1
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Helgoe J, Davy SK, Weis VM, Rodriguez-Lanetty M. Triggers, cascades, and endpoints: connecting the dots of coral bleaching mechanisms. Biol Rev Camb Philos Soc 2024; 99:715-752. [PMID: 38217089 DOI: 10.1111/brv.13042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/15/2024]
Abstract
The intracellular coral-dinoflagellate symbiosis is the engine that underpins the success of coral reefs, one of the most diverse ecosystems on the planet. However, the breakdown of the symbiosis and the loss of the microalgal symbiont (i.e. coral bleaching) due to environmental changes are resulting in the rapid degradation of coral reefs globally. There is an urgent need to understand the cellular physiology of coral bleaching at the mechanistic level to help develop solutions to mitigate the coral reef crisis. Here, at an unprecedented scope, we present novel models that integrate putative mechanisms of coral bleaching within a common framework according to the triggers (initiators of bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, e.g. photoinhibition, unfolded protein response, nitric oxide), and endpoints (mechanisms of symbiont loss, e.g. apoptosis, necrosis, exocytosis/vomocytosis). The models are supported by direct evidence from cnidarian systems, and indirectly through comparative evolutionary analyses from non-cnidarian systems. With this approach, new putative mechanisms have been established within and between cascades initiated by different bleaching triggers. In particular, the models provide new insights into the poorly understood connections between bleaching cascades and endpoints and highlight the role of a new mechanism of symbiont loss, i.e. 'symbiolysosomal digestion', which is different from symbiophagy. This review also increases the approachability of bleaching physiology for specialists and non-specialists by mapping the vast landscape of bleaching mechanisms in an atlas of comprehensible and detailed mechanistic models. We then discuss major knowledge gaps and how future research may improve the understanding of the connections between the diverse cascade of cellular pathways and the mechanisms of symbiont loss (endpoints).
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Affiliation(s)
- Joshua Helgoe
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 2701 SW Campus Way, 2403 Cordley Hall, Corvallis, OR, USA
| | - Mauricio Rodriguez-Lanetty
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
- Department of Biological Sciences, Biomolecular Sciences Institute, Florida International University, 11200 SW 8th Street, Miami, FL, USA
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2
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Zhou Y, Li Q, Zhang Q, Yuan M, Zhu X, Li Y, Li Q, Downs CA, Huang D, Chou LM, Zhao H. Environmental Concentrations of Herbicide Prometryn Render Stress-Tolerant Corals Susceptible to Ocean Warming. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4545-4557. [PMID: 38386019 DOI: 10.1021/acs.est.3c10417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Global warming has caused the degradation of coral reefs around the world. While stress-tolerant corals have demonstrated the ability to acclimatize to ocean warming, it remains unclear whether they can sustain their thermal resilience when superimposed with other coastal environmental stressors. We report the combined impacts of a photosystem II (PSII) herbicide, prometryn, and ocean warming on the stress-tolerant coral Galaxea fascicularis through physiological and omics analyses. The results demonstrate that the heat-stress-induced inhibition of photosynthetic efficiency in G. fascicularis is exacerbated in the presence of prometryn. Transcriptomics and metabolomics analyses indicate that the prometryn exposure may overwhelm the photosystem repair mechanism in stress-tolerant corals, thereby compromising their capacity for thermal acclimation. Moreover, prometryn might amplify the adverse effects of heat stress on key energy and nutrient metabolism pathways and induce a stronger response to oxidative stress in stress-tolerant corals. The findings indicate that the presence of prometryn at environmentally relevant concentrations would render corals more susceptible to heat stress and exacerbate the breakdown of coral Symbiodiniaceae symbiosis. The present study provides valuable insights into the necessity of prioritizing PSII herbicide pollution reduction in coral reef protection efforts while mitigating the effects of climate change.
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Affiliation(s)
- Yanyu Zhou
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Qiuli Li
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Quan Zhang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Meile Yuan
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Xiaoshan Zhu
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Yuanchao Li
- Hainan Academy of Ocean and Fisheries Sciences, Haikou 571126, China
| | - Qipei Li
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Craig A Downs
- Haereticus Environmental Laboratory, P.O. Box 92, Clifford, Virginia 24533, United States
| | - Danwei Huang
- Lee Kong Chian Natural History Museum, National University of Singapore, Singapore 117377, Singapore
- Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Loke-Ming Chou
- Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Hongwei Zhao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
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3
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Yu X, Yu K, Chen B, Liao Z, Liang J, Qin Z, Gao X. Metabolic and immune costs balance during natural acclimation of corals in fluctuating environments. MARINE ENVIRONMENTAL RESEARCH 2024; 193:106284. [PMID: 38048660 DOI: 10.1016/j.marenvres.2023.106284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/17/2023] [Accepted: 11/21/2023] [Indexed: 12/06/2023]
Abstract
Epigenetic modifications based on DNA methylation can rapidly improve the potential of corals to adapt to environmental pressures by increasing their phenotypic plasticity, a factor important for scleractinian corals to adapt to future global warming. However, the extent to which corals develop similar adaptive mechanisms and their specific adaptation processes remain unclear. Here, to reveal the regulatory mechanism by which DNA methylation improves thermal tolerance in Pocillopora damicornis under fluctuating environments, we analyzed genome-wide DNA methylation signatures in P. damicornis and compared the differences in the methylation and transcriptional responses of P. damicornis from fluctuating and stable environments using whole-genome bisulfite sequencing and nanopore-based RNA sequencingtranscriptome sequencing. We discovered low methylation levels in P. damicornis (average methylation 4.14%), with CpG accounting for 74.88%, CHH for 13.27%, and CHG for 11.85% of this methylation. However, methylation levels did not change between coral samples from the fluctuating and stable environments. The varied methylation levels in different regions of the gene revealed that the overall methylation level of the gene body was relatively high and showed a bimodal methylation pattern. Methylation occurs primarily in exons rather than introns within the gene body In P. damicornis, there was only a weak correlation between methylation and transcriptional changes at the individual gene level, and the methylation and gene expression levels generally exhibited a bell-shaped relationship, which we speculate may be due to the specificity of cnidarian species. Correlation analysis between methylation levels and the transcriptome revealed that the highest proportion of the top 20 enriched KEGG pathways was related to immunity. Additionally, P. damicornis collected from a high-temperature pool had a lower metabolic rate than those collected from a low-temperature pool. We hypothesize that the dynamic balance of energy-expenditure costs between immunity and metabolism is an important strategy for increasing P. damicornis tolerance. The fluctuating environment of high-temperature pools may increase the heat tolerance in corals by increasing their immunity and thus lowering their metabolism.
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Affiliation(s)
- Xiaopeng Yu
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning, China
| | - Kefu Yu
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
| | - Biao Chen
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning, China
| | - Zhiheng Liao
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning, China
| | - Jiayuan Liang
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning, China
| | - Zhenjun Qin
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning, China
| | - Xu Gao
- Guangxi University of Chinese Medicine, Nanning, Guangxi, China
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Selwyn JD, Vollmer SV. Whole genome assembly and annotation of the endangered Caribbean coral Acropora cervicornis. G3 (BETHESDA, MD.) 2023; 13:jkad232. [PMID: 37804092 PMCID: PMC10700113 DOI: 10.1093/g3journal/jkad232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/08/2023]
Abstract
Coral species in the genus Acropora are key ecological components of coral reefs worldwide and represent the most diverse genus of scleractinian corals. While key species of Indo-Pacific Acropora have annotated genomes, no annotated genome has been published for either of the two species of Caribbean Acropora. Here we present the first fully annotated genome of the endangered Caribbean staghorn coral, Acropora cervicornis. We assembled and annotated this genome using high-fidelity nanopore long-read sequencing with gene annotations validated with mRNA sequencing. The assembled genome size is 318 Mb, with 28,059 validated genes. Comparative genomic analyses with other Acropora revealed unique features in A. cervicornis, including contractions in immune pathways and expansions in signaling pathways. Phylogenetic analysis confirms previous findings showing that A. cervicornis diverged from Indo-Pacific relatives around 41 million years ago, with the closure of the western Tethys Sea, prior to the primary radiation of Indo-Pacific Acropora. This new A. cervicornis genome enriches our understanding of the speciose Acropora and addresses evolutionary inquiries concerning speciation and hybridization in this diverse clade.
