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Zhu W, Liu X, Zhang J, Zhao H, Li Z, Wang H, Chen R, Wang A, Li X. Response of coral bacterial composition and function to water quality variations under anthropogenic influence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 884:163837. [PMID: 37137368 DOI: 10.1016/j.scitotenv.2023.163837] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/06/2023] [Accepted: 04/26/2023] [Indexed: 05/05/2023]
Abstract
Microbial communities play key roles in the adaptation of corals living in adverse environments, as the microbiome flexibility can enhance environmental plasticity of coral holobiont. However, the ecological association of coral microbiome and related function to locally deteriorating water quality remains underexplored. In this work, we used 16S rRNA gene sequencing and quantitative microbial element cycling (QMEC) to investigate the seasonal changes of bacterial communities, particularly their functional genes related to carbon (C), nitrogen (N), phosphorus (P) and sulfur (S) cycle, of the scleractinian coral Galaxea fascicularis from nearshore reefs exposed anthropogenic influence. We used nutrient concentrations as the indicator of anthropogenic activities in coastal reefs, and found a higher nutrient pressure in spring than summer. The bacterial diversity, community structure and dominant bacteria of coral shifted significantly due to seasonal variations dominated by nutrient concentrations. Additionally, the network structure and nutrient cycling gene profiles in summer under low nutrient stress was distinct from that under poor environmental conditions in spring, with lower network complexity and abundance of CNPS cycling genes in summer compared with spring. We further identified significant correlations between microbial community (taxonomic composition and co-occurrence network) and geochemical functions (abundance of multiple functional genes and functional community). Nutrient enrichment was proved to be the most important environmental fluctuation in controlling the diversity, community structure, interactional network and functional genes of the coral microbiome. These results highlight that seasonal shifts in coral-associated bacteria due to anthropogenic activities alter the functional potentials, and provide novel insight about the mechanisms of coral adaptation to locally deteriorating environments.
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Affiliation(s)
- Wentao Zhu
- College of Ecology and Environment, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Xiangbo Liu
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Junling Zhang
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - He Zhao
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Zhuoran Li
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Hao Wang
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Rouwen Chen
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Aimin Wang
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Xiubao Li
- College of Marine Science, Hainan University, Haikou, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China.
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2
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Nielsen JJV, Matthews G, Frith KR, Harrison HB, Marzonie MR, Slaughter KL, Suggett DJ, Bay LK. Experimental considerations of acute heat stress assays to quantify coral thermal tolerance. Sci Rep 2022; 12:16831. [PMID: 36207307 PMCID: PMC9546840 DOI: 10.1038/s41598-022-20138-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/08/2022] [Indexed: 11/23/2022] Open
Abstract
Understanding the distribution and abundance of heat tolerant corals across seascapes is imperative for predicting responses to climate change and to support novel management actions. Thermal tolerance is variable in corals and intrinsic and extrinsic drivers of tolerance are not well understood. Traditional experimental evaluations of coral heat and bleaching tolerance typically involve ramp-and-hold experiments run across days to weeks within aquarium facilities with limits to colony replication. Field-based acute heat stress assays have emerged as an alternative experimental approach to rapidly quantify heat tolerance in many samples yet the role of key methodological considerations on the stress response measured remains unresolved. Here, we quantify the effects of coral fragment size, sampling time point, and physiological measures on the acute heat stress response in adult corals. The effect of fragment size differed between species (Acropora tenuis and Pocillopora damicornis). Most physiological parameters measured here declined over time (tissue colour, chlorophyll-a and protein content) from the onset of heating, with the exception of maximum photosynthetic efficiency (Fv/Fm) which was surprisingly stable over this time scale. Based on our experiments, we identified photosynthetic efficiency, tissue colour change, and host-specific assays such as catalase activity as key physiological measures for rapid quantification of thermal tolerance. We recommend that future applications of acute heat stress assays include larger fragments (> 9 cm2) where possible and sample between 10 and 24 h after the end of heat stress. A validated high-throughput experimental approach combined with cost-effective genomic and physiological measurements underpins the development of markers and maps of heat tolerance across seascapes and ocean warming scenarios.
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Affiliation(s)
- J J V Nielsen
- College of Public Health, Medicine, and Veterinary Sciences, James Cook University, Townsville, QLD, 4811, Australia. .,Australian Institute of Marine Science, PMB #3, Townsville, MC, QLD, 4810, Australia. .,AIMS@JCU, Australian Institute of Marine Science, James Cook University, Townsville, QLD, 4811, Australia.
| | - G Matthews
- Wellcome Centre for Human Genetics, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - K R Frith
- Australian Institute of Marine Science, PMB #3, Townsville, MC, QLD, 4810, Australia.,Centre for Resilience in Environment, Water and Waste, Geography, College of Life and Environmental Sciences, University of Exeter, Amory Building, Exeter, EX4 4RJ, Devon, UK
| | - H B Harrison
- Australian Institute of Marine Science, PMB #3, Townsville, MC, QLD, 4810, Australia.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia
| | - M R Marzonie
- Australian Institute of Marine Science, PMB #3, Townsville, MC, QLD, 4810, Australia.,AIMS@JCU, Australian Institute of Marine Science, James Cook University, Townsville, QLD, 4811, Australia.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia
| | - K L Slaughter
- AIMS@JCU, Australian Institute of Marine Science, James Cook University, Townsville, QLD, 4811, Australia.,College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - D J Suggett
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - L K Bay
- Australian Institute of Marine Science, PMB #3, Townsville, MC, QLD, 4810, Australia
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3
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Global change differentially modulates Caribbean coral physiology. PLoS One 2022; 17:e0273897. [PMID: 36054126 PMCID: PMC9439252 DOI: 10.1371/journal.pone.0273897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 08/17/2022] [Indexed: 11/19/2022] Open
Abstract
Global change driven by anthropogenic carbon emissions is altering ecosystems at unprecedented rates, especially coral reefs, whose symbiosis with algal symbionts is particularly vulnerable to increasing ocean temperatures and altered carbonate chemistry. Here, we assess the physiological responses of three Caribbean coral (animal host + algal symbiont) species from an inshore and offshore reef environment after exposure to simulated ocean warming (28, 31°C), acidification (300–3290 μatm), and the combination of stressors for 93 days. We used multidimensional analyses to assess how a variety of coral physiological parameters respond to ocean acidification and warming. Our results demonstrate reductions in coral health in Siderastrea siderea and Porites astreoides in response to projected ocean acidification, while future warming elicited severe declines in Pseudodiploria strigosa. Offshore S. siderea fragments exhibited higher physiological plasticity than inshore counterparts, suggesting that this offshore population was more susceptible to changing conditions. There were no plasticity differences in P. strigosa and P. astreoides between natal reef environments, however, temperature evoked stronger responses in both species. Interestingly, while each species exhibited unique physiological responses to ocean acidification and warming, when data from all three species are modelled together, convergent stress responses to these conditions are observed, highlighting the overall sensitivities of tropical corals to these stressors. Our results demonstrate that while ocean warming is a severe acute stressor that will have dire consequences for coral reefs globally, chronic exposure to acidification may also impact coral physiology to a greater extent in some species than previously assumed. Further, our study identifies S. siderea and P. astreoides as potential ‘winners’ on future Caribbean coral reefs due to their resilience under projected global change stressors, while P. strigosa will likely be a ‘loser’ due to their sensitivity to thermal stress events. Together, these species-specific responses to global change we observe will likely manifest in altered Caribbean reef assemblages in the future.
