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MacVittie S, Doroodian S, Alberto A, Sogin M. Microbiome depletion and recovery in the sea anemone, Exaiptasia diaphana, following antibiotic exposure. mSystems 2024:e0134223. [PMID: 38757963 DOI: 10.1128/msystems.01342-23] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 04/19/2024] [Indexed: 05/18/2024] Open
Abstract
Microbial species that comprise host-associated microbiomes play an essential role in maintaining and mediating the health of plants and animals. While defining the role of individual or even complex communities is important toward quantifying the effect of the microbiome on host health, it is often challenging to develop causal studies that link microbial populations to changes in host fitness. Here, we investigated the impacts of reduced microbial load following antibiotic exposure on the fitness of the anemone, Exaiptasia diaphana and subsequent recovery of the host's microbiome. Anemones were exposed to two different types of antibiotic solutions for 3 weeks and subsequently held in sterilized seawater for a 3-week recovery period. Our results revealed that both antibiotic treatments reduced the overall microbial load during and up to 1 week post-treatment. The observed reduction in microbial load was coupled with reduced anemone biomass, halted asexual reproduction rates, and for one of the antibiotic treatments, the partial removal of the anemone's algal symbiont. Finally, our amplicon sequencing results of the 16S rRNA gene revealed that anemone bacterial composition only shifted in treated individuals during the recovery phase of the experiment, where we also observed a significant reduction in the overall diversity of the microbial community. Our work implies that the E. diaphana's microbiome contributes to host fitness and that the recovery of the host's microbiome following disturbance with antibiotics leads to a reduced, but stable microbial state.IMPORTANCEExaiptasia diaphana is an emerging model used to define the cellular and molecular mechanisms of coral-algal symbioses. E. diaphana also houses a diverse microbiome, consisting of hundreds of microbial partners with undefined function. Here, we applied antibiotics to quantify the impact of microbiome removal on host fitness as well as define trajectories in microbiome recovery following disturbance. We showed that reduction of the microbiome leads to negative impacts on host fitness, and that the microbiome does not recover to its original composition while held under aseptic conditions. Rather the microbiome becomes less diverse, but more consistent across individuals. Our work is important because it suggests that anemone microbiomes play a role in maintaining host fitness, that they are susceptible to disturbance events, and that it is possible to generate gnotobiotic individuals that can be leveraged in microbiome manipulation studies to investigate the role of individual species on host health.
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Affiliation(s)
- Sophie MacVittie
- Department of Molecular Cell Biology, University of California, Merced, California, USA
| | - Saam Doroodian
- Department of Molecular Cell Biology, University of California, Merced, California, USA
| | - Aaron Alberto
- Department of Molecular Cell Biology, University of California, Merced, California, USA
| | - Maggie Sogin
- Department of Molecular Cell Biology, University of California, Merced, California, USA
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Voolstra CR, Raina JB, Dörr M, Cárdenas A, Pogoreutz C, Silveira CB, Mohamed AR, Bourne DG, Luo H, Amin SA, Peixoto RS. The coral microbiome in sickness, in health and in a changing world. Nat Rev Microbiol 2024:10.1038/s41579-024-01015-3. [PMID: 38438489 DOI: 10.1038/s41579-024-01015-3] [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] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2024] [Indexed: 03/06/2024]
Abstract
Stony corals, the engines and engineers of reef ecosystems, face unprecedented threats from anthropogenic environmental change. Corals are holobionts that comprise the cnidarian animal host and a diverse community of bacteria, archaea, viruses and eukaryotic microorganisms. Recent research shows that the bacterial microbiome has a pivotal role in coral biology. A healthy bacterial assemblage contributes to nutrient cycling and stress resilience, but pollution, overfishing and climate change can break down these symbiotic relationships, which results in disease, bleaching and, ultimately, coral death. Although progress has been made in characterizing the spatial-temporal diversity of bacteria, we are only beginning to appreciate their functional contribution. In this Review, we summarize the ecological and metabolic interactions between bacteria and other holobiont members, highlight the biotic and abiotic factors influencing the structure of bacterial communities and discuss the impact of climate change on these communities and their coral hosts. We emphasize how microbiome-based interventions can help to decipher key mechanisms underpinning coral health and promote reef resilience. Finally, we explore how recent technological developments may be harnessed to address some of the most pressing challenges in coral microbiology, providing a road map for future research in this field.