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Affiliation(s)
- Jason D Selwyn
- Department of Marine and Environmental Sciences, Northeastern University, Nahant, MA 01908, USA
| | - Steven V Vollmer
- Department of Marine and Environmental Sciences, Northeastern University, Nahant, MA 01908, USA
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5
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Akbar MA, Mohd Yusof NY, Usup G, Ahmad A, Baharum SN, Bunawan H. Nutrient Deficiencies Impact on the Cellular and Metabolic Responses of Saxitoxin Producing Alexandrium minutum: A Transcriptomic Perspective. Mar Drugs 2023; 21:497. [PMID: 37755110 PMCID: PMC10532982 DOI: 10.3390/md21090497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 09/28/2023] Open
Abstract
Dinoflagellate Alexandrium minutum Halim is commonly associated with harmful algal blooms (HABs) in tropical marine waters due to its saxitoxin production. However, limited information is available regarding the cellular and metabolic changes of A. minutum in nutrient-deficient environments. To fill this gap, our study aimed to investigate the transcriptomic responses of A. minutum under nitrogen and phosphorus deficiency. The induction of nitrogen and phosphorus deficiency resulted in the identification of 1049 and 763 differently expressed genes (DEGs), respectively. Further analysis using gene set enrichment analysis (GSEA) revealed 702 and 1251 enriched gene ontology (GO) terms associated with nitrogen and phosphorus deficiency, respectively. Our results indicate that in laboratory cultures, nitrogen deficiency primarily affects meiosis, carbohydrate catabolism, ammonium assimilation, ion homeostasis, and protein kinase activity. On the other hand, phosphorus deficiency primarily affects the carbon metabolic response, cellular ion transfer, actin-dependent cell movement, signalling pathways, and protein recycling. Our study provides valuable insights into biological processes and genes regulating A. minutum's response to nutrient deficiencies, furthering our understanding of the ecophysiological response of HABs to environmental change.
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Affiliation(s)
- Muhamad Afiq Akbar
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Nurul Yuziana Mohd Yusof
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (N.Y.M.Y.); (G.U.)
| | - Gires Usup
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (N.Y.M.Y.); (G.U.)
| | - Asmat Ahmad
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Syarul Nataqain Baharum
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Hamidun Bunawan
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
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6
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Species-Specific Response of Corals to Imbalanced Ratios of Inorganic Nutrients. Int J Mol Sci 2023; 24:ijms24043119. [PMID: 36834529 PMCID: PMC9962417 DOI: 10.3390/ijms24043119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 02/09/2023] Open
Abstract
Dissolved inorganic phosphorus (DIP) is a limiting nutrient in the physiology of scleractinian corals. Anthropogenic addition of dissolved inorganic nitrogen (DIN) to coastal reefs increases the seawater DIN:DIP ratio and further increases P limitation, which is detrimental to coral health. The effects of imbalanced DIN:DIP ratios on coral physiology require further investigation in coral species other than the most studied branching corals. Here we investigated the nutrient uptake rates, elemental tissue composition and physiology of a foliose stony coral, Turbinaria reniformis, and a soft coral, Sarcophyton glaucum, exposed to four different DIN: DIP ratios (0.5:0.2, 0.5:1, 3:0.2, 3:1). The results show that T. reniformis had high uptake rates of DIN and DIP, proportional to the seawater nutrient concentrations. DIN enrichment alone led to an increase in tissue N content, shifting the tissue N:P ratio towards P limitation. However, S. glaucum had 5 times lower uptake rates and only took up DIN when the seawater was simultaneously enriched with DIP. This double uptake of N and P did not alter tissue stoichiometry. This study allows us to better understand the susceptibility of corals to changes in the DIN:DIP ratio and predict how coral species will respond under eutrophic conditions in the reef.
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7
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Davies SW, Gamache MH, Howe-Kerr LI, Kriefall NG, Baker AC, Banaszak AT, Bay LK, Bellantuono AJ, Bhattacharya D, Chan CX, Claar DC, Coffroth MA, Cunning R, Davy SK, del Campo J, Díaz-Almeyda EM, Frommlet JC, Fuess LE, González-Pech RA, Goulet TL, Hoadley KD, Howells EJ, Hume BCC, Kemp DW, Kenkel CD, Kitchen SA, LaJeunesse TC, Lin S, McIlroy SE, McMinds R, Nitschke MR, Oakley CA, Peixoto RS, Prada C, Putnam HM, Quigley K, Reich HG, Reimer JD, Rodriguez-Lanetty M, Rosales SM, Saad OS, Sampayo EM, Santos SR, Shoguchi E, Smith EG, Stat M, Stephens TG, Strader ME, Suggett DJ, Swain TD, Tran C, Traylor-Knowles N, Voolstra CR, Warner ME, Weis VM, Wright RM, Xiang T, Yamashita H, Ziegler M, Correa AMS, Parkinson JE. Building consensus around the assessment and interpretation of Symbiodiniaceae diversity. PeerJ 2023; 11:e15023. [PMID: 37151292 PMCID: PMC10162043 DOI: 10.7717/peerj.15023] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/17/2023] [Indexed: 05/09/2023] Open
Abstract
Within microeukaryotes, genetic variation and functional variation sometimes accumulate more quickly than morphological differences. To understand the evolutionary history and ecology of such lineages, it is key to examine diversity at multiple levels of organization. In the dinoflagellate family Symbiodiniaceae, which can form endosymbioses with cnidarians (e.g., corals, octocorals, sea anemones, jellyfish), other marine invertebrates (e.g., sponges, molluscs, flatworms), and protists (e.g., foraminifera), molecular data have been used extensively over the past three decades to describe phenotypes and to make evolutionary and ecological inferences. Despite advances in Symbiodiniaceae genomics, a lack of consensus among researchers with respect to interpreting genetic data has slowed progress in the field and acted as a barrier to reconciling observations. Here, we identify key challenges regarding the assessment and interpretation of Symbiodiniaceae genetic diversity across three levels: species, populations, and communities. We summarize areas of agreement and highlight techniques and approaches that are broadly accepted. In areas where debate remains, we identify unresolved issues and discuss technologies and approaches that can help to fill knowledge gaps related to genetic and phenotypic diversity. We also discuss ways to stimulate progress, in particular by fostering a more inclusive and collaborative research community. We hope that this perspective will inspire and accelerate coral reef science by serving as a resource to those designing experiments, publishing research, and applying for funding related to Symbiodiniaceae and their symbiotic partnerships.