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Thomas L, Underwood JN, Rose NH, Fuller ZL, Richards ZT, Dugal L, Grimaldi CM, Cooke IR, Palumbi SR, Gilmour JP. Spatially varying selection between habitats drives physiological shifts and local adaptation in a broadcast spawning coral on a remote atoll in Western Australia. SCIENCE ADVANCES 2022; 8:eabl9185. [PMID: 35476443 PMCID: PMC9045720 DOI: 10.1126/sciadv.abl9185] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
At the Rowley Shoals in Western Australia, the prominent reef flat becomes exposed on low tide and the stagnant water in the shallow atoll lagoons heats up, creating a natural laboratory for characterizing the mechanisms of coral resilience to climate change. To explore these mechanisms in the reef coral Acropora tenuis, we collected samples from lagoon and reef slope habitats and combined whole-genome sequencing, ITS2 metabarcoding, experimental heat stress, and transcriptomics. Despite high gene flow across the atoll, we identified clear shifts in allele frequencies between habitats at relatively small linked genomic islands. Common garden heat stress assays showed corals from the lagoon to be more resistant to bleaching, and RNA sequencing revealed marked differences in baseline levels of gene expression between habitats. Our results provide new insight into the complex mechanisms of coral resilience to climate change and highlight the potential for spatially varying selection across complex coral reef seascapes to drive pronounced ecological divergence in climate-related traits.
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Affiliation(s)
- Luke Thomas
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, Crawley, Australia
- UWA Oceans Institute, Oceans Graduate School, The University of Western Australia, Crawley, Australia
- Corresponding author.
| | - Jim N. Underwood
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, Crawley, Australia
| | - Noah H. Rose
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Zachary L. Fuller
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Zoe T. Richards
- Coral Conservation and Research Group, School of Molecular and Life Sciences, Curtin University, Perth, Australia
- Collections and Research, Western Australian Museum, Welshpool, Australia
| | - Laurence Dugal
- UWA Oceans Institute, Oceans Graduate School, The University of Western Australia, Crawley, Australia
| | - Camille M. Grimaldi
- UWA Oceans Institute, Oceans Graduate School, The University of Western Australia, Crawley, Australia
| | - Ira R. Cooke
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
| | - Stephen R. Palumbi
- Hopkins Marine Station, Biology Department, Stanford University, Pacific Grove, CA, USA
| | - James P. Gilmour
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, Crawley, Australia
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Madeira C, Dias M, Ferreira A, Gouveia R, Cabral H, Diniz MS, Vinagre C. Does Predation Exacerbate the Risk of Endosymbiont Loss in Heat Stressed Hermatypic Corals? Molecular Cues Provide Insights Into Species-Specific Health Outcomes in a Multi-Stressor Ocean. Front Physiol 2022; 13:801672. [PMID: 35299660 PMCID: PMC8922028 DOI: 10.3389/fphys.2022.801672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/31/2022] [Indexed: 11/30/2022] Open
Abstract
Ocean warming has been a major driver of coral reef bleaching and mass mortality. Coupled to other biotic pressures, corals’ ability for acclimatization and adaptation may become compromised. Here, we tested the combined effects of warming scenarios (26, 30, and 32°C) and predation (wound vs. no wound) in coral health condition (paleness, bleaching, and mortality), cellular stress responses (heat shock protein 70 kDa Hsp70, total ubiquitin Ub, and total antioxidant capacity TAC), and physiological state (integrated biomarker response index, IBR) of seven Scleractinian coral species, after being exposed for 60 days. Results show that although temperature was the main factor driving coral health condition, thermotolerant species (Galaxea fascicularis, Psammocora contigua, and Turbinaria reniformis) displayed increased paleness, bleaching, and mortality in predation treatments at high temperature, whereas thermosensitive species (Acropora tenuis, Echinopora lamellosa, and Montipora capricornis brown and green morphotypes) all died at 32°C, regardless of predation condition. At the molecular level, results show that there were significant main and interactive effects of species, temperature, and predation in the biomarkers assessed. Temperature affected Hsp70, Ub, and TAC, evidencing the role of protein folding and turnover, as well as reactive oxygen species scavenging in heat stress management. Predation increased Hsp70 and Ub, suggesting the activation of the pro-phenoloxidase system and cytokine activity, whereas the combination of both stressors mainly affected TAC during moderate stress and Ub under severe stress, suggesting that redox balance and defense of homeostasis are crucial in tissue repair at high temperature. IBR levels showed an increasing trend at 32°C in predated coral fragments (although non-significant). We conclude that coral responses to the combination of high temperature and predation pressure display high inter-species variability, but these stressors may pose a higher risk of endosymbiont loss, depending on species physiology and stress intensity.
