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Faulstich NG, Deloach AR, Ksor YB, Mesa GH, Sharma DS, Sisk SL, Mitchell GC. Evidence for phosphate-dependent control of symbiont cell division in the model anemone Exaiptasia diaphana. mBio 2024:e0105924. [PMID: 39105583 DOI: 10.1128/mbio.01059-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 07/09/2024] [Indexed: 08/07/2024] Open
Abstract
Reef-building corals depend on symbiosis with photosynthetic algae that reside within their cells. As important as this relationship is for maintaining healthy reefs, it is strikingly delicate. When ocean temperatures briefly exceed the average summer maximum, corals can bleach, losing their endosymbionts. Although the mechanisms governing bleaching are unknown, studies implicate uncoupling of coral and algal cell divisions at high temperatures. Still, little is known regarding the coordination of host and algal cell divisions. Control of nutrient exchange is one likely mechanism. Both nitrogen and phosphate are necessary for dividing cells, and although nitrogen enrichment is known to increase symbiont density in the host, the consequences of phosphate enrichment are poorly understood. Here, we examined the effects of phosphate depletion on symbiont growth in culture and compared the physiology of phosphate-starved symbionts in culture to symbionts that were freshly isolated from a host. We found that available phosphate is as low in freshly isolated symbionts as it is in phosphate-starved cultures. Furthermore, RNAseq revealed that phosphate-limited and freshly isolated symbionts have similar patterns of gene expression for phosphate-dependent genes, most notably upregulation of phosphatases, which is consistent with phosphate recycling. Similarly, lipid profiling revealed a substantial decrease in phospholipid abundance in both phosphate-starved cultures and freshly isolated symbionts. These findings are important because they suggest that limited access to phosphate controls algal cell divisions within a host. IMPORTANCE The corals responsible for building tropical reefs are disappearing at an alarming rate as elevated sea temperatures cause them to bleach and lose the algal symbionts they rely on. Without these symbionts, corals are unable to harvest energy from sunlight and, therefore, struggle to thrive or even survive in the nutrient-poor waters of the tropics. To devise solutions to address the threat to coral reefs, it is necessary to understand the cellular events underpinning the bleaching process. One model for bleaching proposes that heat stress impairs algal photosynthesis and transfer of sugar to the host. Consequently, the host's demands for nitrogen decrease, increasing nitrogen availability to the symbionts, which leads to an increase in algal proliferation that overwhelms the host. Our work suggests that phosphate may play a similar role to nitrogen in this feedback loop.
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Affiliation(s)
| | | | - Ykok B Ksor
- Wofford College, Spartanburg, South Carolina, USA
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2
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Sikorskaya TV, Ermolenko EV, Ginanova TT, Boroda AV, Efimova KV, Bogdanov M. Membrane vectorial lipidomic features of coral host cells' plasma membrane and lipid profiles of their endosymbionts Cladocopium. Commun Biol 2024; 7:878. [PMID: 39025984 PMCID: PMC11258240 DOI: 10.1038/s42003-024-06578-8] [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: 01/14/2024] [Accepted: 07/11/2024] [Indexed: 07/20/2024] Open
Abstract
The symbiotic relationships between coral animal host and autotrophic dinoflagellates are based on the mutual exchange and tight control of nutritional inputs supporting successful growth. The corals Sinularia heterospiculata and Acropora aspera were cultivated using a flow-through circulation system supplying seawater during cold and warm seasons of the year, then sorted into host cells and symbionts and subjected to phylogenetic, morphological, and advanced lipid analyses. Here we show, that the lipidomes of the dinoflagellates Cladocopium C1/C3 and acroporide-specific Cladocopium hosted by the corals, are determined by lipidomic features of different thermosensitivity and unique betaine- and phospholipid molecular species. Phosphatidylserines and ceramiaminoethylphosphonates are not detected in the symbionts and predominantly localized on the inner leaflet of the S. heterospiculata host plasma membrane. The transmembrane distribution of phosphatidylethanolamines of S. heterospiculata host changes during different seasons of the year, possibly contributing to mutualistic nutritional exchange across this membrane complex to provide the host with a secure adaptive mechanism and ecological benefits.
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Affiliation(s)
- Tatyana V Sikorskaya
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation.
| | - Ekaterina V Ermolenko
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation
| | - Taliya T Ginanova
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation
| | - Andrey V Boroda
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation
| | - Kseniya V Efimova
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation
| | - Mikhail Bogdanov
- Department of Biochemistry and Molecular Biology, the University of Texas Health Science Center, McGovern Medical School, Houston, TX, USA.
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3
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Helgoe J, Davy SK, Weis VM, Rodriguez-Lanetty M. Triggers, cascades, and endpoints: connecting the dots of coral bleaching mechanisms. Biol Rev Camb Philos Soc 2024; 99:715-752. [PMID: 38217089 DOI: 10.1111/brv.13042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/15/2024]
Abstract
The intracellular coral-dinoflagellate symbiosis is the engine that underpins the success of coral reefs, one of the most diverse ecosystems on the planet. However, the breakdown of the symbiosis and the loss of the microalgal symbiont (i.e. coral bleaching) due to environmental changes are resulting in the rapid degradation of coral reefs globally. There is an urgent need to understand the cellular physiology of coral bleaching at the mechanistic level to help develop solutions to mitigate the coral reef crisis. Here, at an unprecedented scope, we present novel models that integrate putative mechanisms of coral bleaching within a common framework according to the triggers (initiators of bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, e.g. photoinhibition, unfolded protein response, nitric oxide), and endpoints (mechanisms of symbiont loss, e.g. apoptosis, necrosis, exocytosis/vomocytosis). The models are supported by direct evidence from cnidarian systems, and indirectly through comparative evolutionary analyses from non-cnidarian systems. With this approach, new putative mechanisms have been established within and between cascades initiated by different bleaching triggers. In particular, the models provide new insights into the poorly understood connections between bleaching cascades and endpoints and highlight the role of a new mechanism of symbiont loss, i.e. 'symbiolysosomal digestion', which is different from symbiophagy. This review also increases the approachability of bleaching physiology for specialists and non-specialists by mapping the vast landscape of bleaching mechanisms in an atlas of comprehensible and detailed mechanistic models. We then discuss major knowledge gaps and how future research may improve the understanding of the connections between the diverse cascade of cellular pathways and the mechanisms of symbiont loss (endpoints).
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Affiliation(s)
- Joshua Helgoe
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 2701 SW Campus Way, 2403 Cordley Hall, Corvallis, OR, USA
| | - Mauricio Rodriguez-Lanetty
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
- Department of Biological Sciences, Biomolecular Sciences Institute, Florida International University, 11200 SW 8th Street, Miami, FL, USA
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4
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Mizobata H, Tomita K, Yonezawa R, Hayashi K, Kinoshita S, Yoshitake K, Asakawa S. The highly developed symbiotic system between the solar-powered nudibranch Pteraeolidia semperi and Symbiodiniacean algae. iScience 2023; 26:108464. [PMID: 38125017 PMCID: PMC10730344 DOI: 10.1016/j.isci.2023.108464] [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: 06/30/2023] [Revised: 10/09/2023] [Accepted: 11/13/2023] [Indexed: 12/23/2023] Open
Abstract
The intricate coexistence of Symbiodiniacean algae with a diverse range of marine invertebrates underpins the flourishing biodiversity observed within coral reef ecosystems. However, the breakdown of Symbiodiniaceae-host symbiosis endangers these ecosystems, necessitating urgent study of the symbiotic mechanisms. The symbiosis between nudibranchs and Symbiodiniaceae has been identified as an efficacious model for examining these mechanisms, yet a comprehensive understanding of their histological structures and cellular processes remains elusive. A meticulous histological exploration of the nudibranch Pteraeolidia semperi, employing optical, fluorescence, and electron microscopy, has revealed fine tubules extending to the body surface, with associated epithelial cells having been shown to adeptly encapsulate Symbiodiniaceae intracellularly. By tracing the stages of the "bleaching" in nudibranchs, it was inferred that algal cells, translocated via the digestive gland, are directly phagocytosed and expelled by these epithelial cells. Collectively, these insights contribute substantially to the scholarly discourse on critical marine symbiotic associations.
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Affiliation(s)
- Hideaki Mizobata
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kenji Tomita
- Technology Advancement Center, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryo Yonezawa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kentaro Hayashi
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shigeharu Kinoshita
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kazutoshi Yoshitake
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shuichi Asakawa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
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5
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Kawamura K, Shoguchi E, Nishitsuji K, Sekida S, Narisoko H, Zhao H, Shu Y, Fu P, Yamashita H, Fujiwara S, Satoh N. In Vitro Phagocytosis of Different Dinoflagellate Species by Coral Cells. Zoolog Sci 2023; 40:444-454. [PMID: 38064371 DOI: 10.2108/zs230045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/14/2023] [Indexed: 12/18/2023]
Abstract
Coral-dinoflagellate symbiosis is a unique biological phenomenon, in which animal cells engulf single-celled photosynthetic algae and maintain them in their cytoplasm mutualistically. Studies are needed to reveal the complex mechanisms involved in symbiotic processes, but it is difficult to answer these questions using intact corals. To tackle these issues, our previous studies established an in vitro system of symbiosis between cells of the scleractinian coral Acropora tenuis and the dinoflagellate Breviolum minutum, and showed that corals direct phagocytosis, while algae are likely engulfed by coral cells passively. Several genera of the family Symbiodiniaceae can establish symbioses with corals, but the symbiotic ratio differs depending on the dinoflagellate clades involved. To understand possible causes of these differences, this study examined whether cultured coral cells show phagocytotic activity with various dinoflagellate strains similar to those shown by intact A. tenuis. We found that (a) A. tenuis larvae incorporate Symbiodinium and Breviolum, but not Cladocopium, and very few Effrenium, (b) cultured coral cells engulfed all four species but the ratio of engulfment was significantly higher with Symbiodinium and Breviolum than Cladocopium and Effrenium, (c) cultured coral cells also phagocytosed inorganic latex beads differently than they do dinoflagellates . It is likely that cultured coral cells preferentially phagocytose Symbiodinium and Breviolum, suggesting that specific molecular mechanisms involved in initiation of symbiosis should be investigated in the future.