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Affiliation(s)
| | - Jean-Baptiste Raina
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, Australia.
| | - Melanie Dörr
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Anny Cárdenas
- Department of Biology, American University, Washington, DC, USA
| | - Claudia Pogoreutz
- PSL Université Paris: EPHE-UPVD-CNRS, UAR 3278 CRIOBE, Université de Perpignan, Perpignan, France
| | | | - Amin R Mohamed
- Marine Microbiomics Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - David G Bourne
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Haiwei Luo
- Simon F.S. Li Marine Science Laboratory, School of Life Sciences, State Key Laboratory of Agrobiotechnology and Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Shady A Amin
- Marine Microbiomics Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
- Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Raquel S Peixoto
- Red Sea Research Center (RSRC) and Computational Biology Research Center (CBRC), Biological, Environmental Sciences, and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
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Williams A, Stephens TG, Shumaker A, Bhattacharya D. Peeling back the layers of coral holobiont multi-omics data. iScience 2023; 26:107623. [PMID: 37694134 PMCID: PMC10482995 DOI: 10.1016/j.isci.2023.107623] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/09/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023] Open
Abstract
The integration of multiple 'omics' datasets is a promising avenue for answering many important and challenging questions in biology, particularly those relating to complex ecological systems. Although multi-omics was developed using data from model organisms with significant prior knowledge and resources, its application to non-model organisms, such as coral holobionts, is less clear-cut. We explore, in the emerging rice coral model Montipora capitata, the intersection of holobiont transcriptomic, proteomic, metabolomic, and microbiome amplicon data and investigate how well they correlate under high temperature treatment. Using a typical thermal stress regime, we show that transcriptomic and proteomic data broadly capture the stress response of the coral, whereas the metabolome and microbiome datasets show patterns that likely reflect stochastic and homeostatic processes associated with each sample. These results provide a framework for interpreting multi-omics data generated from non-model systems, particularly those with complex biotic interactions among microbial partners.
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Affiliation(s)
- Amanda Williams
- Microbial Biology Graduate Program, Rutgers University, New Brunswick, NJ 08901, USA
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Timothy G. Stephens
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Alexander Shumaker
- Microbial Biology Graduate Program, Rutgers University, New Brunswick, NJ 08901, USA
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
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4
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Wuerz M, Lawson CA, Oakley CA, Possell M, Wilkinson SP, Grossman AR, Weis VM, Suggett DJ, Davy SK. Symbiont Identity Impacts the Microbiome and Volatilome of a Model Cnidarian-Dinoflagellate Symbiosis. Biology (Basel) 2023; 12:1014. [PMID: 37508443 PMCID: PMC10376011 DOI: 10.3390/biology12071014] [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] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/28/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023]
Abstract
The symbiosis between cnidarians and dinoflagellates underpins the success of reef-building corals in otherwise nutrient-poor habitats. Alterations to symbiotic state can perturb metabolic homeostasis and thus alter the release of biogenic volatile organic compounds (BVOCs). While BVOCs can play important roles in metabolic regulation and signalling, how the symbiotic state affects BVOC output remains unexplored. We therefore characterised the suite of BVOCs that comprise the volatilome of the sea anemone Exaiptasia diaphana ('Aiptasia') when aposymbiotic and in symbiosis with either its native dinoflagellate symbiont Breviolum minutum or the non-native symbiont Durusdinium trenchii. In parallel, the bacterial community structure in these different symbiotic states was fully characterised to resolve the holobiont microbiome. Based on rRNA analyses, 147 unique amplicon sequence variants (ASVs) were observed across symbiotic states. Furthermore, the microbiomes were distinct across the different symbiotic states: bacteria in the family Vibrionaceae were the most abundant in aposymbiotic anemones; those in the family Crocinitomicaceae were the most abundant in anemones symbiotic with D. trenchii; and anemones symbiotic with B. minutum had the highest proportion of low-abundance ASVs. Across these different holobionts, 142 BVOCs were detected and classified into 17 groups based on their chemical structure, with BVOCs containing multiple functional groups being the most abundant. Isoprene was detected in higher abundance when anemones hosted their native symbiont, and dimethyl sulphide was detected in higher abundance in the volatilome of both Aiptasia-Symbiodiniaceae combinations relative to aposymbiotic anemones. The volatilomes of aposymbiotic anemones and anemones symbiotic with B. minutum were distinct, while the volatilome of anemones symbiotic with D. trenchii overlapped both of the others. Collectively, our results are consistent with previous reports that D. trenchii produces a metabolically sub-optimal symbiosis with Aiptasia, and add to our understanding of how symbiotic cnidarians, including corals, may respond to climate change should they acquire novel dinoflagellate partners.
