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Edmunds PJ, Combosch DJ, Torrado H, Sakai K, Sinniger F, Burgess SC. Latitudinal variation in thermal performance of the common coral Pocillopora spp. J Exp Biol 2024; 227:jeb247090. [PMID: 38699869 DOI: 10.1242/jeb.247090] [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: 11/23/2023] [Accepted: 04/26/2024] [Indexed: 05/05/2024]
Abstract
Understanding how tropical corals respond to temperatures is important to evaluating their capacity to persist in a warmer future. We studied the common Pacific coral Pocillopora over 44° of latitude, and used populations at three islands with different thermal regimes to compare their responses to temperature using thermal performance curves (TPCs) for respiration and gross photosynthesis. Corals were sampled in the local autumn from Moorea, Guam and Okinawa, where mean±s.d. annual seawater temperature is 28.0±0.9°C, 28.9±0.7°C and 25.1±3.4°C, respectively. TPCs for respiration were similar among latitudes, the thermal optimum (Topt) was above the local maximum temperature at all three islands, and maximum respiration was lowest at Okinawa. TPCs for gross photosynthesis were wider, implying greater thermal eurytopy, with a higher Topt in Moorea versus Guam and Okinawa. Topt was above the maximum temperature in Moorea, but was similar to daily temperatures over 13% of the year in Okinawa and 53% of the year in Guam. There was greater annual variation in daily temperatures in Okinawa than Guam or Moorea, which translated to large variation in the supply of metabolic energy and photosynthetically fixed carbon at higher latitudes. Despite these trends, the differences in TPCs for Pocillopora spp. were not profoundly different across latitudes, reducing the likelihood that populations of these corals could better match their phenotypes to future more extreme temperatures through migration. Any such response would place a premium on high metabolic plasticity and tolerance of large seasonal variations in energy budgets.
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Affiliation(s)
- P J Edmunds
- Department of Biology, California State University, Northridge, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA
| | - D J Combosch
- Marine Laboratory, University of Guam, 303 University Drive, Mangilao, 96923 Guam, USA
| | - H Torrado
- Marine Laboratory, University of Guam, 303 University Drive, Mangilao, 96923 Guam, USA
| | - K Sakai
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, 905-0227 Okinawa, Japan
| | - F Sinniger
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, 905-0227 Okinawa, Japan
| | - S C Burgess
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
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2
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Allen-Waller LR, Jones KG, Martynek MP, Brown KT, Barott KL. Comparative physiology reveals heat stress disrupts acid-base homeostasis independent of symbiotic state in the model cnidarian Exaiptasia diaphana. J Exp Biol 2024; 227:jeb246222. [PMID: 38269486 PMCID: PMC10911193 DOI: 10.1242/jeb.246222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 01/17/2024] [Indexed: 01/26/2024]
Abstract
Climate change threatens the survival of symbiotic cnidarians by causing photosymbiosis breakdown in a process known as bleaching. Direct effects of temperature on cnidarian host physiology remain difficult to describe because heatwaves depress symbiont performance, leading to host stress and starvation. The symbiotic sea anemone Exaiptasia diaphana provides an opportune system to disentangle direct versus indirect heat effects on the host, as it can survive indefinitely without symbionts. We tested the hypothesis that heat directly impairs cnidarian physiology by comparing symbiotic and aposymbiotic individuals of two laboratory subpopulations of a commonly used clonal strain of E. diaphana, CC7. We exposed anemones to a range of temperatures (ambient, +2°C, +4°C and +6°C) for 15-18 days, then measured their symbiont population densities, autotrophic carbon assimilation and translocation, photosynthesis, respiration and host intracellular pH (pHi). Symbiotic anemones from the two subpopulations differed in size and symbiont density and exhibited distinct heat stress responses, highlighting the importance of acclimation to different laboratory conditions. Specifically, the cohort with higher initial symbiont densities experienced dose-dependent symbiont loss with increasing temperature and a corresponding decline in host photosynthate accumulation. In contrast, the cohort with lower initial symbiont densities did not lose symbionts or assimilate less photosynthate when heated, similar to the response of aposymbiotic anemones. However, anemone pHi decreased at higher temperatures regardless of cohort, symbiont presence or photosynthate translocation, indicating that heat consistently disrupts cnidarian acid-base homeostasis independent of symbiotic status or mutualism breakdown. Thus, pH regulation may be a critical vulnerability for cnidarians in a changing climate.