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Affiliation(s)
- Kaz Kawamura
- Department of Applied Science, Kochi University, Kochi 780-8520, Japan,
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Koki Nishitsuji
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Satoko Sekida
- Kuroshio Science Program, Graduate School of Integrated Arts and Sciences, Kochi University, Kochi 780-8520, Japan
| | - Haruhi Narisoko
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Hongwei Zhao
- College of Ecology and Environment & State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Yang Shu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Pengcheng Fu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Hiroshi Yamashita
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Ishigaki, Okinawa 907-0451, Japan
| | - Shigeki Fujiwara
- Department of Applied Science, Kochi University, Kochi 780-8520, Japan
| | - Noriyuki Satoh
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan,
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6
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Mihirogi Y, Kaneda M, Yamagishi D, Ishii Y, Maruyama S, Nakamura S, Shimoyama N, Oohori C, Hatta M. Establishment of a New Model Sea Anemone for Comparative Studies on Cnidarian-Algal Symbiosis. Zoolog Sci 2023; 40:235-245. [PMID: 37256571 DOI: 10.2108/zs220099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/25/2022] [Indexed: 06/01/2023]
Abstract
Frequent coral bleaching has drawn attention to the mechanisms of coral dinoflagellate endosymbiosis. Owing to the difficulty of rearing corals in the laboratory, model symbiosis systems are desired. The sea anemone Exaiptasia diaphana, hosting clade B1 of the genus Breviolum, has long been studied as a model system; however, a single species is insufficient for comparative studies and thus provides only limited resources for symbiosis research, especially regarding the specificity of host-symbiont associations. We established a clonal strain of the sea anemone Anthopleura atodai, whose symbiont was identified as a novel subclade of Symbiodinium (clade A) using a novel feeding method. We also developed a method to efficiently bleach various sea anemone species using a quinoclamine-based herbicide. Bleached A. atodai polyps were vital and able to reproduce asexually, exhibiting no signs of harmful effects of the drug treatment. Pilot studies have suggested that host-symbiont specificity is influenced by multiple steps differently in A. atodai and E. diaphana. RNAseq analyses of A. atodai showed that multiple NPC2 genes were expressed in the symbiotic state, which have been suggested to function in the transport of sterols from symbionts to host cells. These results reveal the usefulness of A. atodai in comparative studies of cnidarian-algal symbiosis.
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Affiliation(s)
- Yukie Mihirogi
- Department of Life Science, Graduate School of Humanities and Sciences, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Michika Kaneda
- Department of Biology, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Daisuke Yamagishi
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Yuu Ishii
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
- Department of Biology, Miyagi University of Education, Aoba-ku, Sendai 980-0845, Japan
| | - Shinichiro Maruyama
- Department of Life Science, Graduate School of Humanities and Sciences, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Sumika Nakamura
- Department of Life Science, Graduate School of Humanities and Sciences, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Natsuno Shimoyama
- Department of Biology, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Chihiro Oohori
- Department of Life Science, Graduate School of Humanities and Sciences, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Masayuki Hatta
- Department of Life Science, Graduate School of Humanities and Sciences, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan
- Department of Biology, Ochanoizu University, Bunkyo-ku, Tokyo 112-8610, Japan,
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7
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Hu M, Bai Y, Zheng X, Zheng Y. Coral-algal endosymbiosis characterized using RNAi and single-cell RNA-seq. Nat Microbiol 2023:10.1038/s41564-023-01397-9. [PMID: 37217718 DOI: 10.1038/s41564-023-01397-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 04/25/2023] [Indexed: 05/24/2023]
Abstract
Corals form an endosymbiotic relationship with the dinoflagellate algae Symbiodiniaceae, but ocean warming can trigger algal loss, coral bleaching and death, and the degradation of ecosystems. Mitigation of coral death requires a mechanistic understanding of coral-algal endosymbiosis. Here we report an RNA interference (RNAi) method and its application to study genes involved in early steps of endosymbiosis in the soft coral Xenia sp. We show that a host endosymbiotic cell marker called LePin (lectin and kazal protease inhibitor domains) is a secreted Xenia lectin that binds to algae to initiate phagocytosis of the algae and coral immune response modulation. The evolutionary conservation of domains in LePin among marine anthozoans performing endosymbiosis suggests a general role in coral-algal recognition. Our work sheds light on the phagocytic machinery and posits a mechanism for symbiosome formation, helping in efforts to understand and preserve coral-algal relationships in the face of climate change.
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Affiliation(s)
- Minjie Hu
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA.
- College of Life Sciences, Zhejiang University, Hangzhou, China.
| | - Yun Bai
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA
| | - Xiaobin Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA.
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8
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Mohamed AR, Ochsenkühn MA, Kazlak AM, Moustafa A, Amin SA. The coral microbiome: towards an understanding of the molecular mechanisms of coral-microbiota interactions. FEMS Microbiol Rev 2023; 47:fuad005. [PMID: 36882224 PMCID: PMC10045912 DOI: 10.1093/femsre/fuad005] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 03/09/2023] Open
Abstract
Corals live in a complex, multipartite symbiosis with diverse microbes across kingdoms, some of which are implicated in vital functions, such as those related to resilience against climate change. However, knowledge gaps and technical challenges limit our understanding of the nature and functional significance of complex symbiotic relationships within corals. Here, we provide an overview of the complexity of the coral microbiome focusing on taxonomic diversity and functions of well-studied and cryptic microbes. Mining the coral literature indicate that while corals collectively harbour a third of all marine bacterial phyla, known bacterial symbionts and antagonists of corals represent a minute fraction of this diversity and that these taxa cluster into select genera, suggesting selective evolutionary mechanisms enabled these bacteria to gain a niche within the holobiont. Recent advances in coral microbiome research aimed at leveraging microbiome manipulation to increase coral's fitness to help mitigate heat stress-related mortality are discussed. Then, insights into the potential mechanisms through which microbiota can communicate with and modify host responses are examined by describing known recognition patterns, potential microbially derived coral epigenome effector proteins and coral gene regulation. Finally, the power of omics tools used to study corals are highlighted with emphasis on an integrated host-microbiota multiomics framework to understand the underlying mechanisms during symbiosis and climate change-driven dysbiosis.
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Affiliation(s)
- Amin R Mohamed
- Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Michael A Ochsenkühn
- Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Ahmed M Kazlak
- Systems Genomics Laboratory, American University in Cairo, New Cairo 11835, Egypt
- Biotechnology Graduate Program, American University in Cairo, New Cairo 11835, Egypt
| | - Ahmed Moustafa
- Systems Genomics Laboratory, American University in Cairo, New Cairo 11835, Egypt
- Biotechnology Graduate Program, American University in Cairo, New Cairo 11835, Egypt
- Department of Biology, American University in Cairo, New Cairo 11835, Egypt
| | - Shady A Amin
- Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
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9
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Puntin G, Sweet M, Fraune S, Medina M, Sharp K, Weis VM, Ziegler M. Harnessing the Power of Model Organisms To Unravel Microbial Functions in the Coral Holobiont. Microbiol Mol Biol Rev 2022; 86:e0005322. [PMID: 36287022 PMCID: PMC9769930 DOI: 10.1128/mmbr.00053-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Stony corals build the framework of coral reefs, ecosystems of immense ecological and economic importance. The existence of these ecosystems is threatened by climate change and other anthropogenic stressors that manifest in microbial dysbiosis such as coral bleaching and disease, often leading to coral mortality. Despite a significant amount of research, the mechanisms ultimately underlying these destructive phenomena, and what could prevent or mitigate them, remain to be resolved. This is mostly due to practical challenges in experimentation on corals and the highly complex nature of the coral holobiont that also includes bacteria, archaea, protists, and viruses. While the overall importance of these partners is well recognized, their specific contributions to holobiont functioning and their interspecific dynamics remain largely unexplored. Here, we review the potential of adopting model organisms as more tractable systems to address these knowledge gaps. We draw on parallels from the broader biological and biomedical fields to guide the establishment, implementation, and integration of new and emerging model organisms with the aim of addressing the specific needs of coral research. We evaluate the cnidarian models Hydra, Aiptasia, Cassiopea, and Astrangia poculata; review the fast-evolving field of coral tissue and cell cultures; and propose a framework for the establishment of "true" tropical reef-building coral models. Based on this assessment, we also suggest future research to address key aspects limiting our ability to understand and hence improve the response of reef-building corals to future ocean conditions.
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Affiliation(s)
- Giulia Puntin
- Department of Animal Ecology and Systematics, Marine Holobiomics Lab, Justus Liebig University Giessen, Giessen, Germany
| | - Michael Sweet
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, United Kingdom
| | - Sebastian Fraune
- Institute for Zoology and Organismic Interactions, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Mónica Medina
- Department of Biology, Pennsylvania State University, State College, Pennsylvania, USA
| | - Koty Sharp
- Department of Biology, Marine Biology, and Environmental Science, Roger Williams University, Bristol, Rhode Island, USA
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, USA
| | - Maren Ziegler
- Department of Animal Ecology and Systematics, Marine Holobiomics Lab, Justus Liebig University Giessen, Giessen, Germany
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10
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Zhu Y, Liao X, Han T, Chen JY, He C, Lu Z. Utilizing an artificial intelligence system to build the digital structural proteome of reef-building corals. Gigascience 2022; 11:giac117. [PMID: 36399057 PMCID: PMC9673494 DOI: 10.1093/gigascience/giac117] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/03/2022] [Accepted: 10/31/2022] [Indexed: 08/12/2023] Open
Abstract
BACKGROUND Reef-building corals play an important role in the marine ecosystem, and analyzing their proteomes from a structural perspective will exert positive effects on exploring their biology. Here we integrated mass spectrometry with newly published ColabFold to obtain digital structural proteomes of dominant reef-building corals. RESULTS Of the 8,382 homologous proteins in Acropora muricata, Montipora foliosa, and Pocillopora verrucosa identified, 8,166 received predicted structures after about 4,060 GPU hours of computation. The resulting dataset covers 83.6% of residues with a confident prediction, while 25.9% have very high confidence. CONCLUSIONS Our work provides insight-worthy predictions for coral research, confirms the reliability of ColabFold in practice, and is expected to be a reference case in the impending high-throughput era of structural proteomics.
