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Eckert RJ, Sturm AB, Carreiro AM, Klein AM, Voss JD. Cryptic diversity of shallow and mesophotic Stephanocoenia intersepta corals across Florida Keys National Marine Sanctuary. Heredity (Edinb) 2024; 133:137-148. [PMID: 38937604 PMCID: PMC11350147 DOI: 10.1038/s41437-024-00698-x] [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: 08/31/2023] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 06/29/2024] Open
Abstract
Population genetic analyses can provide useful data on species' regional connectivity and diversity which can inform conservation and restoration efforts. In this study, we quantified the genetic connectivity and diversity of Stephanocoenia intersepta corals from shallow (<30 m) to mesophotic (30-45 m) depths across Florida Keys National Marine Sanctuary. We generated single nucleotide polymorphism (SNP) markers to identify genetic structuring of shallow and mesophotic S. intersepta corals. We uncovered four distinct, cryptic genetic lineages with varying levels of depth-specificity. Shallow-specific lineages exhibited lower heterozygosity and higher inbreeding relative to depth-generalist lineages found across both shallow and mesophotic reefs. Estimation of recent genetic migration rates demonstrated that mesophotic sites are more prolific sources than shallow sites, particularly in the Lower Keys and Upper Keys. Additionally, we compared endosymbiotic Symbiodiniaceae among sampled S. intersepta using the ITS2 region and SYMPORTAL analysis framework, identifying symbionts from the genera Symbiodinium, Breviolum, and Cladocopium. Symbiodiniaceae varied significantly across depth and location and exhibited significant, but weak correlation with host lineage and genotype. Together, these data demonstrate that despite population genetic structuring across depth, some mesophotic populations may provide refuge for shallow populations moving forward and remain important contributors to the overall genetic diversity of this species throughout the region. This study highlights the importance of including mesophotic as well as shallow corals in population genetic assessments and informs future science-based management, conservation, and restoration efforts within Florida Keys National Marine Sanctuary.
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Affiliation(s)
- Ryan J Eckert
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA.
| | - Alexis B Sturm
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
| | - Ashley M Carreiro
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
| | - Allison M Klein
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
| | - Joshua D Voss
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
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2
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Li R, Deng Y, Shang L, Liu Y, Tao Z, Chai Z, Tang YZ. Evidence for the production of asexual resting cysts in a free-living species of Symbiodiniaceae (Dinophyceae). HARMFUL ALGAE 2024; 137:102658. [PMID: 39003022 DOI: 10.1016/j.hal.2024.102658] [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: 04/13/2024] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 07/15/2024]
Abstract
Coral reef ecosystems are the most productive and biodiverse marine ecosystems, with their productivity levels highly dependent on the symbiotic dinoflagellates belonging to the family Symbiodiniaceae. As a unique life history strategy, resting cyst production is of great significance in the ecology of many dinoflagellate species, those HABs-causing species in particular, however, there has been no confirmative evidence for the resting cyst production in any species of the family Symbiodiniaceae. Based on morphological and life history observations of cultures in the laboratory and morpho-molecular detections of cysts from the marine sediments via fluorescence in situ hybridization (FISH), cyst photography, and subsequent singe-cyst PCR sequencing, here we provide evidences for the asexual production of resting cysts by Effrenium voratum, the free-living, red tide-forming, and the type species of the genus Effrenium in Symbiodiniaceae. The evidences from the marine sediments were obtained through a sequential detections: Firstly, E. voratum amplicon sequence variants (ASVs) were detected in the cyst assemblages that were concentrated with the sodium polytungstate (SPT) method from the sediments collected from different regions of China Seas by high-throughput next generation sequencing (NGS); Secondly, the presence of E. voratum in the sediments was detected by PCR using the species-specific primers for the DNA directly extracted from sediment; Thirdly, E. voratum cysts were confirmed by a combined approach of FISH using the species-specific probes, light microscopic (LM) photography of the FISH-positive cysts, and a subsequent single-cyst PCR sequencing for the FISH-positive and photographed cysts. The evidences from the laboratory-reared clonal cultures of E. voratum include that: 1) numerous cysts formed in the two clonal cultures and exhibited a spherical shape, a smooth surface, absence of ornaments, and a large red accumulation body; 2) cysts could maintain morphologically intact for a storage of two weeks to six months at 4 °C in darkness and of which 76-92 % successfully germinated through an internal development processes within a time period of 3-21 days after being transferred back to the normal culturing conditions; 3) two or four germlings were released from each cyst through the cryptopylic archeopyle in all cysts with continuous observations of germination processes; and 4) while neither sexual mating of gametes nor planozygote (cells with two longitudinal flagella) were observed, the haploidy of cysts was proven with flow cytometric measurements and direct LM measurements of fluorescence from cells stained with either propidium iodide (PI) or DAPI, which together suggest that the cysts were formed asexually. All evidences led to a conclusion that E. voratum is capable of producing asexual resting cysts, although its sexuality cannot be completely excluded, which guarantees a more intensive investigation. This work fills a gap in the knowledge about the life cycle, particularly the potential of resting cyst formation, of the species in Symbiodiniaceae, a group of dinoflagellates having unique life forms and vital significance in the ecology of coral reefs, and may provide novel insights into understanding the recovery mechanisms of coral reefs destructed by the global climate change and suggest various forms of resting cysts in the cyst assemblages of dinoflagellates observed in the field sediments, including HABs-causing species.
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Affiliation(s)
- Ruoxi Li
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao, 266071 China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yunyan Deng
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao, 266071 China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Lixia Shang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao, 266071 China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yuyang Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao, 266071 China
| | - Zhe Tao
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao, 266071 China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaoyang Chai
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao, 266071 China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Ying Zhong Tang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao, 266071 China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
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3
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Cunning R, Lenz EA, Edmunds PJ. Measuring multi-year changes in the Symbiodiniaceae algae in Caribbean corals on coral-depleted reefs. PeerJ 2024; 12:e17358. [PMID: 38827291 PMCID: PMC11141555 DOI: 10.7717/peerj.17358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 04/18/2024] [Indexed: 06/04/2024] Open
Abstract
Monitoring coral cover can describe the ecology of reef degradation, but rarely can it reveal the proximal mechanisms of change, or achieve its full potential in informing conservation actions. Describing temporal variation in Symbiodiniaceae within corals can help address these limitations, but this is rarely a research priority. Here, we augmented an ecological time series of the coral reefs of St. John, US Virgin Islands, by describing the genetic complement of symbiotic algae in common corals. Seventy-five corals from nine species were marked and sampled in 2017. Of these colonies, 41% were sampled in 2018, and 72% in 2019; 28% could not be found and were assumed to have died. Symbiodiniaceae ITS2 sequencing identified 525 distinct sequences (comprising 42 ITS2 type profiles), and symbiont diversity differed among host species and individuals, but was in most cases preserved within hosts over 3 yrs that were marked by physical disturbances from major hurricanes (2017) and the regional onset of stony coral tissue loss disease (2019). While changes in symbiont communities were slight and stochastic over time within colonies, variation in the dominant symbionts among colonies was observed for all host species. Together, these results indicate that declining host abundances could lead to the loss of rare algal lineages that are found in a low proportion of few coral colonies left on many reefs, especially if coral declines are symbiont-specific. These findings highlight the importance of identifying Symbiodiniaceae as part of a time series of coral communities to support holistic conservation planning. Repeated sampling of tagged corals is unlikely to be viable for this purpose, because many Caribbean corals are dying before they can be sampled multiple times. Instead, random sampling of large numbers of corals may be more effective in capturing the diversity and temporal dynamics of Symbiodiniaceae metacommunities in reef corals.
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Affiliation(s)
- Ross Cunning
- Conservation Research Department, John G. Shedd Aquarium, Chicago, Illinois, United States
| | - Elizabeth A. Lenz
- University of Hawai‘i Sea Grant College Program, University of Hawai‘i at Mānoa, Honolulu, Hawaii, United States
| | - Peter J. Edmunds
- Department of Biology, California State University, Northridge, Northridge, California, United States
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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: 16] [Impact Index Per Article: 16.0] [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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5
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Sheahan K, Zarate D, Chalifour B, Li J. Intraspecific transfer of algal symbionts can occur in photosymbiotic Exaiptasia sea anemones. Symbiosis 2022. [DOI: 10.1007/s13199-022-00891-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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6
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Quigley KM, Ramsby B, Laffy P, Harris J, Mocellin VJL, Bay LK. Symbioses are restructured by repeated mass coral bleaching. SCIENCE ADVANCES 2022; 8:eabq8349. [PMID: 36475796 PMCID: PMC9728966 DOI: 10.1126/sciadv.abq8349] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Survival of symbiotic reef-building corals under global warming requires rapid acclimation or adaptation. The impact of accumulated heat stress was compared across 1643 symbiont communities before and after the 2016 mass bleaching in three coral species and free-living in the environment across ~900 kilometers of the Great Barrier Reef. Resilient reefs (less aerial bleaching than predicted from high satellite sea temperatures) showed low variation in symbioses. Before 2016, heat-tolerant environmental symbionts were common in ~98% of samples and moderately abundant (9 to 40% in samples). In corals, heat-tolerant symbionts were at low abundances (0 to 7.3%) but only in a minority (13 to 27%) of colonies. Following bleaching, environmental diversity doubled (including heat-tolerant symbionts) and increased in one coral species. Communities were dynamic (Acropora millepora) and conserved (Acropora hyacinthus and Acropora tenuis), including symbiont community turnover and redistribution. Symbiotic restructuring after bleaching occurs but is a taxon-specific ecological opportunity.