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Affiliation(s)
- Carolina Madeira
- i4HB – Associate Laboratory Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO – Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University of Lisbon, Caparica, Portugal
- MARE – Marine and Environmental Sciences Centre, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
- *Correspondence: Carolina Madeira, , orcid.org/0000-0003-1632-634X
| | - Marta Dias
- MARE – Marine and Environmental Sciences Centre, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
- Marta Dias, , orcid.org/0000-0003-0447-6009
| | - Ana Ferreira
- Biology Department, Oceanário de Lisboa, Lisbon, Portugal
| | - Raúl Gouveia
- Biology Department, Oceanário de Lisboa, Lisbon, Portugal
| | - Henrique Cabral
- MARE – Marine and Environmental Sciences Centre, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
- INRAE – National Research Institute for Agriculture, Food and Environment, UR EABX, Cestas, France
| | - Mário S. Diniz
- i4HB – Associate Laboratory Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO – Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University of Lisbon, Caparica, Portugal
| | - Catarina Vinagre
- MARE – Marine and Environmental Sciences Centre, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
- CCMAR – Centre of Marine Sciences, University of Algarve, Faro, Portugal
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Abstract
Recent human activity has profoundly transformed Earth biomes on a scale and at rates that are unprecedented. Given the central role of symbioses in ecosystem processes, functions, and services throughout the Earth biosphere, the impacts of human-driven change on symbioses are critical to understand. Symbioses are not merely collections of organisms, but co-evolved partners that arise from the synergistic combination and action of different genetic programs. They function with varying degrees of permanence and selection as emergent units with substantial potential for combinatorial and evolutionary innovation in both structure and function. Following an articulation of operational definitions of symbiosis and related concepts and characteristics of the Anthropocene, we outline a basic typology of anthropogenic change (AC) and a conceptual framework for how AC might mechanistically impact symbioses with select case examples to highlight our perspective. We discuss surprising connections between symbiosis and the Anthropocene, suggesting ways in which new symbioses could arise due to AC, how symbioses could be agents of ecosystem change, and how symbioses, broadly defined, of humans and “farmed” organisms may have launched the Anthropocene. We conclude with reflections on the robustness of symbioses to AC and our perspective on the importance of symbioses as ecosystem keystones and the need to tackle anthropogenic challenges as wise and humble stewards embedded within the system.
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Affiliation(s)
- Erik F Y Hom
- Department of Biology and Center for Biodiversity and Conservation Research, University of Mississippi, University, MS 38677 USA
| | - Alexandra S Penn
- Department of Sociology and Centre for Evaluation of Complexity Across the Nexus, University of Surrey, Guildford, Surrey, GU2 7XH UK
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Xiao B, Li D, Liao B, Zheng H, Yang X, Xie Y, Xie Z, Li C. Effects of Microplastics Exposure on the Acropora sp. Antioxidant, Immunization and Energy Metabolism Enzyme Activities. Front Microbiol 2021; 12:666100. [PMID: 34149652 PMCID: PMC8213336 DOI: 10.3389/fmicb.2021.666100] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/15/2021] [Indexed: 11/13/2022] Open
Abstract
Microplastic pollution in marine environments has increased rapidly in recent years, with negative influences on the health of marine organisms. Scleractinian coral, one of the most important species in the coral ecosystems, is highly sensitive to microplastic. However, whether microplastic causes physiological disruption of the coral, via oxidative stress, immunity, and energy metabolism, is unclear. In the present study, the physiological responses of the coral Acropora sp. were determined after exposure to polyethylene terephthalate (PET), polyamide 66 (PA66), and polyethylene (PE) microplastic for 96 h. The results showed that there were approximately 4-22 items/nubbin on the surface of the coral skeleton and 2-10 items/nubbin on the inside of the skeleton in the MPs exposure groups. The density of endosymbiont decreased (1.12 × 105-1.24 × 105 cell/cm2) in MPs exposure groups compared with the control group. Meanwhile, the chlorophyll content was reduced (0.11-0.76 μg/cm2) after MPs exposure. Further analysis revealed that the antioxidant enzymes in coral tissues were up-regulated (Total antioxidant capacity T-AOC 2.35 × 10-3-1.05 × 10-2 mmol/mg prot, Total superoxide dismutase T-SOD 3.71-28.67 U/mg prot, glutathione GSH 10.21-10.51 U/mg prot). The alkaline phosphatase (AKP) was inhibited (1.44-4.29 U/mg prot), while nitric oxide (NO) increased (0.69-2.26 μmol/g prot) for cell signal. Moreover, lactate dehydrogenase (LDH) was down-regulated in the whole experiment period (0.19-0.22 U/mg prot), and Glucose-6-phosphate dehydrogenase (G6PDH) for cell the phosphate pentoses pathway was also reduced (0.01-0.04 U/mg port). Results showed that the endosymbiont was released and chlorophyll was decreased. In addition, a disruption could occur under MPs exposure, which was related to anti-oxidant, immune, and energy metabolism.
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Affiliation(s)
- Baohua Xiao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Dongdong Li
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Baolin Liao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Huina Zheng
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Xiaodong Yang
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Yongqi Xie
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Ziqiang Xie
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Chengyong Li
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
- Southern Marine Science and Engineering Guangdong Laboratory, School of Chemistry and Environment, Guangdong Ocean University, Zhanjiang, China
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8
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Mendrik FM, Henry TB, Burdett H, Hackney CR, Waller C, Parsons DR, Hennige SJ. Species-specific impact of microplastics on coral physiology. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 269:116238. [PMID: 33321308 DOI: 10.1016/j.envpol.2020.116238] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/18/2020] [Accepted: 12/04/2020] [Indexed: 05/23/2023]
Abstract
There is evidence that microplastic (MP) pollution can negatively influence coral health; however, mechanisms are unknown and most studies have used MP exposure concentrations that are considerably higher than current environmental conditions. Furthermore, whether MP exposure influences coral susceptibility to other stressors such as ocean warming is unknown. Our objective was to determine the physiology response of corals exposed to MP concentrations that have been observed in-situ at ambient and elevated temperature that replicates ocean warming. Here, two sets of short-term experiments were conducted at ambient and elevated temperature, exposing the corals Acroporasp. and Seriatopora hystrix to microspheres and microfibres. Throughout the experiments, gross photosynthesis and net respiration was quantified using a 4-chamber coral respirometer, and photosynthetic yields of photosystem II were measured using Pulse-Amplitude Modulated (PAM) fluorometry. Results indicate the effect of MP exposure is dependent on MP type, coral species, and temperature. MP fibres (but not spheres) reduced photosynthetic capability of Acropora sp., with a 41% decrease in photochemical efficiency at ambient temperature over 12 days. No additional stress response was observed at elevated temperature; photosynthetic performance significantly increased in Seriatopora hystrix exposed to MP spheres. These findings show that a disruption to coral photosynthetic ability can occur at MP concentrations that have been observed in the marine environment and that MP pollution impact on corals remains an important aspect for further research.