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Affiliation(s)
- Yunchi Zhu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, 210096, China
| | - Xin Liao
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, China
| | - Tingyu Han
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, 210096, China
| | - J-Y Chen
- Nanjing Institute of Paleontology and Geology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Chunpeng He
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, 210096, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, 210096, China
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11
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Changsut I, Womack HR, Shickle A, Sharp KH, Fuess LE. Variation in symbiont density is linked to changes in constitutive immunity in the facultatively symbiotic coral,
Astrangia poculata. Biol Lett 2022; 18:20220273. [PMID: 36382375 PMCID: PMC9667134 DOI: 10.1098/rsbl.2022.0273] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Scleractinian corals are essential ecosystem engineers, forming the basis of coral reef ecosystems. However, these organisms are in decline globally, in part due to rising disease prevalence. Most corals are dependent on symbiotic interactions with single-celled algae from the family Symbiodiniaceae to meet their nutritional needs, however, suppression of host immunity may be essential to this relationship. To explore immunological consequences of algal symbioses in scleractinian corals, we investigated constitutive immune activity in the facultatively symbiotic coral, Astrangia poculata. We compared immune metrics (melanin synthesis, antioxidant production and antibacterial activity) between coral colonies of varying symbiont density. Symbiont density was positively correlated to both antioxidant activity and melanin concentration, likely as a result of the dual roles of these pathways in immunity and symbiosis regulation. Our results confirm the complex nature of relationships between algal symbiosis and host immunity and highlight the need for nuanced approaches when considering these relationships.
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12
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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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13
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Full-Length Transcriptome Maps of Reef-Building Coral Illuminate the Molecular Basis of Calcification, Symbiosis, and Circa-Dian Genes. Int J Mol Sci 2022; 23:ijms231911135. [PMID: 36232445 PMCID: PMC9570262 DOI: 10.3390/ijms231911135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/08/2022] [Accepted: 09/19/2022] [Indexed: 11/17/2022] Open
Abstract
Coral transcriptomic data largely rely on short-read sequencing, which severely limits the understanding of coral molecular mechanisms and leaves many important biological questions unresolved. Here, we sequence the full-length transcriptomes of four common and frequently dominant reef-building corals using the PacBio Sequel II platform. We obtain information on reported gene functions, structures, and expression profiles. Among them, a comparative analysis of biomineralization-related genes provides insights into the molecular basis of coral skeletal density. The gene expression profiles of the symbiont Symbiodiniaceae are also isolated and annotated from the holobiont sequence data. Finally, a phylogenetic analysis of key circadian clock genes among 40 evolutionarily representative species indicates that there are four key members in early metazoans, including cry genes; Clock or Npas2; cyc or Arntl; and tim, while per, as the fifth member, occurs in Bilateria. In summary, this work provides a foundation for further work on the manipulation of skeleton production or symbiosis to promote the survival of these important organisms.
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14
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Huene AL, Koch JC, Arregui L, Liu Y, Nicotra ML, Weis VM, Tiersch TR. Cryopreservation of Hydractinia symbiolongicarpus Sperm to Support Community-Based Repository Development for Preservation of Genetic Resources. Animals (Basel) 2022; 12:ani12192537. [PMID: 36230277 PMCID: PMC9559378 DOI: 10.3390/ani12192537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/03/2022] [Accepted: 09/13/2022] [Indexed: 11/16/2022] Open
Abstract
Hydractinia symbiolongicarpus is an emerging model organism in which cutting-edge genomic tools and resources are being developed for use in a growing number of research fields. One limitation of this model system is the lack of long-term storage for genetic resources. The goal of this study was to establish a generalizable cryopreservation approach for Hydractinia that would support future repository development for other cnidarian species. Specific objectives were to: (1) characterize basic parameters related to sperm quality; (2) develop a generalizable approach for sperm collection; (3) assess the feasibility of in vitro fertilization (IVF) with sperm after refrigerated storage; (4) assess the feasibility of IVF with sperm cryopreserved with various sperm concentrations; (5) evaluate feasibility of cryopreservation with various freezing conditions, and (6) explore the feasibility of cryopreservation by use of a 3-D printed open-hardware (CryoKit) device. Animal husbandry and sperm collection were facilitated by use of 3-D printed open hardware. Hydractinia sperm at a concentration of 2 × 107 cells/mL stored at 4 °C for 6 d were able to achieve 50% fertilization rate. It appeared that relatively higher sperm concentration (>5 × 107 cells/mL) for cryopreservation could promote fertilization. A fertilization rate of 41−69% was observed using sperm equilibrated with 5, 10, or 15% (v/v) cryoprotectant (dimethyl sulfoxide or methanol) for 20 min, cooled at a rate of 5, 10, or 20 °C/min from 4 °C to −80 °C, at a cell concentration of 108/mL, in 0.25 mL French straws. Samples cryopreserved with the CryoKit produced a fertilization rate of 72−82%. Establishing repository capabilities for the Hydractinia research community will be essential for future development, maintenance, protection, and distribution of genetic resources. More broadly, these generalizable approaches can be used as a model to develop germplasm repositories for other cnidarian species.
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Affiliation(s)
- Aidan L. Huene
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70820, USA
| | - Jack C. Koch
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70820, USA
| | - Lucía Arregui
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70820, USA
| | - Yue Liu
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70820, USA
| | - Matthew L. Nicotra
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Correspondence: (M.L.N.); (T.R.T.)
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Terrence R. Tiersch
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70820, USA
- Correspondence: (M.L.N.); (T.R.T.)
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15
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Ip JCH, Zhang Y, Xie JY, Yeung YH, Qiu JW. Comparative transcriptomics of two coral holobionts collected during the 2017 El Niño heat wave reveal differential stress response mechanisms. MARINE POLLUTION BULLETIN 2022; 182:114017. [PMID: 35963227 DOI: 10.1016/j.marpolbul.2022.114017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/28/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
Although coral species exhibit differential susceptibility to stressors, little is known about the underlying molecular mechanisms. Here we compared scleractinian corals Montipora peltiformis and Platygyra carnosa collected during the 2017 El Niño heat wave. Zooxanthellae density and chlorophyll a content declined and increased substantially during and after heat stress event, respective. However, the magnitude of change was larger in M. peltiformis. Transcriptome analysis showed that heat-stressed corals corresponded to metabolic depression and catabolism of amino acids in both hosts which might promote their survival. However, only M. peltiformis has developed the bleached coral phenotype with corresponding strong stress- and immune-related responses in the host and symbiont, and strong suppression of photosynthesis-related genes in the symbiont. Overall, our study reveals differences among species in the homeostatic capacity to prevent the development of the bleached phenotype under environmental stressors, eventually determining their likelihood of survival in the warming ocean.
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Affiliation(s)
- Jack Chi-Ho Ip
- Department of Biology, Hong Kong Baptist University, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; HKBU Institute of Research and Continuing Education, Virtual University Park, Shenzhen, China
| | - Yanjie Zhang
- School of Life Sciences, Hainan University, Haikou, China.
| | - James Y Xie
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Yip Hung Yeung
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jian-Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; HKBU Institute of Research and Continuing Education, Virtual University Park, Shenzhen, China.
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16
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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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17
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Heat Stress of Algal Partner Hinders Colonization Success and Alters the Algal Cell Surface Glycome in a Cnidarian-Algal Symbiosis. Microbiol Spectr 2022; 10:e0156722. [PMID: 35639004 PMCID: PMC9241721 DOI: 10.1128/spectrum.01567-22] [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] [Indexed: 11/20/2022] Open
Abstract
Corals owe their ecological success to their symbiotic relationship with dinoflagellate algae (family Symbiodiniaceae). While the negative effects of heat stress on this symbiosis are well studied, how heat stress affects the onset of symbiosis and symbiont specificity is less explored. In this work, we used the model sea anemone, Exaiptasia diaphana (commonly referred to as Aiptasia), and its native symbiont, Breviolum minutum, to study the effects of heat stress on the colonization of Aiptasia by algae and the algal cell-surface glycome. Heat stress caused a decrease in the colonization of Aiptasia by algae that were not due to confounding variables such as algal motility or oxidative stress. With mass spectrometric analysis and lectin staining, a thermally induced enrichment of glycans previously found to be associated with free-living strains of algae (high-mannoside glycans) and a concomitant reduction in glycans putatively associated with symbiotic strains of algae (galactosylated glycans) were identified. Differential enrichment of specific sialic acid glycans was also identified, although their role in this symbiosis remains unclear. We also discuss the methods used to analyze the cell-surface glycome of algae, evaluate current limitations, and provide suggestions for future work in algal-coral glycobiology. Overall, this study provided insight into how stress may affect the symbiosis between cnidarians and their algal symbionts by altering the glycome of the symbiodinian partner. IMPORTANCE Coral reefs are under threat from global climate change. Their decline is mainly caused by the fragility of their symbiotic relationship with dinoflagellate algae which they rely upon for their ecological success. To better understand coral biology, researchers used the sea anemone, Aiptasia, a model system for the study of coral-algal symbiosis, and characterized how heat stress can alter the algae's ability to communicate to the coral host. This study found that heat stress caused a decline in algal colonization success and impacted the cell surface molecules of the algae such that it became more like that of nonsymbiotic species of algae. This work adds to our understanding of the molecular signals involved in coral-algal symbiosis and how it breaks down during heat stress.