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Affiliation(s)
- Sarah W. Davies
- Department of Biology, Boston University, Boston, MA, United States
| | - Matthew H. Gamache
- Department of Integrative Biology, University of South Florida, Tampa, FL, United States
| | | | | | - Andrew C. Baker
- Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, FL, United States
| | - Anastazia T. Banaszak
- Unidad Académica de Sistemas Arrecifales, Universidad Nacional Autónoma de México, Puerto Morelos, Mexico
| | - Line Kolind Bay
- Australian Institute of Marine Science, Townsville, Australia
| | - Anthony J. Bellantuono
- Department of Biological Sciences, Florida International University, Miami, FL, United States
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, United States
| | - Cheong Xin Chan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Danielle C. Claar
- Nearshore Habitat Program, Washington State Department of Natural Resources, Olympia, WA, USA
| | | | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL, United States
| | - Simon K. Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Javier del Campo
- Institut de Biologia Evolutiva (CSIC - Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | | | - Jörg C. Frommlet
- Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Lauren E. Fuess
- Department of Biology, Texas State University, San Marcos, TX, United States
| | - Raúl A. González-Pech
- Department of Integrative Biology, University of South Florida, Tampa, FL, United States
- Department of Biology, Pennsylvania State University, State College, PA, United States
| | - Tamar L. Goulet
- Department of Biology, University of Mississippi, University, MS, United States
| | - Kenneth D. Hoadley
- Department of Biological Sciences, University of Alabama—Tuscaloosa, Tuscaloosa, AL, United States
| | - Emily J. Howells
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | | | - Dustin W. Kemp
- Department of Biology, University of Alabama—Birmingham, Birmingham, Al, United States
| | - Carly D. Kenkel
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Sheila A. Kitchen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Todd C. LaJeunesse
- Department of Biology, Pennsylvania State University, University Park, PA, United States
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, Mansfield, CT, United States
| | - Shelby E. McIlroy
- Swire Institute of Marine Science, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Ryan McMinds
- Center for Global Health and Infectious Disease Research, University of South Florida, Tampa, FL, United States
| | | | - Clinton A. Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Raquel S. Peixoto
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Carlos Prada
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States
| | - Hollie M. Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States
| | | | - Hannah G. Reich
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States
| | - James Davis Reimer
- Department of Biology, Chemistry and Marine Sciences, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | | | - Stephanie M. Rosales
- The Cooperative Institute For Marine and Atmospheric Studies, Miami, FL, United States
| | - Osama S. Saad
- Department of Biological Oceanography, Red Sea University, Port-Sudan, Sudan
| | - Eugenia M. Sampayo
- School of Biological Sciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Scott R. Santos
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, United States
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Edward G. Smith
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Michael Stat
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Timothy G. Stephens
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, United States
| | - Marie E. Strader
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - David J. Suggett
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Timothy D. Swain
- Department of Marine and Environmental Science, Nova Southeastern University, Dania Beach, FL, United States
| | - Cawa Tran
- Department of Biology, University of San Diego, San Diego, CA, United States
| | - Nikki Traylor-Knowles
- Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, FL, United States
| | | | - Mark E. Warner
- School of Marine Science and Policy, University of Delaware, Lewes, DE, United States
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States
| | - Rachel M. Wright
- Department of Biological Sciences, Southern Methodist University, Dallas, TX, United States
| | - Tingting Xiang
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Hiroshi Yamashita
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Ishigaki, Okinawa, Japan
| | - Maren Ziegler
- Department of Animal Ecology & Systematics, Justus Liebig University Giessen (Germany), Giessen, Germany
| | | | - John Everett Parkinson
- Department of Integrative Biology, University of South Florida, Tampa, FL, United States
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8
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Nawaz K, Cziesielski MJ, Mariappan KG, Cui G, Aranda M. Histone modifications and DNA methylation act cooperatively in regulating symbiosis genes in the sea anemone Aiptasia. BMC Biol 2022; 20:265. [DOI: 10.1186/s12915-022-01469-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
Abstract
Background
The symbiotic relationship between cnidarians and dinoflagellates is one of the most widespread endosymbiosis in our oceans and provides the ecological basis of coral reef ecosystems. Although many studies have been undertaken to unravel the molecular mechanisms underlying these symbioses, we still know little about the epigenetic mechanisms that control the transcriptional responses to symbiosis.
Results
Here, we used the model organism Exaiptasia diaphana to study the genome-wide patterns and putative functions of the histone modifications H3K27ac, H3K4me3, H3K9ac, H3K36me3, and H3K27me3 in symbiosis. While we find that their functions are generally conserved, we observed that colocalization of more than one modification and or DNA methylation correlated with significantly higher gene expression, suggesting a cooperative action of histone modifications and DNA methylation in promoting gene expression. Analysis of symbiosis genes revealed that activating histone modifications predominantly associated with symbiosis-induced genes involved in glucose metabolism, nitrogen transport, amino acid biosynthesis, and organism growth while symbiosis-suppressed genes were involved in catabolic processes.
Conclusions
Our results provide new insights into the mechanisms of prominent histone modifications and their interaction with DNA methylation in regulating symbiosis in cnidarians.
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9
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Rouan A, Pousse M, Tambutté E, Djerbi N, Zozaya W, Capasso L, Zoccola D, Tambutté S, Gilson E. Telomere dysfunction is associated with dark-induced bleaching in the reef coral Stylophora pistillata. Mol Ecol 2022; 31:6087-6099. [PMID: 34587336 DOI: 10.1111/mec.16199] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 08/23/2021] [Accepted: 09/15/2021] [Indexed: 01/31/2023]
Abstract
Telomere DNA length is a complex trait controlled by both multiple loci and environmental factors. A growing number of studies are focusing on the impact of stress and stress accumulation on telomere length and the link with survival and fitness in ecological contexts. Here, we investigated the telomere changes occurring in a symbiotic coral, Stylophora pistillata, that has experienced continuous darkness over 6 months. This stress condition led to the loss of its symbionts in a similar manner to that observed during large-scale bleaching events due to climate changes and anthropogenic activities, threatening reef ecosystems worldwide. We found that continuous darkness was associated with telomere length shortening. This result, together with a phylogenetic analysis of the telomere coral proteins and a transcriptome survey of the continuous darkness condition, paves the way for future studies on the role of telomeres in the coral stress response and the importance of environmentally induced telomere shortening in endangered coral species.
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Affiliation(s)
- Alice Rouan
- Université Côte d'Azur-CNRS-Inserm, IRCAN, Nice, France
| | | | - Eric Tambutté
- Department of Marine Biology, Centre Scientifique de Monaco, Monte Carlo, Principality of Monaco
| | - Nadir Djerbi
- Université Côte d'Azur-CNRS-Inserm, IRCAN, Nice, France
| | | | - Laura Capasso
- Department of Marine Biology, Centre Scientifique de Monaco, Monte Carlo, Principality of Monaco.,Collège Doctoral, Sorbonne Université, Paris, France
| | - Didier Zoccola
- Department of Marine Biology, Centre Scientifique de Monaco, Monte Carlo, Principality of Monaco
| | - Sylvie Tambutté
- Department of Marine Biology, Centre Scientifique de Monaco, Monte Carlo, Principality of Monaco
| | - Eric Gilson
- Université Côte d'Azur-CNRS-Inserm, IRCAN, Nice, France.,Department of Medical Genetics, CHU, Nice, France
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10
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Cowen LJ, Putnam HM. Bioinformatics of Corals: Investigating Heterogeneous Omics Data from Coral Holobionts for Insight into Reef Health and Resilience. Annu Rev Biomed Data Sci 2022; 5:205-231. [PMID: 35537462 DOI: 10.1146/annurev-biodatasci-122120-030732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Coral reefs are home to over two million species and provide habitat for roughly 25% of all marine animals, but they are being severely threatened by pollution and climate change. A large amount of genomic, transcriptomic, and other omics data is becoming increasingly available from different species of reef-building corals, the unicellular dinoflagellates, and the coral microbiome (bacteria, archaea, viruses, fungi, etc.). Such new data present an opportunity for bioinformatics researchers and computational biologists to contribute to a timely, compelling, and urgent investigation of critical factors that influence reef health and resilience. Expected final online publication date for the Annual Review of Biomedical Data Science, Volume 5 is August 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Lenore J Cowen
- Department of Computer Science, Tufts University, Medford, Massachusetts, USA;
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, USA;
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11
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Schlecker L, Page C, Matz M, Wright RM. Mechanisms and potential immune tradeoffs of accelerated coral growth induced by microfragmentation. PeerJ 2022; 10:e13158. [PMID: 35368334 PMCID: PMC8973463 DOI: 10.7717/peerj.13158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 03/02/2022] [Indexed: 01/12/2023] Open
Abstract
Microfragmentation is the act of cutting corals into small pieces (~1 cm2) to accelerate the growth rates of corals relative to growth rates observed when maintaining larger-sized fragments. This rapid tissue and skeletal expansion technique offers great potential for supporting reef restoration, yet the biological processes and tradeoffs involved in microfragmentation-mediated accelerated growth are not well understood. Here we compared growth rates across a range of successively smaller fragment sizes in multiple genets of reef-building corals, Orbicella faveolata and Montastraea cavernosa. Our results confirm prior findings that smaller initial sizes confer accelerated growth after four months of recovery in a raceway. O. faveolata transcript levels associated with growth rate include genes encoding carbonic anhydrase and glutamic acid-rich proteins, which have been previously implicated in coral biomineralization, as well as a number of unannotated transcripts that warrant further characterization. Innate immunity enzyme activity assays and gene expression results suggest a potential tradeoff between growth rate after microfragmentation and immune investment. Microfragmentation-based restoration practices have had great success on Caribbean reefs, despite widespread mortality among wild corals due to infectious diseases. Future studies should continue to examine potential immune tradeoffs throughout the microfragmentation recovery period that may affect growout survival and disease transmission after outplanting.
