°C) and bleaching-relevant (31°C) temperatures in a monoclonal, wild-type (WT) strain of Symbiodiniaceae to those of a selected-strain (SS), derived from the same monoclonal culture and experimentally evolved to elevated temperature over 80 generations (2.5 years). Thousands of genes were differentially expressed at a log fold-change of >8 between the WT and SS over a 35 days temperature treatment period. At 31°C, WT cells exhibited a temporally unstable transcriptomic response upregulating genes involved in the universal stress response such as molecular chaperoning, protein repair, protein degradation and DNA repair. Comparatively, SS cells exhibited a temporally stable transcriptomic response and downregulated many stress response genes that were upregulated by the WT. Among the most highly upregulated genes in the SS at 31°C were algal transcription factors and a gene probably of bacterial origin that encodes a type II secretion system protein, suggesting interactions with bacteria may contribute to the increased thermal tolerance of the SS. Genes and functional pathways conferring thermal tolerance in the SS could be targeted in future genetic engineering experiments designed to develop thermally resilient algal symbionts for use in coral restoration and conservation.
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Affiliation(s)
- Leela J Chakravarti
- Australian Institute of Marine Science, Townsville MC, Qld, Australia.,AIMS@JCU, Australian Institute of Marine Science, College of Marine and Environmental Sciences, James Cook University, Townsville, Qld, Australia.,College of Marine and Environmental Sciences, James Cook University, Townsville, Qld, Australia.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, Australia
| | - Patrick Buerger
- CSIRO, Land & Water, Canberra, ACT, Australia.,School of BioSciences, University of Melbourne, Parkville, Vic, Australia
| | | | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville MC, Qld, Australia.,School of BioSciences, University of Melbourne, Parkville, Vic, Australia
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Damjanovic K, Menéndez P, Blackall LL, van Oppen MJH. Early Life Stages of a Common Broadcast Spawning Coral Associate with Specific Bacterial Communities Despite Lack of Internalized Bacteria. Microb Ecol 2020; 79:706-719. [PMID: 31435691 DOI: 10.1007/s00248-019-01428-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
Coral-associated bacteria are critical for the well-being of their host and may play essential roles during ontogeny, as suggested by the vertical transmission of some bacteria in brooding corals. Bacterial acquisition patterns in broadcast spawners remain uncertain, as 16S rRNA gene metabarcoding of coral early life stages suggests the presence of bacterial communities, which have not been detected by microscopic examinations. Here, we combined 16S rRNA gene metabarcoding with fluorescence in situ hybridization (FISH) microscopy to analyze bacterial assemblages in Acropora tenuis egg-sperm bundles, embryos, and larvae following a spawning event. Metabarcoding results indicated that A. tenuis offspring ≤ 4-day-old were associated with diverse and dynamic bacterial microbiomes, dominated by Rhodobacteraceae, Alteromonadaceae, and Oceanospirillaceae. While FISH analyses confirmed the lack of internalized bacteria in A. tenuis offspring, metabarcoding showed that even the earliest life stages examined (egg-sperm bundles and two-cell stages) were associated with a diverse bacterial community, suggesting the bacteria were confined to the mucus layer. These results can be explained by vertical transmission of certain taxa (mainly Endozoicomonas) in the mucus surrounding the gametes within bundles, or by horizontal bacterial transmission through the release of bacteria by spawning adults into the water column.
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Affiliation(s)
- Katarina Damjanovic
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
- Australian Institute of Marine Science, PMB No 3, Townsville MC, QLD, 4810, Australia.