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Affiliation(s)
- Maggie Wuerz
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Caitlin A Lawson
- Climate Change Cluster, University of Technology Sydney, Sydney Broadway, Sydney, NSW 2007, Australia
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Malcolm Possell
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | | | - Arthur R Grossman
- Carnegie Institution for Science, Department of Plant Biology, Stanford, CA 94305, USA
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - David J Suggett
- Climate Change Cluster, University of Technology Sydney, Sydney Broadway, Sydney, NSW 2007, Australia
- KAUST Reefscape Restoration Initiative (KRRI) and Red Sea Research Center (RSRC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
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Bove CB, Ingersoll MV, Davies SW. Help Me, Symbionts, You're My Only Hope: Approaches to Accelerate our Understanding of Coral Holobiont Interactions. Integr Comp Biol 2022; 62:1756-1769. [PMID: 36099871 DOI: 10.1093/icb/icac141] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/24/2022] [Accepted: 09/05/2022] [Indexed: 01/05/2023] Open
Abstract
Tropical corals construct the three-dimensional framework for one of the most diverse ecosystems on the planet, providing habitat to a plethora of species across taxa. However, these ecosystem engineers are facing unprecedented challenges, such as increasing disease prevalence and marine heatwaves associated with anthropogenic global change. As a result, major declines in coral cover and health are being observed across the world's oceans, often due to the breakdown of coral-associated symbioses. Here, we review the interactions between the major symbiotic partners of the coral holobiont-the cnidarian host, algae in the family Symbiodiniaceae, and the microbiome-that influence trait variation, including the molecular mechanisms that underlie symbiosis and the resulting physiological benefits of different microbial partnerships. In doing so, we highlight the current framework for the formation and maintenance of cnidarian-Symbiodiniaceae symbiosis, and the role that immunity pathways play in this relationship. We emphasize that understanding these complex interactions is challenging when you consider the vast genetic variation of the cnidarian host and algal symbiont, as well as their highly diverse microbiome, which is also an important player in coral holobiont health. Given the complex interactions between and among symbiotic partners, we propose several research directions and approaches focused on symbiosis model systems and emerging technologies that will broaden our understanding of how these partner interactions may facilitate the prediction of coral holobiont phenotype, especially under rapid environmental change.
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Affiliation(s)
- Colleen B Bove
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Sarah W Davies
- Department of Biology, Boston University, Boston, MA 02215, USA
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6
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Puntin G, Sweet M, Fraune S, Medina M, Sharp K, Weis VM, Ziegler M. Harnessing the Power of Model Organisms To Unravel Microbial Functions in the Coral Holobiont. Microbiol Mol Biol Rev 2022; 86:e0005322. [PMID: 36287022 PMCID: PMC9769930 DOI: 10.1128/mmbr.00053-22] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Stony corals build the framework of coral reefs, ecosystems of immense ecological and economic importance. The existence of these ecosystems is threatened by climate change and other anthropogenic stressors that manifest in microbial dysbiosis such as coral bleaching and disease, often leading to coral mortality. Despite a significant amount of research, the mechanisms ultimately underlying these destructive phenomena, and what could prevent or mitigate them, remain to be resolved. This is mostly due to practical challenges in experimentation on corals and the highly complex nature of the coral holobiont that also includes bacteria, archaea, protists, and viruses. While the overall importance of these partners is well recognized, their specific contributions to holobiont functioning and their interspecific dynamics remain largely unexplored. Here, we review the potential of adopting model organisms as more tractable systems to address these knowledge gaps. We draw on parallels from the broader biological and biomedical fields to guide the establishment, implementation, and integration of new and emerging model organisms with the aim of addressing the specific needs of coral research. We evaluate the cnidarian models Hydra, Aiptasia, Cassiopea, and Astrangia poculata; review the fast-evolving field of coral tissue and cell cultures; and propose a framework for the establishment of "true" tropical reef-building coral models. Based on this assessment, we also suggest future research to address key aspects limiting our ability to understand and hence improve the response of reef-building corals to future ocean conditions.