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Affiliation(s)
| | | | - Mikhail Matz
- University of Texas at Austin, Austin, Texas, United States
| | - Rachel M. Wright
- Smith College, Northampton, Massachusetts, United States,University of Texas at Austin, Austin, Texas, United States
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12
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Roquis D, Cosseau C, Brener Raffalli K, Romans P, Masanet P, Mitta G, Grunau C, Vidal-Dupiol J. The tropical coral Pocillopora acuta displays an unusual chromatin structure and shows histone H3 clipping plasticity upon bleaching. Wellcome Open Res 2022; 6:195. [PMID: 35252590 PMCID: PMC8889044 DOI: 10.12688/wellcomeopenres.17058.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2022] [Indexed: 12/05/2022] Open
Abstract
Background: Pocillopora acuta is a hermatypic coral with strong ecological importance. Anthropogenic disturbances and global warming are major threats that can induce coral bleaching, the disruption of the mutualistic symbiosis between the coral host and its endosymbiotic algae. Previous works have shown that somaclonal colonies display different levels of survival depending on the environmental conditions they previously faced. Epigenetic mechanisms are good candidates to explain this phenomenon. However, almost no work had been published on the P. acuta epigenome, especially on histone modifications. In this study, we aim at providing the first insight into chromatin structure of this species. Methods: We aligned the amino acid sequence of P. acuta core histones with histone sequences from various phyla. We developed a centri-filtration on sucrose gradient to separate chromatin from the host and the symbiont. The presence of histone H3 protein and specific histone modifications were then detected by western blot performed on histone extraction done from bleached and healthy corals. Finally, micrococcal nuclease (MNase) digestions were undertaken to study nucleosomal organization. Results: The centri-filtration enabled coral chromatin isolation with less than 2% of contamination by endosymbiont material. Histone sequences alignments with other species show that P. acuta displays on average ~90% of sequence similarities with mice and ~96% with other corals. H3 detection by western blot showed that H3 is clipped in healthy corals while it appeared to be intact in bleached corals. MNase treatment failed to provide the usual mononucleosomal digestion, a feature shared with some cnidarian, but not all; suggesting an unusual chromatin structure. Conclusions: These results provide a first insight into the chromatin, nucleosome and histone structure of P. acuta. The unusual patterns highlighted in this study and partly shared with other cnidarian will need to be further studied to better understand its role in corals.
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Affiliation(s)
| | - Céline Cosseau
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Kelly Brener Raffalli
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Pascal Romans
- Observatoire Océanologique de Banyuls, Paris, France
| | - Patrick Masanet
- Aquarium de Canet-en-Roussillon, Canet-en-Roussillon, France
| | - Guillaume Mitta
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Christoph Grunau
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Jeremie Vidal-Dupiol
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
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13
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Alderdice R, Pernice M, Cárdenas A, Hughes DJ, Harrison PL, Boulotte N, Chartrand K, Kühl M, Suggett DJ, Voolstra CR. Hypoxia as a physiological cue and pathological stress for coral larvae. Mol Ecol 2021; 31:571-587. [PMID: 34716959 DOI: 10.1111/mec.16259] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022]
Abstract
Ocean deoxygenation events are intensifying worldwide and can rapidly drive adult corals into a state of metabolic crisis and bleaching-induced mortality, but whether coral larvae are subject to similar stress remains untested. We experimentally exposed apo-symbiotic coral larvae of Acropora selago to deoxygenation stress with subsequent reoxygenation aligned to their night-day light cycle, and followed their gene expression using RNA-Seq. After 12 h of deoxygenation stress (~2 mg O2 /L), coral planulae demonstrated a low expression of HIF-targeted hypoxia response genes concomitant with a significantly high expression of PHD2 (a promoter of HIFα proteasomal degradation), similar to corresponding adult corals. Despite exhibiting a consistent swimming phenotype compared to control samples, the differential gene expression observed in planulae exposed to deoxygenation-reoxygenation suggests a disruption of pathways involved in developmental regulation, mitochondrial activity, lipid metabolism, and O2 -sensitive epigenetic regulators. Importantly, we found that treated larvae exhibited a disruption in the expression of conserved HIF-targeted developmental regulators, for example, Homeobox (HOX) genes, corroborating how changes in external oxygen levels can affect animal development. We discuss how the observed deoxygenation responses may be indicative of a possible acclimation response or alternatively may imply negative latent impacts for coral larval fitness.
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Affiliation(s)
- Rachel Alderdice
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Mathieu Pernice
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - David J Hughes
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Peter L Harrison
- Marine Ecology Research Centre, Southern Cross University, Lismore, NSW, Australia
| | - Nadine Boulotte
- Marine Ecology Research Centre, Southern Cross University, Lismore, NSW, Australia
| | - Katie Chartrand
- Centre of Tropical Water and Aquatic Ecosystem Research, James Cook University, Townsville, Qld, Australia
| | - Michael Kühl
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia.,Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - David J Suggett
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
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14
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Trigg SA, Venkataraman YR, Gavery MR, Roberts SB, Bhattacharya D, Downey-Wall A, Eirin-Lopez JM, Johnson KM, Lotterhos KE, Puritz JB, Putnam HM. Invertebrate methylomes provide insight into mechanisms of environmental tolerance and reveal methodological biases. Mol Ecol Resour 2021; 22:1247-1261. [PMID: 34709728 DOI: 10.1111/1755-0998.13542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022]
Abstract
There is a growing focus on the role of DNA methylation in the ability of marine invertebrates to rapidly respond to changing environmental factors and anthropogenic impacts. However, genome-wide DNA methylation studies in nonmodel organisms are currently hampered by a limited understanding of methodological biases. Here, we compare three methods for quantifying DNA methylation at single base-pair resolution-whole genome bisulfite sequencing (WGBS), reduced representation bisulfite sequencing (RRBS), and methyl-CpG binding domain bisulfite sequencing (MBDBS)-using multiple individuals from two reef-building coral species with contrasting environmental sensitivity. All methods reveal substantially greater methylation in Montipora capitata (11.4%) than the more sensitive Pocillopora acuta (2.9%). The majority of CpG methylation in both species occurs in gene bodies and flanking regions. In both species, MBDBS has the greatest capacity for detecting CpGs in coding regions at our sequencing depth, but MBDBS may be influenced by intrasample methylation heterogeneity. RRBS yields robust information for specific loci albeit without enrichment of any particular genome feature and with significantly reduced genome coverage. Relative genome size strongly influences the number and location of CpGs detected by each method when sequencing depth is limited, illuminating nuances in cross-species comparisons. As genome-wide methylation differences, supported by data across bisulfite sequencing methods, may contribute to environmental sensitivity phenotypes in critical marine invertebrate taxa, these data provide a genomic resource for investigating the functional role of DNA methylation in environmental tolerance.