| | - Patricia Menéndez
- Australian Institute of Marine Science, PMB No 3, Townsville MC, QLD, 4810, Australia
- Department of Econometrics and Business Statistics, Monash University, Clayton, VIC, 3800, 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, PMB No 3, Townsville MC, QLD, 4810, Australia
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Maor‐Landaw K, van Oppen MJH, McFadden GI. Symbiotic lifestyle triggers drastic changes in the gene expression of the algal endosymbiont Breviolum minutum (Symbiodiniaceae). Ecol Evol 2020; 10:451-466. [PMID: 31993121 PMCID: PMC6972872 DOI: 10.1002/ece3.5910] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 10/25/2019] [Accepted: 11/18/2019] [Indexed: 01/13/2023] Open
Abstract
Coral-dinoflagellate symbiosis underpins the evolutionary success of corals reefs. Successful exchange of molecules between the cnidarian host and the Symbiodiniaceae algae enables the mutualistic partnership. The algae translocate photosynthate to their host in exchange for nutrients and shelter. The photosynthate must traverse multiple membranes, most likely facilitated by transporters. Here, we compared gene expression profiles of cultured, free-living Breviolum minutum with those of the homologous symbionts freshly isolated from the sea anemone Exaiptasia diaphana, a widely used model for coral hosts. Additionally, we assessed expression levels of a list of candidate host transporters of interest in anemones with and without symbionts. Our transcriptome analyses highlight the distinctive nature of the two algal life stages, with many gene expression level changes correlating to the different morphologies, cell cycles, and metabolisms adopted in hospite versus free-living. Morphogenesis-related genes that likely underpin the metamorphosis process observed when symbionts enter a host cell were up-regulated. Conversely, many down-regulated genes appear to be indicative of the protective and confined nature of the symbiosome. Our results emphasize the significance of transmembrane transport to the symbiosis, and in particular of ammonium and sugar transport. Further, we pinpoint and characterize candidate transporters-predicted to be localized variously to the algal plasma membrane, the host plasma membrane, and the symbiosome membrane-that likely serve pivotal roles in the interchange of material during symbiosis. Our study provides new insights that expand our understanding of the molecular exchanges that underpin the cnidarian-algal symbiotic relationship.
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Affiliation(s)
- Keren Maor‐Landaw
- School of BioSciencesThe University of MelbourneMelbourneVic.Australia
| | - Madeleine J. H. van Oppen
- School of BioSciencesThe University of MelbourneMelbourneVic.Australia
- Australian Institute of Marine ScienceTownsvilleQldAustralia
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41
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Quigley KM, Bay LK, van Oppen MJH. The active spread of adaptive variation for reef resilience. Ecol Evol 2019; 9:11122-11135. [PMID: 31641460 PMCID: PMC6802068 DOI: 10.1002/ece3.5616] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/03/2019] [Accepted: 08/06/2019] [Indexed: 12/26/2022] Open
Abstract
The speed at which species adapt depends partly on the rates of beneficial adaptation generation and how quickly they spread within and among populations. Natural rates of adaptation of corals may not be able to keep pace with climate warming. Several interventions have been proposed to fast-track thermal adaptation, including the intentional translocation of warm-adapted adults or their offspring (assisted gene flow, AGF) and the ex situ crossing of warm-adapted corals with conspecifics from cooler reefs (hybridization or selective breeding) and field deployment of those offspring. The introgression of temperature tolerance loci into the genomic background of cooler-environment corals aims to facilitate adaptation to warming while maintaining fitness under local conditions. Here we use research on selective sweeps and connectivity to understand the spread of adaptive variants as it applies to AGF on the Great Barrier Reef (GBR), focusing on the genus Acropora. Using larval biophysical dispersal modeling, we estimate levels of natural connectivity in warm-adapted northern corals. We then model the spread of adaptive variants from single and multiple reefs and assess if the natural and assisted spread of adaptive variants will occur fast enough to prepare receiving central and southern populations given current rates of warming. We also estimate fixation rates and spatial extent of fixation under multiple release scenarios to inform intervention design. Our results suggest that thermal tolerance is unlikely to spread beyond northern reefs to the central and southern GBR without intervention, and if it does, 30+ generations are needed for adaptive gene variants to reach fixation even under multiple release scenarios. We argue that if translocation, breeding, and reseeding risks are managed, AGF using multiple release reefs can be beneficial for the restoration of coral populations. These interventions should be considered in addition to conventional management and accompanied by strong mitigation of CO2 emissions.