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18
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Zhu Y, Liao X, Han T, Chen JY, He C, Lu Z. Symbiodiniaceae microRNAs and their targeting sites in coral holobionts: A transcriptomics-based exploration. Genomics 2022; 114:110404. [PMID: 35714829 DOI: 10.1016/j.ygeno.2022.110404] [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: 03/17/2022] [Revised: 05/30/2022] [Accepted: 06/09/2022] [Indexed: 01/23/2023]
Abstract
Corals should make excellent models for cross-kingdom research because of their natural animal-photobiont holobiont composition, yet a lack of studies and experimental data restricts their use. Here we integrate new full-length transcriptomes and small RNAs of four common reef-building corals with the published Cladocopium genomes to gain deeper insight into gene regulation in coral-Symbiodiniaceae holobionts. Eleven novel Symbiodiniaceae miRNAs get identified, and enrichment results of their target genes show that they might play a role in downregulating rejection from host coral cells, protecting symbiont from autophagy and apoptosis in parallel. This work provides evidence for the early origin of cross-kingdom regulation as a mechanism of self-defense autotrophs can use against heterotrophs, sheds more light on coral-Symbiodiniaceae holobionts, and contributes valuable data for further coral research.
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Affiliation(s)
- Yunchi Zhu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, China
| | - Xin Liao
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Beihai, Guangxi, China
| | - Tingyu Han
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, China
| | - J-Y Chen
- Nanjing Institute of Paleontology and Geology, Nanjing, China
| | - Chunpeng He
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, China.
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu, China.
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19
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Shoguchi E. Gene clusters for biosynthesis of mycosporine-like amino acids in dinoflagellate nuclear genomes: Possible recent horizontal gene transfer between species of Symbiodiniaceae (Dinophyceae). JOURNAL OF PHYCOLOGY 2022; 58:1-11. [PMID: 34699617 PMCID: PMC9298759 DOI: 10.1111/jpy.13219] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 10/01/2021] [Accepted: 10/12/2021] [Indexed: 05/12/2023]
Abstract
Global warming increases the temperature of the ocean surface, which can disrupt dinoflagellate-coral symbioses and result in coral bleaching. Photosynthetic dinoflagellates of the family Symbiodiniaceae include bleaching-tolerant and bleaching-sensitive coral symbionts. Therefore, understanding the molecular mechanisms for changing symbiont diversity is potentially useful to assist recovery of coral holobionts (corals and their associated microbes, including multiple species of Symbiodiniaceae), although sexual reproduction has not been observed in the Symbiodiniaceae. Recent molecular phylogenetic analyses estimate that the Symbiodiniaceae appeared 160 million years ago and diversified into 15 groups, five genera of which now have available draft genomes (i.e., Symbiodinium, Durusdinium, Breviolum, Fugacium, and Cladocopium). Comparative genomic analyses have suggested that crown groups have fewer gene families than early-diverging groups, although many genes that were probably acquired via gene duplications and horizontal gene transfers (HGTs) have been found in each decoded genome. Because UV stress is likely a contributor to coral bleaching, and because the highly conserved gene cluster for mycosporine-like amino acid (MAA) biosynthesis has been found in thermal-tolerant symbiont genomes, I reviewed genomic features of the Symbiodiniaceae, focusing on possible acquisition of a biosynthetic gene cluster for MAAs, which absorb UV radiation. On the basis of highly conserved noncoding sequences, I hypothesized that HGTs have occurred among members of the Symbiodiniaceae and have contributed to the diversification of Symbiodiniaceae-host relationships. Finally, I proposed that bleaching tolerance may be strengthened by multiple MAAs from both symbiotic dinoflagellates and corals.
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Affiliation(s)
- Eiichi Shoguchi
- Marine Genomics UnitOkinawa Institute of Science and Technology Graduate UniversityOnnaOkinawa904‐0495Japan
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20
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Presnell JS, Wirsching E, Weis VM. Tentacle patterning during Exaiptasia diaphana pedal lacerate development differs between symbiotic and aposymbiotic animals. PeerJ 2022; 10:e12770. [PMID: 35047238 PMCID: PMC8757374 DOI: 10.7717/peerj.12770] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 12/19/2021] [Indexed: 01/07/2023] Open
Abstract
Exaiptasia diaphana, a tropical sea anemone known as Aiptasia, is a tractable model system for studying the cellular, physiological, and ecological characteristics of cnidarian-dinoflagellate symbiosis. Aiptasia is widely used as a proxy for coral-algal symbiosis, since both Aiptasia and corals form a symbiosis with members of the family Symbiodiniaceae. Laboratory strains of Aiptasia can be maintained in both the symbiotic (Sym) and aposymbiotic (Apo, without algae) states. Apo Aiptasia allow for the study of the influence of symbiosis on different biological processes and how different environmental conditions impact symbiosis. A key feature of Aiptasia is the ease of propagating both Sym and Apo individuals in the laboratory through a process called pedal laceration. In this form of asexual reproduction, small pieces of tissue rip away from the pedal disc of a polyp, then these lacerates eventually develop tentacles and grow into new polyps. While pedal laceration has been described in the past, details of how tentacles are formed or how symbiotic and nutritional state influence this process are lacking. Here we describe the stages of development in both Sym and Apo pedal lacerates. Our results show that Apo lacerates develop tentacles earlier than Sym lacerates, while over the course of 20 days, Sym lacerates end up with a greater number of tentacles. We describe both tentacle and mesentery patterning during lacerate development and show that they form through a single pattern in early stages regardless of symbiotic state. In later stages of development, Apo lacerate tentacles and mesenteries progress through a single pattern, while variable patterns were observed in Sym lacerates. We discuss how Aiptasia lacerate mesentery and tentacle patterning differs from oral disc regeneration and how these patterning events compare to postembryonic development in Nematostella vectensis, another widely-used sea anemone model. In addition, we demonstrate that Apo lacerates supplemented with a putative nutrient source developed an intermediate number of tentacles between un-fed Apo and Sym lacerates. Based on these observations, we hypothesize that pedal lacerates progress through two different, putatively nutrient-dependent phases of development. In the early phase, the lacerate, regardless of symbiotic state, preferentially uses or relies on nutrients carried over from the adult polyp. These resources are sufficient for lacerates to develop into a functional polyp. In the late phase of development, continued growth and tentacle formation is supported by nutrients obtained from either symbionts and/or the environment through heterotrophic feeding. Finally, we advocate for the implementation of pedal lacerates as an additional resource in the Aiptasia model system toolkit for studies of cnidarian-dinoflagellate symbiosis.
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Affiliation(s)
- Jason S. Presnell
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America,Department of Human Genetics, University of Utah, Salt Lake City, UT, United States of America
| | - Elizabeth Wirsching
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America,Department of Biology, Western Washington University, Bellingham, WA, United States of America
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America
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21
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Will coral reefs survive by adaptive bleaching? Emerg Top Life Sci 2021; 6:11-15. [PMID: 34881775 DOI: 10.1042/etls20210227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022]
Abstract
Some reef-building corals form symbioses with multiple algal partners that differ in ecologically important traits like heat tolerance. Coral bleaching and recovery can drive symbiont community turnover toward more heat-tolerant partners, and this 'adaptive bleaching' response can increase future bleaching thresholds by 1-2°C, aiding survival in warming oceans. However, this mechanism of rapid acclimatization only occurs in corals that are compatible with multiple symbionts, and only when the disturbance regime and competitive dynamics among symbionts are sufficient to bring about community turnover. The full scope of coral taxa and ecological scenarios in which symbiont shuffling occurs remains poorly understood, though its prevalence is likely to increase as warming oceans boost the competitive advantage of heat-tolerant symbionts, increase the frequency of bleaching events, and strengthen metacommunity feedbacks. Still, the constraints, limitations, and potential tradeoffs of symbiont shuffling suggest it will not save coral reef ecosystems; however, it may significantly improve the survival trajectories of some, or perhaps many, coral species. Interventions to manipulate coral symbionts and symbiont communities may expand the scope of their adaptive potential, which may boost coral survival until climate change is addressed.
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22
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Liu Y, Liao X, Han T, Su A, Guo Z, Lu N, He C, Lu Z. Full-Length Transcriptome Sequencing of the Scleractinian Coral Montipora foliosa Reveals the Gene Expression Profile of Coral-Zooxanthellae Holobiont. BIOLOGY 2021; 10:biology10121274. [PMID: 34943189 PMCID: PMC8698432 DOI: 10.3390/biology10121274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Coral-zooxanthellae holobionts are one of the most productive ecosystems in the ocean. With global warming and ocean acidification, coral ecosystems are facing unprecedented challenges. To save the coral ecosystems, we need to understand the symbiosis of coral-zooxanthellae. Although some Scleractinia (stony corals) transcriptomes have been sequenced, the reliable full-length transcriptome is still lacking due to the short-read length of second-generation sequencing and the uncertainty of the assembly results. Herein, PacBio Sequel II sequencing technology polished with the Illumina RNA-seq platform was used to obtain relatively complete scleractinian coral M. foliosa transcriptome data and to quantify M. foliosa gene expression. A total of 38,365 consensus sequences and 20,751 unique genes were identified. Seven databases were used for the gene function annotation, and 19,972 genes were annotated in at least one database. We found 131 zooxanthellae transcripts and 18,829 M. foliosa transcripts. A total of 6328 lncRNAs, 847 M. foliosa transcription factors (TFs), and 2 zooxanthellae TF were identified. In zooxanthellae we found pathways related to symbiosis, such as photosynthesis and nitrogen metabolism. Pathways related to symbiosis in M. foliosa include oxidative phosphorylation and nitrogen metabolism, etc. We summarized the isoforms and expression level of the symbiont recognition genes. Among the membrane proteins, we found three pathways of glycan biosynthesis, which may be involved in the organic matter storage and monosaccharide stabilization in M. foliosa. Our results provide better material for studying coral symbiosis.