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Affiliation(s)
- Shelly A Trigg
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
| | - Yaamini R Venkataraman
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA.,Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Mackenzie R Gavery
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, USA
| | - Steven B Roberts
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, USA
| | - Alan Downey-Wall
- Department of Marine and Environmental Sciences, Northeastern University, Nahant, Massachusetts, USA
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, North Miami, Florida, USA
| | - Kevin M Johnson
- Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, California, USA.,California Sea Grant, University of California San Diego, La Jolla, California, USA
| | - Katie E Lotterhos
- Department of Marine and Environmental Sciences, Northeastern University, Nahant, Massachusetts, USA
| | - Jonathan B Puritz
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, USA
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15
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Rodriguez-Casariego JA, Cunning R, Baker AC, Eirin-Lopez JM. Symbiont shuffling induces differential DNA methylation responses to thermal stress in the coral Montastraea cavernosa. Mol Ecol 2021; 31:588-602. [PMID: 34689363 DOI: 10.1111/mec.16246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 12/11/2022]
Abstract
Algal symbiont shuffling in favour of more thermotolerant species has been shown to enhance coral resistance to heat-stress. Yet, the mechanistic underpinnings and long-term implications of these changes are poorly understood. This work studied the modifications in coral DNA methylation, an epigenetic mechanism involved in coral acclimatization, in response to symbiont manipulation and subsequent heat stress exposure. Symbiont composition was manipulated in the great star coral Montastraea cavernosa through controlled thermal bleaching and recovery, producing paired ramets of three genets dominated by either their native symbionts (genus Cladocopium) or the thermotolerant species (Durusdinium trenchi). Single-base genome-wide analyses showed significant modifications in DNA methylation concentrated in intergenic regions, introns and transposable elements. Remarkably, DNA methylation changes in response to heat stress were dependent on the dominant symbiont, with twice as many differentially methylated regions found in heat-stressed corals hosting different symbionts (Cladocopium vs. D. trenchii) compared to all other comparisons. Interestingly, while differential gene body methylation was not correlated with gene expression, an enrichment in differentially methylated regions was evident in repetitive genome regions. Overall, these results suggest that changes in algal symbionts favouring heat tolerant associations are accompanied by changes in DNA methylation in the coral host. The implications of these results for coral adaptation, along with future avenues of research based on current knowledge gaps, are discussed in the present work.
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Affiliation(s)
- Javier A Rodriguez-Casariego
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, Illinois, USA.,Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
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16
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Barno AR, Villela HDM, Aranda M, Thomas T, Peixoto RS. Host under epigenetic control: A novel perspective on the interaction between microorganisms and corals. Bioessays 2021; 43:e2100068. [PMID: 34463364 DOI: 10.1002/bies.202100068] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 12/13/2022]
Abstract
Coral reefs have been challenged by the current rate and severity of environmental change that might outpace their ability to adapt and survive. Current research focuses on understanding how microbial communities and epigenetic changes separately affect phenotypes and gene expression of corals. Here, we provide the hypothesis that coral-associated microorganisms may directly or indirectly affect the coral's phenotypic response through the modulation of its epigenome. Homologs of ankyrin-repeat protein A and internalin B, which indirectly cause histone modifications in humans, as well as Rv1988 histone methyltransferase, and the DNA methyltransferases Rv2966c, Mhy1, Mhy2, and Mhy3 found in coral-associated bacteria indicate that there are potential host epigenome-modifying proteins in the coral microbiome. With the ideas presented here, we suggest that microbiome manipulation may be a means to alter a coral's epigenome, which could aid the current efforts to protect coral reefs. Also see the video abstract here: https://youtu.be/CW9GbChjKM4.
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Affiliation(s)
- Adam R Barno
- Division of Biological and Environmental Science and Engineering (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Saudi Arabia
| | - Helena D M Villela
- Division of Biological and Environmental Science and Engineering (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Saudi Arabia
| | - Manuel Aranda
- Division of Biological and Environmental Science and Engineering (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Saudi Arabia
| | - Torsten Thomas
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
| | - Raquel S Peixoto
- Division of Biological and Environmental Science and Engineering (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Saudi Arabia.,Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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17
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Buist M, Fuss D, Rastegar M. Transcriptional Regulation of MECP2E1-E2 Isoforms and BDNF by Metformin and Simvastatin through Analyzing Nascent RNA Synthesis in a Human Brain Cell Line. Biomolecules 2021; 11:biom11081253. [PMID: 34439919 PMCID: PMC8391797 DOI: 10.3390/biom11081253] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 08/14/2021] [Accepted: 08/19/2021] [Indexed: 12/25/2022] Open
Abstract
Methyl CpG binding protein 2 (MeCP2) is the main DNA methyl-binding protein in the brain that binds to 5-methylcytosine and 5-hydroxymethyl cytosine. MECP2 gene mutations are the main origin of Rett Syndrome (RTT), a neurodevelopmental disorder in young females. The disease has no existing cure, however, metabolic drugs such as metformin and statins have recently emerged as potential therapeutic candidates. In addition, induced MECP2-BDNF homeostasis regulation has been suggested as a therapy avenue. Here, we analyzed nascent RNA synthesis versus steady state total cellular RNA to study the transcriptional effects of metformin (an anti-diabetic drug) on MECP2 isoforms (E1 and E2) and BNDF in a human brain cell line. Additionally, we investigated the impact of simvastatin (a cholesterol lowering drug) on transcriptional regulation of MECP2E1/E2-BDNF. Metformin was capable of post-transcriptionally inducing BDNF and/or MECP2E1, while transcriptionally inhibiting MECP2E2. In contrast simvastatin significantly inhibited BDNF transcription without significantly impacting MECP2E2 transcripts. Further analysis of ribosomal RNA transcripts confirmed that the drug neither individually nor in combination affected these fundamentally important transcripts. Experimental analysis was completed in conditions of the presence or absence of serum starvation that showed minimal impact for serum deprival, although significant inhibition of steady state MECP2E1 by simvastatin was only detected in non-serum starved cells. Taken together, our results suggest that metformin controls MECP2E1/E2-BDNF transcriptionally and/or post-transcriptionally, and that simvastatin is a potent transcriptional inhibitor of BDNF. The transcriptional effect of these drugs on MECP2E1/E2-BDNF were not additive under these tested conditions, however, either drug may have potential application for related disorders.
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Affiliation(s)
| | | | - Mojgan Rastegar
- Correspondence: ; Tel.: +1-(204)-272-3108; Fax: +1-(204)-789-3900
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18
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Rinkevich B. Augmenting coral adaptation to climate change via coral gardening (the nursery phase). JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 291:112727. [PMID: 33957417 DOI: 10.1016/j.jenvman.2021.112727] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 04/16/2021] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
Unceasing climate change and anthropogenic impacts on coral reefs worldwide lead the needs for augmenting adaptive potential of corals. Currently, the most successful approach for restoring degraded reefs is 'coral gardening', where corals are farmed in underwater nurseries, then outplanted to damaged reefs. Dealing with enhanced coral adaptation, the 'coral gardening' approach is conceptually structured here within a hierarchical list of five encircling tiers that include all restoration activities, focusing on the nursery phase. Each tier encompasses all the activities performed in the levels below it hierarchically. The first is the 'coral mariculture' tier, followed by the 'ecological engineering' tier. The third is the adaptation-based reef restoration (ABRR) tier, preceding the fourth ('ecosystem seascape') and the fifth ('ecosystem services') tiers. The ABRR tier is further conceptualized and its constituent five classes (phenotypic plasticity, assisted migration, epigenetics, coral chimerism, holobiont modification) are detailed. It is concluded that the nursery phase of the 'gardening' tenet may further serve as a platform to enhance the adaptation capacities of corals to climate change through the five ABBR classes. Employing the 'gardening' tiers in reef restoration without considering ABRR will scarcely be able to meet global targets for healthy reef ecosystems in the future.
