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Ng MS, Soon N, Afiq-Rosli L, Kunning I, Mana RR, Chang Y, Wainwright BJ. Highly Diverse Symbiodiniaceae Types Hosted by Corals in a Global Hotspot of Marine Biodiversity. MICROBIAL ECOLOGY 2024; 87:92. [PMID: 38987492 PMCID: PMC11236936 DOI: 10.1007/s00248-024-02407-x] [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: 02/21/2024] [Accepted: 06/27/2024] [Indexed: 07/12/2024]
Abstract
Symbiotic dinoflagellates in the genus Symbiodiniaceae play vital roles in promoting resilience and increasing stress tolerance in their coral hosts. While much of the world's coral succumb to the stresses associated with increasingly severe and frequent thermal bleaching events, live coral cover in Papua New Guinea (PNG) remains some of the highest reported globally despite the historically warm waters surrounding the country. Yet, in spite of the high coral cover in PNG and the acknowledged roles Symbiodiniaceae play within their hosts, these communities have not been characterized in this global biodiversity hotspot. Using high-throughput sequencing of the ITS2 rDNA gene, we profiled the endosymbionts of four coral species, Diploastrea heliopora, Pachyseris speciosa, Pocillopora acuta, and Porites lutea, across six sites in PNG. Our findings reveal patterns of Cladocopium and Durusdinium dominance similar to other reefs in the Coral Triangle, albeit with much greater intra- and intergenomic variation. Host- and site-specific variations in Symbiodiniaceae type profiles were observed across collection sites, appearing to be driven by environmental conditions. Notably, the extensive intra- and intergenomic variation, coupled with many previously unreported sequences, highlight PNG as a potential hotspot of symbiont diversity. This work represents the first characterization of the coral-symbiont community structure in the PNG marine biodiversity hotspot, serving as a baseline for future studies.
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Affiliation(s)
- Ming Sheng Ng
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Nathaniel Soon
- Yale-NUS College, National University of Singapore, 16 College Avenue West, Singapore, 138527, Singapore
- Thrive Conservation, Jl. Subak Sari No. 13, Kuta Utara, Badung, Bali, 80361, Indonesia
| | - Lutfi Afiq-Rosli
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Ismael Kunning
- School of Natural and Physical Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
| | - Ralph R Mana
- School of Natural and Physical Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
| | - Ying Chang
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Yale-NUS College, National University of Singapore, 16 College Avenue West, Singapore, 138527, Singapore
| | - Benjamin J Wainwright
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
- Yale-NUS College, National University of Singapore, 16 College Avenue West, Singapore, 138527, Singapore.
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Strader ME, Wright RM, Pezner AK, Nuttall MF, Aichelman HE, Davies SW. Intersection of coral molecular responses to a localized mortality event and ex situ deoxygenation. Ecol Evol 2024; 14:e11275. [PMID: 38654712 PMCID: PMC11036075 DOI: 10.1002/ece3.11275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 03/22/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
In July 2016, East Bank of Flower Garden Banks (FGB) National Marine Sanctuary experienced a localized mortality event (LME) of multiple invertebrate species that ultimately led to reductions in coral cover. Abiotic data taken directly after the event suggested that acute deoxygenation contributed to the mortality. Despite the large impact of this event on the coral community, there was no direct evidence that this LME was driven by acute deoxygenation, and thus we explored whether gene expression responses of corals to the LME would indicate what abiotic factors may have contributed to the LME. Gene expression of affected and unaffected corals sampled during the mortality event revealed evidence of the physiological consequences of the LME on coral hosts and their algal symbionts from two congeneric species (Orbicella franksi and Orbicella faveolata). Affected colonies of both species differentially regulated genes involved in mitochondrial regulation and oxidative stress. To further test the hypothesis that deoxygenation led to the LME, we measured coral host and algal symbiont gene expression in response to ex situ experimental deoxygenation (control = 6.9 ± 0.08 mg L-1, anoxic = 0.083 ± 0.017 mg L-1) in healthy O. faveolata colonies from the FGB. However, this deoxygenation experiment revealed divergent gene expression patterns compared to the corals sampled during the LME and was more similar to a generalized coral environmental stress response. It is therefore likely that while the LME was connected to low oxygen, it was a series of interconnected stressors that elicited the unique gene expression responses observed here. These in situ and ex situ data highlight how field responses to stressors are unique from those in controlled laboratory conditions, and that the complexities of deoxygenation events in the field likely arise from interactions between multiple environmental factors simultaneously.
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Affiliation(s)
- Marie E. Strader
- Department of BiologyTexas A&M UniversityCollege StationTexasUSA
| | - Rachel M. Wright
- Department of Biological SciencesSouthern Methodist UniversityDallasTexasUSA
| | | | | | | | - Sarah W. Davies
- Department of BiologyBoston UniversityBostonMassachusettsUSA
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Cheng K, Li X, Tong M, Jong MC, Cai Z, Zheng H, Xiao B, Zhou J. Integrated metagenomic and metaproteomic analyses reveal bacterial micro-ecological mechanisms in coral bleaching. mSystems 2023; 8:e0050523. [PMID: 37882797 PMCID: PMC10734480 DOI: 10.1128/msystems.00505-23] [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: 05/19/2023] [Accepted: 09/18/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE Coral reefs worldwide are facing rapid decline due to coral bleaching. However, knowledge of the physiological characteristics and molecular mechanisms of coral symbionts respond to stress is scarce. Here, metagenomic and metaproteomic approaches were utilized to shed light on the changes in the composition and functions of coral symbiotic bacteria during coral bleaching. The results demonstrated that coral bleaching significantly affected the composition of symbionts, with bacterial communities dominating in bleached corals. Through differential analyses of gene and protein expression, it becomes evident that symbionts experience functional disturbances in response to heat stress. These disturbances result in abnormal energy metabolism, which could potentially compromise the health and resilience of the symbionts. Furthermore, our findings highlighted the highly diverse microbial communities of coral symbionts, with beneficial bacteria providing critical services to corals in stress responses and pathogenic bacteria driving coral bleaching. This study provides comprehensive insights into the complex response mechanisms of coral symbionts under heat stress from the micro-ecological perspective and offers fundamental data for future monitoring of coral health.