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Affiliation(s)
- Kate M. Quigley
- Australian Institute of Marine Science, Townsville, QLD, Australia
- Minderoo Foundation, Perth, WA, Australia
- Oceans Institute, University of Western Australia, Perth, WA, Australia
- James Cook University, Townsville, QLD, Australia
| | - Blake Ramsby
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Patrick Laffy
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | | | | | - Line K. Bay
- Australian Institute of Marine Science, Townsville, QLD, Australia
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7
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Kitchen SA, Jiang D, Harii S, Satoh N, Weis VM, Shinzato C. Coral larvae suppress heat stress response during the onset of symbiosis decreasing their odds of survival. Mol Ecol 2022; 31:5813-5830. [PMID: 36168983 DOI: 10.1111/mec.16708] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 09/06/2022] [Accepted: 09/15/2022] [Indexed: 01/13/2023]
Abstract
The endosymbiosis between most corals and their photosynthetic dinoflagellate partners begins early in the host life history, when corals are larvae or juvenile polyps. The capacity of coral larvae to buffer climate-induced stress while in the process of symbiont acquisition could come with physiological trade-offs that alter behaviour, development, settlement and survivorship. Here we examined the joint effects of thermal stress and symbiosis onset on colonization dynamics, survival, metamorphosis and host gene expression of Acropora digitifera larvae. We found that thermal stress decreased symbiont colonization of hosts by 50% and symbiont density by 98.5% over 2 weeks. Temperature and colonization also influenced larval survival and metamorphosis in an additive manner, where colonized larvae fared worse or prematurely metamorphosed more often than noncolonized larvae under thermal stress. Transcriptomic responses to colonization and thermal stress treatments were largely independent, while the interaction of these treatments revealed contrasting expression profiles of genes that function in the stress response, immunity, inflammation and cell cycle regulation. The combined treatment either cancelled or lowered the magnitude of expression of heat-stress responsive genes in the presence of symbionts, revealing a physiological cost to acquiring symbionts at the larval stage with elevated temperatures. In addition, host immune suppression, a hallmark of symbiosis onset under ambient temperature, turned to immune activation under heat stress. Thus, by integrating the physical environment and biotic pressures that mediate presettlement event in corals, our results suggest that colonization may hinder larval survival and recruitment under projected climate scenarios.
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Affiliation(s)
- Sheila A Kitchen
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, USA
| | - Duo Jiang
- Statistics Department, Oregon State University, Corvallis, Oregon, USA
| | - Saki Harii
- Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan
| | - Noriyuki Satoh
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, USA
| | - Chuya Shinzato
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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8
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Nitschke MR, Rosset SL, Oakley CA, Gardner SG, Camp EF, Suggett DJ, Davy SK. The diversity and ecology of Symbiodiniaceae: A traits-based review. ADVANCES IN MARINE BIOLOGY 2022; 92:55-127. [PMID: 36208879 DOI: 10.1016/bs.amb.2022.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Among the most successful microeukaryotes to form mutualisms with animals are dinoflagellates in the family Symbiodiniaceae. These photosynthetic symbioses drive significant primary production and are responsible for the formation of coral reef ecosystems but are particularly sensitive when environmental conditions become extreme. Annual episodes of widespread coral bleaching (disassociation of the mutualistic partnership) and mortality are forecasted from the year 2060 under current trends of ocean warming. However, host cnidarians and dinoflagellate symbionts display exceptional genetic and functional diversity, and meaningful predictions of the future that embrace this biological complexity are difficult to make. A recent move to trait-based biology (and an understanding of how traits are shaped by the environment) has been adopted to move past this problem. The aim of this review is to: (1) provide an overview of the major cnidarian lineages that are symbiotic with Symbiodiniaceae; (2) summarise the symbiodiniacean genera associated with cnidarians with reference to recent changes in taxonomy and systematics; (3) examine the knowledge gaps in Symbiodiniaceae life history from a trait-based perspective; (4) review Symbiodiniaceae trait variation along three abiotic gradients (light, nutrients, and temperature); and (5) provide recommendations for future research of Symbiodiniaceae traits. We anticipate that a detailed understanding of traits will further reveal basic knowledge of the evolution and functional diversity of these mutualisms, as well as enhance future efforts to model stability and change in ecosystems dependent on cnidarian-dinoflagellate organisms.
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Affiliation(s)
- Matthew R Nitschke
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand; Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia.
| | - Sabrina L Rosset
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Stephanie G Gardner
- Center for Marine Science and Innovation, University of New South Wales Sydney, Kensington, NSW, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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Camp EF, Nitschke MR, Clases D, Gonzalez de Vega R, Reich HG, Goyen S, Suggett DJ. Micronutrient content drives elementome variability amongst the Symbiodiniaceae. BMC PLANT BIOLOGY 2022; 22:184. [PMID: 35395710 PMCID: PMC8994382 DOI: 10.1186/s12870-022-03512-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Elements are the basis of life on Earth, whereby organisms are essentially evolved chemical substances that dynamically interact with each other and their environment. Determining species elemental quotas (their elementome) is a key indicator for their success across environments with different resource availabilities. Elementomes remain undescribed for functionally diverse dinoflagellates within the family Symbiodiniaceae that includes coral endosymbionts. We used dry combustion and ICP-MS to assess whether Symbiodiniaceae (ten isolates spanning five genera Breviolum, Cladocopium, Durusdinium, Effrenium, Symbiodinium) maintained under long-term nutrient replete conditions have unique elementomes (six key macronutrients and nine micronutrients) that would reflect evolutionarily conserved preferential elemental acquisition. For three isolates we assessed how elevated temperature impacted their elementomes. Further, we tested whether Symbiodiniaceae conform to common stoichiometric hypotheses (e.g., the growth rate hypothesis) documented in other marine algae. This study considers whether Symbiodiniaceae isolates possess unique elementomes reflective of their natural ecologies, evolutionary histories, and resistance to environmental change. RESULTS Symbiodiniaceae isolates maintained under long-term luxury uptake conditions, all exhibited highly divergent elementomes from one another, driven primarily by differential content of micronutrients. All N:P and C:P ratios were below the Redfield ratio values, whereas C:N was close to the Redfield value. Elevated temperature resulted in a more homogenised elementome across isolates. The Family-level elementome was (C19.8N2.6 P1.0S18.8K0.7Ca0.1) · 1000 (Fe55.7Mn5.6Sr2.3Zn0.8Ni0.5Se0.3Cu0.2Mo0.1V0.04) mmol Phosphorous-1 versus (C25.4N3.1P1.0S23.1K0.9Ca0.4) · 1000 (Fe66.7Mn6.3Sr7.2Zn0.8Ni0.4Se0.2Cu0.2Mo0.2V0.05) mmol Phosphorous -1 at 27.4 ± 0.4 °C and 30.7 ± 0.01 °C, respectively. Symbiodiniaceae isolates tested here conformed to some, but not all, stoichiometric principles. CONCLUSIONS Elementomes for Symbiodiniaceae diverge from those reported for other marine algae, primarily via lower C:N:P and different micronutrient expressions. Long-term maintenance of Symbiodiniaceae isolates in culture under common nutrient replete conditions suggests isolates have evolutionary conserved preferential uptake for certain elements that allows these unique elementomes to be identified. Micronutrient content (normalised to phosphorous) commonly increased in the Symbiodiniaceae isolates in response to elevated temperature, potentially indicating a common elemental signature to warming.
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Affiliation(s)
- Emma F Camp
- Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, Ultimo, NSW, 2007, Australia.
| | - Matthew R Nitschke
- Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, Ultimo, NSW, 2007, Australia
- School of Biological Sciences, Victoria University, Wellington, 6012, New Zealand
| | - David Clases
- The Atomic Medicine Initiative, University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia
- Institute of Chemistry, University of Graz, Graz, 8010, Austria
| | - Raquel Gonzalez de Vega
- The Atomic Medicine Initiative, University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia
- Institute of Chemistry, University of Graz, Graz, 8010, Austria
| | - Hannah G Reich
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, RI, 02881, USA
| | - Samantha Goyen
- Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, Ultimo, NSW, 2007, Australia
| | - David J Suggett
- Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, Ultimo, NSW, 2007, Australia
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10
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Proteome metabolome and transcriptome data for three Symbiodiniaceae under ambient and heat stress conditions. Sci Data 2022; 9:153. [PMID: 35383179 PMCID: PMC8983644 DOI: 10.1038/s41597-022-01258-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 03/14/2022] [Indexed: 12/12/2022] Open
Abstract
The Symbiodiniaceae are a taxonomically and functionally diverse family of marine dinoflagellates. Their symbiotic relationship with invertebrates such as scleractinian corals has made them the focus of decades of research to resolve the underlying biology regulating their sensitivity to stressors, particularly thermal stress. Research to-date suggests that Symbiodiniaceae stress sensitivity is governed by a complex interplay between phylogenetic dependent and independent traits (diversity of characteristics of a species). Consequently, there is a need for datasets that simultaneously broadly resolve molecular and physiological processes under stressed and non-stressed conditions. Therefore, we provide a dataset simultaneously generating transcriptome, metabolome, and proteome data for three ecologically important Symbiodiniaceae isolates under nutrient replete growth conditions and two temperature treatments (ca. 26 °C and 32 °C). Elevated sea surface temperature is primarily responsible for coral bleaching events that occur when the coral-Symbiodiniaceae relationship has been disrupted. Symbiodiniaceae can strongly influence their host's response to thermal stress and consequently it is necessary to resolve drivers of Symbiodiniaceae heat stress tolerance. We anticipate these datasets to expand our understanding on the key genotypic and functional properties that influence the sensitivities of Symbiodiniaceae to thermal stress.
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11
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Matsuda SB, Chakravarti LJ, Cunning R, Huffmyer AS, Nelson CE, Gates RD, van Oppen MJH. Temperature-mediated acquisition of rare heterologous symbionts promotes survival of coral larvae under ocean warming. GLOBAL CHANGE BIOLOGY 2022; 28:2006-2025. [PMID: 34957651 PMCID: PMC9303745 DOI: 10.1111/gcb.16057] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Reef-building corals form nutritional symbioses with endosymbiotic dinoflagellates (Symbiodiniaceae), a relationship that facilitates the ecological success of coral reefs. These symbionts are mostly acquired anew each generation from the environment during early life stages ("horizontal transmission"). Symbiodiniaceae species exhibit trait variation that directly impacts the health and performance of the coral host under ocean warming. Here, we test the capacity for larvae of a horizontally transmitting coral, Acropora tenuis, to establish symbioses with Symbiodiniaceae species in four genera that have varying thermal thresholds (the common symbiont genera, Cladocopium and Durusdinium, and the less common Fugacium and Gerakladium). Over a 2-week period in January 2018, a series of both no-choice and four-way choice experiments were conducted at three temperatures (27, 30, and 31°C). Symbiont acquisition success and cell proliferation were measured in individual larvae. Larvae successfully acquired and maintained symbionts of all four genera in no-choice experiments, and >80% of larvae were infected with at least three genera when offered a four-way choice. Unexpectedly, Gerakladium symbionts increased in dominance over time, and at high temperatures outcompeted Durusdinium, which is regarded as thermally tolerant. Although Fugacium displayed the highest thermal tolerance in culture and reached similar cell densities to the other three symbionts at 31°C, it remained a background symbiont in choice experiments, suggesting host preference for other symbiont species. Larval survivorship at 1 week was highest in larvae associated with Gerakladium and Fugacium symbionts at 27 and 30°C, however at 31°C, mortality was similar for all treatments. We hypothesize that symbionts that are currently rare in corals (e.g., Gerakladium) may become more common and widespread in early life stages under climate warming. Uptake of such symbionts may function as a survival strategy in the wild, and has implications for reef restoration practices that use sexually produced coral stock.