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Affiliation(s)
- Baruch Rinkevich
- Israel Oceanography and Limnological Research, National Institute of Oceanography, Tel Shikmona, PO Box 9753, Haifa, 3109701, Israel.
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19
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Roquis D, Cosseau C, Brener Raffalli K, Romans P, Masanet P, Mitta G, Grunau C, Vidal-Dupiol J. The tropical coral Pocillopora acuta displays an unusual chromatin structure and shows histone H3 clipping plasticity upon bleaching. Wellcome Open Res 2021; 6:195. [PMID: 35252590 PMCID: PMC8889044 DOI: 10.12688/wellcomeopenres.17058.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2021] [Indexed: 05/13/2024] Open
Abstract
Background: Pocillopora acuta is a hermatypic coral with strong ecological importance. Anthropogenic disturbances and global warming are major threats that can induce coral bleaching, the disruption of the mutualistic symbiosis between the coral host and its endosymbiotic algae. Previous works have shown that somaclonal colonies display different levels of survival depending on the environmental conditions they previously faced. Epigenetic mechanisms are good candidates to explain this phenomenon. However, almost no work had been published on the P. acuta epigenome, especially on histone modifications. In this study, we aim at providing the first insight into chromatin structure of this species. Methods: We aligned the amino acid sequence of P. acuta core histones with histone sequences from various phyla. We developed a centri-filtration on sucrose gradient to separate chromatin from the host and the symbiont. The presence of histone H3 protein and specific histone modifications were then detected by western blot performed on histone extraction done from bleached and healthy corals. Finally, micrococcal nuclease (MNase) digestions were undertaken to study nucleosomal organization. Results: The centri-filtration enabled coral chromatin isolation with less than 2% of contamination by endosymbiont material. Histone sequences alignments with other species show that P. acuta displays on average ~90% of sequence similarities with mice and ~96% with other corals. H3 detection by western blot showed that H3 is clipped in healthy corals while it appeared to be intact in bleached corals. MNase treatment failed to provide the usual mononucleosomal digestion, a feature shared with some cnidarian, but not all; suggesting an unusual chromatin structure. Conclusions: These results provide a first insight into the chromatin, nucleosome and histone structure of P. acuta. The unusual patterns highlighted in this study and partly shared with other cnidarian will need to be further studied to better understand its role in corals.
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Affiliation(s)
| | - Céline Cosseau
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Kelly Brener Raffalli
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Pascal Romans
- Observatoire Océanologique de Banyuls, Paris, France
| | - Patrick Masanet
- Aquarium de Canet-en-Roussillon, Canet-en-Roussillon, France
| | - Guillaume Mitta
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Christoph Grunau
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
| | - Jeremie Vidal-Dupiol
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France
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20
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Hackerott S, Martell HA, Eirin-Lopez JM. Coral environmental memory: causes, mechanisms, and consequences for future reefs. Trends Ecol Evol 2021; 36:1011-1023. [PMID: 34366170 DOI: 10.1016/j.tree.2021.06.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 12/14/2022]
Abstract
The apparent ability of corals to acquire and maintain enhanced stress tolerance through a dose-dependent environmental memory, which may persist for multiple years, has critical implications for coral reef conservation research. Such responses are variable across coral species and environmental stressors, with primed corals exhibiting a modified response to secondary stress exposures. While the mechanisms underlying coral memory responses are poorly understood, they likely involve both the coral host and microbiome. With advances in molecular technologies, it is now possible to investigate potential memory mechanisms in non-model organisms, including transcriptional regulation through epigenetic modifications. We integrate evidence of coral environmental memory and suggest future research directions to evaluate the potential for this process to enhance coral resilience under climate change.
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Affiliation(s)
- Serena Hackerott
- Environmental Epigenetics Laboratory, Institute of Environment, Biological Sciences Department, Florida International University, North Miami, FL, 33181, USA
| | - Harmony A Martell
- Climate and Coastal Ecosystem Laboratory, Department of Geography & Institute of Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Laboratory, Institute of Environment, Biological Sciences Department, Florida International University, North Miami, FL, 33181, USA.
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21
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Rosner A, Armengaud J, Ballarin L, Barnay-Verdier S, Cima F, Coelho AV, Domart-Coulon I, Drobne D, Genevière AM, Jemec Kokalj A, Kotlarska E, Lyons DM, Mass T, Paz G, Pazdro K, Perić L, Ramšak A, Rakers S, Rinkevich B, Spagnuolo A, Sugni M, Cambier S. Stem cells of aquatic invertebrates as an advanced tool for assessing ecotoxicological impacts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 771:144565. [PMID: 33736145 DOI: 10.1016/j.scitotenv.2020.144565] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/10/2020] [Accepted: 12/13/2020] [Indexed: 06/12/2023]
Abstract
Environmental stressors are assessed through methods that quantify their impacts on a wide range of metrics including species density, growth rates, reproduction, behaviour and physiology, as on host-pathogen interactions and immunocompetence. Environmental stress may induce additional sublethal effects, like mutations and epigenetic signatures affecting offspring via germline mediated transgenerational inheritance, shaping phenotypic plasticity, increasing disease susceptibility, tissue pathologies, changes in social behaviour and biological invasions. The growing diversity of pollutants released into aquatic environments requires the development of a reliable, standardised and 3R (replacement, reduction and refinement of animals in research) compliant in vitro toolbox. The tools have to be in line with REACH regulation 1907/2006/EC, aiming to improve strategies for potential ecotoxicological risks assessment and monitoring of chemicals threatening human health and aquatic environments. Aquatic invertebrates' adult stem cells (ASCs) are numerous and can be pluripotent, as illustrated by high regeneration ability documented in many of these taxa. This is of further importance as in many aquatic invertebrate taxa, ASCs are able to differentiate into germ cells. Here we propose that ASCs from key aquatic invertebrates may be harnessed for applicable and standardised new tests in ecotoxicology. As part of this approach, a battery of modern techniques and endpoints are proposed to be tested for their ability to correctly identify environmental stresses posed by emerging contaminants in aquatic environments. Consequently, we briefly describe the current status of the available toxicity testing and biota-based monitoring strategies in aquatic environmental ecotoxicology and highlight some of the associated open issues such as replicability, consistency and reliability in the outcomes, for understanding and assessing the impacts of various chemicals on organisms and on the entire aquatic environment. Following this, we describe the benefits of aquatic invertebrate ASC-based tools for better addressing ecotoxicological questions, along with the current obstacles and possible overhaul approaches.
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Affiliation(s)
- Amalia Rosner
- Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Tel Shikmona, Haifa 3108001, Israel.
| | - Jean Armengaud
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, F-30200 Bagnols-sur-Cèze, France.
| | - Loriano Ballarin
- Department of Biology, University of Padova, via Ugo Bassi 58/B, 35121 Padova, Italy.
| | - Stéphanie Barnay-Verdier
- Sorbonne Université; CNRS, INSERM, Université Côte d'Azur, Institute for Research on Cancer and Aging Nice, F-06107 Nice, France.
| | - Francesca Cima
- Department of Biology, University of Padova, via Ugo Bassi 58/B, 35121 Padova, Italy.
| | - Ana Varela Coelho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| | - Isabelle Domart-Coulon
- Muséum National d'Histoire Naturelle, CNRS, Microorganism Communication and Adaptation Molecules MCAM, Paris F-75005, France.
| | - Damjana Drobne
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111,D, 1000 Ljubljana, Slovenia.
| | - Anne-Marie Genevière
- Sorbonne Université, CNRS, Integrative Biology of Marine Organisms, BIOM, F-6650 Banyuls-sur-mer, France.
| | - Anita Jemec Kokalj
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111,D, 1000 Ljubljana, Slovenia.
| | - Ewa Kotlarska
- Institute of Oceanology of the Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland.
| | - Daniel Mark Lyons
- Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, HR-52210 Rovinj, Croatia.
| | - Tali Mass
- Marine Biology Department, Leon H. Charney School of Marine Sciences, 199 Aba Khoushy Ave, University of Haifa, 3498838, Israel.
| | - Guy Paz
- Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Tel Shikmona, Haifa 3108001, Israel.
| | - Ksenia Pazdro
- Institute of Oceanology of the Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland
| | - Lorena Perić
- Rudjer Boskovic Institute, Laboratory for Aquaculture and Pathology of Aquaculture Organisms, Bijenička cesta 54, HR-10000 Zagreb, Croatia.
| | - Andreja Ramšak
- National Institute of Biology, Marine Biology Station, Fornače 41, 6330 Piran, Slovenia.
| | | | - Baruch Rinkevich
- Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Tel Shikmona, Haifa 3108001, Israel.
| | - Antonietta Spagnuolo
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
| | - Michela Sugni
- Department of Environmental Science and Policy, University of Milan, Via Celoria 2, 20133 Milano, Italy.
| | - Sébastien Cambier
- Luxembourg Institute of Science and Technology, 5, avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg.