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Affiliation(s)
| | - Katelyn G. Jones
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Kristen T. Brown
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Katie L. Barott
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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3
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Manullang C, Singh T, Sakai K, Miyagi A, Iwasaki A, Nojiri Y, Iguchi A. Separate and combined effects of elevated pCO 2 and temperature on the branching reef corals Acropora digitifera and Montipora digitata. MARINE ENVIRONMENTAL RESEARCH 2023; 188:106030. [PMID: 37267662 DOI: 10.1016/j.marenvres.2023.106030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 06/04/2023]
Abstract
Ocean acidification (OA) and warming (OW) are major global threats to coral reef ecosystems; however, studies on their combined effects (OA + OW) are scarce. Therefore, we evaluated the effects of OA, OW, and OA + OW in the branching reef corals Acropora digitifera and Montipora digitata, which have been found to respond differently to environmental changes. Our results indicate that OW has a greater impact on A. digitifera and M. digitata than OA and that the former species is more vulnerable to OW than the latter. OW was the main stressor for increased mortality and decreased calcification in the OA + OW group, and the effect of OA + OW was additive in both species. Our findings suggest that the relative abundance and cover of M. digitata are expected to increase whereas those of A. digitifera may decrease in the near future in Okinawa.
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Affiliation(s)
- Cristiana Manullang
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Motobu, Okinawa, Japan
| | - Tanya Singh
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Motobu, Okinawa, Japan
| | - Kazuhiko Sakai
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Motobu, Okinawa, Japan.
| | - Aika Miyagi
- Department of Bioresources Engineering, National Institute of Technology, Okinawa College, Nago-City, Okinawa, Japan
| | - Aiko Iwasaki
- Asamushi Research Center for Marine Biology, Graduate School of Life Sciences, Tohoku University, Aomori, Aomori, Japan
| | - Yukihiro Nojiri
- Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan; Graduate School of Earth and Environmental Sciences, Hirosaki University, Hirosaki, Aomori, Japan
| | - Akira Iguchi
- Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan; Research Laboratory on Environmentally-conscious Developments and Technologies [E-code], National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
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4
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Capasso L, Aranda M, Cui G, Pousse M, Tambutté S, Zoccola D. Investigating calcification-related candidates in a non-symbiotic scleractinian coral, Tubastraea spp. Sci Rep 2022; 12:13515. [PMID: 35933557 PMCID: PMC9357087 DOI: 10.1038/s41598-022-17022-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/19/2022] [Indexed: 11/23/2022] Open
Abstract
In hermatypic scleractinian corals, photosynthetic fixation of CO2 and the production of CaCO3 are intimately linked due to their symbiotic relationship with dinoflagellates of the Symbiodiniaceae family. This makes it difficult to study ion transport mechanisms involved in the different pathways. In contrast, most ahermatypic scleractinian corals do not share this symbiotic relationship and thus offer an advantage when studying the ion transport mechanisms involved in the calcification process. Despite this advantage, non-symbiotic scleractinian corals have been systematically neglected in calcification studies, resulting in a lack of data especially at the molecular level. Here, we combined a tissue micro-dissection technique and RNA-sequencing to identify calcification-related ion transporters, and other candidates, in the ahermatypic non-symbiotic scleractinian coral Tubastraea spp. Our results show that Tubastraea spp. possesses several calcification-related candidates previously identified in symbiotic scleractinian corals (such as SLC4-γ, AMT-1like, CARP, etc.). Furthermore, we identify and describe a role in scleractinian calcification for several ion transporter candidates (such as SLC13, -16, -23, etc.) identified for the first time in this study. Taken together, our results provide not only insights about the molecular mechanisms underlying non-symbiotic scleractinian calcification, but also valuable tools for the development of biotechnological solutions to better control the extreme invasiveness of corals belonging to this particular genus.