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Affiliation(s)
- Yunqing Liu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Xin Liao
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Beihai 536000, China;
| | - Tingyu Han
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Ao Su
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Zhuojun Guo
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Na Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Chunpeng He
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
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23
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Bollati E, Rosenberg Y, Simon-Blecher N, Tamir R, Levy O, Huang D. Untangling the molecular basis of coral response to sedimentation. Mol Ecol 2021; 31:884-901. [PMID: 34738686 DOI: 10.1111/mec.16263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 12/23/2022]
Abstract
Urbanized coral reefs are often chronically affected by sedimentation and reduced light levels, yet many species of corals appear to be able to thrive under these highly disturbed conditions. Recently, these marginal ecosystems have gained attention as potential climate change refugia due to the shading effect of suspended sediment, as well as potential reservoirs for stress-tolerant species. However, little research exists on the impact of sedimentation on coral physiology, particularly at the molecular level. Here, we investigated the transcriptomic response to sediment stress in corals of the family Merulinidae from a chronically turbid reef (one genet each of Goniastrea pectinata and Mycedium elephantotus from Singapore) and a clear-water reef (multiple genets of G. pectinata from the Gulf of Aqaba/Eilat). In two ex-situ experiments, we exposed corals to either natural sediment or artificial sediment enriched with organic matter and used whole-transcriptome sequencing (RNA sequencing) to quantify gene expression. Analysis revealed a shared basis for the coral transcriptomic response to sediment stress, which involves the expression of genes broadly related to energy metabolism and immune response. In particular, sediment exposure induced upregulation of anaerobic glycolysis and glyoxylate bypass enzymes, as well as genes involved in hydrogen sulphide metabolism and in pathogen pattern recognition. Our results point towards hypoxia as a probable driver of this transcriptomic response, providing a molecular basis to previous work that identified hypoxia as a primary cause of tissue necrosis in sediment-stressed corals. Potential metabolic and immunity trade-offs of corals living under chronic sedimentation should be considered in future studies on the ecology and conservation of turbid reefs.
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Affiliation(s)
- Elena Bollati
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Department of Biology, Marine Biology Section, University of Copenhagen, Helsingør, Denmark
| | - Yaeli Rosenberg
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Noa Simon-Blecher
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Raz Tamir
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Oren Levy
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Danwei Huang
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore.,Centre for Nature-based Climate Solutions, National University of Singapore, Singapore, Singapore
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24
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Geraghty S, Koutsouveli V, Hall C, Chang L, Sacristan-Soriano O, Hill M, Riesgo A, Hill A. Establishment of Host-Algal Endosymbioses: Genetic Response to Symbiont Versus Prey in a Sponge Host. Genome Biol Evol 2021; 13:6427630. [PMID: 34791195 PMCID: PMC8633732 DOI: 10.1093/gbe/evab252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2021] [Indexed: 12/13/2022] Open
Abstract
The freshwater sponge Ephydatia muelleri and its Chlorella-like algal partner is an emerging model for studying animal: algal endosymbiosis. The sponge host is a tractable laboratory organism, and the symbiotic algae are easily cultured. We took advantage of these traits to interrogate questions about mechanisms that govern the establishment of durable intracellular partnerships between hosts and symbionts in facultative symbioses. We modified a classical experimental approach to discern the phagocytotic mechanisms that might be co-opted to permit persistent infections, and identified genes differentially expressed in sponges early in the establishment of endosymbiosis. We exposed algal-free E. muelleri to live native algal symbionts and potential food items (bacteria and native heat-killed algae), and performed RNA-Seq to compare patterns of gene expression among treatments. We found a relatively small but interesting suite of genes that are differentially expressed in the host exposed to live algal symbionts, and a larger number of genes triggered by host exposure to heat-killed algae. The upregulated genes in sponges exposed to live algal symbionts were mostly involved in endocytosis, ion transport, metabolic processes, vesicle-mediated transport, and oxidation–reduction. One of the host genes, an ATP-Binding Cassette transporter that is downregulated in response to live algal symbionts, was further evaluated for its possible role in the establishment of the symbiosis. We discuss the gene expression profiles associated with host responses to living algal cells in the context of conditions necessary for long-term residency within host cells by phototrophic symbionts as well as the genetic responses to sponge phagocytosis and immune-driven pathways.
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Affiliation(s)
- Sara Geraghty
- Department of Biology, University of Richmond, Virginia, USA.,Lewis-Sigler Institute for Integrative Genomics, Princeton University, New Jersey, USA
| | - Vasiliki Koutsouveli
- Department of Life Sciences, Natural History Museum, London, United Kingdom.,Department of Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Chelsea Hall
- Department of Biology, University of Richmond, Virginia, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Lillian Chang
- Department of Biology, Bates College, Lewiston, Maine, USA
| | - Oriol Sacristan-Soriano
- Department of Biology, University of Richmond, Virginia, USA.,Centro de Estudios Avanzados de Blanes (CEAB, CSIC), Blanes, Spain
| | - Malcolm Hill
- Department of Biology, University of Richmond, Virginia, USA.,Department of Biology, Bates College, Lewiston, Maine, USA
| | - Ana Riesgo
- Department of Life Sciences, Natural History Museum, London, United Kingdom.,Department of Biodiversity and Evolutionary Biology, National Museum of Natural Sciences, Madrid, Spain
| | - April Hill
- Department of Biology, University of Richmond, Virginia, USA.,Department of Biology, Bates College, Lewiston, Maine, USA
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25
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Rivera HE, Davies SW. Symbiosis maintenance in the facultative coral, Oculina arbuscula, relies on nitrogen cycling, cell cycle modulation, and immunity. Sci Rep 2021; 11:21226. [PMID: 34707162 PMCID: PMC8551165 DOI: 10.1038/s41598-021-00697-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/11/2021] [Indexed: 12/24/2022] Open
Abstract
Symbiosis with unicellular algae in the family Symbiodiniaceae is common across tropical marine invertebrates. Reef-building corals offer a clear example of cellular dysfunction leading to a dysbiosis that disrupts entire ecosystems in a process termed coral bleaching. Due to their obligate symbiotic relationship, understanding the molecular underpinnings that sustain this symbiosis in tropical reef-building corals is challenging, as any aposymbiotic state is inherently coupled with severe physiological stress. Here, we leverage the subtropical, facultatively symbiotic and calcifying coral Oculina arbuscula to investigate gene expression differences between aposymbiotic and symbiotic branches within the same colonies under baseline conditions. We further compare gene ontology (GO) and KOG enrichment in gene expression patterns from O. arbuscula with prior work in the sea anemone Exaiptasia pallida (Aiptasia) and the salamander Ambystoma maculatum-both of which exhibit endophotosymbiosis with unicellular algae. We identify nitrogen cycling, cell cycle control, and immune responses as key pathways involved in the maintenance of symbiosis under baseline conditions. Understanding the mechanisms that sustain a healthy symbiosis between corals and Symbiodiniaceae algae is of urgent importance given the vulnerability of these partnerships to changing environmental conditions and their role in the continued functioning of critical and highly diverse marine ecosystems.
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Affiliation(s)
- H E Rivera
- Department of Biology, Boston University, Boston, MA, USA.
| | - S W Davies
- Department of Biology, Boston University, Boston, MA, USA.
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26
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McKenna V, Archibald JM, Beinart R, Dawson MN, Hentschel U, Keeling PJ, Lopez JV, Martín-Durán JM, Petersen JM, Sigwart JD, Simakov O, Sutherland KR, Sweet M, Talbot N, Thompson AW, Bender S, Harrison PW, Rajan J, Cochrane G, Berriman M, Lawniczak M, Blaxter M. The Aquatic Symbiosis Genomics Project: probing the evolution of symbiosis across the tree of life. Wellcome Open Res 2021. [DOI: 10.12688/wellcomeopenres.17222.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We present the Aquatic Symbiosis Genomics Project, a global collaboration to generate high quality genome sequences for a wide range of eukaryotes and their microbial symbionts. Launched under the Symbiosis in Aquatic Systems Initiative of the Gordon and Betty Moore Foundation, the ASG Project brings together researchers from across the globe who hope to use these reference genomes to augment and extend their analyses of the dynamics, mechanisms and environmental importance of symbiosis. Applying large-scale, high-throughput sequencing and assembly technologies, the ASG collaboration will assemble and annotate the genomes of 500 symbiotic organisms – both the “hosts” and the microbial symbionts with which they associate. These data will be released openly to benefit all who work on symbiosis, from conservation geneticists to those interested in the origin of the eukaryotic cell.
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27
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Abstract
Recent human activity has profoundly transformed Earth biomes on a scale and at rates that are unprecedented. Given the central role of symbioses in ecosystem processes, functions, and services throughout the Earth biosphere, the impacts of human-driven change on symbioses are critical to understand. Symbioses are not merely collections of organisms, but co-evolved partners that arise from the synergistic combination and action of different genetic programs. They function with varying degrees of permanence and selection as emergent units with substantial potential for combinatorial and evolutionary innovation in both structure and function. Following an articulation of operational definitions of symbiosis and related concepts and characteristics of the Anthropocene, we outline a basic typology of anthropogenic change (AC) and a conceptual framework for how AC might mechanistically impact symbioses with select case examples to highlight our perspective. We discuss surprising connections between symbiosis and the Anthropocene, suggesting ways in which new symbioses could arise due to AC, how symbioses could be agents of ecosystem change, and how symbioses, broadly defined, of humans and “farmed” organisms may have launched the Anthropocene. We conclude with reflections on the robustness of symbioses to AC and our perspective on the importance of symbioses as ecosystem keystones and the need to tackle anthropogenic challenges as wise and humble stewards embedded within the system.
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Affiliation(s)
- Erik F Y Hom
- Department of Biology and Center for Biodiversity and Conservation Research, University of Mississippi, University, MS 38677 USA
| | - Alexandra S Penn
- Department of Sociology and Centre for Evaluation of Complexity Across the Nexus, University of Surrey, Guildford, Surrey, GU2 7XH UK
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28
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Snyder GA, Eliachar S, Connelly MT, Talice S, Hadad U, Gershoni-Yahalom O, Browne WE, Palmer CV, Rosental B, Traylor-Knowles N. Functional Characterization of Hexacorallia Phagocytic Cells. Front Immunol 2021; 12:662803. [PMID: 34381444 PMCID: PMC8350327 DOI: 10.3389/fimmu.2021.662803] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/03/2021] [Indexed: 11/20/2022] Open
Abstract
Phagocytosis is the cellular defense mechanism used to eliminate antigens derived from dysregulated or damaged cells, and microbial pathogens. Phagocytosis is therefore a pillar of innate immunity, whereby foreign particles are engulfed and degraded in lysolitic vesicles. In hexacorallians, phagocytic mechanisms are poorly understood, though putative anthozoan phagocytic cells (amoebocytes) have been identified histologically. We identify and characterize phagocytes from the coral Pocillopora damicornis and the sea anemone Nematostella vectensis. Using fluorescence-activated cell sorting and microscopy, we show that distinct populations of phagocytic cells engulf bacteria, fungal antigens, and beads. In addition to pathogenic antigens, we show that phagocytic cells engulf self, damaged cells. We show that target antigens localize to low pH phagolysosomes, and that degradation is occurring within them. Inhibiting actin filament rearrangement interferes with efficient particle phagocytosis but does not affect small molecule pinocytosis. We also demonstrate that cellular markers for lysolitic vesicles and reactive oxygen species (ROS) correlate with hexacorallian phagocytes. These results establish a foundation for improving our understanding of hexacorallian immune cell biology.