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22
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Vogt G. Epigenetic variation in animal populations: Sources, extent, phenotypic implications, and ecological and evolutionary relevance. J Biosci 2021. [DOI: 10.1007/s12038-021-00138-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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23
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Putnam HM. Avenues of reef-building coral acclimatization in response to rapid environmental change. J Exp Biol 2021; 224:224/Suppl_1/jeb239319. [DOI: 10.1242/jeb.239319] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
ABSTRACT
The swiftly changing climate presents a challenge to organismal fitness by creating a mismatch between the current environment and phenotypes adapted to historic conditions. Acclimatory mechanisms may be especially crucial for sessile benthic marine taxa, such as reef-building corals, where climate change factors including ocean acidification and increasing temperature elicit strong negative physiological responses such as bleaching, disease and mortality. Here, within the context of multiple stressors threatening marine organisms, I describe the wealth of metaorganism response mechanisms to rapid ocean change and the ontogenetic shifts in organism interactions with the environment that can generate plasticity. I then highlight the need to consider the interactions of rapid and evolutionary responses in an adaptive (epi)genetic continuum. Building on the definitions of these mechanisms and continuum, I also present how the interplay of the microbiome, epigenetics and parental effects creates additional avenues for rapid acclimatization. To consider under what conditions epigenetic inheritance has a more substantial role, I propose investigation into the offset of timing of gametogenesis leading to different environmental integration times between eggs and sperm and the consequences of this for gamete epigenetic compatibility. Collectively, non-genetic, yet heritable phenotypic plasticity will have significant ecological and evolutionary implications for sessile marine organism persistence under rapid climate change. As such, reef-building corals present ideal and time-sensitive models for further development of our understanding of adaptive feedback loops in a multi-player (epi)genetic continuum.
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Affiliation(s)
- Hollie M. Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
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24
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Reich HG, Tu WC, Rodriguez IB, Chou Y, Keister EF, Kemp DW, LaJeunesse TC, Ho TY. Iron Availability Modulates the Response of Endosymbiotic Dinoflagellates to Heat Stress. JOURNAL OF PHYCOLOGY 2021; 57:3-13. [PMID: 32996595 DOI: 10.1111/jpy.13078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/03/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
Warming and nutrient limitation are stressors known to weaken the health of microalgae. In situations of stress, access to energy reserves can minimize physiological damage. Because of its widespread requirements in biochemical processes, iron is an important trace metal, especially for photosynthetic organisms. Lowered iron availability in oceans experiencing rising temperatures may contribute to the thermal sensitivity of reef-building corals, which rely on mutualisms with dinoflagellates to survive. To test the influence of iron concentration on thermal sensitivity, the physiological responses of cultured symbiotic dinoflagellates (genus Breviolum; family Symbiodiniaceae) were evaluated when exposed to increasing temperatures (26 to 30°C) and iron concentrations ranging from replete (500 pM Fe') to limiting (50 pM Fe') under a diurnal light cycle with saturating radiance. Declines in photosynthetic efficiency at elevated temperatures indicated sensitivity to heat stress. Furthermore, five times the amount of iron was needed to reach exponential growth during heat stress (50 pM Fe' at 26-28°C vs. 250 pM Fe' at 30°C). In treatments where exponential growth was reached, Breviolum psygmophilum grew faster than B.minutum, possibly due to greater cellular contents of iron and other trace metals. The metal composition of B.psygmophilum shifted only at the highest temperature (30°C), whereas changes in B.minutum were observed at lower temperatures (28°C). The influence of iron availability in modulating each alga's response to thermal stress suggests the importance of trace metals to the health of coral-algal mutualisms. Ultimately, a greater ability to acquire scarce metals may improve the tolerance of corals to physiological stressors and contribute to the differences in performance associated with hosting one symbiont species over another.
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Affiliation(s)
- Hannah G Reich
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Wan-Chen Tu
- Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan
| | - Irene B Rodriguez
- Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan
| | - Yalan Chou
- Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan
| | - Elise F Keister
- Department of Biology, The University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Dustin W Kemp
- Department of Biology, The University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Todd C LaJeunesse
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Tung-Yuan Ho
- Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
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25
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Wong JM, Hofmann GE. Gene expression patterns of red sea urchins (Mesocentrotus franciscanus) exposed to different combinations of temperature and pCO 2 during early development. BMC Genomics 2021; 22:32. [PMID: 33413121 PMCID: PMC7792118 DOI: 10.1186/s12864-020-07327-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The red sea urchin Mesocentrotus franciscanus is an ecologically important kelp forest herbivore and an economically valuable wild fishery species. To examine how M. franciscanus responds to its environment on a molecular level, differences in gene expression patterns were observed in embryos raised under combinations of two temperatures (13 °C or 17 °C) and two pCO2 levels (475 μatm or 1050 μatm). These combinations mimic various present-day conditions measured during and between upwelling events in the highly dynamic California Current System with the exception of the 17 °C and 1050 μatm combination, which does not currently occur. However, as ocean warming and acidification continues, warmer temperatures and higher pCO2 conditions are expected to increase in frequency and to occur simultaneously. The transcriptomic responses of the embryos were assessed at two developmental stages (gastrula and prism) in light of previously described plasticity in body size and thermotolerance under these temperature and pCO2 treatments. RESULTS Although transcriptomic patterns primarily varied by developmental stage, there were pronounced differences in gene expression as a result of the treatment conditions. Temperature and pCO2 treatments led to the differential expression of genes related to the cellular stress response, transmembrane transport, metabolic processes, and the regulation of gene expression. At each developmental stage, temperature contributed significantly to the observed variance in gene expression, which was also correlated to the phenotypic attributes of the embryos. On the other hand, the transcriptomic response to pCO2 was relatively muted, particularly at the prism stage. CONCLUSIONS M. franciscanus exhibited transcriptomic plasticity under different temperatures, indicating their capacity for a molecular-level response that may facilitate red sea urchins facing ocean warming as climate change continues. In contrast, the lack of a robust transcriptomic response, in combination with observations of decreased body size, under elevated pCO2 levels suggest that this species may be negatively affected by ocean acidification. High present-day pCO2 conditions that occur due to coastal upwelling may already be influencing populations of M. franciscanus.
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Affiliation(s)
- Juliet M Wong
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.