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Affiliation(s)
- Kate M. Quigley
- Australian Institute of Marine ScienceTownsvilleQldAustralia
| | - Line K. Bay
- Australian Institute of Marine ScienceTownsvilleQldAustralia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine ScienceTownsvilleQldAustralia
- School of BioSciencesThe University of MelbourneParkvilleVic.Australia
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Cavicchioli R, Ripple WJ, Timmis KN, Azam F, Bakken LR, Baylis M, Behrenfeld MJ, Boetius A, Boyd PW, Classen AT, Crowther TW, Danovaro R, Foreman CM, Huisman J, Hutchins DA, Jansson JK, Karl DM, Koskella B, Mark Welch DB, Martiny JBH, Moran MA, Orphan VJ, Reay DS, Remais JV, Rich VI, Singh BK, Stein LY, Stewart FJ, Sullivan MB, van Oppen MJH, Weaver SC, Webb EA, Webster NS. Scientists' warning to humanity: microorganisms and climate change. Nat Rev Microbiol 2019; 17:569-586. [PMID: 31213707 PMCID: PMC7136171 DOI: 10.1038/s41579-019-0222-5] [Citation(s) in RCA: 623] [Impact Index Per Article: 124.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2019] [Indexed: 11/27/2022]
Abstract
In the Anthropocene, in which we now live, climate change is impacting most life on Earth. Microorganisms support the existence of all higher trophic life forms. To understand how humans and other life forms on Earth (including those we are yet to discover) can withstand anthropogenic climate change, it is vital to incorporate knowledge of the microbial 'unseen majority'. We must learn not just how microorganisms affect climate change (including production and consumption of greenhouse gases) but also how they will be affected by climate change and other human activities. This Consensus Statement documents the central role and global importance of microorganisms in climate change biology. It also puts humanity on notice that the impact of climate change will depend heavily on responses of microorganisms, which are essential for achieving an environmentally sustainable future.
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Affiliation(s)
- Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia.
| | - William J Ripple
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, USA
| | - Kenneth N Timmis
- Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany
| | - Farooq Azam
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Lars R Bakken
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Matthew Baylis
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Michael J Behrenfeld
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA
| | - Antje Boetius
- Alfred Wegener Institute, Helmholtz Center for Marine and Polar Research, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Aimée T Classen
- Rubenstein School of Environment and Natural Resources, and The Gund Institute for Environment, University of Vermont, Burlington, VT, USA
| | | | - Roberto Danovaro
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
- Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Christine M Foreman
- Center for Biofilm Engineering, and Chemical and Biological Engineering Department, Montana State University, Bozeman, MT, USA
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - David A Hutchins
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, CA, USA
| | - Janet K Jansson
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - David M Karl
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science & Technology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Britt Koskella
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | | | - Jennifer B H Martiny
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, USA
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - David S Reay
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Justin V Remais
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Virginia I Rich
- Microbiology Department, and the Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, USA
| | - Brajesh K Singh
- Hawkesbury Institute for the Environment, and Global Centre for Land-Based Innovation, Western Sydney University, Penrith, NSW, Australia
| | - Lisa Y Stein
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Frank J Stewart
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Matthew B Sullivan
- Department of Microbiology, and Department of Civil, Environmental and Geodetic Engineering, and the Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, USA
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Scott C Weaver
- Department of Microbiology and Immunology, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA
| | - Eric A Webb
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, CA, USA
| | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, QLD, Australia
- Australian Centre for Ecogenomics, University of Queensland, Brisbane, QLD, Australia
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Epstein HE, Smith HA, Cantin NE, Mocellin VJL, Torda G, van Oppen MJH. Temporal Variation in the Microbiome of Acropora Coral Species Does Not Reflect Seasonality. Front Microbiol 2019; 10:1775. [PMID: 31474944 PMCID: PMC6706759 DOI: 10.3389/fmicb.2019.01775] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/18/2019] [Indexed: 12/22/2022] Open
Abstract
The coral microbiome is known to fluctuate in response to environmental variation and has been suggested to vary seasonally. However, most studies to date, particularly studies on bacterial communities, have examined temporal variation over a time frame of less than 1 year, which is insufficient to establish if microbiome variations are indeed seasonal in nature. The present study focused on expanding our understanding of long-term variability in microbial community composition using two common coral species, Acropora hyacinthus, and Acropora spathulata, at two mid-shelf reefs on the Great Barrier Reef. By sampling over a 2-year time period, this study aimed to determine whether temporal variations reflect seasonal cycles. Community composition of both bacteria and Symbiodiniaceae was characterized through 16S rRNA gene and ITS2 rDNA metabarcoding. We observed significant variations in community composition of both bacteria and Symbiodiniaceae among time points for A. hyacinthus and A. spathulata. However, there was no evidence to suggest that temporal variations were cyclical in nature and represented seasonal variation. Clear evidence for differences in the microbial communities found between reefs suggests that reef location and coral species play a larger role than season in driving microbial community composition in corals. In order to identify the basis of temporal patterns in coral microbial community composition, future studies should employ longer time series of sampling at sufficient temporal resolution to identify the environmental correlates of microbiome variation.
