1
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Poding LH, Jägers P, Herlitze S, Huhn M. Diversity and function of fluorescent molecules in marine animals. Biol Rev Camb Philos Soc 2024; 99:1391-1410. [PMID: 38468189 DOI: 10.1111/brv.13072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 02/24/2024] [Accepted: 02/29/2024] [Indexed: 03/13/2024]
Abstract
Fluorescence in marine animals has mainly been studied in Cnidaria but is found in many different phyla such as Annelida, Crustacea, Mollusca, and Chordata. While many fluorescent proteins and molecules have been identified, very little information is available about the biological functions of fluorescence. In this review, we focus on describing the occurrence of fluorescence in marine animals and the behavioural and physiological functions of fluorescent molecules based on experimental approaches. These biological functions of fluorescence range from prey and symbiont attraction, photoprotection, photoenhancement, stress mitigation, mimicry, and aposematism to inter- and intraspecific communication. We provide a comprehensive list of marine taxa that utilise fluorescence, including demonstrated effects on behavioural or physiological responses. We describe the numerous known functions of fluorescence in anthozoans and their underlying molecular mechanisms. We also highlight that other marine taxa should be studied regarding the functions of fluorescence. We suggest that an increase in research effort in this field could contribute to understanding the capacity of marine animals to respond to negative effects of climate change, such as rising sea temperatures and increasing intensities of solar irradiation.
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Affiliation(s)
- Lars H Poding
- Department of General Zoology and Neurobiology, Institute of Biology and Biotechnology, Ruhr-University Bochum, Bochum, 44801, Germany
| | - Peter Jägers
- Department of General Zoology and Neurobiology, Institute of Biology and Biotechnology, Ruhr-University Bochum, Bochum, 44801, Germany
| | - Stefan Herlitze
- Department of General Zoology and Neurobiology, Institute of Biology and Biotechnology, Ruhr-University Bochum, Bochum, 44801, Germany
| | - Mareike Huhn
- Department of General Zoology and Neurobiology, Institute of Biology and Biotechnology, Ruhr-University Bochum, Bochum, 44801, Germany
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2
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Gong S, Liang J, Li G, Xu L, Tan Y, Zheng X, Jin X, Yu K, Xia X. Linking coral fluorescence phenotypes to thermal bleaching in the reef-building Galaxea fascicularis from the northern South China Sea. MARINE LIFE SCIENCE & TECHNOLOGY 2024; 6:155-167. [PMID: 38433965 PMCID: PMC10902222 DOI: 10.1007/s42995-023-00190-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/31/2023] [Indexed: 03/05/2024]
Abstract
Coral fluorescence phenotypes have been suggested as an adaptation to a broad range of environmental conditions, yet the mechanisms linking thermal bleaching tolerance in reef-building coral populations, associated with fluorescence phenotypes due to GFP-like proteins, remains unclear. In this study, the relationship between the thermal sensitivity and phenotypic plasticity of corals was investigated using two phenotypes of Galaxea fascicularis, green and brown. The results reveal that brown G. fascicularis was more susceptible to bleaching than green G. fascicularis when exposed to a higher growth temperature of 32 °C. Both phenotypes of G. fascicularis were associated with the thermotolerant Symbiodiniaceae symbiont, Durusdinium trenchii. However, the brown G. fascicularis showed a significant decrease in Symbiodiniaceae cell density and a significant increase in pathogenic bacteria abundance when the growth temperature was raised from 29 to 32 °C. The physiological traits and transcriptomic profiles of Symbiodiniaceae were not notably affected, but there were differences in the transcriptional levels of certain genes between the two phenotype hosts of G. fascicularis. Under heat stress of 32 °C, the gene encoding green fluorescent protein (GFP)-like and chromosome-associated proteins, as well as genes related to oxidative phosphorylation, cell growth and death showed lower transcriptional levels in the brown G. fascicularis compared to the green G. fascicularis. Overall, the results demonstrate that the green form of G. fascicularis is better able to tolerate ocean warming and defend against pathogenic bacteria, likely due to higher gene transcription levels and defense ability. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-023-00190-1.
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Affiliation(s)
- Sanqiang Gong
- Key Laboratory of Tropical Marine Bio-Resources and Ecology & Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301 China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 510301 China
| | - Jiayuan Liang
- Coral Reef Research Center of China, Guangxi University, Nanning, 53004 China
| | - Gang Li
- Key Laboratory of Tropical Marine Bio-Resources and Ecology & Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301 China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 510301 China
| | - Lijia Xu
- South China Institute of Environmental Sciences, The Ministry of Ecology and Environment of PRC, Guangzhou, 510530 China
| | - Yehui Tan
- Key Laboratory of Tropical Marine Bio-Resources and Ecology & Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301 China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 510301 China
| | - Xinqing Zheng
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005 China
| | - Xuejie Jin
- Key Laboratory of Tropical Marine Bio-Resources and Ecology & Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301 China
| | - Kefu Yu
- Coral Reef Research Center of China, Guangxi University, Nanning, 53004 China
| | - Xiaomin Xia
- Key Laboratory of Tropical Marine Bio-Resources and Ecology & Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301 China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 510301 China
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3
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Bollati E, Lyndby NH, D'Angelo C, Kühl M, Wiedenmann J, Wangpraseurt D. Green fluorescent protein-like pigments optimize the internal light environment in symbiotic reef building corals. eLife 2022; 11:73521. [PMID: 35801683 PMCID: PMC9342951 DOI: 10.7554/elife.73521] [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: 09/01/2021] [Accepted: 07/07/2022] [Indexed: 11/25/2022] Open
Abstract
Pigments homologous to the green fluorescent protein (GFP) have been proposed to fine-tune the internal light microclimate of corals, facilitating photoacclimation of photosynthetic coral symbionts (Symbiodiniaceae) to life in different reef habitats and environmental conditions. However, direct measurements of the in vivo light conditions inside the coral tissue supporting this conclusion are lacking. Here, we quantified the intra-tissue spectral light environment of corals expressing GFP-like proteins from widely different light regimes. We focus on: (1) photoconvertible red fluorescent proteins (pcRFPs), thought to enhance photosynthesis in mesophotic habitats via wavelength conversion, and (2) chromoproteins (CPs), which provide photoprotection to the symbionts in shallow water via light absorption. Optical microsensor measurements indicated that both pigment groups strongly alter the coral intra-tissue light environment. Estimates derived from light spectra measured in pcRFP-containing corals showed that fluorescence emission can contribute to >50% of orange-red light available to the photosynthetic symbionts at mesophotic depths. We further show that upregulation of pink CPs in shallow-water corals during bleaching leads to a reduction of orange light by 10–20% compared to low-CP tissue. Thus, screening by CPs has an important role in mitigating the light-enhancing effect of coral tissue scattering and skeletal reflection during bleaching. Our results provide the first experimental quantification of the importance of GFP-like proteins in fine-tuning the light microclimate of corals during photoacclimation.