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Affiliation(s)
- Keke Cheng
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
| | - Xinyang Li
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
| | - Mengmeng Tong
- Ocean College, Zhejiang University, Zhoushan, Zhejiang, China
| | - Mui-Choo Jong
- Institute of Environment and Ecology, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
| | - Zhonghua Cai
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
| | - Huina Zheng
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong, China
| | - Baohua Xiao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong, China
| | - Jin Zhou
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
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Wang C, Zheng X, Kvitt H, Sheng H, Sun D, Niu G, Tchernov D, Shi T. Lineage-specific symbionts mediate differential coral responses to thermal stress. MICROBIOME 2023; 11:211. [PMID: 37752514 PMCID: PMC10521517 DOI: 10.1186/s40168-023-01653-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 08/23/2023] [Indexed: 09/28/2023]
Abstract
BACKGROUND Ocean warming is a leading cause of increasing episodes of coral bleaching, the dissociation between coral hosts and their dinoflagellate algal symbionts in the family Symbiodiniaceae. While the diversity and flexibility of Symbiodiniaceae is presumably responsible for variations in coral response to physical stressors such as elevated temperature, there is little data directly comparing physiological performance that accounts for symbiont identity associated with the same coral host species. Here, using Pocillopora damicornis harboring genotypically distinct Symbiodiniaceae strains, we examined the physiological responses of the coral holobiont and the dynamics of symbiont community change under thermal stress in a laboratory-controlled experiment. RESULTS We found that P. damicornis dominated with symbionts of metahaplotype D1-D4-D6 in the genus Durusdinium (i.e., PdD holobiont) was more robust to thermal stress than its counterpart with symbionts of metahaplotype C42-C1-C1b-C1c in the genus Cladocopium (i.e., PdC holobiont). Under ambient temperature, however, the thermally sensitive Cladocopium spp. exhibited higher photosynthetic efficiency and translocated more fixed carbon to the host, likely facilitating faster coral growth and calcification. Moreover, we observed a thermally induced increase in Durusdinium proportion in the PdC holobiont; however, this "symbiont shuffling" in the background was overwhelmed by the overall Cladocopium dominance, which coincided with faster coral bleaching and reduced calcification. CONCLUSIONS These findings support that lineage-specific symbiont dominance is a driver of distinct coral responses to thermal stress. In addition, we found that "symbiont shuffling" may begin with stress-forced, subtle changes in the rare biosphere to eventually trade off growth for increased resilience. Furthermore, the flexibility in corals' association with thermally tolerant symbiont lineages to adapt or acclimatize to future warming oceans should be viewed with conservative optimism as the current rate of environmental changes may outpace the evolutionary capabilities of corals. Video Abstract.
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Affiliation(s)
- Chenying Wang
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Xinqing Zheng
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China.
- Observation and Research Station of Wetland Ecosystem in the Beibu Gulf, Ministry of Natural Resources, Beihai, 536015, China.
| | - Hagit Kvitt
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, 31905, Haifa, Israel
- Israel Oceanographic and Limnological Research, National Center for Mariculture, 88112, Eilat, Israel
| | - Huaxia Sheng
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Danye Sun
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Gaofeng Niu
- Marine Genomics and Biotechnology Program, Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China
| | - Dan Tchernov
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, 31905, Haifa, Israel.
| | - Tuo Shi
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
- Marine Genomics and Biotechnology Program, Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangzhou, 510000, China.
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5
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Armstrong EJ, Lê-Hoang J, Carradec Q, Aury JM, Noel B, Hume BCC, Voolstra CR, Poulain J, Belser C, Paz-García DA, Cruaud C, Labadie K, Da Silva C, Moulin C, Boissin E, Bourdin G, Iwankow G, Romac S, Agostini S, Banaigs B, Boss E, Bowler C, de Vargas C, Douville E, Flores M, Forcioli D, Furla P, Galand PE, Gilson E, Lombard F, Pesant S, Reynaud S, Sullivan MB, Sunagawa S, Thomas OP, Troublé R, Thurber RV, Zoccola D, Planes S, Allemand D, Wincker P. Host transcriptomic plasticity and photosymbiotic fidelity underpin Pocillopora acclimatization across thermal regimes in the Pacific Ocean. Nat Commun 2023; 14:3056. [PMID: 37264036 DOI: 10.1038/s41467-023-38610-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/10/2023] [Indexed: 06/03/2023] Open
Abstract
Heat waves are causing declines in coral reefs globally. Coral thermal responses depend on multiple, interacting drivers, such as past thermal exposure, endosymbiont community composition, and host genotype. This makes the understanding of their relative roles in adaptive and/or plastic responses crucial for anticipating impacts of future warming. Here, we extracted DNA and RNA from 102 Pocillopora colonies collected from 32 sites on 11 islands across the Pacific Ocean to characterize host-photosymbiont fidelity and to investigate patterns of gene expression across a historical thermal gradient. We report high host-photosymbiont fidelity and show that coral and microalgal gene expression respond to different drivers. Differences in photosymbiotic association had only weak impacts on host gene expression, which was more strongly correlated with the historical thermal environment, whereas, photosymbiont gene expression was largely determined by microalgal lineage. Overall, our results reveal a three-tiered strategy of thermal acclimatization in Pocillopora underpinned by host-photosymbiont specificity, host transcriptomic plasticity, and differential photosymbiotic association under extreme warming.