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Affiliation(s)
- Giulia Puntin
- Department of Animal Ecology and Systematics, Marine Holobiomics Lab, Justus Liebig University Giessen, Giessen, Germany
| | - Michael Sweet
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, United Kingdom
| | - Sebastian Fraune
- Institute for Zoology and Organismic Interactions, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Mónica Medina
- Department of Biology, Pennsylvania State University, State College, Pennsylvania, USA
| | - Koty Sharp
- Department of Biology, Marine Biology, and Environmental Science, Roger Williams University, Bristol, Rhode Island, USA
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, USA
| | - Maren Ziegler
- Department of Animal Ecology and Systematics, Marine Holobiomics Lab, Justus Liebig University Giessen, Giessen, Germany
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7
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Schmittmann L, Rahn T, Busch K, Fraune S, Pita L, Hentschel U. Stability of a dominant sponge-symbiont in spite of antibiotic-induced microbiome disturbance. Environ Microbiol 2022; 24:6392-6410. [PMID: 36250983 DOI: 10.1111/1462-2920.16249] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 10/13/2022] [Indexed: 01/12/2023]
Abstract
Marine sponges are known for their complex and stable microbiomes. However, the lack of a gnotobiotic sponge-model and experimental methods to manipulate both the host and the microbial symbionts currently limit our mechanistic understanding of sponge-microbial symbioses. We have used the North Atlantic sponge species Halichondria panicea to evaluate the use of antibiotics to generate gnotobiotic sponges. We further asked whether the microbiome can be reestablished via recolonization with the natural microbiome. Experiments were performed in marine gnotobiotic facilities equipped with a custom-made, sterile, flow-through aquarium system. Bacterial abundance dynamics were monitored qualitatively and quantitatively by 16 S rRNA gene amplicon sequencing and qPCR, respectively. Antibiotics induced dysbiosis by favouring an increase of opportunistic, antibiotic-resistant bacteria, resulting in more complex, but less specific bacteria-bacteria interactions than in untreated sponges. The abundance of the dominant symbiont, Candidatus Halichondribacter symbioticus, remained overall unchanged, reflecting its obligately symbiotic nature. Recolonization with the natural microbiome could not reverse antibiotic-induced dysbiosis. However, single bacterial taxa that were transferred, successfully recolonized the sponge and affected bacteria-bacteria interactions. By experimentally manipulating microbiome composition, we could show the stability of a sponge-symbiont clade despite microbiome dysbiosis. This study contributes to understanding both host-bacteria and bacteria-bacteria interactions in the sponge holobiont.