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Affiliation(s)
- Grace A Snyder
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States
| | - Shir Eliachar
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Regenerative Medicine and Stem Cell Research Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Michael T Connelly
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States
| | - Shani Talice
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Regenerative Medicine and Stem Cell Research Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Uzi Hadad
- Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Orly Gershoni-Yahalom
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Regenerative Medicine and Stem Cell Research Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - William E Browne
- Department of Biology, University of Miami, Coral Gables, FL, United States
| | - Caroline V Palmer
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, United Kingdom
| | - Benyamin Rosental
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Regenerative Medicine and Stem Cell Research Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Nikki Traylor-Knowles
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States
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29
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Majerova E, Carey FC, Drury C, Gates RD. Preconditioning improves bleaching tolerance in the reef-building coral Pocillopora acuta through modulations in the programmed cell death pathways. Mol Ecol 2021; 30:3560-3574. [PMID: 34008873 DOI: 10.1111/mec.15988] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 12/25/2022]
Abstract
Reef-building corals rely on intracellular algal symbionts to meet energetic demands. Increasing extreme weather driven by climate change often leads to disruption of this symbiosis and to coral death. Corals can better withstand stress after previous exposure to sublethal conditions, but the mechanisms for this resilience remain unclear. Here, we show that a three-day thermal preconditioning increases tolerance of acute heat stress through modulations in cell death pathways in the stony coral Pocillopora acuta. In preconditioned corals, the ratio of pro-survival (pa-Bcl-2 and pa-BI-1) to pro-death (pa-BAK and pa-BAX) gene expression increased and the corals underwent significantly less bleaching. When treated with Bcl-2 inhibitor, corals lost the improved thermal tolerance, suggesting an important role of programmed cell death in coral bleaching and acclimatization. During heat stress, the activity of acid phosphatase increased but caspase-3 did not, suggesting the involvement of autophagy/symbiophagy rather than apoptosis in this process. A similar shift in gene expression also occurs in thermally stressed corals that have been exposed to naturally higher temperatures during summer thermal maxima in Kāne'ohe Bay, Hawai'i, suggesting that corals can increase their resilience to realistic warming events during high-risk periods through alterations in cell signalling. These data suggest that programmed cell death pathways underly coral acclimatization and resilience and may be important for coral reef conservation and management.
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Affiliation(s)
- Eva Majerova
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Fiona C Carey
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Crawford Drury
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
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30
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Maire J, Blackall LL, van Oppen MJH. Microbiome characterization of defensive tissues in the model anemone Exaiptasia diaphana. BMC Microbiol 2021; 21:152. [PMID: 34020587 PMCID: PMC8140459 DOI: 10.1186/s12866-021-02211-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/29/2021] [Indexed: 01/04/2023] Open
Abstract
Background Coral reefs are among the most diverse and productive ecosystems on Earth. This success relies on the coral’s association with a wide range of microorganisms, including dinoflagellates of the family Symbiodiniaceae that provide coral hosts with most of their organic carbon requirements. While bacterial associates have long been overlooked, research on these microorganisms is gaining traction, and deciphering bacterial identity and function is greatly enhancing our understanding of cnidarian biology. Here, we investigated bacterial communities in defensive tissues (acontia) of the coral model, the sea anemone Exaiptasia diaphana. Acontia are internal filaments that are ejected upon detection of an external threat and release toxins to repel predators. Results Using culturing techniques and 16S rRNA gene metabarcoding we identified bacterial communities associated with acontia of four Great Barrier Reef-sourced E. diaphana genotypes. We show that bacterial communities are similar across genotypes, and dominated by Alteromonadaceae, Vibrionaceae, Rhodobacteraceae, and Saprospiraceae. By analyzing abundant amplicon sequence variants (ASVs) from metabarcoding data from acontia and comparing these to data from whole anemones, we identified five potentially important bacterial genera of the acontia microbiome: Vibrio, Sulfitobacter, Marivita, Alteromonas, and Lewinella. The role of these bacteria within the acontia remains uninvestigated but could entail assistance in defense processes such as toxin production. Conclusions This study provides insight into potential bacterial involvement in cnidarian defense tissues and highlights the need to study bacterial communities in individual compartments within a holobiont. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02211-4.
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Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.
| | - Linda L Blackall
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Madeleine J H van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.,Australian Institute of Marine Science, Townsville, QLD, Australia
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31
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González-Pech RA, Stephens TG, Chen Y, Mohamed AR, Cheng Y, Shah S, Dougan KE, Fortuin MDA, Lagorce R, Burt DW, Bhattacharya D, Ragan MA, Chan CX. Comparison of 15 dinoflagellate genomes reveals extensive sequence and structural divergence in family Symbiodiniaceae and genus Symbiodinium. BMC Biol 2021; 19:73. [PMID: 33849527 PMCID: PMC8045281 DOI: 10.1186/s12915-021-00994-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/25/2021] [Indexed: 02/07/2023] Open
Abstract
Background Dinoflagellates in the family Symbiodiniaceae are important photosynthetic symbionts in cnidarians (such as corals) and other coral reef organisms. Breakdown of the coral-dinoflagellate symbiosis due to environmental stress (i.e. coral bleaching) can lead to coral death and the potential collapse of reef ecosystems. However, evolution of Symbiodiniaceae genomes, and its implications for the coral, is little understood. Genome sequences of Symbiodiniaceae remain scarce due in part to their large genome sizes (1–5 Gbp) and idiosyncratic genome features. Results Here, we present de novo genome assemblies of seven members of the genus Symbiodinium, of which two are free-living, one is an opportunistic symbiont, and the remainder are mutualistic symbionts. Integrating other available data, we compare 15 dinoflagellate genomes revealing high sequence and structural divergence. Divergence among some Symbiodinium isolates is comparable to that among distinct genera of Symbiodiniaceae. We also recovered hundreds of gene families specific to each lineage, many of which encode unknown functions. An in-depth comparison between the genomes of the symbiotic Symbiodinium tridacnidorum (isolated from a coral) and the free-living Symbiodinium natans reveals a greater prevalence of transposable elements, genetic duplication, structural rearrangements, and pseudogenisation in the symbiotic species. Conclusions Our results underscore the potential impact of lifestyle on lineage-specific gene-function innovation, genome divergence, and the diversification of Symbiodinium and Symbiodiniaceae. The divergent features we report, and their putative causes, may also apply to other microbial eukaryotes that have undergone symbiotic phases in their evolutionary history. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-00994-6.
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Affiliation(s)
- Raúl A González-Pech
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia. .,Present address: Department of Integrative Biology, University of South Florida, Tampa, FL, 33620, USA.
| | - Timothy G Stephens
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia.,Present address: Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Yibi Chen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia.,Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, 4072, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Amin R Mohamed
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Queensland Bioscience Precinct, St Lucia, QLD, 4072, Australia.,Present address: Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Yuanyuan Cheng
- UQ Genomics Initiative, The University of Queensland, Brisbane, QLD, 4072, Australia.,Present address: School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Sarah Shah
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia.,Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, 4072, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Katherine E Dougan
- Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, 4072, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Michael D A Fortuin
- Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, 4072, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Rémi Lagorce
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia.,École Polytechnique Universitaire de l'Université de Nice, Université Nice-Sophia-Antipolis, 06410, Nice, Provence-Alpes-Côte d'Azur, France
| | - David W Burt
- UQ Genomics Initiative, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Mark A Ragan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Cheong Xin Chan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia. .,Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, 4072, Australia. .,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia.
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32
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Hall C, Camilli S, Dwaah H, Kornegay B, Lacy C, Hill MS, Hill AL. Freshwater sponge hosts and their green algae symbionts: a tractable model to understand intracellular symbiosis. PeerJ 2021; 9:e10654. [PMID: 33614268 PMCID: PMC7882143 DOI: 10.7717/peerj.10654] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/05/2020] [Indexed: 12/15/2022] Open
Abstract
In many freshwater habitats, green algae form intracellular symbioses with a variety of heterotrophic host taxa including several species of freshwater sponge. These sponges perform important ecological roles in their habitats, and the poriferan:green algae partnerships offers unique opportunities to study the evolutionary origins and ecological persistence of endosymbioses. We examined the association between Ephydatia muelleri and its chlorophyte partner to identify features of host cellular and genetic responses to the presence of intracellular algal partners. Chlorella-like green algal symbionts were isolated from field-collected adult E. muelleri tissue harboring algae. The sponge-derived algae were successfully cultured and subsequently used to reinfect aposymbiotic E. muelleri tissue. We used confocal microscopy to follow the fate of the sponge-derived algae after inoculating algae-free E. muelleri grown from gemmules to show temporal patterns of symbiont location within host tissue. We also infected aposymbiotic E. muelleri with sponge-derived algae, and performed RNASeq to study differential expression patterns in the host relative to symbiotic states. We compare and contrast our findings with work in other systems (e.g., endosymbiotic Hydra) to explore possible conserved evolutionary pathways that may lead to stable mutualistic endosymbioses. Our work demonstrates that freshwater sponges offer many tractable qualities to study features of intracellular occupancy and thus meet criteria desired for a model system.