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Affiliation(s)
- Elena Bollati
- Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Niclas H Lyndby
- Laboratory for Biological Geochemistry, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Cecilia D'Angelo
- Coral Reef Laboratory, University of Southampton, Southampton, United Kingdom
| | - Michael Kühl
- Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Jörg Wiedenmann
- Coral Reef Laboratory, University of Southampton, Southampton, United Kingdom
| | - Daniel Wangpraseurt
- Department of NanoEngineering, University of California, San Diego, San Diego, United States
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4
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Cox KD, Woods MB, Reimchen TE. Regional heterogeneity in coral species richness and hue reveals novel global predictors of reef fish intra-family diversity. Sci Rep 2021; 11:18275. [PMID: 34521952 PMCID: PMC8440613 DOI: 10.1038/s41598-021-97862-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 08/31/2021] [Indexed: 02/08/2023] Open
Abstract
Habitat heterogeneity shapes biological communities, a well-known process in terrestrial ecosystems but substantially unresolved within coral reef ecosystems. We investigated the extent to which coral richness predicts intra-family fish richness, while simultaneously integrating a striking aspect of reef ecosystems-coral hue. To do so, we quantified the coral richness, coral hue diversity, and species richness within 25 fish families in 74 global ecoregions. We then expanded this to an analysis of all reef fishes (4465 species). Considering coral bleaching as a natural experiment, we subsequently examined hue's contribution to fish communities. Coral species and hue diversity significantly predict each family's fish richness, with the highest correlations (> 80%) occurring in damselfish, butterflyfish, emperors and rabbitfish, lower (60-80%) in substrate-bound and mid-water taxa such as blennies, seahorses, and parrotfish, and lowest (40-60%) in sharks, morays, grunts and triggerfish. The observed trends persisted globally. Coral bleaching's homogenization of reef colouration revealed hue's contribution to maintaining fish richness, abundance, and recruit survivorship. We propose that each additional coral species and associated hue provide added ecological opportunities (e.g. camouflage, background contrast for intraspecific display), facilitating the evolution and co-existence of diverse fish assemblages.
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Affiliation(s)
- Kieran D Cox
- Department of Biology, University of Victoria, Cunningham 202, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.
- Hakai Institute, Heriot Bay, BC, V0P 1H0, Canada.
| | - Mackenzie B Woods
- Department of Biology, University of Victoria, Cunningham 202, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
| | - Thomas E Reimchen
- Department of Biology, University of Victoria, Cunningham 202, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.
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5
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Nienhaus K, Nienhaus GU. Fluorescent proteins of the EosFP clade: intriguing marker tools with multiple photoactivation modes for advanced microscopy. RSC Chem Biol 2021; 2:796-814. [PMID: 34458811 PMCID: PMC8341165 DOI: 10.1039/d1cb00014d] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/27/2021] [Indexed: 02/04/2023] Open
Abstract
Optical fluorescence microscopy has taken center stage in the exploration of biological structure and dynamics, especially on live specimens, and super-resolution imaging methods continue to deliver exciting new insights into the molecular foundations of life. Progress in the field, however, crucially hinges on advances in fluorescent marker technology. Among these, fluorescent proteins (FPs) of the GFP family are advantageous because they are genetically encodable, so that live cells, tissues or organisms can produce these markers all by themselves. A subclass of them, photoactivatable FPs, allow for control of their fluorescence emission by light irradiation, enabling pulse-chase imaging and super-resolution microscopy. In this review, we discuss FP variants of the EosFP clade that have been optimized by amino acid sequence modification to serve as markers for various imaging techniques. In general, two different modes of photoactivation are found, reversible photoswitching between a fluorescent and a nonfluorescent state and irreversible green-to red photoconversion. First, we describe their basic structural and optical properties. We then summarize recent research aimed at elucidating the photochemical processes underlying photoactivation. Finally, we briefly introduce various advanced imaging methods facilitated by specific EosFP variants, and show some exciting sample applications.