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Affiliation(s)
- Eric J Armstrong
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France.
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France.
- PSL Université Paris: EPHE-UPVD-CNRS, UAR 3278 CRIOBE, Université de Perpignan, 52 Avenue Paul Alduy, 66860, Perpignan Cedex, France.
| | - Julie Lê-Hoang
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
| | - Quentin Carradec
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France.
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France.
| | - Jean-Marc Aury
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
| | - Benjamin Noel
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
| | - Benjamin C C Hume
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | | | - Julie Poulain
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
| | - Caroline Belser
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
| | - David A Paz-García
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Av. IPN 195, La Paz, Baja California Sur, 23096, México
| | - Corinne Cruaud
- Genoscope, Institut François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Karine Labadie
- Genoscope, Institut François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Corinne Da Silva
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
| | - Clémentine Moulin
- Fondation Tara Océan, Base Tara, 8 rue de Prague, 75 012, Paris, France
| | - Emilie Boissin
- PSL Université Paris: EPHE-UPVD-CNRS, UAR 3278 CRIOBE, Université de Perpignan, 52 Avenue Paul Alduy, 66860, Perpignan Cedex, France
| | - Guillaume Bourdin
- School of Marine Sciences, University of Maine, Orono, 04469, ME, USA
| | - Guillaume Iwankow
- PSL Université Paris: EPHE-UPVD-CNRS, UAR 3278 CRIOBE, Université de Perpignan, 52 Avenue Paul Alduy, 66860, Perpignan Cedex, France
| | - Sarah Romac
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
- Sorbonne Université, CNRS, Station Biologique de Roscoff, AD2M, UMR 7144, ECOMAP, 29680, Roscoff, France
| | - Sylvain Agostini
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda, Shizuoka, Japan
| | - Bernard Banaigs
- PSL Université Paris: EPHE-UPVD-CNRS, UAR 3278 CRIOBE, Université de Perpignan, 52 Avenue Paul Alduy, 66860, Perpignan Cedex, France
| | - Emmanuel Boss
- School of Marine Sciences, University of Maine, Orono, 04469, ME, USA
| | - Chris Bowler
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005, Paris, France
| | - Colomban de Vargas
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
- Sorbonne Université, CNRS, Station Biologique de Roscoff, AD2M, UMR 7144, ECOMAP, 29680, Roscoff, France
| | - Eric Douville
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, F-91191, Gif-sur-Yvette, France
| | - Michel Flores
- Weizmann Institute of Science, Department of Earth and Planetary Sciences, 76100, Rehovot, Israel
| | - Didier Forcioli
- Université Côte d'Azur, CNRS, INSERM, IRCAN, Medical School, Nice, France
- LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Principality of Monaco, Monaco
| | - Paola Furla
- Université Côte d'Azur, CNRS, INSERM, IRCAN, Medical School, Nice, France
- LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Principality of Monaco, Monaco
| | - Pierre E Galand
- Sorbonne Université, CNRS, Laboratoire d'Ecogéochimie des Environnements Benthiques (LECOB), Observatoire Océanologique de Banyuls, 66650, Banyuls sur mer, France
| | - Eric Gilson
- Université Côte d'Azur, CNRS, INSERM, IRCAN, Medical School, Nice, France
- LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Principality of Monaco, Monaco
- Department of Medical Genetics, CHU, Nice, France
| | - Fabien Lombard
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
- Sorbonne Université, Institut de la Mer de Villefranche sur mer, Laboratoire d'Océanographie de Villefranche, F-06230, Villefranche-sur-Mer, France
| | - Stéphane Pesant
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Stéphanie Reynaud
- LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Principality of Monaco, Monaco
- Centre Scientifique de Monaco, 8 Quai Antoine Ier, MC-98000, Principality of Monaco, Monaco
| | - Matthew B Sullivan
- Departments of Microbiology and Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, 43210, USA
| | - Shinichi Sunagawa
- Institute of Microbiology, Department of Biology, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Olivier P Thomas
- School of Biological and Chemical Sciences, Ryan institute, University of Galway, University Road H91TK33, Galway, Ireland
| | - Romain Troublé
- Fondation Tara Océan, Base Tara, 8 rue de Prague, 75 012, Paris, France
| | - Rebecca Vega Thurber
- Oregon State University, Department of Microbiology, 220 Nash Hall, 97331, Corvallis, OR, USA
| | - Didier Zoccola
- LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Principality of Monaco, Monaco
- Centre Scientifique de Monaco, 8 Quai Antoine Ier, MC-98000, Principality of Monaco, Monaco
| | - Serge Planes
- PSL Research University: EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, 66860, Perpignan Cedex, France
| | - Denis Allemand
- LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Principality of Monaco, Monaco
- Centre Scientifique de Monaco, 8 Quai Antoine Ier, MC-98000, Principality of Monaco, Monaco
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France
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6
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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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7
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Symbiont genotype influences holobiont response to increased temperature. Sci Rep 2022; 12:18394. [PMID: 36319835 PMCID: PMC9626619 DOI: 10.1038/s41598-022-23244-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 10/27/2022] [Indexed: 11/18/2022] Open
Abstract
As coral reefs face warming oceans and increased coral bleaching, a whitening of the coral due to loss of microalgal endosymbionts, the possibility of evolutionary rescue offers some hope for reef persistence. In tightly linked mutualisms, evolutionary rescue may occur through evolution of the host and/or endosymbionts. Many obligate mutualisms are composed of relatively small, fast-growing symbionts with greater potential to evolve on ecologically relevant time scales than their relatively large, slower growing hosts. Numerous jellyfish species harbor closely related endosymbiont taxa to other cnidarian species such as coral, and are commonly used as a model system for investigating cnidarian mutualisms. We examined the potential for adaptation of the upside-down jellyfish Cassiopea xamachana to increased temperature via evolution of its microalgal endosymbiont, Symbiodinium microadriaticum. We quantified trait variation among five algal genotypes in response to three temperatures (26 °C, 30 °C, and 32 °C) and fitness of hosts infected with each genotype. All genotypes showed positive growth rates at each temperature, but rates of respiration and photosynthesis decreased with increased temperature. Responses varied among genotypes but were unrelated to genetic similarity. The effect of temperature on asexual reproduction and the timing of development in the host also depended on the genotype of the symbiont. Natural selection could favor different algal genotypes at different temperatures, affecting host fitness. This eco-evolutionary interaction may be a critical component of understanding species resilience in increasingly stressful environments.