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Affiliation(s)
- Chelsea Hall
- Biology, University of Richmond, Richmond, VA, United States of America.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Sara Camilli
- Biology, University of Richmond, Richmond, VA, United States of America.,Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, United States of America
| | - Henry Dwaah
- Biology, University of Richmond, Richmond, VA, United States of America
| | - Benjamin Kornegay
- Biology, University of Richmond, Richmond, VA, United States of America
| | - Christie Lacy
- Biology, University of Richmond, Richmond, VA, United States of America
| | - Malcolm S Hill
- Biology, University of Richmond, Richmond, VA, United States of America.,Biology, Bates College, Lewiston, ME, United States of America
| | - April L Hill
- Biology, University of Richmond, Richmond, VA, United States of America.,Biology, Bates College, Lewiston, ME, United States of America
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33
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Maruyama S, Weis VM. Limitations of Using Cultured Algae to Study Cnidarian-Algal Symbioses and Suggestions for Future Studies. JOURNAL OF PHYCOLOGY 2021; 57:30-38. [PMID: 33191496 DOI: 10.1111/jpy.13102] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
Much of our understanding of the cellular mechanisms underlying cnidarian-algal symbiosis comes from studying the biological differences between the partners when they are engaged in symbiosis and when they are isolated from one another. When comparing the in hospite and ex hospite states in Symbiodiniaceae, the in hospite state is represented by algae sampled from hosts, and the ex hospite state is commonly represented by cultured algae. The use of cultured algae in this comparison may introduce nutrition as a confounding variable because, while hosts are kept in nutrient-depleted conditions, culture media is nutrient rich and designed to facilitate algal growth. In this perspective, we reexamine how nutrition may be a confounding variable in studies that compare the biology of Symbiodiniaceae in hospite and in culture. We also suggest several innovations in experimental design to strengthen the comparison of the two lifestyles, including the adoption of nutritional controls, alternatives to culture for the representation of Symbiodiniaceae ex hospite, and the adoption of several proteomic approaches to find novel Symbiodiniaceae genes important for symbiosis.
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Affiliation(s)
- Shumpei Maruyama
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, Oregon, 97331, USA
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, Oregon, 97331, USA
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34
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Gilbert SF. Evolutionary developmental biology and sustainability: A biology of resilience. Evol Dev 2021; 23:273-291. [PMID: 33400344 DOI: 10.1111/ede.12366] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 12/26/2022]
Abstract
Evolutionary developmental biology, and especially ecological developmental biology, is essential for discussions of sustainability and the responses to global climate change. First, this paper explores examples of animals that have successfully altered their development to accommodate human-made changes to their environments. We next document the ability of global warming to disrupt the development of those organisms with temperature-dependent sex-determination or with phenologies coordinating that organism's development with those of other species. The thermotolerance of Homo sapiens is also related to key developmental factors concerning brain development and maintenance, and the development of corals, the keystone organisms of tropical reefs, is discussed in relation to global warming as well as to other anthropogenic changes. While teratogenic and endocrine-disrupting compounds are not discussed in this essay, the ability of glyphosate herbicides to block insect development is highlighted. Last, the paper discusses the need to creatively integrate developmental biology with ecological, political, religious, and economic perspectives, as the flourishing of contemporary species may require altering the ways that Western science has considered the categories of nature, culture, and self.
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Affiliation(s)
- Scott F Gilbert
- Department of Biology, Swarthmore College, Swarthmore, Pennsylvania, USA
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35
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Cleves PA, Krediet CJ, Lehnert EM, Onishi M, Pringle JR. Insights into coral bleaching under heat stress from analysis of gene expression in a sea anemone model system. Proc Natl Acad Sci U S A 2020; 117:28906-28917. [PMID: 33168733 PMCID: PMC7682557 DOI: 10.1073/pnas.2015737117] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Loss of endosymbiotic algae ("bleaching") under heat stress has become a major problem for reef-building corals worldwide. To identify genes that might be involved in triggering or executing bleaching, or in protecting corals from it, we used RNAseq to analyze gene-expression changes during heat stress in a coral relative, the sea anemone Aiptasia. We identified >500 genes that showed rapid and extensive up-regulation upon temperature increase. These genes fell into two clusters. In both clusters, most genes showed similar expression patterns in symbiotic and aposymbiotic anemones, suggesting that this early stress response is largely independent of the symbiosis. Cluster I was highly enriched for genes involved in innate immunity and apoptosis, and most transcript levels returned to baseline many hours before bleaching was first detected, raising doubts about their possible roles in this process. Cluster II was highly enriched for genes involved in protein folding, and most transcript levels returned more slowly to baseline, so that roles in either promoting or preventing bleaching seem plausible. Many of the genes in clusters I and II appear to be targets of the transcription factors NFκB and HSF1, respectively. We also examined the behavior of 337 genes whose much higher levels of expression in symbiotic than aposymbiotic anemones in the absence of stress suggest that they are important for the symbiosis. Unexpectedly, in many cases, these expression levels declined precipitously long before bleaching itself was evident, suggesting that loss of expression of symbiosis-supporting genes may be involved in triggering bleaching.
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Affiliation(s)
- Phillip A Cleves
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Cory J Krediet
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
- Department of Marine Science, Eckerd College, St. Petersburg, FL 33711
| | - Erik M Lehnert
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Masayuki Onishi
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - John R Pringle
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305;
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36
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Seneca F, Davtian D, Boyer L, Czerucka D. Gene expression kinetics of Exaiptasia pallida innate immune response to Vibrio parahaemolyticus infection. BMC Genomics 2020; 21:768. [PMID: 33167855 PMCID: PMC7654579 DOI: 10.1186/s12864-020-07140-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 10/11/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Recent sequencing projects on early-diverging metazoans such as cnidarians, have unveiled a rich innate immunity gene repertoire; however, little is known about immunity gene regulation in the host's early response against marine bacterial pathogens over time. Here, we used RNA-seq on the sea anemone Exaiptasia pallida (Ep) strain CC7 as a model to depict the innate immune response during the onset of infection with the marine pathogenic bacteria Vibrio parahaemolyticus (Vp) clinical strain O3:K6, and lipopolysaccharides (LPS) exposure. Pairwise and time series analyses identified the genes responsive to infection as well as the kinetics of innate immune genes over time. Comparisons between the responses to live Vp and purified LPS was then performed. RESULTS Gene expression and functional analyses detected hundreds to thousands of genes responsive to the Vp infection after 1, 3, 6 and 12 h, including a few shared with the response to LPS. Our results bring to light the first indications that non-canonical cytoplasmic pattern recognition receptors (PRRs) such as NOD-like and RIG-I-like receptor homologs take part in the immune response of Ep. Over-expression of several members of the lectin-complement pathways in parallel with novel transmembrane and Ig containing ficolins (CniFLs) suggest an active defense against the pathogen. Although lacking typical Toll-like receptors (TLRs), Ep activates a TLR-like pathway including the up-regulation of MyD88, TRAF6, NF-κB and AP-1 genes, which are not induced under LPS treatment and therefore suggest an alternative ligand-to-PRR trigger. Two cytokine-dependent pathways involving Tumor necrosis factor receptors (TNFRs) and several other potential downstream signaling genes likely lead to inflammation and/or apoptosis. Finally, both the extrinsic and intrinsic apoptotic pathways were strongly supported by over-expression of effector and executioner genes. CONCLUSIONS To our knowledge, this pioneering study is first to follow the kinetics of the innate immune response in a cnidarian during the onset of infection with a bacterial pathogen. Overall, our findings reveal the involvement of both novel immune gene candidates such as NLRs, RLRs and CniFLs, and previously identified TLR-like and apoptotic pathways in anthozoan innate immunity with a large amount of transcript-level evidence.
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Affiliation(s)
- François Seneca
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Monaco. .,LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Monaco, Monaco.
| | - David Davtian
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Monaco.,Present Address: Division of Population Health & Genetics, Ninewells Hospital and Medical School, Dundee, DD19SY, UK
| | - Laurent Boyer
- LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Monaco, Monaco.,Université Côte d'Azur, C3M Inserm, U1065, 06204, Nice Cedex 3, France
| | - Dorota Czerucka
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000, Monaco, Monaco.,LIA ROPSE, Laboratoire International Associé Université Côte d'Azur - Centre Scientifique de Monaco, Monaco, Monaco
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37
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Young BD, Serrano XM, Rosales SM, Miller MW, Williams D, Traylor-Knowles N. Innate immune gene expression in Acropora palmata is consistent despite variance in yearly disease events. PLoS One 2020; 15:e0228514. [PMID: 33091033 PMCID: PMC7580945 DOI: 10.1371/journal.pone.0228514] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 09/28/2020] [Indexed: 12/20/2022] Open
Abstract
Coral disease outbreaks are expected to increase in prevalence, frequency and severity due to climate change and other anthropogenic stressors. This is especially worrying for the Caribbean branching coral Acropora palmata which has already seen an 80% decrease in cover primarily due to disease. Despite the importance of this keystone species, there has yet to be a characterization of its transcriptomic response to disease exposure. In this study we provide the first transcriptomic analysis of 12 A. palmata genotypes and their symbiont Symbiodiniaceae exposed to disease in 2016 and 2017. Year was the primary driver of gene expression variance for A. palmata and the Symbiodiniaceae. We hypothesize that lower expression of ribosomal genes in the coral, and higher expression of transmembrane ion transport genes in the Symbiodiniaceae indicate that a compensation or dysbiosis may be occurring between host and symbiont. Disease response was the second driver of gene expression variance for A. palmata and included a core set of 422 genes that were significantly differentially expressed. Of these, 2 genes (a predicted cyclin-dependent kinase 11b and aspartate 1-decarboxylase) showed negative Log2 fold changes in corals showing transmission of disease, and positive Log2 fold changes in corals showing no transmission of disease, indicating that these may be important in disease resistance. Co-expression analysis identified two modules positively correlated to disease exposure, one enriched for lipid biosynthesis genes, and the other enriched in innate immune genes. The hub gene in the immune module was identified as D-amino acid oxidase, a gene implicated in phagocytosis and microbiome homeostasis. The role of D-amino acid oxidase in coral immunity has not been characterized but could be an important enzyme for responding to disease. Our results indicate that A. palmata mounts a core immune response to disease exposure despite differences in the disease type and virulence between 2016 and 2017. These identified genes may be important for future biomarker development in this Caribbean keystone species.