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Affiliation(s)
- Shayle B. Matsuda
- Hawai‘i Institute of Marine BiologyUniversity of Hawai‘i at MānoaKāne‘oheHawai‘iUSA
| | | | - Ross Cunning
- Daniel P. Haerther Center for Conservation and ResearchJohn G. Shedd AquariumChicagoIllinoisUSA
| | - Ariana S. Huffmyer
- Department of Biological SciencesUniversity of Rhode IslandKingstonRhode IslandUSA
| | - Craig E. Nelson
- Daniel K. Inouye Center for Microbial Oceanography: Research and EducationDepartment of Oceanography and Sea Grant College ProgramUniversity of Hawai‘i at MānoaHonoluluHawai‘iUSA
| | - Ruth D. Gates
- Hawai‘i Institute of Marine BiologyUniversity of Hawai‘i at MānoaKāne‘oheHawai‘iUSA
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine ScienceTownsvilleQueenslandAustralia
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
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12
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Contingency planning for coral reefs in the Anthropocene; The potential of reef safe havens. Emerg Top Life Sci 2022; 6:107-124. [PMID: 35225326 DOI: 10.1042/etls20210232] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/07/2022] [Accepted: 02/09/2022] [Indexed: 02/07/2023]
Abstract
Reducing the global reliance on fossil fuels is essential to ensure the long-term survival of coral reefs, but until this happens, alternative tools are required to safeguard their future. One emerging tool is to locate areas where corals are surviving well despite the changing climate. Such locations include refuges, refugia, hotspots of resilience, bright spots, contemporary near-pristine reefs, and hope spots that are collectively named reef 'safe havens' in this mini-review. Safe havens have intrinsic value for reefs through services such as environmental buffering, maintaining near-pristine reef conditions, or housing corals naturally adapted to future environmental conditions. Spatial and temporal variance in physicochemical conditions and exposure to stress however preclude certainty over the ubiquitous long-term capacity of reef safe havens to maintain protective service provision. To effectively integrate reef safe havens into proactive reef management and contingency planning for climate change scenarios, thus requires an understanding of their differences, potential values, and predispositions to stress. To this purpose, I provide a high-level review on the defining characteristics of different coral reef safe havens, how they are being utilised in proactive reef management and what risk and susceptibilities they inherently have. The mini-review concludes with an outline of the potential for reef safe haven habitats to support contingency planning of coral reefs under an uncertain future from intensifying climate change.
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13
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Reich HG, Kitchen SA, Stankiewicz KH, Devlin-Durante M, Fogarty ND, Baums IB. Genomic variation of an endosymbiotic dinoflagellate (Symbiodinium 'fitti') among closely related coral hosts. Mol Ecol 2021; 30:3500-3514. [PMID: 33964051 DOI: 10.1111/mec.15952] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 05/01/2021] [Accepted: 05/04/2021] [Indexed: 12/20/2022]
Abstract
Mutualisms where hosts are coupled metabolically to their symbionts often exhibit high partner fidelity. Most reef-building coral species form obligate symbioses with a specific species of photosymbionts, dinoflagellates in the family Symbiodiniaceae, despite needing to acquire symbionts early in their development from environmental sources. Three Caribbean acroporids (Acropora palmata, A. cervicornis and their F1 hybrid) are sympatric across much of their range, but often occupy different depth and light habitats. Throughout this range, both species and their hybrid associate with the endosymbiotic dinoflagellate Symbiodinium 'fitti'. Because light (and therefore depth) influences the physiology of dinoflagellates, we investigated whether S. 'fitti' populations from each host taxon were differentiated genetically. Single nucleotide polymorphisms (SNPs) among S. 'fitti' strains were identified by aligning shallow metagenomic sequences of acroporid colonies sampled from across the Caribbean to a ~600-Mb draft assembly of the S. 'fitti' genome (from the CFL14120 A. cervicornis metagenome). Phylogenomic and multivariate analyses revealed that genomic variation among S. 'fitti' strains partitioned to each host taxon rather than by biogeographical origin. This is particularly noteworthy because the hybrid has a sparse fossil record and may be of relatively recent origin. A subset (37.6%) of the SNPs putatively under selection were nonsynonymous mutations predicted to alter protein efficiency. Differences in genomic variation of S. 'fitti' strains from each host taxon may reflect the unique selection pressures created by the microenvironments associated with each host. The nonrandom sorting among S. 'fitti' strains to different hosts could be the basis for lineage diversification via disruptive selection, leading to ecological specialization and ultimately speciation.
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Affiliation(s)
- Hannah G Reich
- Department of Biology, The Pennsylvania State University, University Park, PA, USA
| | - Sheila A Kitchen
- Department of Biology, The Pennsylvania State University, University Park, PA, USA
| | | | | | - Nicole D Fogarty
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Iliana B Baums
- Department of Biology, The Pennsylvania State University, University Park, PA, USA
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14
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Li T, Chen X, Lin S. Physiological and transcriptomic responses to N-deficiency and ammonium: Nitrate shift in Fugacium kawagutii (Symbiodiniaceae). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:141906. [PMID: 32890873 DOI: 10.1016/j.scitotenv.2020.141906] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Symbiodiniaceae are the source of essential coral symbionts of reef building corals. The growth and density of endosymbiotic Symbiodiniaceae within the coral host is dependent on nutrient availability, yet little is known about how Symbiodiniaceae respond to the dynamics of the nutrients, including switch between different chemical forms and changes in abundance. In this study, we investigated physiological, cytometric, and transcriptomic responses in Fugacium kawagutii to nitrogen (N)-nutrient deficiency and different chemical N forms (nitrate and ammonium) in batch culture conditions. We mainly found that ammonium was consumed faster than nitrate when provided separately, and was preferentially utilized over nitrate when both N compounds were supplied at 1:2, 1:1 and 2:1 molarity ratios. Besides, N-deficiency caused decreases in growth, energy production, antioxidative capacity and investment in photosynthate transport but increased energy consumption. Growing on ammonium produced a similar cell yield as nitrate, but with a reduced investment in nutrient transport and assimilation; yet at high concentrations ammonium exhibited inhibitory effects. These findings together have important implications in N-nutrient regulation of coral symbiosis. In addition, we identified ten highly and stably expressed genes as candidate reference genes, which will be potentially useful for gene expression studies in the future.
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Affiliation(s)
- Tangcheng Li
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA
| | - Xibei Chen
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao 266237, China; Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
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15
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Fujise L, Suggett DJ, Stat M, Kahlke T, Bunce M, Gardner SG, Goyen S, Woodcock S, Ralph PJ, Seymour JR, Siboni N, Nitschke MR. Unlocking the phylogenetic diversity, primary habitats, and abundances of free-living Symbiodiniaceae on a coral reef. Mol Ecol 2020; 30:343-360. [PMID: 33141992 DOI: 10.1111/mec.15719] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 01/04/2023]
Abstract
Dinoflagellates of the family Symbiodiniaceae form mutualistic symbioses with marine invertebrates such as reef-building corals, but also inhabit reef environments as free-living cells. Most coral species acquire Symbiodiniaceae horizontally from the surrounding environment during the larval and/or recruitment phase, however the phylogenetic diversity and ecology of free-living Symbiodiniaceae on coral reefs is largely unknown. We coupled environmental DNA sequencing and genus-specific qPCR to resolve the community structure and cell abundances of free-living Symbiodiniaceae in the water column, sediment, and macroalgae and compared these to coral symbionts. Sampling was conducted at two time points, one of which coincided with the annual coral spawning event when recombination between hosts and free-living Symbiodiniaceae is assumed to be critical. Amplicons of the internal transcribed spacer (ITS2) region were assigned to 12 of the 15 Symbiodiniaceae genera or genera-equivalent lineages. Community compositions were separated by habitat, with water samples containing a high proportion of sequences corresponding to coral symbionts of the genus Cladocopium, potentially as a result of cell expulsion from in hospite populations. Sediment-associated Symbiodiniaceae communities were distinct, potentially due to the presence of exclusively free-living species. Intriguingly, macroalgal surfaces displayed the highest cell abundances of Symbiodiniaceae, suggesting a key role for macroalgae in ensuring the ecological success of corals through maintenance of a continuum between environmental and symbiotic populations of Symbiodiniaceae.