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Affiliation(s)
- Laura Capasso
- Marine Biology Department, Centre Scientifique de Monaco (CSM), 8 Quai Antoine 1er, Monte Carlo, 9800, Monaco
- Sorbonne Université, Collège Doctoral, 75005, Paris, France
| | - Manuel Aranda
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Guoxin Cui
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Melanie Pousse
- Université Côte d'Azur, CNRS, Inserm, Institut for Research On Cancer and Aging, Nice (IRCAN), Medical School of Nice, Nice, France
| | - Sylvie Tambutté
- Marine Biology Department, Centre Scientifique de Monaco (CSM), 8 Quai Antoine 1er, Monte Carlo, 9800, Monaco.
| | - Didier Zoccola
- Marine Biology Department, Centre Scientifique de Monaco (CSM), 8 Quai Antoine 1er, Monte Carlo, 9800, Monaco.
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Woo S, Yum S. Transcriptional response of the azooxanthellate octocoral Scleronephthya gracillimum to seawater acidification and thermal stress. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2022; 42:100978. [PMID: 35259638 DOI: 10.1016/j.cbd.2022.100978] [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: 10/12/2021] [Revised: 01/28/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
The stress responses to increased seawater temperature and marine acidification were investigated using a microarray to reveal transcriptional changes in S. gracillimum. For the study, corals were exposed to different stress experiments; high temperature only (26 °C, 28 °C and 30 °C), low-pH only (pH 7.5, pH 7.0 and pH 6.5) and dual stress experiments (28 °C + pH 7.8, 28 °C + pH 7.5 and 28 °C + pH 7.0), mortality and morphological changes in 24 h exposure experiments were investigated. The survival rates of each experimental group were observed. The gene expression changes in single and dual stress exposed coals were measured and the differentially expressed genes were classified with gene ontology analysis. The top three enriched gene ontology terms of DEGs in response to dual stress were metal ion binding (23.4%), extracellular region (17.2%), and calcium ion binding (12.8%). The gene showing the greatest increase in expression as a response to the dual stress was hemagglutinin/amebocyte aggregation factor, followed by interferon-inducible GTPase 5 and the gene showing the greatest decrease as a response to the dual stress was Fas-associating death domain-containing protein, followed by oxidase 2. These results represented the transcriptomic study focused on the stress responses of the temperate asymbiotic soft coral exposed to single and dual stresses. The combined effect of thermal and acidification stress on corals triggered the negative regulation of ion binding and extracellular matrix coding genes and these genes might serve as a basis for research into coral-specific adaptations to stress responses and global climate change.
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Affiliation(s)
- Seonock Woo
- Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, South Korea
| | - Seungshic Yum
- Ecological Risk Research Division, Korea Institute of Ocean Sciences and Technology, Geoje 53201, South Korea; KIOST School, University of Science and Technology, Geoje 53201, South Korea.