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Affiliation(s)
- Lara Schmittmann
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany
| | - Tanja Rahn
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany
| | - Kathrin Busch
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany
| | - Sebastian Fraune
- Heinrich-Heine-University, Zoology and Organismic Interactions, Düsseldorf, Germany
| | - Lucía Pita
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany.,Institut de Ciències del Mar - CSIC, Marine Biology and Oceanography, Marine Biogeochemistry, Atmosphere and Climate, Barcelona, Spain
| | - Ute Hentschel
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany.,Christian-Albrechts-University Kiel, Kiel, Germany
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8
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Xiang N, Rädecker N, Pogoreutz C, Cárdenas A, Meibom A, Wild C, Gärdes A, Voolstra CR. Presence of algal symbionts affects denitrifying bacterial communities in the sea anemone Aiptasia coral model. ISME Commun 2022; 2:105. [PMID: 37938763 PMCID: PMC9723753 DOI: 10.1038/s43705-022-00190-9] [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] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 09/28/2022] [Accepted: 10/10/2022] [Indexed: 11/09/2023]
Abstract
The coral-algal symbiosis is maintained by a constant and limited nitrogen availability in the holobiont. Denitrifiers, i.e., prokaryotes reducing nitrate/nitrite to dinitrogen, could contribute to maintaining the nitrogen limitation in the coral holobiont, however the effect of host and algal identity on their community is still unknown. Using the coral model Aiptasia, we quantified and characterized the denitrifier community in a full-factorial design combining two hosts (CC7 and H2) and two strains of algal symbionts of the family Symbiodiniaceae (SSA01 and SSB01). Strikingly, relative abundance of denitrifiers increased by up to 22-fold in photosymbiotic Aiptasia compared to their aposymbiotic (i.e., algal-depleted) counterparts. In line with this, while the denitrifier community in aposymbiotic Aiptasia was largely dominated by diet-associated Halomonas, we observed an increasing relative abundance of an unclassified bacterium in photosymbiotic CC7, and Ketobacter in photosymbiotic H2, respectively. Pronounced changes in denitrifier communities of Aiptasia with Symbiodinium linucheae strain SSA01 aligned with the higher photosynthetic carbon availability of these holobionts compared to Aiptasia with Breviolum minutum strain SSB01. Our results reveal that the presence of algal symbionts increases abundance and alters community structure of denitrifiers in Aiptasia. Thereby, patterns in denitrifier community likely reflect the nutritional status of aposymbiotic vs. symbiotic holobionts. Such a passive regulation of denitrifiers may contribute to maintaining the nitrogen limitation required for the functioning of the cnidarian-algal symbiosis.
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Affiliation(s)
- Nan Xiang
- Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, 28359, Bremen, Germany.
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570, Bremerhaven, Germany.
| | - Nils Rädecker
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Claudia Pogoreutz
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Anders Meibom
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
- Center for Advanced Surface Analysis (CASA), Institute of Earth Science, University of Lausanne, 1015, Lausanne, Switzerland
| | - Christian Wild
- Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, 28359, Bremen, Germany
| | - Astrid Gärdes
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570, Bremerhaven, Germany
- Hochschule Bremerhaven, Fachbereich 1, An der Karlstadt 8, 27568, Bremerhaven, Germany
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9
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Hughes DJ, Raina JB, Nielsen DA, Suggett DJ, Kühl M. Disentangling compartment functions in sessile marine invertebrates. Trends Ecol Evol 2022; 37:740-748. [PMID: 35570130 DOI: 10.1016/j.tree.2022.04.008] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/09/2022] [Accepted: 04/13/2022] [Indexed: 01/01/2023]
Abstract
Sessile invertebrates are frequently sampled and processed whole for downstream analyses. However, their apparent structural simplicity is deceptive as these organisms often harbour discrete compartments. These compartments have physicochemical conditions that differ markedly from neighbouring tissues, and that have likely evolved to support specific functions. Here, we argue that such compartments should be specifically targeted when characterising sessile invertebrate biology and we use the coral gastrovascular cavity to support our argument. This complex compartment displays steep and dynamic chemical gradients, harbours distinct microorganisms, and presumably plays a key role in coral biology. Disentangling the functions played by (and amongst) compartments will likely provide transformative insight into the biology of sessile invertebrates and their future under environmental change.
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Affiliation(s)
- David J Hughes
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW 2007, Australia.
| | - Jean-Baptiste Raina
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW 2007, Australia.
| | - Daniel A Nielsen
- University of Technology Sydney, School of Life Sciences, Ultimo, NSW 2007, Australia
| | - David J Suggett
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW 2007, Australia
| | - Michael Kühl
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW 2007, Australia; Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK 3000 Helsingør, Denmark.