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Affiliation(s)
- Lisa Fujise
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - David J Suggett
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Michael Stat
- Trace and Environmental DNA (TrEnD) Laboratory, Curtin University, Bentley, Perth, WA, Australia.,School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, Australia
| | - Tim Kahlke
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Michael Bunce
- Trace and Environmental DNA (TrEnD) Laboratory, Curtin University, Bentley, Perth, WA, Australia
| | - Stephanie G Gardner
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia.,Centre for Marine Science and Innovation, University of New South Wales Australia, Kensington, NSW, Australia
| | - Samantha Goyen
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Stephen Woodcock
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Peter J Ralph
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Justin R Seymour
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Nachshon Siboni
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Matthew R Nitschke
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia.,School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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16
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Shi T, Niu G, Kvitt H, Zheng X, Qin Q, Sun D, Ji Z, Tchernov D. Untangling ITS2 genotypes of algal symbionts in zooxanthellate corals. Mol Ecol Resour 2020; 21:137-152. [PMID: 32876380 DOI: 10.1111/1755-0998.13250] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 08/10/2020] [Accepted: 08/17/2020] [Indexed: 11/28/2022]
Abstract
Collectively called zooxanthellae, photosynthetic dinoflagellates in the family Symbiodiniaceae are typical endosymbionts that unequivocally mediate coral responses to environmental changes. Symbiodiniaceae are genetically diverse, encompassing at least nine phylogenetically distinct genera (clades A-I). The ribosomal internal transcribed spacer 2 (ITS2) region is commonly utilized for determining Symbiodiniaceae diversity within clades. However, ITS2 is often inadvertently interpreted together with the tailing part of the ribosomal RNA genes (5.8S and 28S or equivalent), leading to unresolved taxonomy and equivocal annotations. To overcome this hurdle, we mined in GenBank and expert reference databases for ITS2 sequences of Symbiodiniaceae having explicit boundaries with adjacent rRNAs. We profiled a Hidden Markov Model of the ITS2-proximal 5.8S-28S rRNA interaction, which was shown to facilitate the delimitation of Symbiodiniaceae ITS2 from GenBank, while considerably reducing sequence ambiguity and redundancy in reference databases. The delineation of ITS2 sequences unveiled intra-clade sequence diversity and inter-clade secondary structure conservation. We compiled the clean data into a non-redundant database that archives the largest number of Symbiodiniaceae ITS2 sequences known to date with definite genotype/subclade representations and well-defined secondary structures. This database provides a fundamental reference catalog for consistent and precise genotyping of Symbiodiniaceae and a tool for automated annotation of user-supplied sequences.
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Affiliation(s)
- Tuo Shi
- Marine Genomics and Biotechnology Program, Institute of Marine Science and Technology, Shandong University, Qingdao, P. R. China.,State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, P. R. China
| | - Gaofeng Niu
- Marine Genomics and Biotechnology Program, Institute of Marine Science and Technology, Shandong University, Qingdao, P. R. China.,Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, P. R. China
| | - Hagit Kvitt
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel.,Israel Oceanographic and Limnological Research, National Center for Mariculture, Eilat, Israel
| | - Xinqing Zheng
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, P. R. China
| | - Qiaoyun Qin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, P. R. China
| | - Danye Sun
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, P. R. China
| | - Zhiliang Ji
- School of Life Sciences, Xiamen University, Xiamen, P. R. China
| | - Dan Tchernov
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
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17
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Li J, Long L, Zou Y, Zhang S. Microbial community and transcriptional responses to increased temperatures in coral Pocillopora damicornis holobiont. Environ Microbiol 2020; 23:826-843. [PMID: 32686311 PMCID: PMC7984454 DOI: 10.1111/1462-2920.15168] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 05/31/2020] [Accepted: 07/14/2020] [Indexed: 12/14/2022]
Abstract
A few studies have holistically examined successive changes in coral holobionts in response to increased temperatures. Here, responses of the coral host Pocillopora damicornis, its Symbiodiniaceae symbionts, and associated bacteria to increased water temperatures were investigated. High temperatures induced bleaching, but no coral mortality was observed. Transcriptome analyses showed that P. damicornis responded more quickly to elevated temperatures than its algal symbionts. Numerous genes putatively associated with apoptosis, exocytosis, and autophagy were upregulated in P. damicornis, suggesting that Symbiodiniaceae can be eliminated or expelled through these mechanisms when P. damicornis experiences heat stress. Furthermore, apoptosis in P. damicornis is presumably induced through tumour necrosis factor and p53 signalling and caspase pathways. The relative abundances of several coral disease-associated bacteria increased at 32°C, which may affect immune responses in heat-stressed corals and potentially accelerates the loss of algal symbionts. Additionally, consistency of Symbiodiniaceae community structures under heat stress suggests non-selective loss of Symbiodiniaceae. We propose that heat stress elicits interrelated response mechanisms in all parts of the coral holobiont.
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Affiliation(s)
- Jie Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China.,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Lijuan Long
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China.,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Yiyang Zou
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Si Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China.,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, Guangdong, China
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18
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Nitschke MR, Craveiro SC, Brandão C, Fidalgo C, Serôdio J, Calado AJ, Frommlet JC. Description of Freudenthalidium gen. nov. and Halluxium gen. nov. to Formally Recognize Clades Fr3 and H as Genera in the Family Symbiodiniaceae (Dinophyceae). JOURNAL OF PHYCOLOGY 2020; 56:923-940. [PMID: 32267533 DOI: 10.1111/jpy.12999] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/03/2020] [Indexed: 05/13/2023]
Abstract
The Symbiodiniaceae are a family of marine dinoflagellates known mostly for their endosymbiotic interactions with invertebrates and protists, but facultatively and exclusively free-living life histories in this family are also evident. A recent systematic revision of the Symbiodiniaceae replaced the clade-based nomenclature of seven divergent lineages of "Symbiodinium" sensu lato with one based on formally described genera. The revised taxonomy was not extended to the whole group because type species to describe a new genus for each of the remaining clades and subclades were lacking. In an effort to characterize benthic habitats of symbiodiniaceans in sediments at Heron Island (Great Barrier Reef, Australia), we isolated >100 monoclonal Symbiodiniaceae cultures. Four of these belonged to Symbiodiniaceae 'subclade' Fr3, and three to Clade H, based on nucleotide sequence similarity (ITS2, LSU, cp23S, and mtCOB), representing the first cultures of these taxa. Based on these isolates, we propose two new genera: Freudenthalidium gen. nov. and Halluxium gen. nov., circumscribing Clades Fr3 and H, respectively. Three new species are described: Freudenthalidium heronense, F. endolithicum, and Halluxium pauxillum. Kofoidian tabulations of motile cells confirm previous observations that amphiesmal vesicle arrangements are generally conserved across the family. These descriptions are an important step toward completing the systematic revision of the Symbiodiniaceae. That this contribution was enabled by isolates from an endopsammic habitat highlights the potential of discovering new symbiodiniacean species in the environment, the study of which will lead to a deeper understanding of free-living versus symbiotic life histories in this ecologically important family of dinoflagellates.
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Affiliation(s)
- Matthew R Nitschke
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193, Aveiro, Portugal
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6012, New Zealand
| | - Sandra C Craveiro
- Department of Biology and GeoBioTec Research Unit, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Cláudio Brandão
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193, Aveiro, Portugal
| | - Cátia Fidalgo
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193, Aveiro, Portugal
| | - João Serôdio
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193, Aveiro, Portugal
| | - António J Calado
- Department of Biology and GeoBioTec Research Unit, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Jörg C Frommlet
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193, Aveiro, Portugal
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19
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Guibert I, Bourdreux F, Bonnard I, Pochon X, Dubousquet V, Raharivelomanana P, Berteaux-Lecellier V, Lecellier G. Dimethylsulfoniopropionate concentration in coral reef invertebrates varies according to species assemblages. Sci Rep 2020; 10:9922. [PMID: 32555283 PMCID: PMC7303174 DOI: 10.1038/s41598-020-66290-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/18/2020] [Indexed: 11/28/2022] Open
Abstract
Dimethylsulfoniopropionate (DMSP) is a key compound in the marine sulfur cycle, and is produced in large quantities in coral reefs. In addition to Symbiodiniaceae, corals and associated bacteria have recently been shown to play a role in DMSP metabolism. Numerous ecological studies have focused on DMSP concentrations in corals, which led to the hypothesis that increases in DMSP levels might be a general response to stress. Here we used multiple species assemblages of three common Indo-Pacific holobionts, the scleractinian corals Pocillopora damicornis and Acropora cytherea, and the giant clam Tridacna maxima and examined the DMSP concentrations associated with each species within different assemblages and thermal conditions. Results showed that the concentration of DMSP in A. cytherea and T. maxima is modulated according to the complexity of species assemblages. To determine the potential importance of symbiotic dinoflagellates in DMSP production, we then explored the relative abundance of Symbiodiniaceae clades in relation to DMSP levels using metabarcoding, and found no significant correlation between these factors. Finally, this study also revealed the existence of homologs involved in DMSP production in giant clams, suggesting for the first time that, like corals, they may also contribute to DMSP production. Taken together, our results demonstrated that corals and giant clams play important roles in the sulfur cycle. Because DMSP production varies in response to specific species-environment interactions, this study offers new perspectives for future global sulfur cycling research.
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Affiliation(s)
- Isis Guibert
- Swire Institute of Marine Science, The University of Hong Kong, Hong Kong S.A.R, China.
- Sorbonne Université, UMR250/9220 ENTROPIE IRD-CNRS-UR-IFREMER-UNC, Promenade Roger-Laroque, Noumea cedex, New Caledonia, France.