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Affiliation(s)
- F M Mendrik
- School of GeoSciences, University of Edinburgh, Edinburgh, EH93FE, UK; Energy and Environment Institute, University of Hull, Cottingham Road, Hull, East Riding, HU6 7RX, UK.
| | - T B Henry
- School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - H Burdett
- School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, EH14 4AS, UK; Lyell Centre for Earth and Marine Science and Technology, Edinburgh, EH14 4BA, UK
| | - C R Hackney
- Geography, Politics and Sociology, Newcastle University, Newcastle Upon Tyne, UK
| | - C Waller
- Department of Biology and Marine Sciences, School of Science and Engineering, University of Hull, Cottingham Road, Hull, East Riding, HU6 7RX, UK
| | - D R Parsons
- Energy and Environment Institute, University of Hull, Cottingham Road, Hull, East Riding, HU6 7RX, UK
| | - S J Hennige
- School of GeoSciences, University of Edinburgh, Edinburgh, EH93FE, UK
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Aichelman HE, Barshis DJ. Adaptive divergence, neutral panmixia, and algal symbiont population structure in the temperate coral Astrangia poculata along the Mid-Atlantic United States. PeerJ 2020; 8:e10201. [PMID: 33240603 PMCID: PMC7680023 DOI: 10.7717/peerj.10201] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/27/2020] [Indexed: 12/11/2022] Open
Abstract
Astrangia poculata is a temperate scleractinian coral that exists in facultative symbiosis with the dinoflagellate alga Breviolum psygmophilum across a range spanning the Gulf of Mexico to Cape Cod, Massachusetts. Our previous work on metabolic thermal performance of Virginia (VA) and Rhode Island (RI) populations of A. poculata revealed physiological signatures of cold (RI) and warm (VA) adaptation of these populations to their respective local thermal environments. Here, we used whole-transcriptome sequencing (mRNA-Seq) to evaluate genetic differences and identify potential loci involved in the adaptive signature of VA and RI populations. Sequencing data from 40 A. poculata individuals, including 10 colonies from each population and symbiotic state (VA-white, VA-brown, RI-white, and RI-brown), yielded a total of 1,808 host-associated and 59 algal symbiont-associated single nucleotide polymorphisms (SNPs) post filtration. Fst outlier analysis identified 66 putative high outlier SNPs in the coral host and 4 in the algal symbiont. Differentiation of VA and RI populations in the coral host was driven by putatively adaptive loci, not neutral divergence (Fst = 0.16, p = 0.001 and Fst = 0.002, p = 0.269 for outlier and neutral SNPs respectively). In contrast, we found evidence of neutral population differentiation in B. psygmophilum (Fst = 0.093, p = 0.001). Several putatively adaptive host loci occur on genes previously associated with the coral stress response. In the symbiont, three of four putatively adaptive loci are associated with photosystem proteins. The opposing pattern of neutral differentiation in B. psygmophilum, but not the A. poculata host, reflects the contrasting dynamics of coral host and algal symbiont population connectivity, dispersal, and gene by environment interactions.
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Affiliation(s)
- Hannah E Aichelman
- Department of Biology, Boston University, Boston, MA, USA.,Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Daniel J Barshis
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
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10
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Anthropogenic invaders: historical biogeography, current genetic status and distribution range of the “peludo” Chaetophractus villosus (Xenarthra) in Patagonia and Tierra del Fuego, southern South America. MAMMALIA 2020. [DOI: 10.1515/mammalia-2019-0076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Chaetophractus villosus was once distributed from the south of Bolivia and Paraguay to the northwest of Patagonia, where the species survived in glacial refugia during Pleistocene. After the ice retreated, the species expanded its distribution further south reaching Chubut River. In the last two centuries, the species colonized the rest of Patagonia on both sides of the Andes and was introduced in Tierra del Fuego (TDF) in 1982, where it expanded its distribution range along 484 km2 until 2005. A single mitochondrial Control Region haplotype (HC) was described across Argentine Patagonia based on the low number of samples. This lack of variability was exceptional and impressive, taking into account that the northern neighboring areas of distribution are considered ancestral due to the haplotype richness. Here, we added new field and genetic data and compiled recent bibliography to update the biogeography and phylogeography of the species in southern South America. To explain the unprecedent lack of genetic variability, we discussed three main aspects: a historical biogeographic aspect related to the natural barriers for the species, a strong stochastic component, and the possible adaptive advantages of the only mitochondrial lineage detected, whose colonization and acclimatization to the new environment were mediated by man. We also estimated that the current distribution range in TDF is about 8527 km2.
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11
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Mansfield KM, Gilmore TD. Innate immunity and cnidarian-Symbiodiniaceae mutualism. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 90:199-209. [PMID: 30268783 DOI: 10.1016/j.dci.2018.09.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
The phylum Cnidaria (sea anemones, corals, hydra, jellyfish) is one the most distantly related animal phyla to humans, and yet cnidarians harbor many of the same cellular pathways involved in innate immunity in mammals. In addition to its role in pathogen recognition, the innate immune system has a role in managing beneficial microbes and supporting mutualistic microbial symbioses. Some corals and sea anemones undergo mutualistic symbioses with photosynthetic algae in the family Symbiodiniaceae. These symbioses can be disrupted by anthropogenic disturbances of ocean environments, which can have devastating consequences for the health of coral reef ecosystems. Several studies of cnidarian-Symbiodiniaceae symbiosis have implicated proteins in the host immune system as playing a role in both symbiont tolerance and loss of symbiosis (i.e., bleaching). In this review, we critically evaluate current knowledge about the role of host immunity in the regulation of symbiosis in cnidarians.
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Affiliation(s)
| | - Thomas D Gilmore
- Department of Biology, Boston University, Boston, MA, 02215, USA.
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12
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Sekizawa A, Uechi H, Iguchi A, Nakamura T, Kumagai NH, Suzuki A, Sakai K, Nojiri Y. Intraspecific variations in responses to ocean acidification in two branching coral species. MARINE POLLUTION BULLETIN 2017; 122:282-287. [PMID: 28655461 DOI: 10.1016/j.marpolbul.2017.06.061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 06/17/2017] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO2, respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration.
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Affiliation(s)
- Ayami Sekizawa
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905-0227, Japan
| | - Hikaru Uechi
- Department of Bioresources Engineering, National Institute of Technology, Okinawa College, 905 Henoko, Nago-City, Okinawa 905-2192, Japan
| | - Akira Iguchi
- Department of Bioresources Engineering, National Institute of Technology, Okinawa College, 905 Henoko, Nago-City, Okinawa 905-2192, Japan.
| | - Takashi Nakamura
- Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Naoki H Kumagai
- Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
| | - Atsushi Suzuki
- Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8567, Japan
| | - Kazuhiko Sakai
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905-0227, Japan
| | - Yukihiro Nojiri
- Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
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Rocker MM, Francis DS, Fabricius KE, Willis BL, Bay LK. Variation in the health and biochemical condition of the coral Acropora tenuis along two water quality gradients on the Great Barrier Reef, Australia. MARINE POLLUTION BULLETIN 2017; 119:106-119. [PMID: 28460877 DOI: 10.1016/j.marpolbul.2017.03.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 03/19/2017] [Accepted: 03/31/2017] [Indexed: 06/07/2023]
Abstract
This study explores how plasticity in biochemical attributes, used as indicators of health and condition, enables the coral Acropora tenuis to respond to differing water quality regimes in inshore regions of the Great Barrier Reef. Health attributes were monitored along a strong and weak water quality gradient, each with three reefs at increasing distances from a major river source. Attributes differed significantly only along the strong gradient; corals grew fastest, had the least dense skeletons, highest symbiont densities and highest lipid concentrations closest to the river mouth, where water quality was poorest. High nutrient and particulate loads were only detrimental to skeletal density, which decreased as linear extension increased, highlighting a trade-off. Our study underscores the importance of assessing multiple health attributes in coral reef monitoring. For example, autotrophic indices are poor indicators of coral health and condition, but improve when combined with attributes like lipid content and biomass.