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8
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Brown AL, Pfab F, Baxter EC, Detmer AR, Moeller HV, Nisbet RM, Cunning R. Analysis of a mechanistic model of corals in association with multiple symbionts: within-host competition and recovery from bleaching. CONSERVATION PHYSIOLOGY 2022; 10:coac066. [PMID: 36247693 PMCID: PMC9558299 DOI: 10.1093/conphys/coac066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 07/25/2022] [Accepted: 09/09/2022] [Indexed: 06/14/2023]
Abstract
Coral reefs are increasingly experiencing stressful conditions, such as high temperatures, that cause corals to undergo bleaching, a process where they lose their photosynthetic algal symbionts. Bleaching threatens both corals' survival and the health of the reef ecosystems they create. One possible mechanism for corals to resist bleaching is through association with stress-tolerant symbionts, which are resistant to bleaching but may be worse partners in mild conditions. Some corals have been found to associate with multiple symbiont species simultaneously, which potentially gives them access to the benefits of both stress-sensitive and -tolerant symbionts. However, within-host competition between symbionts may lead to competitive exclusion of one partner, and the consequences of associating with multiple partners simultaneously are not well understood. We modify a mechanistic model of coral-algal symbiosis to investigate the effect of environmental conditions on within-host competitive dynamics between stress-sensitive and -tolerant symbionts and the effect of access to a tolerant symbiont on the dynamics of recovery from bleaching. We found that the addition of a tolerant symbiont can increase host survival and recovery from bleaching in high-light conditions. Competitive exclusion of the tolerant symbiont occurred slowly at intermediate light levels. Interestingly, there were some cases of post-bleaching competitive exclusion after the tolerant symbiont had helped the host recover.
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Affiliation(s)
- Alexandra Lynne Brown
- Corresponding author: Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. E-mail:
| | - Ferdinand Pfab
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ethan C Baxter
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - A Raine Detmer
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Roger M Nisbet
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL 60605, USA
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9
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Walker NS, Cornwell BH, Nestor V, Armstrong KC, Golbuu Y, Palumbi SR. Persistence of phenotypic responses to short-term heat stress in the tabletop coral Acropora hyacinthus. PLoS One 2022; 17:e0269206. [PMID: 36084033 PMCID: PMC9462741 DOI: 10.1371/journal.pone.0269206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/23/2022] [Indexed: 12/26/2022] Open
Abstract
Widespread mapping of coral thermal resilience is essential for developing effective management strategies and requires replicable and rapid multi-location assays of heat resistance and recovery. One- or two-day short-term heat stress experiments have been previously employed to assess heat resistance, followed by single assays of bleaching condition. We tested the reliability of short-term heat stress resistance, and linked resistance and recovery assays, by monitoring the phenotypic response of fragments from 101 Acropora hyacinthus colonies located in Palau (Micronesia) to short-term heat stress. Following short-term heat stress, bleaching and mortality were recorded after 16 hours, daily for seven days, and after one and two months of recovery. To follow corals over time, we utilized a qualitative, non-destructive visual bleaching score metric that correlated with standard symbiont retention assays. The bleaching state of coral fragments 16 hours post-heat stress was highly indicative of their state over the next 7 days, suggesting that symbiont population sizes within corals may quickly stabilize post-heat stress. Bleaching 16 hours post-heat stress predicted likelihood of mortality over the subsequent 3–5 days, after which there was little additional mortality. Together, bleaching and mortality suggested that rapid assays of the phenotypic response following short-term heat stress were good metrics of the total heat treatment effect. Additionally, our data confirm geographic patterns of intraspecific variation in Palau and show that bleaching severity among colonies was highly correlated with mortality over the first week post-stress. We found high survival (98%) and visible recovery (100%) two months after heat stress among coral fragments that survived the first week post-stress. These findings help simplify rapid, widespread surveys of heat sensitivity in Acropora hyacinthus by showing that standardized short-term experiments can be confidently assayed after 16 hours, and that bleaching sensitivity may be linked to subsequent survival using experimental assessments.