- USR3278 PSL CRIOBE CNRS-EPHE-UPVD, LabEx CORAIL, Papetoai, Moorea, French Polynesia.
| | - Flavien Bourdreux
- Université de Paris-Saclay, UVSQ, 45 avenue des Etats-Unis, Versailles Cedex, France
- Institut Lavoisier de Versailles, UMR CNRS 8180, 45 avenue des Etats-Unis, Versailles Cedex, France
| | - Isabelle Bonnard
- USR3278 PSL CRIOBE CNRS-EPHE-UPVD, LabEx CORAIL, Université de Perpignan, 58 avenue Paul Alduy, 66860, Perpignan, France
| | - Xavier Pochon
- Coastal and Freshwater Group, Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
- Institute of Marine Science, University of Auckland, Private Bag 349, Warkworth, 0941, New Zealand
| | - Vaimiti Dubousquet
- Délégation à la recherche, Government of French Polynesia BP 20981, 98713, Papeete, Tahiti, French Polynesia
| | - Phila Raharivelomanana
- UMR 241 EIO, Université de la Polynésie Française, BP 6570 Faaa, 98702, Faaa, Tahiti, French Polynesia
| | - Véronique Berteaux-Lecellier
- USR3278 PSL CRIOBE CNRS-EPHE-UPVD, LabEx CORAIL, Papetoai, Moorea, French Polynesia
- UMR250/9220 ENTROPIE IRD-CNRS-UR-IFREMER-UNC, Promenade Roger-Laroque, Noumea cedex, New Caledonia, France
| | - Gael Lecellier
- Université de Paris-Saclay, UVSQ, 45 avenue des Etats-Unis, Versailles Cedex, France
- UMR250/9220 ENTROPIE IRD-CNRS-UR-IFREMER-UNC, Promenade Roger-Laroque, Noumea cedex, New Caledonia, France
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20
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McIlroy SE, Wong JCY, Baker DM. Competitive traits of coral symbionts may alter the structure and function of the microbiome. ISME JOURNAL 2020; 14:2424-2432. [PMID: 32518247 PMCID: PMC7490369 DOI: 10.1038/s41396-020-0697-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 05/06/2020] [Accepted: 05/14/2020] [Indexed: 01/08/2023]
Abstract
In the face of global warming and unprecedented coral bleaching, a new avenue of research is focused on relatively rare algal symbionts and their ability to confer thermal tolerance to their host by association. Yet, thermal tolerance is just one of many physiological attributes inherent to the diversity of symbiodinians, a result of millions of years of competition and niche partitioning. Here, we revealed that competition among cocultured symbiodinians alters nutrient assimilation and compound production with species-specific responses. For Cladocopium goreaui, a species ubiquitous within stable coral associations, temperature stress increased sensitivity to competition eliciting a shift toward investment in cell replication, i.e., putative niche exploitation. Meanwhile, competition led Durusdinium trenchii, a thermally tolerant “background” symbiodinian, to divert resources from immediate growth to storage. As such, competition may be driving the dominance of C. goreaui outside of temperature stress, the destabilization of symbioses under thermal stress, the repopulation of coral tissues by D. trenchii following bleaching, and ultimately undermine the efficacy of symbiont turnover as an adaptive mechanism.
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Affiliation(s)
- Shelby E McIlroy
- The Swire Institute of Marine Science, The University of Hong Kong, Hong Kong, Hong Kong, PRC.,School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong, PRC
| | - Jane C Y Wong
- The Swire Institute of Marine Science, The University of Hong Kong, Hong Kong, Hong Kong, PRC.,School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong, PRC
| | - David M Baker
- The Swire Institute of Marine Science, The University of Hong Kong, Hong Kong, Hong Kong, PRC. .,School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong, PRC.
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21
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Saad OS, Lin X, Ng TY, Li L, Ang P, Lin S. Genome Size, rDNA Copy, and qPCR Assays for Symbiodiniaceae. Front Microbiol 2020; 11:847. [PMID: 32528423 PMCID: PMC7264167 DOI: 10.3389/fmicb.2020.00847] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/08/2020] [Indexed: 11/29/2022] Open
Abstract
Symbiodiniaceae community structure in corals is crucial for understanding the plasticity of different holobionts under environmental stress. While this relies on molecular analyses, accuracy of molecular quantification, as influenced by DNA extraction efficiency and rDNA copy number variations in particular, has rarely been systematically investigated. Here, we report the development of a set of genus-specific qPCR assays. First, a protocol for efficient DNA isolation and accurate measurements of genome size and rDNA copy number was established. Second, seven newly designed genus-specific ITS2 primer sets were validated using computational and empirical analyses and qPCR assays were developed. We find that while the genome size ranges between 1.75 ± 0.21 and 4.5 ± 0.96 Gbp, rDNA copy number shows over 10-fold variation among Symbiodiniaceae species. Our protocol produced standard curves with high efficiencies (89.8–99.3%; R2 ≥ 0.999) and tight Cq values over different PCR conditions, illustrating high specificity and sensitivity of the qPCR assays. Tested on mock communities of mixed culture species, our qPCR results agreed well with microscopic counts and facilitated calibration of metabarcoding data. To test the applicability of our protocol for field samples, we analyzed three different Hong Kong coral samples. Six Symbiodiniaceae genera were detected in Acropora valida, Oulastrea crispata, and Platygyra acuta, with Breviolum, Effrenium, Fugacium, and Gerakladium sp. being reported for the first time. Our results suggest that aggressively disrupting cells to ensure thorough cell lysis, estimating cell loss and DNA loss, and validating qPCR assays are critical for success. The number of species examined here is limited, but the primers are potentially applicable to most species in respective genera, and the protocol and the approach to develop it provide a base and template toward a standardized procedure for quantitatively characterizing Symbiodiniaceae communities in corals.
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Affiliation(s)
- Osama S Saad
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.,Department of Biological Oceanography, Red Sea University, Port-Sudan, Sudan
| | - Xin Lin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Tsz Yan Ng
- Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ling Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Put Ang
- Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.,Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Hong Kong, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.,Department of Marine Sciences, University of Connecticut, Groton, CT, United States
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22
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Guibert I, Lecellier G, Torda G, Pochon X, Berteaux-Lecellier V. Metabarcoding reveals distinct microbiotypes in the giant clam Tridacna maxima. MICROBIOME 2020; 8:57. [PMID: 32317019 PMCID: PMC7175534 DOI: 10.1186/s40168-020-00835-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Giant clams and scleractinian (reef-building) corals are keystone species of coral reef ecosystems. The basis of their ecological success is a complex and fine-tuned symbiotic relationship with microbes. While the effect of environmental change on the composition of the coral microbiome has been heavily studied, we know very little about the composition and sensitivity of the microbiome associated with clams. Here, we explore the influence of increasing temperature on the microbial community (bacteria and dinoflagellates from the family Symbiodiniaceae) harbored by giant clams, maintained either in isolation or exposed to other reef species. We created artificial benthic assemblages using two coral species (Pocillopora damicornis and Acropora cytherea) and one giant clam species (Tridacna maxima) and studied the microbial community in the latter using metagenomics. RESULTS Our results led to three major conclusions. First, the health status of giant clams depended on the composition of the benthic species assemblages. Second, we discovered distinct microbiotypes in the studied T. maxima population, one of which was disproportionately dominated by Vibrionaceae and directly linked to clam mortality. Third, neither the increase in water temperature nor the composition of the benthic assemblage had a significant effect on the composition of the Symbiodiniaceae and bacterial communities of T. maxima. CONCLUSIONS Altogether, our results suggest that at least three microbiotypes naturally exist in the studied clam populations, regardless of water temperature. These microbiotypes plausibly provide similar functions to the clam host via alternate molecular pathways as well as microbiotype-specific functions. This redundancy in functions among microbiotypes together with their specificities provides hope that giant clam populations can tolerate some levels of environmental variation such as increased temperature. Importantly, the composition of the benthic assemblage could make clams susceptible to infections by Vibrionaceae, especially when water temperature increases. Video abstract.
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Affiliation(s)
- Isis Guibert
- Swire Institute of Marine Science, The University of Hong Kong, Hong Kong, SAR China
- UMR250/9220 ENTROPIE IRD-CNRS-UR, Promenade Roger-Laroque, Sorbonne Université, Noumea Cedex, New Caledonia France
- USR3278 PSL CRIOBE CNRS-EPHE-UPVD, Papetoai, Moorea, French Polynesia
| | - Gael Lecellier
- UMR250/9220 ENTROPIE IRD-CNRS-UR, Promenade Roger-Laroque, Sorbonne Université, Noumea Cedex, New Caledonia France
- UVSQ, Université de Paris-Saclay, 45 Avenue des Etats-Unis, Versailles Cedex, France
| | - Gergely Torda
- ARC, Centre of Excellence for Coral Reef Studies, James Cook University, QLD, Townsville, 4811 Australia
| | - Xavier Pochon
- Coastal and Freshwater Group, Cawthron Institute, Private Bag 2, Nelson, 7042 New Zealand
- Institute of Marine Science, University of Auckland, Private Bag 349, Warkworth, 0941 New Zealand
| | - Véronique Berteaux-Lecellier
- UMR250/9220 ENTROPIE IRD-CNRS-UR, Promenade Roger-Laroque, Sorbonne Université, Noumea Cedex, New Caledonia France
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23
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Eckert RJ, Reaume AM, Sturm AB, Studivan MS, Voss JD. Depth Influences Symbiodiniaceae Associations Among Montastraea cavernosa Corals on the Belize Barrier Reef. Front Microbiol 2020; 11:518. [PMID: 32328040 PMCID: PMC7160519 DOI: 10.3389/fmicb.2020.00518] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 03/10/2020] [Indexed: 12/21/2022] Open
Abstract
In Belize, shallow populations (10 and 16 m) of the coral species Montastraea cavernosa from the back reef and reef crest are genetically differentiated from deeper populations on the fore reef and reef wall (25 and 35 m). Like many species of scleractinian corals, M. cavernosa has an obligate symbiosis with dinoflagellate microalgae from the family Symbiodiniaceae. Here, we describe the Symbiodiniaceae taxa found within previously sampled and genotyped M. cavernosa populations along a depth gradient on the Belize Barrier Reef by implementing high-throughput sequencing of the ITS2 region of Symbiodiniaceae ribosomal DNA and the SymPortal analysis framework. While Symbiodiniaceae ITS2 type profiles across all sampling depths were almost entirely (99.99%) from the genus Cladocopium (formerly Symbiodinium Clade C), shallow (10 and 16 m) populations had a greater diversity of ITS2 type profiles in comparison to deeper (25 and 35 m) populations. Permutational multivariate analysis of variance (PERMANOVA) confirmed significant differences in ITS2 type profiles between shallow and deep sample populations. Overall Symbiodiniaceae communities changed significantly with depth, following patterns similar to the coral host's population genetic structure. Though physiological differences among species in the cosmopolitan genus Cladocopium are not well-described, our results suggest that although some members of Cladocopium are depth-generalists, shallow M. cavernosa populations in Belize may harbor shallow-specialized Symbiodiniaceae not found in deeper populations.