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Affiliation(s)
- Hannah E. Epstein
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
- AIMS@JCU, James Cook University, Townsville, QLD, Australia
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Hillary A. Smith
- College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - Neal E. Cantin
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | | | - Gergely Torda
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville, QLD, Australia
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
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Damjanovic K, van Oppen MJH, Menéndez P, Blackall LL. Experimental Inoculation of Coral Recruits With Marine Bacteria Indicates Scope for Microbiome Manipulation in Acropora tenuis and Platygyra daedalea. Front Microbiol 2019; 10:1702. [PMID: 31396197 PMCID: PMC6668565 DOI: 10.3389/fmicb.2019.01702] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 07/10/2019] [Indexed: 12/19/2022] Open
Abstract
Coral-associated microorganisms are essential for maintaining the health of the coral holobiont by participating in nutrient cycling and protecting the coral host from pathogens. Under stressful conditions, disruption of the coral prokaryotic microbiome is linked to increased susceptibility to diseases and mortality. Inoculation of corals with beneficial microbes could confer enhanced stress tolerance to the host and may be a powerful tool to help corals thrive under challenging environmental conditions. Here, we explored the feasibility of coral early life stage microbiome manipulation by repeatedly inoculating coral recruits with a bacterial cocktail generated in the laboratory. Co-culturing the two species Acropora tenuis and Platygyra daedalea allowed us to simultaneously investigate the effect of host factors on the coral microbiome. Inoculation cocktails were regularly prepared from freshly grown pure bacterial cultures, which were hence assumed viable, and characterized via the optical density measurement of each individual strain put in suspension. Coral early recruits were inoculated seven times over 3 weeks and sampled once 36 h following the last inoculation event. At this time point, the cumulative inoculations with the bacterial cocktails had a strong effect on the bacterial community composition in recruits of both coral species. While the location of bacterial cells within the coral hosts was not assessed, metabarcoding using the 16S rRNA gene revealed that two and six of the seven bacterial strains administered through the cocktails were significantly enriched in inoculated recruits of A. tenuis and P. daedalea, respectively, compared to control recruits. Despite being reared in the same environment, A. tenuis and P. daedalea established significantly different bacterial communities, both in terms of taxonomic composition and diversity measurements. These findings indicate that coral host factors as well as the environmental bacterial pool play a role in shaping coral-associated bacterial community composition. Host factors may include microbe transmission mode (horizontal versus maternal) and host specificity. While the long-term stability of taxa included in the bacterial inocula as members of the host-associated microbiome remains to be evaluated, our results provide support for the feasibility of coral microbiome manipulation, at least in a laboratory setting.
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Affiliation(s)
- Katarina Damjanovic
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.,Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.,Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Patricia Menéndez
- Australian Institute of Marine Science, Townsville, QLD, Australia.,School of Mathematics and Physics, University of Queensland, Saint Lucia, QLD, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
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45
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van Oppen MJH, Blackall LL. Coral microbiome dynamics, functions and design in a changing world. Nat Rev Microbiol 2019; 17:557-567. [DOI: 10.1038/s41579-019-0223-4] [Citation(s) in RCA: 137] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2019] [Indexed: 12/20/2022]
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46
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Chan WY, Peplow LM, van Oppen MJH. Interspecific gamete compatibility and hybrid larval fitness in reef-building corals: Implications for coral reef restoration. Sci Rep 2019; 9:4757. [PMID: 30894593 PMCID: PMC6426996 DOI: 10.1038/s41598-019-41190-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/28/2019] [Indexed: 11/27/2022] Open
Abstract
Climate warming is a major cause of the global decline of coral reefs. Active reef restoration, although still in its infancy, is one of several possible ways to help restore coral cover and reef ecosystem function. The deployment of mature coral larvae onto depauperate reef substratum has been shown to significantly increase larval recruitment, providing a novel option for the delivery of ex situ bred coral stock to the reef for restoration purposes. The success of such reef restoration approaches may be improved by the use of coral larval stock augmented for climate resilience. Here we explore whether coral climate resilience can be enhanced via interspecific hybridization through hybrid vigour. Firstly, we assessed cross-fertility of four pairs of Acropora species from the Great Barrier Reef. Temporal isolation in gamete release between the Acropora species was limited, but gametic incompatibility was present with varying strength between species pairs and depending on the direction of the hybrid crosses. We subsequently examined the fitness of hybrid and purebred larvae under heat stress by comparing their survival and settlement success throughout 10 days of exposure to 28 °C, 29.5 °C and 31 °C. Fitness of the majority of Acropora hybrid larvae was similar to that of the purebred larvae of both parental species, and in some instances it was higher than that of the purebred larvae of one of the parental species. Lower hybrid fertilization success did not affect larval fitness. These findings indicate that high hybrid fitness can be achieved after overcoming partial prezygotic barriers, and that interspecific hybridization may be a tool to enhance coral recruitment and climate resilience.