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Affiliation(s)
- Nia S. Walker
- Department of Biology, Hopkins Marine Station of Stanford University, Pacific Grove, California, United States of America
- * E-mail:
| | - Brendan H. Cornwell
- Department of Biology, Hopkins Marine Station of Stanford University, Pacific Grove, California, United States of America
| | | | - Katrina C. Armstrong
- Department of Biology, Hopkins Marine Station of Stanford University, Pacific Grove, California, United States of America
| | | | - Stephen R. Palumbi
- Department of Biology, Hopkins Marine Station of Stanford University, Pacific Grove, California, United States of America
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10
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Global change differentially modulates Caribbean coral physiology. PLoS One 2022; 17:e0273897. [PMID: 36054126 PMCID: PMC9439252 DOI: 10.1371/journal.pone.0273897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 08/17/2022] [Indexed: 11/19/2022] Open
Abstract
Global change driven by anthropogenic carbon emissions is altering ecosystems at unprecedented rates, especially coral reefs, whose symbiosis with algal symbionts is particularly vulnerable to increasing ocean temperatures and altered carbonate chemistry. Here, we assess the physiological responses of three Caribbean coral (animal host + algal symbiont) species from an inshore and offshore reef environment after exposure to simulated ocean warming (28, 31°C), acidification (300–3290 μatm), and the combination of stressors for 93 days. We used multidimensional analyses to assess how a variety of coral physiological parameters respond to ocean acidification and warming. Our results demonstrate reductions in coral health in Siderastrea siderea and Porites astreoides in response to projected ocean acidification, while future warming elicited severe declines in Pseudodiploria strigosa. Offshore S. siderea fragments exhibited higher physiological plasticity than inshore counterparts, suggesting that this offshore population was more susceptible to changing conditions. There were no plasticity differences in P. strigosa and P. astreoides between natal reef environments, however, temperature evoked stronger responses in both species. Interestingly, while each species exhibited unique physiological responses to ocean acidification and warming, when data from all three species are modelled together, convergent stress responses to these conditions are observed, highlighting the overall sensitivities of tropical corals to these stressors. Our results demonstrate that while ocean warming is a severe acute stressor that will have dire consequences for coral reefs globally, chronic exposure to acidification may also impact coral physiology to a greater extent in some species than previously assumed. Further, our study identifies S. siderea and P. astreoides as potential ‘winners’ on future Caribbean coral reefs due to their resilience under projected global change stressors, while P. strigosa will likely be a ‘loser’ due to their sensitivity to thermal stress events. Together, these species-specific responses to global change we observe will likely manifest in altered Caribbean reef assemblages in the future.
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11
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Al-Hammady MA, Silva TF, Hussein HN, Saxena G, Modolo LV, Belasy MB, Westphal H, Farag MA. How do algae endosymbionts mediate for their coral host fitness under heat stress? A comprehensive mechanistic overview. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Expression plasticity regulates intraspecific variation in the acclimatization potential of a reef-building coral. Nat Commun 2022; 13:4790. [PMID: 35970904 PMCID: PMC9378650 DOI: 10.1038/s41467-022-32452-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 08/01/2022] [Indexed: 11/09/2022] Open
Abstract
Phenotypic plasticity is an important ecological and evolutionary response for organisms experiencing environmental change, but the ubiquity of this capacity within coral species and across symbiont communities is unknown. We exposed ten genotypes of the reef-building coral Montipora capitata with divergent symbiont communities to four thermal pre-exposure profiles and quantified gene expression before stress testing 4 months later. Here we show two pre-exposure profiles significantly enhance thermal tolerance despite broadly different expression patterns and substantial variation in acclimatization potential based on coral genotype. There was no relationship between a genotype’s basal thermal sensitivity and ability to acquire heat tolerance, including in corals harboring naturally tolerant symbionts, which illustrates the potential for additive improvements in coral response to climate change. These results represent durable improvements from short-term stress hardening of reef-building corals and substantial cryptic complexity in the capacity for plasticity. Phenotypic plasticity is an important response for organisms experiencing climate change. Here, Drury et al. show that stress-hardening can produce durable improvements in coral thermal tolerance, masking substantial variation between individuals.
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13
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The role of gene expression and symbiosis in reef-building coral acquired heat tolerance. Nat Commun 2022; 13:4513. [PMID: 35922443 PMCID: PMC9349291 DOI: 10.1038/s41467-022-32217-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Predicting how reef-building corals will respond to accelerating ocean warming caused by climate change requires knowledge of how acclimation and symbiosis modulate heat tolerance in coral early life-history stages. We assayed transcriptional responses to heat in larvae and juveniles of 11 reproductive crosses of Acropora tenuis colonies along the Great Barrier Reef. Larvae produced from the warmest reef had the highest heat tolerance, although gene expression responses to heat were largely conserved by cross identity. Juvenile transcriptional responses were driven strongly by symbiosis – when in symbiosis with heat-evolved Symbiodiniaceae, hosts displayed intermediate expression between its progenitor Cladocopium and the more stress tolerant Durusdinium, indicating the acquisition of tolerance is a conserved evolutionary process in symbionts. Heat-evolved Symbiodiniaceae facilitated juvenile survival under heat stress, although host transcriptional responses to heat were positively correlated among those hosting different genera of Symbiodiniaceae. These findings reveal the relative contribution of parental environmental history as well as symbiosis establishment in coral molecular responses to heat in early life-history stages. Coral responses to ocean warming depend not only on the coral themselves, but also on their symbionts. Here, the authors experimentally assess how symbiosis and gene expression plasticity contribute to the heat stress responses of a common coral.