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Affiliation(s)
- Ryan J. Eckert
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Boca Raton, FL, United States
| | | | | | | | - Joshua D. Voss
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Boca Raton, FL, United States
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24
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Howe-Kerr LI, Bachelot B, Wright RM, Kenkel CD, Bay LK, Correa AMS. Symbiont community diversity is more variable in corals that respond poorly to stress. GLOBAL CHANGE BIOLOGY 2020; 26:2220-2234. [PMID: 32048447 DOI: 10.1111/gcb.14999] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 12/20/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
Coral reefs are declining globally as climate change and local water quality press environmental conditions beyond the physiological tolerances of holobionts-the collective of the host and its microbial symbionts. To assess the relationship between symbiont composition and holobiont stress tolerance, community diversity metrics were quantified for dinoflagellate endosymbionts (Family: Symbiodiniaceae) from eight Acropora millepora genets that thrived under or responded poorly to various stressors. These eight selected genets represent the upper and lower tails of the response distribution of 40 coral genets that were exposed to four stress treatments (and control conditions) in a 10-day experiment. Specifically, four 'best performer' coral genets were analyzed at the end of the experiment because they survived high temperature, high pCO2 , bacterial exposure, or combined stressors, whereas four 'worst performer' genets were characterized because they experienced substantial mortality under these stressors. At the end of the experiment, seven of eight coral genets mainly hosted Cladocopium symbionts, whereas the eighth genet was dominated by both Cladocopium and Durusdinium symbionts. Symbiodiniaceae alpha and beta diversity were higher in worst performing genets than in best performing genets. Symbiont communities in worst performers also differed more after stress exposure relative to their controls (based on normalized proportional differences in beta diversity), than did best performers. A generalized joint attribute model estimated the influence of host genet and treatment on Symbiodiniaceae community composition and identified strong associations among particular symbionts and host genet performance, as well as weaker associations with treatment. Although dominant symbiont physiology and function contribute to host performance, these findings emphasize the importance of symbiont community diversity and stochasticity as components of host performance. Our findings also suggest that symbiont community diversity metrics may function as indicators of resilience and have potential applications in diverse disciplines from climate change adaptation to agriculture and medicine.
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Affiliation(s)
| | | | | | - Carly D Kenkel
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Line K Bay
- Australian Institute of Marine Science, Townsville, Qld, Australia
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25
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Claar DC, Tietjen KL, Cox KD, Gates RD, Baum JK. Chronic disturbance modulates symbiont (Symbiodiniaceae) beta diversity on a coral reef. Sci Rep 2020; 10:4492. [PMID: 32161299 PMCID: PMC7066189 DOI: 10.1038/s41598-020-60929-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/30/2020] [Indexed: 11/09/2022] Open
Abstract
Chronic disturbance can disrupt ecological interactions including the foundational symbiosis between reef-building corals and the dinoflagellate family Symbiodiniaceae. Symbiodiniaceae are photosynthetic endosymbionts necessary for coral survival, but many Symbiodiniaceae can also be found free-living in the environment. Since most coral species acquire new Symbiodiniaceae from the environment each generation, free-living Symbiodiniaceae represent important pools for coral symbiont acquisition. Yet, little is known about the diversity of, or impacts of disturbance on, free-living Symbiodiniaceae. To determine how chronic and pulse disturbances influence Symbiodiniaceae communities, we sampled three reef habitat compartments - sediment, water, and coral (Pocillopora grandis, Montipora aequituberculata, Porites lobata) - at sites exposed to different levels of chronic anthropogenic disturbance, before, during, and after a major storm. Almost no (4%) Symbiodiniaceae amplicon sequence variants (ASVs) were found in all three compartments, and over half were found uniquely in coral. Sites experiencing chronic disturbance were typically associated with higher symbiont beta diversity (i.e., variability and turnover) across reef habitat compartments. Pulse stress, from the storm, exhibited some influence on symbiont beta diversity but the effect was inconsistent. This suggests that in this ecosystem, the effects of chronic disturbance are more prominent than temporal variability during a pulse disturbance for shaping symbiont communities.
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Affiliation(s)
- Danielle C Claar
- Department of Biology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada. .,University of Washington, School of Aquatic and Fisheries Science, 1122 NE Boat St, Seattle, WA, 98105, USA.
| | - Kristina L Tietjen
- Department of Biology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada
| | - Kieran D Cox
- Department of Biology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada.,Hakai Institute, Calvert Island, British Columbia, Canada
| | - Ruth D Gates
- Hawaii Institute of Marine Biology, Kaneohe, HI, 96744, USA
| | - Julia K Baum
- Department of Biology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada. .,Hawaii Institute of Marine Biology, Kaneohe, HI, 96744, USA.
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26
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Howells EJ, Bauman AG, Vaughan GO, Hume BCC, Voolstra CR, Burt JA. Corals in the hottest reefs in the world exhibit symbiont fidelity not flexibility. Mol Ecol 2020; 29:899-911. [DOI: 10.1111/mec.15372] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/17/2020] [Accepted: 01/29/2020] [Indexed: 12/25/2022]
Affiliation(s)
- Emily J. Howells
- Center for Genomics and Systems Biology New York University Abu Dhabi Abu Dhabi United Arab Emirates
- Centre for Sustainable Ecosystem Solutions and School of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong NSW Australia
| | - Andrew G. Bauman
- Experimental Marine Ecology Laboratory Department of Biological Sciences National University of Singapore Singapore City Singapore
| | - Grace O. Vaughan
- Center for Genomics and Systems Biology New York University Abu Dhabi Abu Dhabi United Arab Emirates
| | - Benjamin C. C. Hume
- Red Sea Research Center Division of Biological and Environmental Sciences and Engineering King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia
| | - Christian R. Voolstra
- Red Sea Research Center Division of Biological and Environmental Sciences and Engineering King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia
- Department of Biology University of Konstanz Konstanz Germany
| | - John A. Burt
- Center for Genomics and Systems Biology New York University Abu Dhabi Abu Dhabi United Arab Emirates
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27
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Matthews JL, Raina J, Kahlke T, Seymour JR, Oppen MJH, Suggett DJ. Symbiodiniaceae‐bacteria interactions: rethinking metabolite exchange in reef‐building corals as multi‐partner metabolic networks. Environ Microbiol 2020; 22:1675-1687. [DOI: 10.1111/1462-2920.14918] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Jennifer L. Matthews
- Climate Change Cluster University of Technology Sydney 2007 New South Wales Australia
| | - Jean‐Baptiste Raina
- Climate Change Cluster University of Technology Sydney 2007 New South Wales Australia
| | - Tim Kahlke
- Climate Change Cluster University of Technology Sydney 2007 New South Wales Australia
| | - Justin R. Seymour
- Climate Change Cluster University of Technology Sydney 2007 New South Wales Australia
| | - Madeleine J. H. Oppen
- The University of Melbourne Parkville 3010 Victoria Australia
- Australian Institute of Marine Science PMB No 3 Townsville MC 4810 QLD Australia
| | - David J. Suggett
- Climate Change Cluster University of Technology Sydney 2007 New South Wales Australia
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28
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Slattery M, Pankey MS, Lesser MP. Annual Thermal Stress Increases a Soft Coral's Susceptibility to Bleaching. Sci Rep 2019; 9:8064. [PMID: 31147567 PMCID: PMC6542812 DOI: 10.1038/s41598-019-44566-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/17/2019] [Indexed: 11/08/2022] Open
Abstract
Like scleractinian corals, soft corals contain photosymbionts (Family Symbiodiniaceae) that provide energy for the host. Recent thermal events have resulted in soft coral bleaching in four of five years on Guam, where they dominated back-reef communities. Soft coral bleaching was examined in Sinularia maxima, S. polydactyla, and their hybrid S. maxima x polydactyla. Results from annual field surveys indicated that S. maxima and the hybrid were more susceptible to bleaching than S. polydactyla, and this was related to differences in their Symbiodiniaceae communities in 2016 and 2017. The photosymbionts of S. polydactyla were apparently more stress tolerant and maintained higher photosynthetic potential through three years of bleaching, in contrast to the other species that exhibited a decline in photosynthetic potential after the first year of bleaching. Nonetheless, by the 2017 bleaching event all soft coral populations exhibited significant bleaching-mediated declines and loss of photosynthetic efficiency suggesting a declining resiliency to annual thermal stress events. While S. polydactyla initially looked to succeed the other species as the dominant space occupying soft coral on Guam back-reefs, cumulative bleaching events ultimately turned this "winner" into a "loser", suggesting the trajectory for coral reefs is towards continued loss of structure and function.
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Affiliation(s)
- Marc Slattery
- University of Mississippi, Department of BioMolecular Sciences, Oxford, MS, 38677, USA.
| | - M Sabrina Pankey
- University of New Hampshire, Department of Molecular, Cellular, and Biomedical Sciences, Durham, NH, 03824, USA
| | - Michael P Lesser
- University of New Hampshire, Department of Molecular, Cellular, and Biomedical Sciences, Durham, NH, 03824, USA
- University of New Hampshire, School of Marine Science and Ocean Engineering, Durham, NH, 03824, USA
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29
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Unique quantitative Symbiodiniaceae signature of coral colonies revealed through spatio-temporal survey in Moorea. Sci Rep 2019; 9:7921. [PMID: 31138834 PMCID: PMC6538640 DOI: 10.1038/s41598-019-44017-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 04/25/2019] [Indexed: 12/20/2022] Open
Abstract
One of the mechanisms of rapid adaptation or acclimatization to environmental changes in corals is through the dynamics of the composition of their associated endosymbiotic Symbiodiniaceae community. The various species of these dinoflagellates are characterized by different biological properties, some of which can confer stress tolerance to the coral host. Compelling evidence indicates that the corals’ Symbiodiniaceae community can change via shuffling and/or switching but the ecological relevance and the governance of these processes remain elusive. Using a qPCR approach to follow the dynamics of Symbiodiniaceae genera in tagged colonies of three coral species over a 10–18 month period, we detected putative genus-level switching of algal symbionts, with coral species-specific rates of occurrence. However, the dynamics of the corals’ Symbiodiniaceae community composition was not driven by environmental parameters. On the contrary, putative shuffling event were observed in two coral species during anomalous seawater temperatures and nutrient concentrations. Most notably, our results reveal that a suit of permanent Symbiodiniaceae genera is maintained in each colony in a specific range of quantities, giving a unique ‘Symbiodiniaceae signature’ to the host. This individual signature, together with sporadic symbiont switching may account for the intra-specific differences in resistance and resilience observed during environmental anomalies.