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6
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Innis T, Allen-Waller L, Brown KT, Sparagon W, Carlson C, Kruse E, Huffmyer AS, Nelson CE, Putnam HM, Barott KL. Marine heatwaves depress metabolic activity and impair cellular acid-base homeostasis in reef-building corals regardless of bleaching susceptibility. GLOBAL CHANGE BIOLOGY 2021; 27:2728-2743. [PMID: 33784420 DOI: 10.1111/gcb.15622] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/18/2021] [Accepted: 03/21/2021] [Indexed: 06/12/2023]
Abstract
Ocean warming is causing global coral bleaching events to increase in frequency, resulting in widespread coral mortality and disrupting the function of coral reef ecosystems. However, even during mass bleaching events, many corals resist bleaching despite exposure to abnormally high temperatures. While the physiological effects of bleaching have been well documented, the consequences of heat stress for bleaching-resistant individuals are not well understood. In addition, much remains to be learned about how heat stress affects cellular-level processes that may be overlooked at the organismal level, yet are crucial for coral performance in the short term and ecological success over the long term. Here we compared the physiological and cellular responses of bleaching-resistant and bleaching-susceptible corals throughout the 2019 marine heatwave in Hawai'i, a repeat bleaching event that occurred 4 years after the previous regional event. Relative bleaching susceptibility within species was consistent between the two bleaching events, yet corals of both resistant and susceptible phenotypes exhibited pronounced metabolic depression during the heatwave. At the cellular level, bleaching-susceptible corals had lower intracellular pH than bleaching-resistant corals at the peak of bleaching for both symbiont-hosting and symbiont-free cells, indicating greater disruption of acid-base homeostasis in bleaching-susceptible individuals. Notably, cells from both phenotypes were unable to compensate for experimentally induced cellular acidosis, indicating that acid-base regulation was significantly impaired at the cellular level even in bleaching-resistant corals and in cells containing symbionts. Thermal disturbances may thus have substantial ecological consequences, as even small reallocations in energy budgets to maintain homeostasis during stress can negatively affect fitness. These results suggest concern is warranted for corals coping with ocean acidification alongside ocean warming, as the feedback between temperature stress and acid-base regulation may further exacerbate the physiological effects of climate change.
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Affiliation(s)
- Teegan Innis
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Kristen T Brown
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
- ARC Centre of Excellence for Coral Reef Studies and School of Biological Sciences, University of Queensland, St. Lucia, Qld, Australia
| | - Wesley Sparagon
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | | | - Elisa Kruse
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ariana S Huffmyer
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA
| | - Craig E Nelson
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA
| | - Katie L Barott
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
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7
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Capasso L, Ganot P, Planas-Bielsa V, Tambutté S, Zoccola D. Intracellular pH regulation: characterization and functional investigation of H + transporters in Stylophora pistillata. BMC Mol Cell Biol 2021; 22:18. [PMID: 33685406 PMCID: PMC7941709 DOI: 10.1186/s12860-021-00353-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/22/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Reef-building corals regularly experience changes in intra- and extracellular H+ concentrations ([H+]) due to physiological and environmental processes. Stringent control of [H+] is required to maintain the homeostatic acid-base balance in coral cells and is achieved through the regulation of intracellular pH (pHi). This task is especially challenging for reef-building corals that share an endosymbiotic relationship with photosynthetic dinoflagellates (family Symbiodinaceae), which significantly affect the pHi of coral cells. Despite their importance, the pH regulatory proteins involved in the homeostatic acid-base balance have been scarcely investigated in corals. Here, we report in the coral Stylophora pistillata a full characterization of the genomic structure, domain topology and phylogeny of three major H+ transporter families that are known to play a role in the intracellular pH regulation of animal cells; we investigated their tissue-specific expression patterns and assessed the effect of seawater acidification on their expression levels. RESULTS We identified members of the Na+/H+ exchanger (SLC9), vacuolar-type electrogenic H+-ATP hydrolase (V-ATPase) and voltage-gated proton channel (HvCN) families in the genome and transcriptome of S. pistillata. In addition, we identified a novel member of the HvCN gene family in the cnidarian subclass Hexacorallia that has not been previously described in any species. We also identified key residues that contribute to H+ transporter substrate specificity, protein function and regulation. Last, we demonstrated that some of these proteins have different tissue expression patterns, and most are unaffected by exposure to seawater acidification. CONCLUSIONS In this study, we provide the first characterization of H+ transporters that might contribute to the homeostatic acid-base balance in coral cells. This work will enrich the knowledge of the basic aspects of coral biology and has important implications for our understanding of how corals regulate their intracellular environment.