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Affiliation(s)
- Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology 76049 Karlsruhe Germany
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology 76049 Karlsruhe Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76021 Karlsruhe Germany
- Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology 76021 Karlsruhe Germany
- Department of Physics, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
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6
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Mutalipassi M, Riccio G, Mazzella V, Galasso C, Somma E, Chiarore A, de Pascale D, Zupo V. Symbioses of Cyanobacteria in Marine Environments: Ecological Insights and Biotechnological Perspectives. Mar Drugs 2021; 19:227. [PMID: 33923826 PMCID: PMC8074062 DOI: 10.3390/md19040227] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/14/2021] [Accepted: 04/15/2021] [Indexed: 01/07/2023] Open
Abstract
Cyanobacteria are a diversified phylum of nitrogen-fixing, photo-oxygenic bacteria able to colonize a wide array of environments. In addition to their fundamental role as diazotrophs, they produce a plethora of bioactive molecules, often as secondary metabolites, exhibiting various biological and ecological functions to be further investigated. Among all the identified species, cyanobacteria are capable to embrace symbiotic relationships in marine environments with organisms such as protozoans, macroalgae, seagrasses, and sponges, up to ascidians and other invertebrates. These symbioses have been demonstrated to dramatically change the cyanobacteria physiology, inducing the production of usually unexpressed bioactive molecules. Indeed, metabolic changes in cyanobacteria engaged in a symbiotic relationship are triggered by an exchange of infochemicals and activate silenced pathways. Drug discovery studies demonstrated that those molecules have interesting biotechnological perspectives. In this review, we explore the cyanobacterial symbioses in marine environments, considering them not only as diazotrophs but taking into consideration exchanges of infochemicals as well and emphasizing both the chemical ecology of relationship and the candidate biotechnological value for pharmaceutical and nutraceutical applications.
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Affiliation(s)
- Mirko Mutalipassi
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (G.R.); (C.G.); (D.d.P.)
| | - Gennaro Riccio
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (G.R.); (C.G.); (D.d.P.)
| | - Valerio Mazzella
- Department of Integrated Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy;
| | - Christian Galasso
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (G.R.); (C.G.); (D.d.P.)
| | - Emanuele Somma
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri, 34127 Trieste, Italy;
- Department of Marine Biotechnology, Ischia Marine Centre, Stazione Zoologica Anton Dohrn, Punta San Pietro, 80077 Naples, Italy;
| | - Antonia Chiarore
- Department of Biology, University of Naples Federico II, Via Cinthia, 80126 Naples, Italy;
| | - Donatella de Pascale
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (G.R.); (C.G.); (D.d.P.)
| | - Valerio Zupo
- Department of Marine Biotechnology, Ischia Marine Centre, Stazione Zoologica Anton Dohrn, Punta San Pietro, 80077 Naples, Italy;
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7
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Bollati E, D'Angelo C, Alderdice R, Pratchett M, Ziegler M, Wiedenmann J. Optical Feedback Loop Involving Dinoflagellate Symbiont and Scleractinian Host Drives Colorful Coral Bleaching. Curr Biol 2020; 30:2433-2445.e3. [PMID: 32442463 DOI: 10.1016/j.cub.2020.04.055] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/19/2020] [Accepted: 04/21/2020] [Indexed: 11/25/2022]
Abstract
Coral bleaching, caused by the loss of brownish-colored dinoflagellate photosymbionts from the host tissue of reef-building corals, is a major threat to reef survival. Occasionally, bleached corals become exceptionally colorful rather than white. These colors derive from photoprotective green fluorescent protein (GFP)-like pigments produced by the coral host. There is currently no consensus regarding what causes colorful bleaching events and what the consequences for the corals are. Here, we document that colorful bleaching events are a recurring phenomenon in reef regions around the globe. Our analysis of temperature conditions associated with colorful bleaching events suggests that corals develop extreme coloration within 2 to 3 weeks after exposure to mild or temporary heat stress. We demonstrate that the increase of light fluxes in symbiont-depleted tissue promoted by reflection of the incident light from the coral skeleton induces strong expression of the photoprotective coral host pigments. We describe an optical feedback loop involving both partners of the association, discussing that the mitigation of light stress offered by host pigments could facilitate recolonization of bleached tissue by symbionts. Our data indicate that colorful bleaching has the potential to identify local environmental factors, such as nutrient stress, that can exacerbate the impact of elevated temperatures on corals, to indicate the severity of heat stress experienced by corals and to gauge their post-stress recovery potential. VIDEO ABSTRACT.
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Affiliation(s)
- Elena Bollati
- Coral Reef Laboratory, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK; Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Cecilia D'Angelo
- Coral Reef Laboratory, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK; Institute for Life Sciences (IFLS), University of Southampton, Highfield Campus, Southampton SO17 1BJ, UK
| | - Rachel Alderdice
- Coral Reef Laboratory, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK; Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Morgan Pratchett
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Maren Ziegler
- Systematics & Biodiversity Lab, Justus Liebig University, 35392 Giessen, Germany; Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jörg Wiedenmann
- Coral Reef Laboratory, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK; Institute for Life Sciences (IFLS), University of Southampton, Highfield Campus, Southampton SO17 1BJ, UK.
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8
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Sharma D, Ravindran C. Diseases and pathogens of marine invertebrate corals in Indian reefs. J Invertebr Pathol 2020; 173:107373. [PMID: 32272136 DOI: 10.1016/j.jip.2020.107373] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 03/28/2020] [Accepted: 03/30/2020] [Indexed: 11/16/2022]
Abstract
Diseases in marine invertebrate corals have been reported worldwide and have been associated with infection by various microbial pathogens that cause massive mortality. Several bacterial species, especially Vibrio species but also members of the cyanobacteria, fungi, viruses, and protists, are described as important pathogens associated with coral disease and mortality. The present work provides an updated overview of main diseases and implicated microbial species affecting corals in Indian reefs. Further study on pathogen diversity, classification, spread and environmental factors on pathogen-host interactions may contribute a better understanding of the coral diseases.