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30
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Pochon X, Wecker P, Stat M, Berteaux-Lecellier V, Lecellier G. Towards an in-depth characterization of Symbiodiniaceae in tropical giant clams via metabarcoding of pooled multi-gene amplicons. PeerJ 2019; 7:e6898. [PMID: 31139503 PMCID: PMC6521813 DOI: 10.7717/peerj.6898] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/02/2019] [Indexed: 11/20/2022] Open
Abstract
High-throughput sequencing is revolutionizing our ability to comprehensively characterize free-living and symbiotic Symbiodiniaceae, a diverse dinoflagellate group that plays a critical role in coral reef ecosystems. Most studies however, focus on a single marker for metabarcoding Symbiodiniaceae, potentially missing important ecological traits that a combination of markers may capture. In this proof-of-concept study, we used a small set of symbiotic giant clam (Tridacna maxima) samples obtained from nine French Polynesian locations and tested a dual-index sequence library preparation method that pools and simultaneously sequences multiple Symbiodiniaceae gene amplicons per sample for in-depth biodiversity assessments. The rationale for this approach was to allow the metabarcoding of multiple genes without extra costs associated with additional single amplicon dual indexing and library preparations. Our results showed that the technique effectively recovered very similar proportions of sequence reads and dominant Symbiodiniaceae clades among the three pooled gene amplicons investigated per sample, and captured varying levels of phylogenetic resolution enabling a more comprehensive assessment of the diversity present. The pooled Symbiodiniaceae multi-gene metabarcoding approach described here is readily scalable, offering considerable analytical cost savings while providing sufficient phylogenetic information and sequence coverage.
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Affiliation(s)
- Xavier Pochon
- Coastal & Freshwater Group, Cawthron Institute, Nelson, New Zealand
- Institute of Marine Science, University of Auckland, Auckland, New Zealand
| | | | - Michael Stat
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, Australia
| | | | - Gaël Lecellier
- UMR250/9220 ENTROPIE, IRD-CNRS-UR, LabEx CORAIL, Nouméa, New-Caledonia
- Université Paris-Saclay, UVSQ, Versailles Cedex, France
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Yang T, Cheng H, Wang H, Drews M, Li S, Huang W, Zhou H, Chen CM, Diao X. Comparative study of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in corals, surrounding sediments and surface water at the Dazhou Island, China. CHEMOSPHERE 2019; 218:157-168. [PMID: 30471496 DOI: 10.1016/j.chemosphere.2018.11.063] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/03/2018] [Accepted: 11/10/2018] [Indexed: 06/09/2023]
Abstract
This study investigated polycyclic aromatic hydrocarbons (PAHs) content in corals (Acropora sp.), surficial sediments, and surface seawater, and heavy metals (HMs) contents in corals and sediments from Dazhou Island, Hainan, China. Concentrations of PAHs in seawater and sediment seasonally ranged from 191.5 ng L-1 to 587.7 ng L-1, and from 37.9 ng g-1 to 233 ng g-1, while levels in corals were higher (185.2-545.0 ng g-1) compared to those found in sediments, demonstrating bioaccumulation of PAHs by corals. A similar seasonally variation of PAHs was observed in water/sediments and corals, and the proportions of low molecular weight PAHs (LPAHs) in seawater and corals were higher. Pyrolytic and petrogenic contaminations were identified to be the main sources of PAHs. Lower HMs concentrations were detected in corals (9.8-39.4 μg g-1) than in sediments (65.0-83.3 μg g-1), but HMs bioaccumulation still occurs in corals. Higher concentrations of HMs in sediment and corals were detected in March and December, especially Mn and Zn. Application of an enrichment factor showed that Cu in corals was delivered from non-crustal materials, and anthropogenic inputs were possibly the main sources. According to Biota Sediment Accumulation Factor, corals could strongly bioaccumulate LPAHs and Cd, and PAHs at a higher (p < 0.05) rate than HMs. There was a lack of correlation between the accumulation of PAHs and HMs in corals based on the cluster analysis. Dual hierarchical clustering analysis result revealed that feeding, instead of symbiosis, might be the main process responsible for the bioaccumulation of PAHs and HMs.
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Affiliation(s)
- Tinghan Yang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Huamin Cheng
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China; Xiamen University, Xiamen, 361102, China
| | - Haihua Wang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Marco Drews
- Leibniz Center for Marine Tropical Research, Bremen, 28359, Germany
| | - Sennan Li
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Wei Huang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Hailong Zhou
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Chien Min Chen
- Department of Environmental Resources and Management, Chia Nan University of Science and Pharmacy, Taiwan, ROC
| | - Xiaoping Diao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China.
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32
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Ziegler M, Stone E, Colman D, Takacs-Vesbach C, Shepherd U. Patterns of Symbiodinium (Dinophyceae) diversity and assemblages among diverse hosts and the coral reef environment of Lizard Island, Australia. JOURNAL OF PHYCOLOGY 2018; 54:447-460. [PMID: 29696650 PMCID: PMC6105428 DOI: 10.1111/jpy.12749] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Large-scale environmental disturbances may impact both partners in coral host-Symbiodinium systems. Elucidation of the assembly patterns in such complex and interdependent communities may enable better prediction of environmental impacts across coral reef ecosystems. In this study, we investigated how the community composition and diversity of dinoflagellate symbionts in the genus Symbiodinium were distributed among 12 host species from six taxonomic orders (Actinaria, Alcyonacea, Miliolida, Porifera, Rhizostoma, Scleractinia) and in the reef water and sediments at Lizard Island, Great Barrier Reef before the 3rd Global Coral Bleaching Event. 454 pyrosequencing of the ITS2 region of Symbiodinium yielded 83 operational taxonomic units (OTUs) at a 97% similarity cut-off. Approximately half of the Symbiodinium OTUs from reef water or sediments were also present in symbio. OTUs belonged to six clades (A-D, F-G), but community structure was uneven. The two most abundant OTUs (100% matches to types C1 and A3) comprised 91% of reads and OTU C1 was shared by all species. However, sequence-based analysis of these dominant OTUs revealed host species specificity, suggesting that genetic similarity cut-offs of Symbiodinium ITS2 data sets need careful evaluation. Of the less abundant OTUs, roughly half occurred at only one site or in one species and the background Symbiodinium communities were distinct between individual samples. We conclude that sampling multiple host taxa with differing life history traits will be critical to fully understand the symbiont diversity of a given system and to predict coral ecosystem responses to environmental change and disturbance considering the differential stress response of the taxa within.
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Affiliation(s)
- Maren Ziegler
- Author for correspondence: Maren Ziegler, 4700 King Abdullah University of Science and Technology (KAUST), Building 2, Office 2227, 3955-6900 Thuwal, Saudi Arabia, Tel.: +966 12 808 2446,
| | - Elizabeth Stone
- Department of Biology, University of New Mexico, Castetter Hall, MSC03-2020 1 University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Daniel Colman
- Department of Biology, University of New Mexico, Castetter Hall, MSC03-2020 1 University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Cristina Takacs-Vesbach
- Department of Biology, University of New Mexico, Castetter Hall, MSC03-2020 1 University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Ursula Shepherd
- Department of Biology, University of New Mexico, Castetter Hall, MSC03-2020 1 University of New Mexico, Albuquerque, New Mexico 87131, USA; Honors College, University of New Mexico, Student Health Center Building, MSCO6-3890 1 University of New Mexico, Albuquerque, New Mexico 87131, USA
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33
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34
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Barshis DJ, Birkeland C, Toonen RJ, Gates RD, Stillman JH. High-frequency temperature variability mirrors fixed differences in thermal limits of the massive coral Porites lobata (Dana, 1846). J Exp Biol 2018; 221:jeb.188581. [DOI: 10.1242/jeb.188581] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 10/05/2018] [Indexed: 12/16/2022]
Abstract
Spatial heterogeneity in environmental characteristics can drive adaptive differentiation when contrasting environments exert divergent selection pressures. This environmental and genetic heterogeneity can substantially influence population and community resilience to disturbance events. Here, we investigated corals from the highly variable back reef habitats of Ofu Island in American Samoa that thrive in thermal conditions known to elicit widespread bleaching and mortality elsewhere. To investigate the relative importance of acclimation vs. site of origin in shaping previously observed differences in coral tolerance limits in Ofu, specimens of the common Indo-Pacific coral Porites lobata (Dana, 1846) from locations with differing levels of thermal variability were acclimated to low and high thermal variation in controlled common garden aquaria. Overall, there were minimal effects of the acclimation exposure. Corals native to the site with the highest level of daily variability grew fastest, regardless of acclimation treatment. When exposed to lethal thermal stress, corals native to both variable sites contained elevated levels of heat shock proteins and maintained photosynthetic performance for 1-2 days longer than corals from the stable environment. Despite being separated by<5 km, there was significant genetic differentiation among coral colonies (FST=0.206, p<0.0001; nuclear ribosomal DNA), while Symbiodiniaceae were all Cladocopium sp. (ITS-type C15). Our study demonstrates consistent signatures of adaptation in growth and stress resistance in corals from naturally thermally variable habitats, suggesting that differences in the amount of thermal variability may be an important contributor to adaptive differentiation in reef building corals.