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Affiliation(s)
- Laura Capasso
- Centre Scientifique de Monaco, 8 quai Antoine 1er, 98000, Monaco, Monaco.,Sorbonne Université, Collège Doctoral, F-75005, Paris, France
| | - Philippe Ganot
- Centre Scientifique de Monaco, 8 quai Antoine 1er, 98000, Monaco, Monaco
| | | | - Sylvie Tambutté
- Centre Scientifique de Monaco, 8 quai Antoine 1er, 98000, Monaco, Monaco
| | - Didier Zoccola
- Centre Scientifique de Monaco, 8 quai Antoine 1er, 98000, Monaco, Monaco.
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Mapping coral calcification strategies from in situ boron isotope and trace element measurements of the tropical coral Siderastrea siderea. Sci Rep 2021; 11:472. [PMID: 33436642 PMCID: PMC7804963 DOI: 10.1038/s41598-020-78778-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/30/2020] [Indexed: 02/02/2023] Open
Abstract
Boron isotopic and elemental analysis of coral aragonite can give important insights into the calcification strategies employed in coral skeletal construction. Traditional methods of analysis have limited spatial (and thus temporal) resolution, hindering attempts to unravel skeletal heterogeneity. Laser ablation mass spectrometry allows a much more refined view, and here we employ these techniques to explore boron isotope and co-varying elemental ratios in the tropical coral Siderastrea siderea. We generate two-dimensional maps of the carbonate parameters within the calcification medium that deposited the skeleton, which reveal large heterogeneities in carbonate chemistry across the macro-structure of a coral polyp. These differences have the potential to bias proxy interpretations, and indicate that different processes facilitated precipitation of different parts of the coral skeleton: the low-density columella being precipitated from a fluid with a carbonate composition closer to seawater, compared to the high-density inter-polyp walls where aragonite saturation was ~ 5 times that of external seawater. Therefore, the skeleton does not precipitate from a spatially homogeneous fluid and its different parts may thus have varying sensitivity to environmental stress. This offers new insights into the mechanisms behind the response of the S. siderea skeletal phenotype to ocean acidification.
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9
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Tambutté E, Ganot P, Venn AA, Tambutté S. A role for primary cilia in coral calcification? Cell Tissue Res 2020; 383:1093-1102. [PMID: 33330957 PMCID: PMC7960582 DOI: 10.1007/s00441-020-03343-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022]
Abstract
Cilia are evolutionarily conserved organelles that extend from the surface of cells and are found in diverse organisms from protozoans to multicellular organisms. Motile cilia play various biological functions by their beating motion, including mixing fluids and transporting food particles. Non-motile cilia act as sensors that signal cells about their microenvironment. In corals, cilia have been described in some of the cell layers but never in the calcifying epithelium, which is responsible for skeleton formation. In the present study, we used scanning electron microscopy and immunolabelling to investigate the cellular ciliature of the different tissue layers of the coral Stylophora pistillata, with a focus on the calcifying calicoblastic ectoderm. We show that the cilium of the calcifying cells is different from the cilium of the other cell layers. It is much shorter, and more importantly, its base is structurally distinct from the base observed in cilia of the other tissue layers. Based on these structural observations, we conclude that the cilium of the calcifying cells is a primary cilium. From what is known in other organisms, primary cilia are sensors that signal cells about their microenvironment. We discuss the implications of the presence of a primary cilium in the calcifying epithelium for our understanding of the cellular physiology driving coral calcification and its environmental sensitivity.
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Affiliation(s)
- Eric Tambutté
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1°, 98000, Monaco, Monaco
| | - Philippe Ganot
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1°, 98000, Monaco, Monaco
| | - Alexander A Venn
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1°, 98000, Monaco, Monaco
| | - Sylvie Tambutté
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1°, 98000, Monaco, Monaco.