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Affiliation(s)
- Benjamin D. Young
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States of America
| | - Xaymara M. Serrano
- Atlantic Oceanographic and Meteorological Laboratory, National Oceanographic and Atmospheric Administration, Miami, Florida, United States of America
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, Florida, United States of America
| | - Stephanie M. Rosales
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, Florida, United States of America
| | - Margaret W. Miller
- Southeast Fisheries Science Center, NOAA-National Marine Fisheries Service, Miami, FL, United States of America
- SECORE International, Miami, FL, United States of America
| | - Dana Williams
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, Florida, United States of America
- Southeast Fisheries Science Center, NOAA-National Marine Fisheries Service, Miami, FL, United States of America
| | - Nikki Traylor-Knowles
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States of America
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38
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Rosset SL, Oakley CA, Ferrier-Pagès C, Suggett DJ, Weis VM, Davy SK. The Molecular Language of the Cnidarian-Dinoflagellate Symbiosis. Trends Microbiol 2020; 29:320-333. [PMID: 33041180 DOI: 10.1016/j.tim.2020.08.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/21/2020] [Accepted: 08/27/2020] [Indexed: 12/18/2022]
Abstract
The cnidarian-dinoflagellate symbiosis is of huge importance as it underpins the success of coral reefs, yet we know very little about how the host cnidarian and its dinoflagellate endosymbionts communicate with each other to form a functionally integrated unit. Here, we review the current knowledge of interpartner molecular signaling in this symbiosis, with an emphasis on lipids, glycans, reactive species, biogenic volatiles, and noncoding RNA. We draw upon evidence of these compounds from recent omics-based studies of cnidarian-dinoflagellate symbiosis and discuss the signaling roles that they play in other, better-studied symbioses. We then consider how improved knowledge of interpartner signaling might be used to develop solutions to the coral reef crisis by, for example, engineering more thermally resistant corals.
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Affiliation(s)
- Sabrina L Rosset
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | | | - David J Suggett
- University of Technology Sydney, Climate Change Cluster, Faculty of Science, PO Box 123, Broadway NSW 2007, Australia
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand.
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39
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Mohamed AR, Andrade N, Moya A, Chan CX, Negri AP, Bourne DG, Ying H, Ball EE, Miller DJ. Dual RNA-sequencing analyses of a coral and its native symbiont during the establishment of symbiosis. Mol Ecol 2020; 29:3921-3937. [PMID: 32853430 DOI: 10.1111/mec.15612] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 08/16/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022]
Abstract
Despite the ecological significance of the mutualistic relationship between Symbiodiniaceae and reef-building corals, the molecular interactions during establishment of this relationship are not well understood. This is particularly true of the transcriptional changes that occur in the symbiont. In the current study, a dual RNA-sequencing approach was used to better understand transcriptional changes on both sides of the coral-symbiont interaction during the colonization of Acropora tenuis by a compatible Symbiodiniaceae strain (Cladocopium goreaui; ITS2 type C1). Comparison of transcript levels of the in hospite symbiont 3, 12, 48 and 72 hr after exposure to those of the same strain in culture revealed that extensive and generalized down-regulation of symbiont gene expression occurred during the infection process. Included in this "symbiosis-derived transcriptional repression" were a range of stress response and immune-related genes. In contrast, a suite of symbiont genes implicated in metabolism was upregulated in the symbiotic state. The coral data support the hypothesis that immune-suppression and arrest of phagosome maturation play important roles during the establishment of compatible symbioses, and additionally imply the involvement of some SCRiP family members in the colonization process. Consistent with previous ecological studies, the transcriptomic data suggest that active translocation of metabolites to the host may begin early in the colonization process, and thus that the mutualistic relationship can be established at the larval stage. This dual RNA-sequencing study provides insights into the transcriptomic remodelling that occurs in C. goreaui during transition to a symbiotic lifestyle and the novel coral genes implicated in symbiosis.
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Affiliation(s)
- Amin R Mohamed
- CSIRO Agriculture and Food, Queensland Bioscience Precinct, St Lucia, Qld, Australia.,Zoology Department, Faculty of Science, Benha University, Benha, Egypt.,ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, Australia.,Department of Molecular and Cell Biology, James Cook University, Townsville, Qld, Australia.,Department of Molecular and Cell Biology, AIMS@JCU, Australian Institute of Marine Science, James Cook University, Townsville, Qld, Australia
| | - Natalia Andrade
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, Australia.,Department of Molecular and Cell Biology, James Cook University, Townsville, Qld, Australia
| | - Aurelie Moya
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, Australia.,Department of Molecular and Cell Biology, James Cook University, Townsville, Qld, Australia
| | - Cheong Xin Chan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld, Australia
| | - Andrew P Negri
- Australian Institute of Marine Science, Townsville, Qld, Australia
| | - David G Bourne
- Australian Institute of Marine Science, Townsville, Qld, Australia.,Department of Marine Ecosystems and Impacts, James Cook University, Townsville, Qld, Australia
| | - Hua Ying
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Acton, ACT, Australia
| | - Eldon E Ball
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, Australia.,Division of Ecology and Evolution, Research School of Biology, Australian National University, Acton, ACT, Australia
| | - David J Miller
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, Australia.,Department of Molecular and Cell Biology, James Cook University, Townsville, Qld, Australia
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40
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Kenkel CD, Mocellin VJL, Bay LK. Global gene expression patterns in Porites white patch syndrome: Disentangling symbiont loss from the thermal stress response in reef-building coral. Mol Ecol 2020; 29:3907-3920. [PMID: 32858771 DOI: 10.1111/mec.15608] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 12/14/2022]
Abstract
The mechanisms resulting in the breakdown of the coral symbiosis once the process of bleaching has been initiated remain unclear. Distinguishing the process of symbiont loss from the thermal stress response may shed light on the cellular and molecular pathways involved in each process. This study examined physiological changes and global gene expression patterns associated with white patch syndrome (WPS) in Porites lobata, which manifests in localized bleaching independent of thermal stress. In addition, a meta-analysis of global gene expression studies in other corals and anemones was used to contrast differential regulation as a result of disease and thermal stress from patterns correlated with symbiotic state. Symbiont density, chlorophyll a content, holobiont productivity, instant calcification rate, and total host protein content were uniformly reduced in WPS relative to healthy tissue. While expression patterns associated with WPS were secondary to fixed effects of source colony, specific functional enrichments combined with a lack of immune regulation suggest that the viral infection putatively giving rise to this condition affects symbiont rather than host cells. Expression in response to WPS also clustered independently of patterns in white syndrome impacted A. hyacinthus, further supporting a distinct aetiology of this syndrome. Expression patterns in WPS-affected tissues were significantly correlated with prior studies that examined short-term thermal stress responses independent of symbiotic state, suggesting that the majority of expression changes reflect a nonspecific stress response. Across studies, the magnitude and direction of expression change among particular functional enrichments suggests unique responses to stressor duration and highlights distinct responses to bleaching in an anemone model.
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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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41
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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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42
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Tivey TR, Parkinson JE, Mandelare PE, Adpressa DA, Peng W, Dong X, Mechref Y, Weis VM, Loesgen S. N-Linked Surface Glycan Biosynthesis, Composition, Inhibition, and Function in Cnidarian-Dinoflagellate Symbiosis. MICROBIAL ECOLOGY 2020; 80:223-236. [PMID: 31982929 DOI: 10.1007/s00248-020-01487-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/08/2020] [Indexed: 06/10/2023]
Abstract
The success of symbioses between cnidarian hosts (e.g., corals and sea anemones) and micro-algal symbionts hinges on the molecular interactions that govern the establishment and maintenance of intracellular mutualisms. As a fundamental component of innate immunity, glycan-lectin interactions impact the onset of marine endosymbioses, but our understanding of the effects of cell surface glycome composition on symbiosis establishment remains limited. In this study, we examined the canonical N-glycan biosynthesis pathway in the genome of the dinoflagellate symbiont Breviolum minutum (family Symbiodiniaceae) and found it to be conserved with the exception of the transferase GlcNAc-TII (MGAT2). Using coupled liquid chromatography-mass spectrometry (LC-MS/MS), we characterized the cell surface N-glycan content of B. minutum, providing the first insight into the molecular composition of surface glycans in dinoflagellates. We then used the biosynthesis inhibitors kifunensine and swainsonine to alter the glycan composition of B. minutum. Successful high-mannose enrichment via kifunensine treatment resulted in a significant decrease in colonization of the model sea anemone Aiptasia (Exaiptasia pallida) by B. minutum. Hybrid glycan enrichment via swainsonine treatment, however, could not be confirmed and did not impact colonization. We conclude that functional Golgi processing of N-glycans is critical for maintaining appropriate cell surface glycan composition and for ensuring colonization success by B. minutum.
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Affiliation(s)
- Trevor R Tivey
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA.
- Department of Entomology, Cornell University, Ithaca, NY, USA.
| | - John Everett Parkinson
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Paige E Mandelare
- Department of Chemistry, Oregon State University, Corvallis, OR, USA
- Whitney Laboratory for Marine Bioscience and Department of Chemistry, University of Florida, St. Augustine, FL, USA
| | - Donovon A Adpressa
- Department of Chemistry, Oregon State University, Corvallis, OR, USA
- Analytical Research & Development, Merck & Co. Inc., Boston, MA, USA
| | - Wenjing Peng
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, USA
| | - Xue Dong
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, USA
| | - Yehia Mechref
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, USA
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Sandra Loesgen
- Department of Chemistry, Oregon State University, Corvallis, OR, USA.
- Whitney Laboratory for Marine Bioscience and Department of Chemistry, University of Florida, St. Augustine, FL, USA.
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44
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Inner Workings: A microscopic mystery at the heart of mass-coral bleaching. Proc Natl Acad Sci U S A 2020; 117:2232-2235. [PMID: 32019897 DOI: 10.1073/pnas.1921846117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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