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Affiliation(s)
- D. J. Barshis
- Old Dominion University, Department of Biology, Norfolk VA, USA
| | - C. Birkeland
- University of Hawai'i at Manoa, Department of Biology, Honolulu HI, USA
| | - R. J. Toonen
- Hawai'i Institute of Marine Biology, Kaneohe HI, USA
| | - R. D. Gates
- Hawai'i Institute of Marine Biology, Kaneohe HI, USA
| | - J. H. Stillman
- Estuary & Ocean Science Center, Romberg Tiburon Campus and Department of Biology, San Francisco State University, Tiburon CA, USA
- Department of Integrative Biology, University of California Berkeley, Berkeley CA, USA
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35
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Zhou G, Cai L, Li Y, Tong H, Jiang L, Zhang Y, Lei X, Guo M, Liu S, Qian PY, Huang H. Temperature-Driven Local Acclimatization of Symbiodnium Hosted by the Coral Galaxea fascicularis at Hainan Island, China. Front Microbiol 2017; 8:2487. [PMID: 29312196 PMCID: PMC5733085 DOI: 10.3389/fmicb.2017.02487] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 11/29/2017] [Indexed: 11/13/2022] Open
Abstract
The success of coral reef ecosystems largely depends on mutualistic symbiosis between scleractinian corals and the dinoflagellate photosymbiont Symbiodinium spp. However, further investigation is needed to elucidate the flexibility of coral-algae associations in response to environmental changes. In this study, we applied a molecular method (high-throughput internal transcribed spacer 2 region of ribosomal RNA gene amplicon sequencing) to explore diversity and flexibility of Symbiodinium associated with Galaxea fascicularis, an ecologically important scleractinian coral species collected at five locations around Hainan Island, South China Sea. The results revealed a high diversity of Symbiodinium subclades with C2r and D17 being dominant in G. fascicularis. Clade D Symbiodinium occurred most frequently in habitats where the annual average sea surface temperatures are the highest, suggesting that temperature is an important factor in determining Symbiodinium D abundance in G. fascicularis. The distribution of coral-Symbiodinium associations are possibly mediated by trade-off mechanisms which change the relative abundance of Symbiodinium clades/subclades under different environmental conditions. These findings provide further evidence that reef-building corals such as G. fascicularis can shuffle their symbionts to cope with environmental changes, and have implications for our understanding of the ecology of flexible coral-algal symbiosis.
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Affiliation(s)
- Guowei Zhou
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,Tropical Marine Biological Research Station in Hainan, Sanya Joint Laboratory of Marine Science Research, Chinese Academy of Sciences, Sanya, China
| | - Lin Cai
- Shenzhen Research Institute and Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, Hong Kong
| | - Yuanchao Li
- Hainan Academy of Ocean and Fisheries Sciences, Haikou, China
| | - Haoya Tong
- Shenzhen Research Institute and Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, Hong Kong
| | - Lei Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Yuyang Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Xinming Lei
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Minglan Guo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Sheng Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Pei-Yuan Qian
- Shenzhen Research Institute and Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, Hong Kong
| | - Hui Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,Tropical Marine Biological Research Station in Hainan, Sanya Joint Laboratory of Marine Science Research, Chinese Academy of Sciences, Sanya, China
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36
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Gardner SG, Raina JB, Nitschke MR, Nielsen DA, Stat M, Motti CA, Ralph PJ, Petrou K. A multi-trait systems approach reveals a response cascade to bleaching in corals. BMC Biol 2017; 15:117. [PMID: 29216891 PMCID: PMC5719617 DOI: 10.1186/s12915-017-0459-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/19/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Climate change causes the breakdown of the symbiotic relationships between reef-building corals and their photosynthetic symbionts (genus Symbiodinium), with thermal anomalies in 2015-2016 triggering the most widespread mass coral bleaching on record and unprecedented mortality on the Great Barrier Reef. Targeted studies using specific coral stress indicators have highlighted the complexity of the physiological processes occurring during thermal stress, but have been unable to provide a clear mechanistic understanding of coral bleaching. RESULTS Here, we present an extensive multi-trait-based study in which we compare the thermal stress responses of two phylogenetically distinct and widely distributed coral species, Acropora millepora and Stylophora pistillata, integrating 14 individual stress indicators over time across a simulated thermal anomaly. We found that key stress responses were conserved across both taxa, with the loss of symbionts and the activation of antioxidant mechanisms occurring well before collapse of the physiological parameters, including gross oxygen production and chlorophyll a. Our study also revealed species-specific traits, including differences in the timing of antioxidant regulation, as well as drastic differences in the production of the sulfur compound dimethylsulfoniopropionate during bleaching. Indeed, the concentration of this antioxidant increased two-fold in A. millepora after the corals started to bleach, while it decreased 70% in S. pistillata. CONCLUSIONS We identify a well-defined cascading response to thermal stress, demarking clear pathophysiological reactions conserved across the two species, which might be central to fully understanding the mechanisms triggering thermally induced coral bleaching. These results highlight that bleaching is a conserved mechanism, but specific adaptations linked to the coral's antioxidant capacity drive differences in the sensitivity and thus tolerance of each coral species to thermal stress.
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Affiliation(s)
- Stephanie G Gardner
- Climate Change Cluster, University of Technology Sydney, Ultimo, 2007, NSW, Australia. .,School of Life Sciences, University of Technology Sydney, Ultimo, 2007, NSW, Australia.
| | - Jean-Baptiste Raina
- Climate Change Cluster, University of Technology Sydney, Ultimo, 2007, NSW, Australia
| | - Matthew R Nitschke
- Climate Change Cluster, University of Technology Sydney, Ultimo, 2007, NSW, Australia.,Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193, Aveiro, Portugal
| | - Daniel A Nielsen
- School of Life Sciences, University of Technology Sydney, Ultimo, 2007, NSW, Australia
| | - Michael Stat
- Trace and Environmental DNA (TrEnD) Laboratory, Department of Environment and Agriculture, Curtin University, Perth, 6102, WA, Australia
| | - Cherie A Motti
- Australian Institute of Marine Science, Townsville, 4810, QLD, Australia
| | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, Ultimo, 2007, NSW, Australia
| | - Katherina Petrou
- School of Life Sciences, University of Technology Sydney, Ultimo, 2007, NSW, Australia
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37
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Cunning R, Gates RD, Edmunds PJ. Using high-throughput sequencing of ITS2 to describe Symbiodinium metacommunities in St. John, US Virgin Islands. PeerJ 2017. [PMID: 28649474 PMCID: PMC5482262 DOI: 10.7717/peerj.3472] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Symbiotic microalgae (Symbiodinium spp.) strongly influence the performance and stress-tolerance of their coral hosts, making the analysis of Symbiodinium communities in corals (and metacommunities on reefs) advantageous for many aspects of coral reef research. High-throughput sequencing of ITS2 nrDNA offers unprecedented scale in describing these communities, yet high intragenomic variability at this locus complicates the resolution of biologically meaningful diversity. Here, we demonstrate that generating operational taxonomic units by clustering ITS2 sequences at 97% similarity within, but not across, samples collapses sequence diversity that is more likely to be intragenomic, while preserving diversity that is more likely interspecific. We utilize this ‘within-sample clustering’ to analyze Symbiodinium from ten host taxa on shallow reefs on the north and south shores of St. John, US Virgin Islands. While Symbiodinium communities did not differ between shores, metacommunity network analysis of host-symbiont associations revealed Symbiodinium lineages occupying ‘dominant’ and ‘background’ niches, and coral hosts that are more ‘flexible’ or ‘specific’ in their associations with Symbiodinium. These methods shed new light on important questions in coral symbiosis ecology, and demonstrate how application-specific bioinformatic pipelines can improve the analysis of metabarcoding data in microbial metacommunity studies.
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Affiliation(s)
- Ross Cunning
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America
| | - Peter J Edmunds
- Department of Biology, California State University, Northridge, CA, United States of America
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38
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Host specificity of Symbiodinium variants revealed by an ITS2 metahaplotype approach. ISME JOURNAL 2017; 11:1500-1503. [PMID: 28211848 DOI: 10.1038/ismej.2016.206] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 10/20/2016] [Accepted: 11/25/2016] [Indexed: 11/08/2022]
Abstract
Analysis of the widely used ITS region is confounded by the presence of intragenomic variants (IGVs). In Symbiodinium, the algal symbionts of reef building corals, deep-sequencing analyses are used to characterise communities within corals, yet these analyses largely overlook IGVs. Here we consider that distinct ITS2 sequences could represent IGVs rather than distinct symbiont types and argue that symbionts can be distinguished by their proportional composition of IGVs, described as their ITS2 metahaplotype. Using our metahaplotype approach on Minimum Entropy Decomposition (MED) analysis of ITS2 sequences from the corals Acropora downingi, Cyphastrea microphthalma and Playgyra daedalea, we show the dominance of a single species-specific Symbiodinium C3 variant within each coral species. We confirm the presence of these species-specific symbionts using the psbA non-coding region. Our findings highlight the importance of accounting for IGVs in ITS2 analyses and demonstrate their capacity to resolve biological patterns that would otherwise be overlooked.
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39
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Boulotte NM, Dalton SJ, Carroll AG, Harrison PL, Putnam HM, Peplow LM, van Oppen MJ. Exploring the Symbiodinium rare biosphere provides evidence for symbiont switching in reef-building corals. ISME JOURNAL 2016; 10:2693-2701. [PMID: 27093048 PMCID: PMC5113844 DOI: 10.1038/ismej.2016.54] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 02/12/2016] [Accepted: 02/25/2016] [Indexed: 01/18/2023]
Abstract
Reef-building corals possess a range of acclimatisation and adaptation mechanisms to respond to seawater temperature increases. In some corals, thermal tolerance increases through community composition changes of their dinoflagellate endosymbionts (Symbiodinium spp.), but this mechanism is believed to be limited to the Symbiodinium types already present in the coral tissue acquired during early life stages. Compelling evidence for symbiont switching, that is, the acquisition of novel Symbiodinium types from the environment, by adult coral colonies, is currently lacking. Using deep sequencing analysis of Symbiodinium rDNA internal transcribed spacer 2 (ITS2) PCR amplicons from two pocilloporid coral species, we show evidence consistent with de novo acquisition of Symbiodinium types from the environment by adult corals following two consecutive bleaching events. Most of these newly detected symbionts remained in the rare biosphere (background types occurring below 1% relative abundance), but one novel type reached a relative abundance of ~33%. Two de novo acquired Symbiodinium types belong to the thermally resistant clade D, suggesting that this switching may have been driven by consecutive thermal bleaching events. Our results are particularly important given the maternal mode of Symbiodinium transmission in the study species, which generally results in high symbiont specificity. These findings will cause a paradigm shift in our understanding of coral-Symbiodinium symbiosis flexibility and mechanisms of environmental acclimatisation in corals.
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Affiliation(s)
- Nadine M Boulotte
- National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia.,Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Steven J Dalton
- National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia.,Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Andrew G Carroll
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Peter L Harrison
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Hollie M Putnam
- Hawaii Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i, Kaneohe, HI, USA
| | - Lesa M Peplow
- Australian Institute of Marine Science, Townsville MC, Queensland, Australia
| | - Madeleine Jh van Oppen
- Australian Institute of Marine Science, Townsville MC, Queensland, Australia.,School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
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