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14
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Drury C, Bean NK, Harris CI, Hancock JR, Huckeba J, H CM, Roach TNF, Quinn RA, Gates RD. Intrapopulation adaptive variance supports thermal tolerance in a reef-building coral. Commun Biol 2022; 5:486. [PMID: 35589814 PMCID: PMC9120509 DOI: 10.1038/s42003-022-03428-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 04/28/2022] [Indexed: 01/05/2023] Open
Abstract
Coral holobionts are multi-species assemblages, which adds significant complexity to genotype-phenotype connections underlying ecologically important traits like coral bleaching. Small scale heterogeneity in bleaching is ubiquitous in the absence of strong environmental gradients, which provides adaptive variance needed for the long-term persistence of coral reefs. We used RAD-seq, qPCR and LC-MS/MS metabolomics to characterize host genomic variation, symbiont community and biochemical correlates in two bleaching phenotypes of the vertically transmitting coral Montipora capitata. Phenotype was driven by symbiosis state and host genetic variance. We documented 5 gene ontologies that were significantly associated with both the binary bleaching phenotype and symbiont composition, representing functions that confer a phenotype via host-symbiont interactions. We bred these corals and show that symbiont communities were broadly conserved in bulk-crosses, resulting in significantly higher survivorship under temperature stress in juveniles, but not larvae, from tolerant parents. Using a select and re-sequence approach, we document numerous gene ontologies selected by heat stress, some of which (cell signaling, antioxidant activity, pH regulation) have unique selection dynamics in larvae from thermally tolerant parents. These data show that vertically transmitting corals may have an adaptive advantage under climate change if host and symbiont variance interact to influence bleaching phenotype. Selective breeding of corals with different bleaching phenotypes demonstrates the potential for climate adaptation in vertically transmitting species.
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Affiliation(s)
- Crawford Drury
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA.
| | - Nina K Bean
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Casey I Harris
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Joshua R Hancock
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Joel Huckeba
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA.,University of Amsterdam, Amsterdam, Netherlands
| | - Christian Martin H
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Ty N F Roach
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Robert A Quinn
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
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15
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Yuyama I, Higuchi T, Mezaki T, Tashiro H, Ikeo K. Metatranscriptomic Analysis of Corals Inoculated With Tolerant and Non-Tolerant Symbiont Exposed to High Temperature and Light Stress. Front Physiol 2022; 13:806171. [PMID: 35480050 PMCID: PMC9037784 DOI: 10.3389/fphys.2022.806171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/17/2022] [Indexed: 11/13/2022] Open
Abstract
Algal symbionts of corals can influence host stress resistance; for example, in the Pacific Ocean, whereas Cladocopium (C-type) is generally dominant in corals, Durusdinium (D-type) is found in more heat-resistant corals. Thus, the presence of D-type symbiont likely increases coral heat tolerance, and this symbiotic relationship potentially provides a hint to increase the stress tolerance of coral–algal symbioses. In this study, transcriptome profiles of Cladocopium- and Durusdinium-harboring Acropora solitaryensis (C-coral and D-coral, respectively) and algal photosystem functioning (Fv/Fm) under bleaching conditions (high temperature and light stress) were compared. Stress treatment caused algal photoinhibition that the Fv/Fm value of Symbiodiniaceae was immediately reduced. The transcriptome analysis of corals revealed that genes involved in the following processes were detected: endoplasmic reticulum (ER) stress, mitophagy, apoptosis, endocytosis, metabolic processes (acetyl-CoA, chitin metabolic processes, etc.), and the PI3K-AKT pathway were upregulated, while DNA replication and the calcium signaling pathway were downregulated in both C- and D-corals. These results suggest that unrepaired DNA and protein damages were accumulated in corals under high temperature and light stress. Additionally, some differentially expressed genes (DEGs) were specific to C- or D-corals, which includes genes involved in transient receptor potential (TRP) channels and vitamin B metabolic processes. Algal transcriptome analysis showed the increased expression of gene encoding photosystem and molecular chaperone especially in D-type symbiont. The transcriptome data imply a possible difference in the stress reactions on C-type and D-type symbionts. The results reveal the basic process of coral heat/light stress response and symbiont-type-specific coral transcriptional responses, which provides a perspective on the mechanisms that cause differences in coral stress tolerance.
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Affiliation(s)
- Ikuko Yuyama
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
- *Correspondence: Ikuko Yuyama
| | - Tomihiko Higuchi
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
| | - Takuma Mezaki
- Kuroshio Biological Research Foundation, Otsuki, Japan
| | - Hisako Tashiro
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Japan
| | - Kazuho Ikeo
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Japan
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16
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Schlecker L, Page C, Matz M, Wright RM. Mechanisms and potential immune tradeoffs of accelerated coral growth induced by microfragmentation. PeerJ 2022; 10:e13158. [PMID: 35368334 PMCID: PMC8973463 DOI: 10.7717/peerj.13158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 03/02/2022] [Indexed: 01/12/2023] Open
Abstract
Microfragmentation is the act of cutting corals into small pieces (~1 cm2) to accelerate the growth rates of corals relative to growth rates observed when maintaining larger-sized fragments. This rapid tissue and skeletal expansion technique offers great potential for supporting reef restoration, yet the biological processes and tradeoffs involved in microfragmentation-mediated accelerated growth are not well understood. Here we compared growth rates across a range of successively smaller fragment sizes in multiple genets of reef-building corals, Orbicella faveolata and Montastraea cavernosa. Our results confirm prior findings that smaller initial sizes confer accelerated growth after four months of recovery in a raceway. O. faveolata transcript levels associated with growth rate include genes encoding carbonic anhydrase and glutamic acid-rich proteins, which have been previously implicated in coral biomineralization, as well as a number of unannotated transcripts that warrant further characterization. Innate immunity enzyme activity assays and gene expression results suggest a potential tradeoff between growth rate after microfragmentation and immune investment. Microfragmentation-based restoration practices have had great success on Caribbean reefs, despite widespread mortality among wild corals due to infectious diseases. Future studies should continue to examine potential immune tradeoffs throughout the microfragmentation recovery period that may affect growout survival and disease transmission after outplanting.