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Affiliation(s)
- Melissa M Rocker
- Australian Institute of Marine Science, PMB #3, Townsville MC, QLD 4810, Australia; AIMS@JCU, Australian Institute of Marine Science, James Cook University, Townsville, QLD 4811, Australia; College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia; Deakin University, Geelong, School of Life and Environmental Sciences, Waurn Ponds Campus, Pigdons Rd, Waurn Ponds, VIC 3216, Australia.
| | - David S Francis
- Deakin University, Geelong, School of Life and Environmental Sciences, Warrnambool Campus, Princes Hwy, Sherwood Park, PO Box 423, Warrnambool, VIC 3280, Australia
| | | | - Bette L Willis
- College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Line K Bay
- Australian Institute of Marine Science, PMB #3, Townsville MC, QLD 4810, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
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14
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Hawkins TD, Warner ME. Warm preconditioning protects against acute heat-induced respiratory dysfunction and delays bleaching in a symbiotic sea anemone. ACTA ACUST UNITED AC 2016; 220:969-983. [PMID: 27980125 DOI: 10.1242/jeb.150391] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 12/08/2016] [Indexed: 12/18/2022]
Abstract
Preconditioning to non-stressful warming can protect some symbiotic cnidarians against the high temperature-induced collapse of their mutualistic endosymbiosis with photosynthetic dinoflagellates (Symbiodinium spp.), a process known as bleaching. Here, we sought to determine whether such preconditioning is underpinned by differential regulation of aerobic respiration. We quantified in vivo metabolism and mitochondrial respiratory enzyme activity in the naturally symbiotic sea anemone Exaiptasia pallida preconditioned to 30°C for >7 weeks as well as anemones kept at 26°C. Preconditioning resulted in increased Symbiodinium photosynthetic activity and holobiont (host+symbiont) respiration rates. Biomass-normalised activities of host respiratory enzymes [citrate synthase and the mitochondrial electron transport chain (mETC) complexes I and IV] were higher in preconditioned animals, suggesting that increased holobiont respiration may have been due to host mitochondrial biogenesis and/or enlargement. Subsequent acute heating of preconditioned and 'thermally naive' animals to 33°C induced dramatic increases in host mETC complex I and Symbiodinium mETC complex II activities only in thermally naive E. pallida These changes were not reflected in the activities of other respiratory enzymes. Furthermore, bleaching in preconditioned E. pallida (defined as the significant loss of symbionts) was delayed by several days relative to the thermally naive group. These findings suggest that changes to mitochondrial biogenesis and/or function in symbiotic cnidarians during warm preconditioning might play a protective role during periods of exposure to stressful heating.
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Affiliation(s)
- Thomas D Hawkins
- School of Marine Science and Policy, College of Earth, Ocean and Environment, University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA
| | - Mark E Warner
- School of Marine Science and Policy, College of Earth, Ocean and Environment, University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA
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15
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Recent Advances in Understanding the Effects of Climate Change on Coral Reefs. DIVERSITY-BASEL 2016. [DOI: 10.3390/d8020012] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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16
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Maor-Landaw K, Levy O. Gene expression profiles during short-term heat stress; branching vs. massive Scleractinian corals of the Red Sea. PeerJ 2016; 4:e1814. [PMID: 27069783 PMCID: PMC4824894 DOI: 10.7717/peerj.1814] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/24/2016] [Indexed: 11/20/2022] Open
Abstract
It is well-established that there is a hierarchy of susceptibilities amongst coral genera during heat-stress. However, molecular mechanisms governing these differences are still poorly understood. Here we explored if specific corals possessing different morphologies and different susceptibilities to heat stress may manifest varied gene expression patterns. We examined expression patterns of seven genes in the branching corals Stylophora pistillata and Acropora eurystoma and additionally in the massive robust coral, Porites sp. The tested genes are representatives of key cellular processes occurring during heat-stress in Cnidaria: oxidative stress, ER stress, energy metabolism, DNA repair and apoptosis. Varied response to the heat-stress, in terms of visual coral paling, algal maximum quantum yield and host gene expression was evident in the different growth forms. The two branching corals exhibited similar overall responses that differed from that of the massive coral. A. eurystoma that is considered as a susceptible species did not bleach in our experiment, but tissue sloughing was evident at 34 °C. Interestingly, in this species redox regulation genes were up-regulated at the very onset of the thermal challenge. In S. pistillata, bleaching was evident at 34 °C and most of the stress markers were already up-regulated at 32 °C, either remaining highly expressed or decreasing when temperatures reached 34 °C. The massive Porites species displayed severe bleaching at 32 °C but stress marker genes were only significantly elevated at 34 °C. We postulate that by expelling the algal symbionts from Porites tissues, oxidation damages are reduced and stress genes are activated only at a progressed stage. The differential gene expression responses exhibited here can be correlated with the literature well-documented hierarchy of susceptibilities amongst coral morphologies and genera in Eilat’s coral reef.
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Affiliation(s)
- Keren Maor-Landaw
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University , Ramat Gan , Israel
| | - Oren Levy
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University , Ramat Gan , Israel
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17
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Seveso D, Montano S, Strona G, Orlandi I, Galli P, Vai M. The susceptibility of corals to thermal stress by analyzing Hsp60 expression. MARINE ENVIRONMENTAL RESEARCH 2014; 99:69-75. [PMID: 24999860 DOI: 10.1016/j.marenvres.2014.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/23/2014] [Accepted: 06/13/2014] [Indexed: 06/03/2023]
Abstract
Due to the increasing frequency and severity of the coral bleaching events in the context of global warming, there is an urgent need to improve our understanding of the susceptibility of corals to thermal stresses, particularly at the sub-cellular level. In this context, we examined the modulation of the polyp mitochondrial Hsp60 in three scleractinian coral species (Seriatopora hystrix, Montipora monasteriata and Acropora echinata) under simulated heat shock bleaching at 34 °C during a time course of 36 h. All three species displayed a similar initial increase of Hsp60 level which accompanies the increasing paleness of coral tissue. Afterwards, each of them showed a specific pattern of Hsp60 down-regulation which can be indicative of a different threshold of resistance, although it proceeded in synchrony with the complete bleaching of tissues. The finely branched S. hystrix was the species most susceptible to heat stress while the plating M. monasteriata was the most tolerant one, as its Hsp60 down-regulation was less rapid than the branching corals. On the whole, the Hsp60 modulation appears useful for providing information about the susceptibility of the different coral taxa to environmental disturbances.