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Affiliation(s)
- Diksha Sharma
- Biological Oceanography Division, CSIR - National Institute of Oceanography, Dona Paula, 403004 Goa, India
| | - Chinnarajan Ravindran
- Biological Oceanography Division, CSIR - National Institute of Oceanography, Dona Paula, 403004 Goa, India.
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9
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Bridges MC, Woodley CM, Peters EC, May LA, Galloway SB. Expression and Characterization of a Bright Far-red Fluorescent Protein from the Pink-Pigmented Tissues of Porites lobata. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2020; 22:67-80. [PMID: 31853751 DOI: 10.1007/s10126-019-09931-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/30/2019] [Indexed: 06/10/2023]
Abstract
Members of the anthozoan green fluorescent protein (GFP) family display a diversity of photo-physical properties that can be associated with normal and damaged coral tissues. Poritid coral species often exhibit localized pink pigmentation in diseased or damaged tissues. Our spectral and histological analyses of pink-pigmented Porites lobata lesions show co-localization of bright red fluorescence with putative amoebocytes concentrating in the epidermis, suggesting an activated innate immune response. Here we report the cloning, expression, and characterization of a novel red fluorescent protein (plobRFP) from the pink-pigmented tissues associated with lesions on Porites lobata. In vitro, the recombinant plobRFP exhibits a distinct red emission signal of 614 nm (excitation maximum: 578 nm), making plobRFP the furthest red-shifted natural fluorescent protein isolated from a scleractinian coral. The recombinant protein has a high molar extinction coefficient (84,000 M-1 cm-1) and quantum yield (0.74), conferring a notable brightness to plobRFP. Sequence analysis suggests the distinct brightness and marked red shift may be inherent features of plobRFP's chromophore conformation. While plobRFP displays a tendency to aggregate, its high pH stability, photostability, and spectral properties make it a candidate for cell imaging applications and a potential template for engineering optimized RFPs. The association of plobRFP with a possible immune response furthers its potential use as a visual diagnostic and molecular biomarker for monitoring coral health.
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Affiliation(s)
- Mary C Bridges
- Graduate Program in Marine Biology, College of Charleston, Charleston, SC, USA
- National Centers for Coastal Ocean Science Charleston Laboratory, NOS, NOAA, Charleston, SC, USA
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Cheryl M Woodley
- National Centers for Coastal Ocean Science Charleston Laboratory, NOS, NOAA, Charleston, SC, USA.
| | - Esther C Peters
- Department of Environmental Science & Policy, George Mason University, Fairfax, VA, USA
| | - Lisa A May
- Consolidated Safety Services, Inc., NCCOS Charleston Laboratory, NOS, NOAA, Charleston, SC, USA
| | - Sylvia B Galloway
- National Centers for Coastal Ocean Science Charleston Laboratory, NOS, NOAA, Charleston, SC, USA
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10
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Chiu YL, Shikina S, Chang CF. Testicular somatic cells in the stony coral Euphyllia ancora express an endogenous green fluorescent protein. Mol Reprod Dev 2019; 86:798-811. [PMID: 31056825 DOI: 10.1002/mrd.23157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/30/2019] [Accepted: 04/08/2019] [Indexed: 01/11/2023]
Abstract
In a variety of organisms, adult gonads contain several specialized somatic cells that regulate and support the development of germline cells. In stony corals, the characteristics and functions of gonadal somatic cells remain largely unknown. No molecular markers are currently available that allow for the identification and enrichment of gonadal somatic cells in corals. Here, we showed that the testicular somatic cells of a stony coral, Euphyllia ancora, express an endogenous green fluorescent protein (GFP). Fluorescence microscopy showed that, in contrast to the endogenous expression of the red fluorescent protein of E. ancora ovaries that we have previously reported, the testes displayed a distinct green fluorescence. Molecular identification and spectrum characterization demonstrated that E. ancora testes expressed a GFP (named EaGFP) that is a homolog of the GFP from the jellyfish Aequorea victoria and that possesses an excitation maximum of 506 nm and an emission maximum of 514 nm. Immunohistochemical analyses revealed that the testicular somatic cells, but not the germ cells, expressed EaGFP. EaGFP was enclosed within one or a few granules in the cytoplasm of testicular somatic cells, and the granule number decreased as spermatogenesis proceeded. We also showed that testicular somatic cells could be enriched by using endogenous GFP as an indicator. The present study not only revealed one of the unique cellular characteristics of coral testicular cells but also established a technical basis for more in-depth investigations of the function of testicular somatic cells in spermatogenesis in future studies.