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Affiliation(s)
| | | | - Mikhail Matz
- University of Texas at Austin, Austin, Texas, United States
| | - Rachel M. Wright
- Smith College, Northampton, Massachusetts, United States,University of Texas at Austin, Austin, Texas, United States
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17
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Weeriyanun P, Collins RB, Macadam A, Kiff H, Randle JL, Quigley KM. Predicting selection-response gradients of heat tolerance in a widespread reef-building coral. J Exp Biol 2022; 225:274382. [PMID: 35258617 DOI: 10.1242/jeb.243344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/07/2022] [Indexed: 12/17/2022]
Abstract
Ocean temperatures continue to rise owing to climate change, but it is unclear whether heat tolerance of marine organisms will keep pace with warming. Understanding how tolerance scales from individuals to species and quantifying adaptive potentials is essential to forecasting responses to warming. We reproductively crossed corals from a globally distributed species (Acropora tenuis) on the Great Barrier Reef (Australia) from three thermally distinct reefs to create 85 offspring lineages. Individuals were experimentally exposed to temperatures (27.5, 31 and 35.5°C) in adult and two critical early life stages (larval and settlement) to assess acquired heat tolerance via outcrossing of offspring phenotypes by comparing five physiological responses (photosynthetic yields, bleaching, necrosis, settlement and survival). Adaptive potentials and physiological reaction norms were calculated across three stages to integrate heat tolerance at different biological scales. Selective breeding improved larval survival to heat by 1.5-2.5× but did not result in substantial enhancement of settlement, although population crosses were significantly different. Under heat stress, adults were less variable compared with larval responses in warmer reefs than in the cooler reef. Adults and offspring also differed in their mean population responses, likely underpinned by heat stress imposing strong divergent selection on adults. These results have implications for downstream selection during reproduction, evidenced by variability in a conserved heat tolerance response across offspring lineages. These results inform our ability to forecast the impacts of climate change on wild populations of corals and will aid in developing novel conservation tools such as the assisted evolution of at-risk species.
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Affiliation(s)
- Ponchanok Weeriyanun
- Australian Institute of Marine Science, Townsville 4810, Australia.,Ghent University, Sint-Pietersnieuwstraat 33, 9000 Gent, Belgium
| | - Rachael B Collins
- Australian Institute of Marine Science, Townsville 4810, Australia.,University of Plymouth, Plymouth PL4 8AA, UK
| | - Alex Macadam
- Australian Institute of Marine Science, Townsville 4810, Australia
| | - Hugo Kiff
- Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Janna L Randle
- Australian Institute of Marine Science, Townsville 4810, Australia
| | - Kate M Quigley
- Australian Institute of Marine Science, Townsville 4810, Australia
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18
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Bleaching physiology: who's the 'weakest link' - host vs. symbiont? Emerg Top Life Sci 2022; 6:17-32. [PMID: 35179208 DOI: 10.1042/etls20210228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/20/2022] [Accepted: 02/01/2022] [Indexed: 11/17/2022]
Abstract
Environmental stress, such as an increase in the sea surface temperature, triggers coral bleaching, a profound dysfunction of the mutualist symbiosis between the host cnidarians and their photosynthetic dinoflagellates of the Family Symbiodiniaceae. Because of climate change, mass coral bleaching events will increase in frequency and severity in the future, threatening the persistence of this iconic marine ecosystem at global scale. Strategies adapted to coral reefs preservation and restoration may stem from the identification of the succession of events and of the different molecular and cellular contributors to the bleaching phenomenon. To date, studies aiming to decipher the cellular cascade leading to temperature-related bleaching, emphasized the involvement of reactive species originating from compromised bioenergetic pathways (e.g. cellular respiration and photosynthesis). These molecules are responsible for damage to various cellular components causing the dysregulation of cellular homeostasis and the breakdown of symbiosis. In this review, we synthesize the current knowledge available in the literature on the cellular mechanisms caused by thermal stress, which can initiate or participate in the cell cascade leading to the loss of symbionts, with a particular emphasis on the role of each partner in the initiating processes.
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19
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Rodriguez-Casariego JA, Cunning R, Baker AC, Eirin-Lopez JM. Symbiont shuffling induces differential DNA methylation responses to thermal stress in the coral Montastraea cavernosa. Mol Ecol 2021; 31:588-602. [PMID: 34689363 DOI: 10.1111/mec.16246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 12/11/2022]
Abstract
Algal symbiont shuffling in favour of more thermotolerant species has been shown to enhance coral resistance to heat-stress. Yet, the mechanistic underpinnings and long-term implications of these changes are poorly understood. This work studied the modifications in coral DNA methylation, an epigenetic mechanism involved in coral acclimatization, in response to symbiont manipulation and subsequent heat stress exposure. Symbiont composition was manipulated in the great star coral Montastraea cavernosa through controlled thermal bleaching and recovery, producing paired ramets of three genets dominated by either their native symbionts (genus Cladocopium) or the thermotolerant species (Durusdinium trenchi). Single-base genome-wide analyses showed significant modifications in DNA methylation concentrated in intergenic regions, introns and transposable elements. Remarkably, DNA methylation changes in response to heat stress were dependent on the dominant symbiont, with twice as many differentially methylated regions found in heat-stressed corals hosting different symbionts (Cladocopium vs. D. trenchii) compared to all other comparisons. Interestingly, while differential gene body methylation was not correlated with gene expression, an enrichment in differentially methylated regions was evident in repetitive genome regions. Overall, these results suggest that changes in algal symbionts favouring heat tolerant associations are accompanied by changes in DNA methylation in the coral host. The implications of these results for coral adaptation, along with future avenues of research based on current knowledge gaps, are discussed in the present work.