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Affiliation(s)
- Davide Seveso
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives.
| | - Simone Montano
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives
| | - Giovanni Strona
- European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, I-21027 Ispra, Italy
| | - Ivan Orlandi
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Paolo Galli
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy; MaRHE Centre (Marine Research and High Education Centre), Magoodhoo Island, Faafu Atoll, Maldives
| | - Marina Vai
- Department of Biotechnologies and Biosciences, University of Milan - Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
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18
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Shinzato C, Inoue M, Kusakabe M. A snapshot of a coral "holobiont": a transcriptome assembly of the scleractinian coral, porites, captures a wide variety of genes from both the host and symbiotic zooxanthellae. PLoS One 2014; 9:e85182. [PMID: 24454815 PMCID: PMC3893191 DOI: 10.1371/journal.pone.0085182] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 12/03/2013] [Indexed: 01/09/2023] Open
Abstract
Massive scleractinian corals of the genus Porites are important reef builders in the Indo-Pacific, and they are more resistant to thermal stress than other stony corals, such as the genus Acropora. Because coral health and survival largely depend on the interaction between a coral host and its symbionts, it is important to understand the molecular interactions of an entire “coral holobiont”. We simultaneously sequenced transcriptomes of Porites australiensis and its symbionts using the Illumina Hiseq2000 platform. We obtained 14.3 Gbp of sequencing data and assembled it into 74,997 contigs (average: 1,263 bp, N50 size: 2,037 bp). We successfully distinguished contigs originating from the host (Porites) and the symbiont (Symbiodinium) by aligning nucleotide sequences with the decoded Acropora digitifera and Symbiodinium minutum genomes. In contrast to previous coral transcriptome studies, at least 35% of the sequences were found to have originated from the symbionts, indicating that it is possible to analyze both host and symbiont transcriptomes simultaneously. Conserved protein domain and KEGG analyses showed that the dataset contains broad gene repertoires of both Porites and Symbiodinium. Effective utilization of sequence reads revealed that the polymorphism rate in P. australiensis is 1.0% and identified the major symbiotic Symbiodinium as Type C15. Analyses of amino acid biosynthetic pathways suggested that this Porites holobiont is probably able to synthesize most of the common amino acids and that Symbiodinium is potentially able to provide essential amino acids to its host. We believe this to be the first molecular evidence of complementarity in amino acid metabolism between coral hosts and their symbionts. We successfully assembled genes originating from both the host coral and the symbiotic Symbiodinium to create a snapshot of the coral holobiont transcriptome. This dataset will facilitate a deeper understanding of molecular mechanisms of coral symbioses and stress responses.
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Affiliation(s)
- Chuya Shinzato
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan
- * E-mail:
| | - Mayuri Inoue
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Makoto Kusakabe
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
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19
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Logan CA, Dunne JP, Eakin CM, Donner SD. Incorporating adaptive responses into future projections of coral bleaching. GLOBAL CHANGE BIOLOGY 2014; 20:125-39. [PMID: 24038982 DOI: 10.1111/gcb.12390] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 07/19/2013] [Accepted: 07/30/2013] [Indexed: 05/06/2023]
Abstract
Climate warming threatens to increase mass coral bleaching events, and several studies have projected the demise of tropical coral reefs this century. However, recent evidence indicates corals may be able to respond to thermal stress though adaptive processes (e.g., genetic adaptation, acclimatization, and symbiont shuffling). How these mechanisms might influence warming-induced bleaching remains largely unknown. This study compared how different adaptive processes could affect coral bleaching projections. We used the latest bias-corrected global sea surface temperature (SST) output from the NOAA/GFDL Earth System Model 2 (ESM2M) for the preindustrial period through 2100 to project coral bleaching trajectories. Initial results showed that, in the absence of adaptive processes, application of a preindustrial climatology to the NOAA Coral Reef Watch bleaching prediction method overpredicts the present-day bleaching frequency. This suggests that corals may have already responded adaptively to some warming over the industrial period. We then modified the prediction method so that the bleaching threshold either permanently increased in response to thermal history (e.g., simulating directional genetic selection) or temporarily increased for 2-10 years in response to a bleaching event (e.g., simulating symbiont shuffling). A bleaching threshold that changes relative to the preceding 60 years of thermal history reduced the frequency of mass bleaching events by 20-80% compared with the 'no adaptive response' prediction model by 2100, depending on the emissions scenario. When both types of adaptive responses were applied, up to 14% more reef cells avoided high-frequency bleaching by 2100. However, temporary increases in bleaching thresholds alone only delayed the occurrence of high-frequency bleaching by ca. 10 years in all but the lowest emissions scenario. Future research should test the rate and limit of different adaptive responses for coral species across latitudes and ocean basins to determine if and how much corals can respond to increasing thermal stress.
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20
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Ateweberhan M, Feary DA, Keshavmurthy S, Chen A, Schleyer MH, Sheppard CRC. Climate change impacts on coral reefs: synergies with local effects, possibilities for acclimation, and management implications. MARINE POLLUTION BULLETIN 2013; 74:526-539. [PMID: 23816307 DOI: 10.1016/j.marpolbul.2013.06.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/08/2013] [Indexed: 06/02/2023]
Abstract
Most reviews concerning the impact of climate change on coral reefs discuss independent effects of warming or ocean acidification. However, the interactions between these, and between these and direct local stressors are less well addressed. This review underlines that coral bleaching, acidification, and diseases are expected to interact synergistically, and will negatively influence survival, growth, reproduction, larval development, settlement, and post-settlement development of corals. Interactions with local stress factors such as pollution, sedimentation, and overfishing are further expected to compound effects of climate change. Reduced coral cover and species composition following coral bleaching events affect coral reef fish community structure, with variable outcomes depending on their habitat dependence and trophic specialisation. Ocean acidification itself impacts fish mainly indirectly through disruption of predation- and habitat-associated behavior changes. Zooxanthellate octocorals on reefs are often overlooked but are substantial occupiers of space; these also are highly susceptible to bleaching but because they tend to be more heterotrophic, climate change impacts mainly manifest in terms of changes in species composition and population structure. Non-calcifying macroalgae are expected to respond positively to ocean acidification and promote microbe-induced coral mortality via the release of dissolved compounds, thus intensifying phase-shifts from coral to macroalgal domination. Adaptation of corals to these consequences of CO2 rise through increased tolerance of corals and successful mutualistic associations between corals and zooxanthellae is likely to be insufficient to match the rate and frequency of the projected changes. Impacts are interactive and magnified, and because there is a limited capacity for corals to adapt to climate change, global targets of carbon emission reductions are insufficient for coral reefs, so lower targets should be pursued. Alleviation of most local stress factors such as nutrient discharges, sedimentation, and overfishing is also imperative if sufficient overall resilience of reefs to climate change is to be achieved.