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Affiliation(s)
- Yi-Ling Chiu
- Doctoral Degree Program in Marine Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, Academia Sinica, Taipei, Taiwan
| | - Shinya Shikina
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Ching-Fong Chang
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
- Department of Aquaculture, National Taiwan Ocean University, Keelung, Taiwan
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11
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Takahashi-Kariyazono S, Sakai K, Terai Y. Presence-Absence Polymorphisms of Highly Expressed FP Sequences Contribute to Fluorescent Polymorphisms in Acropora digitifera. Genome Biol Evol 2018; 10:1715-1729. [PMID: 30016429 PMCID: PMC6048989 DOI: 10.1093/gbe/evy122] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2018] [Indexed: 12/30/2022] Open
Abstract
Despite many hypotheses regarding the roles of fluorescent proteins (FPs), their biological roles and the genetic basis of FP-mediated color polymorphisms in Acropora remain unclear. In this study, we determined the genetic mechanism underlying fluorescent polymorphisms in A. digitifera. Using a high-throughput sequencing approach, we found that FP gene sequences in FP multigene family exhibit presence-absence polymorphism among individuals. A few particular sequences in short-to-middle wavelength emission and middle-to-long wavelength emission clades were highly expressed in adults, and different sequences were highly expressed in larvae. These highly expressed sequences were absent in the genomes of individuals with low total FP gene expression. In adults, presence-absence differences of the highly expressed FP sequences were consistent with measurements of emission spectra of corals, suggesting that presence-absence polymorphisms of these FP sequences contributed to the fluorescent polymorphisms. The functions of recombinant FPs encoded by highly expressed sequences in adult and larval stages were different, suggesting that expression of FP sequences with different functions may depend on the life-stage of A. digitifera. Highly expressed FP sequences exhibited presence-absence polymorphisms in subpopulations of A. digitifera, suggesting that presence-absence status is maintained during the evolution of A. digitifera subpopulations. The difference in FPs between adults and larvae and the polymorphisms of highly expressed FP genes may provide key insight into the biological roles of FPs in corals.
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Affiliation(s)
- Shiho Takahashi-Kariyazono
- Department of Evolutionary Studies of Biosystems, Shonan Village, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Japan
| | - Kazuhiko Sakai
- Department of Coral Reef and Biological Science, Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Motobu, Okinawa, Japan
| | - Yohey Terai
- Department of Evolutionary Studies of Biosystems, Shonan Village, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Japan
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12
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Jarett JK, MacManes MD, Morrow KM, Pankey MS, Lesser MP. Comparative Genomics of Color Morphs In the Coral Montastraea cavernosa. Sci Rep 2017; 7:16039. [PMID: 29167578 PMCID: PMC5700045 DOI: 10.1038/s41598-017-16371-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/12/2017] [Indexed: 11/30/2022] Open
Abstract
Montastraea cavernosa is a common coral in the Caribbean basin found in several color morphs. To investigate the causes for brown and orange morphs we undertook a genomics approach on corals collected at the same time and depth in the Bahamas. The coral holobiont includes the host, symbiotic dinoflagellates (Symbiodinium spp.), and a diverse microbiome. While the coral host showed significant genetic differentiation between color morphs both the composition of the Symbiodinium spp. communities and the prokaryotic communities did not. Both targeted and global gene expression differences in the transcriptome of the host show no difference in fluorescent proteins while the metatranscriptome of the microbiome shows that pigments such as phycoerythrin and orange carotenoid protein of cyanobacterial origin are significantly greater in orange morphs, which is also consistent with the significantly greater number of cyanobacteria quantified by 16S rRNA reads and flow cytometry. The microbiome of orange color morphs expressed significantly more nitrogenase (nifH) transcripts consistent with their known ability to fix nitrogen. Both coral and Symbiodinium spp. transcriptomes from orange morphs had significantly increased expression of genes related to immune response and apoptosis, which may potentially be involved in maintaining and regulating the unique symbiont population in orange morphs.
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Affiliation(s)
- Jessica K Jarett
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA
- US Department of Energy, Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Matthew D MacManes
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA
| | - Kathleen M Morrow
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA
| | - M Sabrina Pankey
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA
| | - Michael P Lesser
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA.
- School of Marine Science and Ocean Engineering, University of New Hampshire, Durham, NH, 03824, USA.
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13
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Mallien C, Porro B, Zamoum T, Olivier C, Wiedenmann J, Furla P, Forcioli D. Conspicuous morphological differentiation without speciation in Anemonia viridis (Cnidaria, Actiniaria). SYST BIODIVERS 2017. [DOI: 10.1080/14772000.2017.1383948] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Cédric Mallien
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine – Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
| | - Barbara Porro
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine – Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
| | - Thamilla Zamoum
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine – Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
| | - Caroline Olivier
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine – Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
| | - Jörg Wiedenmann
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, Southampton SO14 3ZH, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Paola Furla
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine – Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
| | - Didier Forcioli
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine – Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
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14
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Functioning of Fluorescent Proteins in Aggregates in Anthozoa Species and in Recombinant Artificial Models. Int J Mol Sci 2017; 18:ijms18071503. [PMID: 28704934 PMCID: PMC5535993 DOI: 10.3390/ijms18071503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/02/2017] [Accepted: 07/10/2017] [Indexed: 11/17/2022] Open
Abstract
Despite great advances in practical applications of fluorescent proteins (FPs), their natural function is poorly understood. FPs display complex spatio-temporal expression patterns in living Anthozoa coral polyps. Here we applied confocal microscopy, specifically, the fluorescence recovery after photobleaching (FRAP) technique to analyze intracellular localization and mobility of endogenous FPs in live tissues. We observed three distinct types of protein distributions in living tissues. One type of distribution, characteristic for Anemonia, Discosoma and Zoanthus, is free, highly mobile cytoplasmic localization. Another pattern is seen in FPs localized to numerous intracellular vesicles, observed in Clavularia. The third most intriguing type of intracellular localization is with respect to the spindle-shaped aggregates and lozenge crystals several micrometers in size observed in Zoanthus samples. No protein mobility within those structures was detected by FRAP. This finding encouraged us to develop artificial aggregating FPs. We constructed “trio-FPs” consisting of three tandem copies of tetrameric FPs and demonstrated that they form multiple bright foci upon expression in mammalian cells. High brightness of the aggregates is advantageous for early detection of weak promoter activities. Simultaneously, larger aggregates can induce significant cytostatic and cytotoxic effects and thus such tags are not suitable for long-term and high-level expression.