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Affiliation(s)
- Javier A Rodriguez-Casariego
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, Illinois, USA.,Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Andrew C Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
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20
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Abbott E, Dixon G, Matz M. Shuffling between Cladocopium and Durusdinium extensively modifies the physiology of each symbiont without stressing the coral host. Mol Ecol 2021; 30:6585-6595. [PMID: 34551161 DOI: 10.1111/mec.16190] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 08/23/2021] [Accepted: 09/10/2021] [Indexed: 12/28/2022]
Abstract
As sea surface temperatures increase, many coral species that used to harbour symbionts of the genus Cladocopium have become colonized with the thermally tolerant genus, Durusdinium. Here, we asked how gene expression in the symbionts of one genus changes depending on the abundance of another symbiont genus within the same coral host, and what effect this interaction has on the host. Symbiont gene expression was overwhelmingly driven by whether the genus was the minority or the majority within the host, which affected 79% (Durusdinium) and 96% (Cladocopium) of all genes. Particularly strong effects in both genera were observed for photosynthesis components (upregulated in the minority state) and proteins putatively associated with cell motility (upregulated in the majority state). Importantly, there was no distinct gene expression signature associated with the mixed symbiosis state when both genera were represented in comparable proportions within the host, which could lead to more intense competition. The mixed symbiosis was also not associated with elevated host stress: in fact, after heat treatment, stress signatures were the lowest in mixed-symbiosis corals compared to both Cladocopium- and Durusdinium-dominated corals. In conclusion, during shuffling between Cladocopium and Durusdinium both symbiont genera go through extensive and largely reciprocal physiological transitions, but there is no evidence of intensifying antagonistic interactions that are detrimental to the host. Unless the mixed-symbiosis corals in this study are not representative of the typical transition between Cladocopium and Durusdinium, the process of shuffling from one symbiont genus to another appears to be cost-free for the coral host, and even appears to be associated with lower stress susceptibility. This raises optimism for the future corals, which will probably have to rely on symbiont shuffling more and more to withstand environmental challenges.
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Affiliation(s)
- Evelyn Abbott
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
| | - Groves Dixon
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
| | - Mikhail Matz
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
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21
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Fifer J, Bentlage B, Lemer S, Fujimura AG, Sweet M, Raymundo LJ. Going with the flow: How corals in high-flow environments can beat the heat. Mol Ecol 2021; 30:2009-2024. [PMID: 33655552 DOI: 10.1111/mec.15869] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 12/18/2022]
Abstract
Coral reefs are experiencing unprecedented declines in health on a global scale leading to severe reductions in coral cover. One major cause of this decline is increasing sea surface temperature. However, conspecific colonies separated by even small spatial distances appear to show varying responses to this global stressor. One factor contributing to differential responses to heat stress is variability in the coral's micro-environment, such as the amount of water flow a coral experiences. High flow provides corals with a variety of health benefits, including heat stress mitigation. Here, we investigate how water flow affects coral gene expression and provides resilience to increasing temperatures. We examined host and photosymbiont gene expression of Acropora cf. pulchra colonies in discrete in situ flow environments during a natural bleaching event. In addition, we conducted controlled ex situ tank experiments where we exposed A. cf. pulchra to different flow regimes and acute heat stress. Notably, we observed distinct flow-driven transcriptomic signatures related to energy expenditure, growth, heterotrophy and a healthy coral host-photosymbiont relationship. We also observed disparate transcriptomic responses during bleaching recovery between the high- and low-flow sites. Additionally, corals exposed to high flow showed "frontloading" of specific heat-stress-related genes such as heat shock proteins, antioxidant enzymes, genes involved in apoptosis regulation, innate immunity and cell adhesion. We posit that frontloading is a result of increased oxidative metabolism generated by the increased water movement. Gene frontloading may at least partially explain the observation that colonies in high-flow environments show higher survival and/or faster recovery in response to bleaching events.
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Affiliation(s)
- James Fifer
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA.,Department of Biology, Boston University, Boston, MA, USA
| | - Bastian Bentlage
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
| | - Sarah Lemer
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
| | | | - Michael Sweet
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, UK
| | - Laurie J Raymundo
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
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22
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Abstract
Climate-driven reef decline has prompted the development of next-generation coral conservation strategies, many of which hinge on the movement of adaptive variation across genetic and environmental gradients. This process is limited by our understanding of how genetic and genotypic drivers of coral bleaching will manifest in different environmental conditions. We reciprocally transplanted 10 genotypes of Acropora cervicornis across eight sites along a 60 km span of the Florida Reef Tract and documented significant genotype × environment interactions in bleaching response during the severe 2015 bleaching event. Performance relative to site mean was significantly different between genotypes and can be mostly explained by ensemble models of correlations with genetic markers. The high explanatory power was driven by significant enrichment of loci associated DNA repair, cell signalling and apoptosis. No genotypes performed above (or below) bleaching average at all sites, so genomic predictors can provide practitioners with 'confidence intervals' about the chance of success in novel habitats. These data have important implications for assisted gene flow and managed relocation, and their integration with traditional active restoration.
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Affiliation(s)
- Crawford Drury
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Diego Lirman
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
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Cunning R, Baker AC. Thermotolerant coral symbionts modulate heat stress‐responsive genes in their hosts. Mol Ecol 2020; 29:2940-2950. [DOI: 10.1111/mec.15526] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/05/2020] [Accepted: 06/15/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Ross Cunning
- Department of Marine Biology and Ecology Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA
- Daniel P. Haerther Center for Conservation and Research John G. Shedd Aquarium Chicago IL USA
| | - Andrew C. Baker
- Department of Marine Biology and Ecology Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA
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