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Affiliation(s)
- Wing Yan Chan
- Australian Institute of Marine Science, Townsville MC, QLD, 4810, Australia. .,School of BioSciences, University of Melbourne, VIC, 3010, Australia.
| | - Lesa M Peplow
- Australian Institute of Marine Science, Townsville MC, QLD, 4810, Australia
| | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville MC, QLD, 4810, Australia.,School of BioSciences, University of Melbourne, VIC, 3010, Australia
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Chakravarti LJ, Negri AP, van Oppen MJH. Thermal and Herbicide Tolerances of Chromerid Algae and Their Ability to Form a Symbiosis With Corals. Front Microbiol 2019; 10:173. [PMID: 30809207 PMCID: PMC6379472 DOI: 10.3389/fmicb.2019.00173] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/22/2019] [Indexed: 11/13/2022] Open
Abstract
Reef-building corals form an obligate symbiosis with photosynthetic microalgae in the family Symbiodiniaceae that meet most of their energy requirements. This symbiosis is under threat from the unprecedented rate of ocean warming as well as the simultaneous pressure of local stressors such as poor water quality. Only 1°C above mean summer sea surface temperatures (SSTs) on the Great Barrier Reef (GBR) can trigger the loss of Symbiodiniaceae from the host, and very low concentrations of the most common herbicide, diuron, can disrupt the photosynthetic activity of microalgae. In an era of rapid environmental change, investigation into the assisted evolution of the coral holobiont is underway in an effort to enhance the resilience of corals. Apicomplexan-like microalgae were discovered in 2008 and the Phylum Chromerida (chromerids) was created. Chromerids have been isolated from corals and contain a functional photosynthetic plastid. Their discovery therefore opens a new avenue of research into the use of alternative/additional photosymbionts of corals. However, only two studies to-date have investigated the symbiotic nature of Chromera velia with corals and thus little is known about the coral-chromerid relationship. Furthermore, the response of chromerids to environmental stressors has not been examined. Here we tested the performance of four chromerid strains and the common dinoflagellate symbiont Cladocopium goreaui (formerly Symbiodinium goreaui, ITS2 type C1) in response to elevated temperature, diuron and their combined exposure. Three of the four chromerid strains exhibited high thermal tolerances and two strains showed exceptional herbicide tolerances, greater than observed for any photosynthetic microalgae, including C. goreaui. We also investigated the onset of symbiosis between the chromerids and larvae of two common GBR coral species under ambient and stress conditions. Levels of colonization of coral larvae with the chromerid strains were low compared to colonization with C. goreaui. We did not observe any overall negative or positive larval fitness effects of the inoculation with chromerid algae vs. C. goreaui. However, we cannot exclude the possibility that chromerid algae may have more important roles in later coral life stages and recommend this be the focus of future studies.
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Affiliation(s)
- Leela J. Chakravarti
- Australian Institute of Marine Science, Townsville MC, QLD, Australia
- AIMS@JCU, Australian Institute of Marine Science, College of Marine and Environmental Sciences, James Cook University, Townsville, QLD, Australia
- College of Marine and Environmental Sciences, James Cook University, Townsville, QLD, Australia
| | - Andrew P. Negri
- Australian Institute of Marine Science, Townsville MC, QLD, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville MC, QLD, Australia
- School of BioSciences University of Melbourne, Parkville, VIC, Australia
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48
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Richards ZT, van Oppen MJH, Wallace CC, Willis BL, Miller DJ. Correction: Some Rare Indo-Pacific Coral Species Are Probable Hybrids. PLoS One 2019; 14:e0211527. [PMID: 30699180 PMCID: PMC6347392 DOI: 10.1371/journal.pone.0211527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0003240.].