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15
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Smith EG, D'Angelo C, Sharon Y, Tchernov D, Wiedenmann J. Acclimatization of symbiotic corals to mesophotic light environments through wavelength transformation by fluorescent protein pigments. Proc Biol Sci 2017; 284:20170320. [PMID: 28679724 PMCID: PMC5524488 DOI: 10.1098/rspb.2017.0320] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 06/22/2017] [Indexed: 11/17/2022] Open
Abstract
The depth distribution of reef-building corals exposes their photosynthetic symbionts of the genus Symbiodinium to extreme gradients in the intensity and spectral quality of the ambient light environment. Characterizing the mechanisms used by the coral holobiont to respond to the low intensity and reduced spectral composition of the light environment in deeper reefs (greater than 20 m) is fundamental to our understanding of the functioning and structure of reefs across depth gradients. Here, we demonstrate that host pigments, specifically photoconvertible red fluorescent proteins (pcRFPs), can promote coral adaptation/acclimatization to deeper-water light environments by transforming the prevalent blue light into orange-red light, which can penetrate deeper within zooxanthellae-containing tissues; this facilitates a more homogeneous distribution of photons across symbiont communities. The ecological importance of pcRFPs in deeper reefs is supported by the increasing proportion of red fluorescent corals with depth (measured down to 45 m) and increased survival of colour morphs with strong expression of pcRFPs in long-term light manipulation experiments. In addition to screening by host pigments from high light intensities in shallow water, the spectral transformation observed in deeper-water corals highlights the importance of GFP-like protein expression as an ecological mechanism to support the functioning of the coral-Symbiodinium association across steep environmental gradients.
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Affiliation(s)
- Edward G Smith
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
- Marine Biology Laboratory/Centre for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Cecilia D'Angelo
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
- IfLS, Institute for Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
| | - Yoni Sharon
- The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel
| | - Dan Tchernov
- The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel
- Department of Marine Biology, University of Haifa, 31905 Mt Carmel, Israel
| | - Joerg Wiedenmann
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
- IfLS, Institute for Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
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16
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FRET-Mediated Long-Range Wavelength Transformation by Photoconvertible Fluorescent Proteins as an Efficient Mechanism to Generate Orange-Red Light in Symbiotic Deep Water Corals. Int J Mol Sci 2017; 18:ijms18071174. [PMID: 28677653 PMCID: PMC5535822 DOI: 10.3390/ijms18071174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 11/16/2022] Open
Abstract
Photoconvertible fluorescent proteins (pcRFPs) are a group of fluorophores that undergo an irreversible green-to-red shift in emission colour upon irradiation with near-ultraviolet (near-UV) light. Despite their wide application in biotechnology, the high-level expression of pcRFPs in mesophotic and depth-generalist coral species currently lacks a biological explanation. Additionally, reduced penetration of near-UV wavelengths in water poses the question whether light-driven photoconversion is relevant in the mesophotic zone, or whether a different mechanism is involved in the post-translational pigment modification in vivo. Here, we show in a long-term mesocosm experiment that photoconversion in vivo is entirely dependent on near-UV wavelengths. However, a near-UV intensity equivalent to the mesophotic underwater light field at 80 m depth is sufficient to drive the process in vitro, suggesting that photoconversion can occur near the lower distribution limits of these corals. Furthermore, live coral colonies showed evidence of efficient Förster Resonance Energy Transfer (FRET). Our simulated mesophotic light field maintained the pcRFP pool in a partially photoconverted state in vivo, maximising intra-tetrameric FRET and creating a long-range wavelength conversion system with higher quantum yield than other native RFPs. We hypothesise that efficient conversion of blue wavelengths, abundant at depth, into orange-red light could constitute an adaptation of corals to life in light-limited environments.
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17
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Wangpraseurt D, Wentzel C, Jacques SL, Wagner M, Kühl M. In vivo imaging of coral tissue and skeleton with optical coherence tomography. J R Soc Interface 2017; 14:20161003. [PMID: 28250104 PMCID: PMC5378135 DOI: 10.1098/rsif.2016.1003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 02/01/2017] [Indexed: 11/12/2022] Open
Abstract
Application of optical coherence tomography (OCT) for in vivo imaging of tissue and skeleton structure of intact living corals enabled the non-invasive visualization of coral tissue layers (endoderm versus ectoderm), skeletal cavities and special structures such as mesenterial filaments and mucus release from intact living corals. Coral host chromatophores containing green fluorescent protein-like pigment granules appeared hyper-reflective to near-infrared radiation allowing for excellent optical contrast in OCT and a rapid characterization of chromatophore size, distribution and abundance. In vivo tissue plasticity could be quantified by the linear contraction velocity of coral tissues upon illumination resulting in dynamic changes in the live coral tissue surface area, which varied by a factor of 2 between the contracted and expanded state of a coral. Our study provides a novel view on the in vivo organization of coral tissue and skeleton and highlights the importance of microstructural dynamics for coral ecophysiology.