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Affiliation(s)
- Mebrahtu Ateweberhan
- Department of Life Science, University of Warwick, CV4 7AL Coventry, United Kingdom.
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21
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Pey A, Catanéo J, Forcioli D, Merle PL, Furla P. Thermal threshold and sensitivity of the only symbiotic Mediterranean gorgonian Eunicella singularis by morphometric and genotypic analyses. C R Biol 2013; 336:331-41. [PMID: 23932253 DOI: 10.1016/j.crvi.2013.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 06/11/2013] [Accepted: 06/25/2013] [Indexed: 11/20/2022]
Abstract
The only symbiotic Mediterranean gorgonian, Eunicella singularis, has faced several mortality events connected to abnormal high temperatures. Since thermotolerance data remain scarce, heat-induced necrosis was monitored in aquarium by morphometric analysis. Gorgonian tips were sampled at two sites: Medes (Spain) and Riou (France) Islands, and at two depths: -15 m and-35 m. Although coming from contrasting thermal regimes, seawater above 28 °C led to rapid and complete tissue necrosis for all four populations. However, at 27 °C, the time length leading to 50% tissue necrosis allowed us to classify samples within three classes of thermal sensitivity. Irrespectively of the depth, Medes specimens were either very sensitive or resistant, while Riou fragments presented a medium sensitivity. Microsatellite analysis revealed that host and symbiont were genetically differentiated between sites, but not between depths. Finally, these genetic differentiations were not directly correlated to a specific thermal sensitivity whose molecular bases remain to be discovered.
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Affiliation(s)
- Alexis Pey
- Université Nice Sophia Antipolis, UMR "Systématique, Adaptation, Évolution", équipe "Symbiose marine", faculté des sciences, Nice, France
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22
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Dunlap WC, Starcevic A, Baranasic D, Diminic J, Zucko J, Gacesa R, van Oppen MJH, Hranueli D, Cullum J, Long PF. KEGG orthology-based annotation of the predicted proteome of Acropora digitifera: ZoophyteBase - an open access and searchable database of a coral genome. BMC Genomics 2013; 14:509. [PMID: 23889801 PMCID: PMC3750612 DOI: 10.1186/1471-2164-14-509] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/15/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Contemporary coral reef research has firmly established that a genomic approach is urgently needed to better understand the effects of anthropogenic environmental stress and global climate change on coral holobiont interactions. Here we present KEGG orthology-based annotation of the complete genome sequence of the scleractinian coral Acropora digitifera and provide the first comprehensive view of the genome of a reef-building coral by applying advanced bioinformatics. DESCRIPTION Sequences from the KEGG database of protein function were used to construct hidden Markov models. These models were used to search the predicted proteome of A. digitifera to establish complete genomic annotation. The annotated dataset is published in ZoophyteBase, an open access format with different options for searching the data. A particularly useful feature is the ability to use a Google-like search engine that links query words to protein attributes. We present features of the annotation that underpin the molecular structure of key processes of coral physiology that include (1) regulatory proteins of symbiosis, (2) planula and early developmental proteins, (3) neural messengers, receptors and sensory proteins, (4) calcification and Ca2+-signalling proteins, (5) plant-derived proteins, (6) proteins of nitrogen metabolism, (7) DNA repair proteins, (8) stress response proteins, (9) antioxidant and redox-protective proteins, (10) proteins of cellular apoptosis, (11) microbial symbioses and pathogenicity proteins, (12) proteins of viral pathogenicity, (13) toxins and venom, (14) proteins of the chemical defensome and (15) coral epigenetics. CONCLUSIONS We advocate that providing annotation in an open-access searchable database available to the public domain will give an unprecedented foundation to interrogate the fundamental molecular structure and interactions of coral symbiosis and allow critical questions to be addressed at the genomic level based on combined aspects of evolutionary, developmental, metabolic, and environmental perspectives.
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Affiliation(s)
- Walter C Dunlap
- Centre for Marine Microbiology and Genetics, Australian Institute of Marine Science, PMB No. 3 Townsville MC, Townsville 4810, Queensland, Australia
- Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - Antonio Starcevic
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Damir Baranasic
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Janko Diminic
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Jurica Zucko
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Ranko Gacesa
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Madeleine JH van Oppen
- Centre for Marine Microbiology and Genetics, Australian Institute of Marine Science, PMB No. 3 Townsville MC, Townsville 4810, Queensland, Australia
| | - Daslav Hranueli
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - John Cullum
- Department of Genetics, University of Kaiserslautern, Postfach 3049, 67653 Kaiserslautern, Germany
| | - Paul F Long
- Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom
- Department of Chemistry King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom
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23
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Rosic NN, Leggat W, Kaniewska P, Dove S, Hoegh-Guldberg O. New-old hemoglobin-like proteins of symbiotic dinoflagellates. Ecol Evol 2013; 3:822-34. [PMID: 23610627 PMCID: PMC3631397 DOI: 10.1002/ece3.498] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 01/04/2013] [Accepted: 01/17/2013] [Indexed: 11/24/2022] Open
Abstract
Symbiotic dinoflagellates are unicellular photosynthetic algae that live in mutualistic symbioses with many marine organisms. Within the transcriptome of coral endosymbionts Symbiodinium sp. (type C3), we discovered the sequences of two novel and highly polymorphic hemoglobin-like genes and proposed their 3D protein structures. At the protein level, four isoforms shared between 87 and 97% sequence identity for Hb-1 and 78-99% for Hb-2, whereas between Hb-1 and Hb-2 proteins, only 15-21% sequence homology has been preserved. Phylogenetic analyses of the dinoflagellate encoding Hb sequences have revealed a separate evolutionary origin of the discovered globin genes and indicated the possibility of horizontal gene transfer. Transcriptional regulation of the Hb-like genes was studied in the reef-building coral Acropora aspera exposed to elevated temperatures (6-7°C above average sea temperature) over a 24-h period and a 72-h period, as well as to nutrient stress. Exposure to elevated temperatures resulted in an increased Hb-1 gene expression of 31% after 72 h only, whereas transcript abundance of the Hb-2 gene was enhanced by up to 59% by both 1-day and 3-day thermal stress conditions. Nutrient stress also increased gene expression of Hb-2 gene by 70%. Our findings describe the differential expression patterns of two novel Hb genes from symbiotic dinoflagellates and their polymorphic nature. Furthermore, the inducible nature of Hb-2 gene by both thermal and nutrient stressors indicates a prospective role of this form of hemoglobin in the initial coral-algal responses to changes in environmental conditions. This novel hemoglobin has potential use as a stress biomarker.