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10
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Tran C. Coral-microbe interactions: their importance to reef function and survival. Emerg Top Life Sci 2022:ETLS20210229. [PMID: 35119475 DOI: 10.1042/ETLS20210229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/04/2022] [Accepted: 01/12/2022] [Indexed: 11/17/2022]
Abstract
Many different microorganisms associate with the coral host in a single entity known as the holobiont, and their interactions with the host contribute to coral health, thereby making them a fundamental part of reef function, survival, and conservation. As corals continue to be susceptible to bleaching due to environmental stress, coral-associated bacteria may have a potential role in alleviating bleaching. This review provides a synthesis of the various roles bacteria have in coral physiology and development, and explores the possibility that changes in the microbiome with environmental stress could have major implications in how corals acclimatize and survive. Recent studies on the interactions between the coral's algal and bacterial symbionts elucidate how bacteria may stabilize algal health and, therefore, mitigate bleaching. A summary of the innovative tools and experiments to examine host-microbe interactions in other cnidarians (a temperate coral, a jellyfish, two anemones, and a freshwater hydroid) is offered in this review to delineate our current knowledge of mechanisms underlying microbial establishment and maintenance in the animal host. A better understanding of these mechanisms may enhance the success of maintaining probiotics long-term in corals as a conservation strategy.
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11
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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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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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Voolstra CR, Valenzuela JJ, Turkarslan S, Cárdenas A, Hume BCC, Perna G, Buitrago-López C, Rowe K, Orellana MV, Baliga NS, Paranjape S, Banc-Prandi G, Bellworthy J, Fine M, Frias-Torres S, Barshis DJ. Contrasting heat stress response patterns of coral holobionts across the Red Sea suggest distinct mechanisms of thermal tolerance. Mol Ecol 2021; 30:4466-4480. [PMID: 34342082 DOI: 10.1111/mec.16064] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/04/2021] [Accepted: 06/30/2021] [Indexed: 12/18/2022]
Abstract
Corals from the northern Red Sea, in particular the Gulf of Aqaba (GoA), have exceptionally high bleaching thresholds approaching >5℃ above their maximum monthly mean (MMM) temperatures. These elevated thresholds are thought to be due to historical selection, as corals passed through the warmer Southern Red Sea during recolonization from the Arabian Sea. To test this hypothesis, we determined thermal tolerance thresholds of GoA versus central Red Sea (CRS) Stylophora pistillata corals using multi-temperature acute thermal stress assays to determine thermal thresholds. Relative thermal thresholds of GoA and CRS corals were indeed similar and exceptionally high (~7℃ above MMM). However, absolute thermal thresholds of CRS corals were on average 3℃ above those of GoA corals. To explore the molecular underpinnings, we determined gene expression and microbiome response of the coral holobiont. Transcriptomic responses differed markedly, with a strong response to the thermal stress in GoA corals and their symbiotic algae versus a remarkably muted response in CRS colonies. Concomitant to this, coral and algal genes showed temperature-induced expression in GoA corals, while exhibiting fixed high expression (front-loading) in CRS corals. Bacterial community composition of GoA corals changed dramatically under heat stress, whereas CRS corals displayed stable assemblages. We interpret the response of GoA corals as that of a resilient population approaching a tipping point in contrast to a pattern of consistently elevated thermal resistance in CRS corals that cannot further attune. Such response differences suggest distinct thermal tolerance mechanisms that may affect the response of coral populations to ocean warming.
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Affiliation(s)
| | | | | | - Anny Cárdenas
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Gabriela Perna
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Katherine Rowe
- School of Science, The University of Waikato, Hamilton, New Zealand
| | - Monica V Orellana
- Institute for Systems Biology, Seattle, USA.,Polar Science Center, University of Washington, Seattle, USA
| | - Nitin S Baliga
- Institute for Systems Biology, Seattle, USA.,Departments of Biology and Microbiology, University of Washington, Seattle, USA.,Molecular and Cellular Biology Program, University of Washington, Seattle, USA.,Lawrence Berkeley National Laboratory, Berkeley, USA
| | | | - Guilhem Banc-Prandi
- The Interuniversity Institute for Marine Sciences (IUI), Eilat, Israel.,The Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | - Jessica Bellworthy
- The Interuniversity Institute for Marine Sciences (IUI), Eilat, Israel.,The Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | - Maoz Fine
- The Interuniversity Institute for Marine Sciences (IUI), Eilat, Israel.,The Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | | | - Daniel J Barshis
- Department of Biological Sciences, Old Dominion University, Norfolk, USA
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