- Present address: Department of Biological Sciences, Florida International University, North Miami, FL, 33181, USA.
| | - Gretchen E Hofmann
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
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26
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Becker DM, Silbiger NJ. Nutrient and sediment loading affect multiple facets of functionality in a tropical branching coral. J Exp Biol 2020; 223:jeb225045. [PMID: 32943577 DOI: 10.1242/jeb.225045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 09/08/2020] [Indexed: 01/01/2023]
Abstract
Coral reefs, one of the most diverse ecosystems in the world, face increasing pressures from global and local anthropogenic stressors. Therefore, a better understanding of the ecological ramifications of warming and land-based inputs (e.g. sedimentation and nutrient loading) on coral reef ecosystems is necessary. In this study, we measured how a natural nutrient and sedimentation gradient affected multiple facets of coral functionality, including endosymbiont and coral host response variables, holobiont metabolic responses and percent cover of Pocillopora acuta colonies in Mo'orea, French Polynesia. We used thermal performance curves to quantify the relationship between metabolic rates and temperature along the environmental gradient. We found that algal endosymbiont percent nitrogen content, endosymbiont densities and total chlorophyll a content increased with nutrient input, while endosymbiont nitrogen content per cell decreased, likely representing competition among the algal endosymbionts. Nutrient and sediment loading decreased coral metabolic responses to thermal stress in terms of their thermal performance and metabolic rate processes. The acute thermal optimum for dark respiration decreased, along with the maximal performance for gross photosynthetic and calcification rates. Gross photosynthetic and calcification rates normalized to a reference temperature (26.8°C) decreased along the gradient. Lastly, percent cover of P. acuta colonies decreased by nearly two orders of magnitude along the nutrient gradient. These findings illustrate that nutrient and sediment loading affect multiple levels of coral functionality. Understanding how local-scale anthropogenic stressors influence the responses of corals to temperature can inform coral reef management, particularly in relation to the mediation of land-based inputs into coastal coral reef ecosystems.
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Affiliation(s)
- Danielle M Becker
- Department of Biology, California State University, Northridge, CA 91330, USA
| | - Nyssa J Silbiger
- Department of Biology, California State University, Northridge, CA 91330, USA
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27
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Genome-wide identification and transcriptional modulation of histone variants and modification related genes in the low pH-exposed marine rotifer Brachionus koreanus. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 36:100748. [PMID: 33032078 DOI: 10.1016/j.cbd.2020.100748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/05/2020] [Accepted: 09/18/2020] [Indexed: 11/22/2022]
Abstract
Histone modification is considered to be a major epigenetic control mechanism. These modifications (e.g. acetylation, phosphorylation, and methylation) may affect the interaction of histones with DNA and/or regulate DNA-based processes (e.g., recombination, repair, replication, and transcription) and chromatin remodeling complexes. Despite their significance in metazoan life and evolution, few studies have been conducted to identify genes undergoing epigenetic control modification in aquatic invertebrates. In this study, we identified whole core histones (70 total genes) and post-translational modification (PTM) histone genes (63 total genes) in the marine rotifer Brachionus koreanus through whole-genome analysis, and annotated them according to the human nomenclature. Notably, upon comparative analysis of cis-regulatory motif sequences, we found that B. koreanus core histone protein structures were similar to those of mammals. Furthermore, to examine the effect of parental low pH stress on the offspring's epigenetic regulation, we investigated the expression of PTM genes in two generations of B. koreanus exposed to low pH conditions. Given that the B. koreanus genome does not possess DNA methyltransferase 1 and 3 genes, we concluded that histone genes could be involved as an important epigenetic mechanism in B. koreanus. Therefore, the histone-associated genes identified in this study could be useful for ecotoxicological studies and facilitate the application of chromatin immunoprecipitation sequencing using high-throughput DNA sequencing based on the genome-wide identification of transcription factor binding sites in rotifers.
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28
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Luter HM, Andersen M, Versteegen E, Laffy P, Uthicke S, Bell JJ, Webster NS. Cross-generational effects of climate change on the microbiome of a photosynthetic sponge. Environ Microbiol 2020; 22:4732-4744. [PMID: 32869905 DOI: 10.1111/1462-2920.15222] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 08/13/2020] [Accepted: 08/27/2020] [Indexed: 01/04/2023]
Abstract
Coral reefs are facing increasing pressure from rising seawater temperatures and ocean acidification. Sponges have been proposed as possible winners in the face of climate change; however, little is known about the mechanisms underpinning their predicted tolerance. Here we assessed whether microbiome-mediated cross-generational acclimatization could enable the photosynthetic sponge Carteriospongia foliascens to survive under future climate scenarios. To achieve this, we first established the potential for vertical (cross-generational) transmission of symbionts. Sixty-four amplicon sequence variants accounting for >90% of the total C. foliascens microbial community were present across adult, larval and juvenile life stages, showing that a large proportion of the microbiome is vertically acquired and maintained. When C. foliascens were exposed to climate scenarios projected for 2050 and 2100, the host remained visibly unaffected (i.e. no necrosis/bleaching) and the overall microbiome was not significantly different amongst treatments in adult tissue, the respective larvae or recruits transplanted amongst climate treatments. However, indicator species analysis revealed that parental exposure to future climate scenarios altered the presence and abundance of a small suite of microbial taxa in the recruits, thereby revealing the potential for microbiome-mediated cross-generational acclimatization through both symbiont shuffling and symbiont switching within a vertically acquired microbiome.
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Affiliation(s)
- Heidi M Luter
- Australian Institute of Marine Science, QLD, Townsville, Australia.,School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Maria Andersen
- Australian Institute of Marine Science, QLD, Townsville, Australia.,AIMS@JCU, QLD, Townsville, Australia
| | - Elien Versteegen
- Australian Institute of Marine Science, QLD, Townsville, Australia.,AIMS@JCU, QLD, Townsville, Australia
| | - Patrick Laffy
- Australian Institute of Marine Science, QLD, Townsville, Australia
| | - Sven Uthicke
- Australian Institute of Marine Science, QLD, Townsville, Australia
| | - James J Bell
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Nicole S Webster
- Australian Institute of Marine Science, QLD, Townsville, Australia.,Australian Centre for Ecogenomics, University of Queensland, QLD, Brisbane, Australia
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29
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Morris LA, Voolstra CR, Quigley KM, Bourne DG, Bay LK. Nutrient Availability and Metabolism Affect the Stability of Coral-Symbiodiniaceae Symbioses. Trends Microbiol 2019; 27:678-689. [PMID: 30987816 DOI: 10.1016/j.tim.2019.03.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/28/2019] [Accepted: 03/13/2019] [Indexed: 01/19/2023]
Abstract
Coral reefs rely upon the highly optimized coral-Symbiodiniaceae symbiosis, making them sensitive to environmental change and susceptible to anthropogenic stress. Coral bleaching is predominantly attributed to photo-oxidative stress, yet nutrient availability and metabolism underpin the stability of symbioses. Recent studies link symbiont proliferation under nutrient enrichment to bleaching; however, the interactions between nutrients and symbiotic stability are nuanced. Here, we demonstrate how bleaching is regulated by the forms and ratios of available nutrients and their impacts on autotrophic carbon metabolism, rather than algal symbiont growth. By extension, historical nutrient conditions mediate host-symbiont compatibility and bleaching tolerance over proximate and evolutionary timescales. Renewed investigations into the coral nutrient metabolism will be required to truly elucidate the cellular mechanisms leading to coral bleaching.
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Affiliation(s)
- Luke A Morris
- AIMS@JCU, Australian Institute of Marine Science, College of Science and Engineering, James Cook University, Townsville, Australia; Australian Institute of Marine Science, Townsville, Australia; College of Science and Engineering, James Cook University, Townsville, Australia. https://twitter.com/ReefLuke
| | - Christian R Voolstra
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia. https://twitter.com/reefgenomics
| | - Kate M Quigley
- AIMS@JCU, Australian Institute of Marine Science, College of Science and Engineering, James Cook University, Townsville, Australia; Australian Institute of Marine Science, Townsville, Australia. https://twitter.com/la__cientifica
| | - David G Bourne
- AIMS@JCU, Australian Institute of Marine Science, College of Science and Engineering, James Cook University, Townsville, Australia; Australian Institute of Marine Science, Townsville, Australia; College of Science and Engineering, James Cook University, Townsville, Australia
| | - Line K Bay
- AIMS@JCU, Australian Institute of Marine Science, College of Science and Engineering, James Cook University, Townsville, Australia; Australian Institute of Marine Science, Townsville, Australia.
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