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Affiliation(s)
- Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingør 3000, Denmark
| | - Camilla Wentzel
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingør 3000, Denmark
| | - Steven L Jacques
- Department of Biomedical Engineering, Oregon Health and Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA
| | - Michael Wagner
- Engler-Bunte Institute, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingør 3000, Denmark
- Climate Change Cluster, University of Technology Sydney, PO Box 123, Broadway, Sydney, New South Wales 2007, Australia
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18
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Takahashi-Kariyazono S, Gojobori J, Satta Y, Sakai K, Terai Y. Acropora digitifera Encodes the Largest Known Family of Fluorescent Proteins that Has Persisted during the Evolution of Acropora Species. Genome Biol Evol 2016; 8:3271-3283. [PMID: 27920057 PMCID: PMC5203795 DOI: 10.1093/gbe/evw265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Fluorescent proteins (FPs) are well known and broadly used as bio-imaging markers in molecular biology research. Many FP genes were cloned from anthozoan species and it was suggested that multi-copies of these genes are present in their genomes. However, the full complement of FP genes in any single coral species remained unidentified. In this study, we analyzed the FP genes in two stony coral species. FP cDNA sequences from Acropora digitifera and Acropora tenuis revealed the presence of a multi-gene family with an unexpectedly large number of genes, separated into short-/middle-wavelength emission (S/MWE), middle-/long-wavelength emission (M/LWE), and chromoprotein (CP) clades. FP gene copy numbers in the genomes of four A. digitifera colonies were estimated as 16–22 in the S/MWE, 3–6 in the M/LWE, and 8–12 in the CP clades, and, in total, 35, 31, 33, and 33 FP gene copies per individual shown by quantitative PCR. To the best of our knowledge, these are the largest sets of FP genes per genome. The fluorescent light produced by recombinant protein products encoded by the newly isolated genes explained the fluorescent range of live A. digitifera, suggesting that the high copy multi-FP gene family generates coral fluorescence. The functionally diverse multi-FP gene family must have existed in the ancestor of Acropora species, as suggested by molecular phylogenetic and evolutionary analyses. The persistence of a diverse function and high copy number multi-FP gene family may indicate the biological importance of diverse fluorescence emission and light absorption in Acropora species.
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Affiliation(s)
- Shiho Takahashi-Kariyazono
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Japan
| | - Jun Gojobori
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Japan
| | - Yoko Satta
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Japan
| | - Kazuhiko Sakai
- Department of Coral Reef and Biological Science, Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905-0227, Japan
| | - Yohey Terai
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Japan
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Nienhaus K, Nienhaus GU. Chromophore photophysics and dynamics in fluorescent proteins of the GFP family. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:443001. [PMID: 27604321 DOI: 10.1088/0953-8984/28/44/443001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Proteins of the green fluorescent protein (GFP) family are indispensable for fluorescence imaging experiments in the life sciences, particularly of living specimens. Their essential role as genetically encoded fluorescence markers has motivated many researchers over the last 20 years to further advance and optimize these proteins by using protein engineering. Amino acids can be exchanged by site-specific mutagenesis, starting with naturally occurring proteins as templates. Optical properties of the fluorescent chromophore are strongly tuned by the surrounding protein environment, and a targeted modification of chromophore-protein interactions requires a profound knowledge of the underlying photophysics and photochemistry, which has by now been well established from a large number of structural and spectroscopic experiments and molecular-mechanical and quantum-mechanical computations on many variants of fluorescent proteins. Nevertheless, such rational engineering often does not meet with success and thus is complemented by random mutagenesis and selection based on the optical properties. In this topical review, we present an overview of the key structural and spectroscopic properties of fluorescent proteins. We address protein-chromophore interactions that govern ground state optical properties as well as processes occurring in the electronically excited state. Special emphasis is placed on photoactivation of fluorescent proteins. These light-induced reactions result in large structural changes that drastically alter the fluorescence properties of the protein, which enables some of the most exciting applications, including single particle tracking, pulse chase imaging and super-resolution imaging. We also present a few examples of fluorescent protein application in live-cell imaging experiments.
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Affiliation(s)
- Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Wolfgang Gaede-Straße 1, 76131 Karlsruhe, Germany
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20
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Lyndby NH, Kühl M, Wangpraseurt D. Heat generation and light scattering of green fluorescent protein-like pigments in coral tissue. Sci Rep 2016; 6:26599. [PMID: 27225857 PMCID: PMC4880895 DOI: 10.1038/srep26599] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/05/2016] [Indexed: 11/29/2022] Open
Abstract
Green fluorescent protein (GFP)-like pigments have been proposed to have beneficial effects on coral photobiology. Here, we investigated the relationships between green fluorescence, coral heating and tissue optics for the massive coral Dipsastraea sp. (previously Favia sp.). We used microsensors to measure tissue scalar irradiance and temperature along with hyperspectral imaging and combined imaging of variable chlorophyll fluorescence and green fluorescence. Green fluorescence correlated positively with coral heating and scalar irradiance enhancement at the tissue surface. Coral tissue heating saturated for maximal levels of green fluorescence. The action spectrum of coral surface heating revealed that heating was highest under red (peaking at 680 nm) irradiance. Scalar irradiance enhancement in coral tissue was highest when illuminated with blue light, but up to 62% (for the case of highest green fluorescence) of this photon enhancement was due to green fluorescence emission. We suggest that GFP-like pigments scatter the incident radiation, which enhances light absorption and heating of the coral. However, heating saturates, because intense light scattering reduces the vertical penetration depth through the tissue eventually leading to reduced light absorption at high fluorescent pigment density. We conclude that fluorescent pigments can have a central role in modulating coral light absorption and heating.