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10
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Venn AA, Bernardet C, Chabenat A, Tambutté E, Tambutté S. Paracellular transport to the coral calcifying medium: effects of environmental parameters. J Exp Biol 2020; 223:jeb227074. [PMID: 32675232 DOI: 10.1242/jeb.227074] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/13/2020] [Indexed: 12/11/2022]
Abstract
Coral calcification relies on the transport of ions and molecules to the extracellular calcifying medium (ECM). Little is known about paracellular transport (via intercellular junctions) in corals and other marine calcifiers. Here, we investigated whether the permeability of the paracellular pathway varied in different environmental conditions in the coral Stylophora pistillata Using the fluorescent dye calcein, we characterised the dynamics of calcein influx from seawater to the ECM and showed that increases in paracellular permeability (leakiness) induced by hyperosmotic treatment could be detected by changes in calcein influx rates. We then used the calcein-imaging approach to investigate the effects of two environmental stressors on paracellular permeability: seawater acidification and temperature change. Under conditions of seawater acidification (pH 7.2) known to depress pH in the ECM and the calcifying cells of S. pistillata, we observed a decrease in half-times of calcein influx, indicating increased paracellular permeability. By contrast, high temperature (31°C) had no effect, whereas low temperature (20°C) caused decreases in paracellular permeability. Overall, our study establishes an approach to conduct further in vivo investigation of paracellular transport and suggests that changes in paracellular permeability could form an uncharacterised aspect of the physiological response of S. pistillata to seawater acidification.
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Affiliation(s)
- Alexander A Venn
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Coralie Bernardet
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Apolline Chabenat
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Eric Tambutté
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
| | - Sylvie Tambutté
- Marine Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, 98000 Monaco
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11
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Glazier A, Herrera S, Weinnig A, Kurman M, Gómez CE, Cordes E. Regulation of ion transport and energy metabolism enables certain coral genotypes to maintain calcification under experimental ocean acidification. Mol Ecol 2020; 29:1657-1673. [PMID: 32286706 DOI: 10.1111/mec.15439] [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: 11/05/2019] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 12/23/2022]
Abstract
Cold-water corals (CWCs) are important foundation species in the world's largest ecosystem, the deep sea. They support a rich faunal diversity but are threatened by climate change and increased ocean acidification. As part of this study, fragments from three genetically distinct Lophelia pertusa colonies were subjected to ambient pH (pH = 7.9) and low pH (pH = 7.6) for six months. RNA was sampled at two, 4.5, and 8.5 weeks and sequenced. The colony from which the fragments were sampled explained most of the variance in expression patterns, but a general pattern emerged where upregulation of ion transport, required to maintain normal function and calcification, was coincident with lowered expression of genes involved in metabolic processes; RNA regulation and processing in particular. Furthermore, there was no differential expression of carbonic anhydrase detected in any analyses, which agrees with a previously described lack of response in enzyme activity in the same corals. However, one colony was able to maintain calcification longer than the other colonies when exposed to low pH and showed increased expression of ion transport genes including proton transport and expression of genes associated with formation of microtubules and the organic matrix, suggesting that certain genotypes may be better equipped to cope with ocean acidification in the future. While these genotypes exist in the contemporary gene pool, further stresses would reduce the genetic variability of the species, which would have repercussions for the maintenance of existing populations and the ecosystem as a whole.
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Affiliation(s)
- Amanda Glazier
- Biology Department, Temple University, Philadelphia, PA, USA
| | - Santiago Herrera
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, USA
| | - Alexis Weinnig
- Biology Department, Temple University, Philadelphia, PA, USA
| | - Melissa Kurman
- Biology Department, Temple University, Philadelphia, PA, USA.,First Hand, University City Science Center Philadelphia, PA, USA
| | - Carlos E Gómez
- Biology Department, Temple University, Philadelphia, PA, USA.,Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, Colombia
| | - Erik Cordes
- Biology Department, Temple University, Philadelphia, PA, USA
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