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Liu H, Stephens TG, González-Pech RA, Beltran VH, Lapeyre B, Bongaerts P, Cooke I, Aranda M, Bourne DG, Forêt S, Miller DJ, van Oppen MJH, Voolstra CR, Ragan MA, Chan CX. Symbiodinium genomes reveal adaptive evolution of functions related to coral-dinoflagellate symbiosis. Commun Biol 2018; 1:95. [PMID: 30271976 PMCID: PMC6123633 DOI: 10.1038/s42003-018-0098-3] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/21/2018] [Indexed: 12/20/2022] Open
Abstract
Symbiosis between dinoflagellates of the genus Symbiodinium and reef-building corals forms the trophic foundation of the world’s coral reef ecosystems. Here we present the first draft genome of Symbiodinium goreaui (Clade C, type C1: 1.03 Gbp), one of the most ubiquitous endosymbionts associated with corals, and an improved draft genome of Symbiodinium kawagutii (Clade F, strain CS-156: 1.05 Gbp) to further elucidate genomic signatures of this symbiosis. Comparative analysis of four available Symbiodinium genomes against other dinoflagellate genomes led to the identification of 2460 nuclear gene families (containing 5% of Symbiodinium genes) that show evidence of positive selection, including genes involved in photosynthesis, transmembrane ion transport, synthesis and modification of amino acids and glycoproteins, and stress response. Further, we identify extensive sets of genes for meiosis and response to light stress. These draft genomes provide a foundational resource for advancing our understanding of Symbiodinium biology and the coral-algal symbiosis. Huanle Liu et al. report draft genomes of two Symbiodinium species, one from the most dominant type of symbionts in reef-building corals. They find evidence of positive selection in genes related to stress response, meiosis and other traits required for forming successful symbiotic relationships.
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Affiliation(s)
- Huanle Liu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Timothy G Stephens
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Raúl A González-Pech
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Victor H Beltran
- Australian Institute of Marine Science, Townsville, QLD, 4810, Australia
| | - Bruno Lapeyre
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.,Department of Molecular and Cell Biology, James Cook University, Townsville, QLD, 4811, Australia.,Laboratoire d'excellence CORAIL, Centre de Recherches Insulaires et Observatoire de l'Environnement, Moorea, 98729, French Polynesia
| | - Pim Bongaerts
- Global Change Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.,Institute for Biodiversity Science and Sustainability, California Academy of Sciences, San Francisco, CA, 94118, USA
| | - Ira Cooke
- Department of Molecular and Cell Biology, James Cook University, Townsville, QLD, 4811, Australia
| | - Manuel Aranda
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - David G Bourne
- Australian Institute of Marine Science, Townsville, QLD, 4810, Australia.,College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Sylvain Forêt
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.,Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| | - David J Miller
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.,Department of Molecular and Cell Biology, James Cook University, Townsville, QLD, 4811, Australia
| | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville, QLD, 4810, Australia.,School of BioSciences, The University of Melbourne, VIC, 3010, Australia
| | - Christian R Voolstra
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Mark A Ragan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Cheong Xin Chan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia. .,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia.
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50
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van Oppen MJH, Bongaerts P, Frade P, Peplow L, Boyd SE, Nim HT, Bay LK. Adaptation to reef habitats through selection on the coral animal and its associated microbiome. Mol Ecol 2018; 27:2956-2971. [DOI: 10.1111/mec.14763] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 01/02/2023]
Affiliation(s)
- Madeleine J. H. van Oppen
- Australian Institute of Marine Science; Townsville MC Qld Australia
- School of BioSciences; University of Melbourne; Parkville Vic. Australia
| | - Pim Bongaerts
- Global Change Institute; The University of Queensland; St Lucia Qld Australia
- California Academy of Sciences; San Francisco California
| | - Pedro Frade
- Centre of Marine Sciences (CCMAR); University of Algarve; Faro Portugal
| | - Lesa M. Peplow
- Australian Institute of Marine Science; Townsville MC Qld Australia
| | - Sarah E. Boyd
- Faculty of Information Technology; Monash University; Melbourne Vic. Australia
| | - Hieu T. Nim
- Faculty of Information Technology; Monash University; Melbourne Vic. Australia
- Australian Regenerative Medicine Institute; Monash University; Melbourne Vic. Australia
| | - Line K. Bay
- Australian Institute of Marine Science; Townsville MC Qld Australia
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