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Affiliation(s)
- Nedeljka N Rosic
- School of Biological Sciences, The University of Queensland St. Lucia, Qld, 4072, Australia
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24
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Bellantuono AJ, Hoegh-Guldberg O, Rodriguez-Lanetty M. Resistance to thermal stress in corals without changes in symbiont composition. Proc Biol Sci 2012; 279:1100-7. [PMID: 21976690 PMCID: PMC3267153 DOI: 10.1098/rspb.2011.1780] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 09/12/2011] [Indexed: 02/01/2023] Open
Abstract
Discovering how corals can adjust their thermal sensitivity in the context of global climate change is important in understanding the long-term persistence of coral reefs. In this study, we showed that short-term preconditioning to higher temperatures, 3°C below the experimentally determined bleaching threshold, for a period of 10 days provides thermal tolerance for the symbiosis stability between the scleractinian coral, Acropora millepora and Symbiodinium. Based on genotypic analysis, our results indicate that the acclimatization of this coral species to thermal stress does not come down to simple changes in Symbiodinium and/or the bacterial communities that associate with reef-building corals. This suggests that the physiological plasticity of the host and/or symbiotic components appears to play an important role in responding to ocean warming. The further study of host and symbiont physiology, both of Symbiodinium and prokaryotes, is of paramount importance in the context of global climate change, as mechanisms for rapid holobiont acclimatization will become increasingly important to the long-standing persistence of coral reefs.
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Affiliation(s)
| | - Ove Hoegh-Guldberg
- Global Change Institute, University of Queensland, Saint Lucia, Queensland 4072, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
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Weston AJ, Dunlap WC, Shick JM, Klueter A, Iglic K, Vukelic A, Starcevic A, Ward M, Wells ML, Trick CG, Long PF. A profile of an endosymbiont-enriched fraction of the coral Stylophora pistillata reveals proteins relevant to microbial-host interactions. Mol Cell Proteomics 2012; 11:M111.015487. [PMID: 22351649 DOI: 10.1074/mcp.m111.015487] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
This study examines the response of Symbiodinium sp. endosymbionts from the coral Stylophora pistillata to moderate levels of thermal "bleaching" stress, with and without trace metal limitation. Using quantitative high throughput proteomics, we identified 8098 MS/MS events relating to individual peptides from the endosymbiont-enriched fraction, including 109 peptides meeting stringent criteria for quantification, of which only 26 showed significant change in our experimental treatments; 12 of 26 increased expression in response to thermal stress with little difference affected by iron limitation. Surprisingly, there were no significant increases in antioxidant or heat stress proteins; those induced to higher expression were generally involved in protein biosynthesis. An outstanding exception was a massive 114-fold increase of a viral replication protein indicating that thermal stress may substantially increase viral load and thereby contribute to the etiology of coral bleaching and disease. In the absence of a sequenced genome for Symbiodinium or other photosymbiotic dinoflagellate, this proteome reveals a plethora of proteins potentially involved in microbial-host interactions. This includes photosystem proteins, DNA repair enzymes, antioxidant enzymes, metabolic redox enzymes, heat shock proteins, globin hemoproteins, proteins of nitrogen metabolism, and a wide range of viral proteins associated with these endosymbiont-enriched samples. Also present were 21 unusual peptide/protein toxins thought to originate from either microbial consorts or from contamination by coral nematocysts. Of particular interest are the proteins of apoptosis, vesicular transport, and endo/exocytosis, which are discussed in context of the cellular processes of coral bleaching. Notably, the protein complement provides evidence that, rather than being expelled by the host, stressed endosymbionts may mediate their own departure.
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Affiliation(s)
- Andrew J Weston
- King's College London Proteomics Facility, Institute of Psychiatry, London SE5 8AF, United Kingdom
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MEYER E, AGLYAMOVA GV, MATZ MV. Profiling gene expression responses of coral larvae (Acropora millepora) to elevated temperature and settlement inducers using a novel RNA-Seq procedure. Mol Ecol 2011; 20:3599-616. [DOI: 10.1111/j.1365-294x.2011.05205.x] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Declining coral skeletal extension for forereef colonies of Siderastrea siderea on the Mesoamerican Barrier Reef System, Southern Belize. PLoS One 2011; 6:e14615. [PMID: 21359203 PMCID: PMC3040180 DOI: 10.1371/journal.pone.0014615] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 11/23/2010] [Indexed: 11/25/2022] Open
Abstract
Background Natural and anthropogenic stressors are predicted to have increasingly negative impacts on coral reefs. Understanding how these environmental stressors have impacted coral skeletal growth should improve our ability to predict how they may affect coral reefs in the future. We investigated century-scale variations in skeletal extension for the slow-growing massive scleractinian coral Siderastrea siderea inhabiting the forereef, backreef, and nearshore reefs of the Mesoamerican Barrier Reef System (MBRS) in the western Caribbean Sea. Methodology/Principal Findings Thirteen S. siderea cores were extracted, slabbed, and X-rayed. Annual skeletal extension was estimated from adjacent low- and high-density growth bands. Since the early 1900s, forereef S. siderea colonies have shifted from exhibiting the fastest to the slowest average annual skeletal extension, while values for backreef and nearshore colonies have remained relatively constant. The rates of change in annual skeletal extension were −0.020±0.005, 0.011±0.006, and −0.008±0.006 mm yr−1 per year [mean±SE] for forereef, backreef, and nearshore colonies respectively. These values for forereef and nearshore S. siderea were significantly lower by 0.031±0.008 and by 0.019±0.009 mm yr−1 per year, respectively, than for backreef colonies. However, only forereef S. siderea exhibited a statistically significant decline in annual skeletal extension over the last century. Conclusions/Significance Our results suggest that forereef S. siderea colonies are more susceptible to environmental stress than backreef and nearshore counterparts, which may have historically been exposed to higher natural baseline stressors. Alternatively, sediment plumes, nutrients, and pollution originating from watersheds of Guatemala and Honduras may disproportionately impact the forereef environment of the MBRS. We are presently reconstructing the history of environmental stressors that have impacted the MBRS to constrain the cause(s) of the observed reductions in coral skeletal growth. This should improve our ability to predict and potentially mitigate the effects of future environmental stressors on coral reef ecosystems.
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