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Affiliation(s)
- Niclas H Lyndby
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark.,Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
| | - Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark.,Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
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21
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Shikina S, Chiu YL, Chung YJ, Chen CJ, Lee YH, Chang CF. Oocytes express an endogenous red fluorescent protein in a stony coral, Euphyllia ancora: a potential involvement in coral oogenesis. Sci Rep 2016; 6:25868. [PMID: 27167722 PMCID: PMC4863156 DOI: 10.1038/srep25868] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 04/25/2016] [Indexed: 11/26/2022] Open
Abstract
To date,the molecular and cellular mechanisms underlying coral sexual reproduction remain largely unknown. We then performed a differential screen to identify genes related to oogenesis in the stony coral Euphyllia ancora. We identified a clone encoding a novel red fluorescent protein cDNA of E. ancora (named EaRFP). Microscopic observation and quantitative RT-PCR revealed that EaRFP is almost exclusively expressed in the ovary of the adult coral. The combination of the ovarian-cell separation method and the RT-PCR analysis revealed that the oocytes, but not the ovarian somatic cells, are the cells expressing EaRFP. Immunohistochemical analysis revealed that the expression of EaRFP starts in the early stage of the oocyte and continues until the maturation period. Furthermore, recombinant EaRFP was shown to possess an H2O2 degradation activity. These results raise the possibility that EaRFP plays a role in protecting the oocytes from oxidative stress from the early to late stages of oogenesis. The present study provides not only the first evidence for the potential involvement of FPs in coral oogenesis but also an insight into a cellular strategy underlying coral sexual reproduction.
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Affiliation(s)
- Shinya Shikina
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung, 20224, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Yi-Ling Chiu
- Department of Aquaculture, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Yi-Jou Chung
- Department of Aquaculture, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Chieh-Jhen Chen
- Department of Aquaculture, National Taiwan Ocean University, Keelung, 20224, Taiwan
- Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan
| | - Yan-Horn Lee
- Tungkang Biotechnology Research Center, Fisheries Research Institute, Tungkang, 20246, Taiwan
| | - Ching-Fong Chang
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, 20224, Taiwan
- Department of Aquaculture, National Taiwan Ocean University, Keelung, 20224, Taiwan
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22
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Strader ME, Aglyamova GV, Matz MV. Red fluorescence in coral larvae is associated with a diapause‐like state. Mol Ecol 2016; 25:559-69. [DOI: 10.1111/mec.13488] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 11/15/2015] [Accepted: 11/17/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Marie E. Strader
- Department of Integrative Biology The University of Texas at Austin 1 University Station C0930 Austin TX 78712 USA
| | - Galina V. Aglyamova
- Department of Integrative Biology The University of Texas at Austin 1 University Station C0930 Austin TX 78712 USA
| | - Mikhail V. Matz
- Department of Integrative Biology The University of Texas at Austin 1 University Station C0930 Austin TX 78712 USA
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23
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Torres-Pérez JL, Guild LS, Armstrong RA, Corredor J, Zuluaga-Montero A, Polanco R. Relative Pigment Composition and Remote Sensing Reflectance of Caribbean Shallow-Water Corals. PLoS One 2015; 10:e0143709. [PMID: 26619210 PMCID: PMC4664284 DOI: 10.1371/journal.pone.0143709] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 11/09/2015] [Indexed: 11/18/2022] Open
Abstract
Reef corals typically contain a number of pigments, mostly due to their symbiotic relationship with photosynthetic dinoflagellates. These pigments usually vary in presence and concentration and influence the spectral characteristics of corals. We studied the variations in pigment composition among seven Caribbean shallow-water Scleractinian corals by means of High Performance Liquid Chromatography (HPLC) analysis to further resolve the discrimination of corals. We found a total of 27 different pigments among the coral species, including some alteration products of the main pigments. Additionally, pigments typically found in endolithic algae were also identified. A Principal Components Analysis and a Hierarchical Cluster Analysis showed the separation of coral species based on pigment composition. All the corals were collected under the same physical environmental conditions. This suggests that pigment in the coral’s symbionts might be more genetically-determined than influenced by prevailing physical conditions of the reef. We further investigated the use of remote sensing reflectance (Rrs) as a tool for estimating the total pigment concentration of reef corals. Depending on the coral species, the Rrs and the total symbiont pigment concentration per coral tissue area correlation showed 79.5–98.5% confidence levels demonstrating its use as a non-invasive robust technique to estimate pigment concentration in studies of coral reef biodiversity and health.
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Affiliation(s)
- Juan L. Torres-Pérez
- Bay Area Environmental Research Institute/NASA Ames Research Center, MS 245-4, Bldg 245, Rm. 120, Moffett Field, CA, 94035, United States of America
- * E-mail:
| | - Liane S. Guild
- Earth Science Division, NASA Ames Research Center, MS 245-4, Bldg 245, Rm. 120, P.O. Box 1, Moffett Field, CA, 94035, United States of America
| | - Roy A. Armstrong
- Bio-optical Oceanography Laboratory, Department of Marine Sciences, University of Puerto Rico, Mayaguez, Puerto Rico, 00680, United States of America
| | - Jorge Corredor
- Chemical Oceanography Laboratory, Department of Marine Sciences, University of Puerto Rico, Mayaguez, Puerto Rico, 00680, United States of America
| | - Anabella Zuluaga-Montero
- Sociedad Ambiente Marino, University of Puerto Rico, San Juan, Puerto Rico, 00931, United States of America
| | - Ramón Polanco
- Universidad del Turabo, Escuela de Ciencias Naturales y Tecnología, Gurabo, Puerto Rico, 00778, United States of America
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24
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Strader ME, Davies SW, Matz MV. Differential responses of coral larvae to the colour of ambient light guide them to suitable settlement microhabitat. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150358. [PMID: 26587247 PMCID: PMC4632519 DOI: 10.1098/rsos.150358] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/09/2015] [Indexed: 05/28/2023]
Abstract
Reef-building corals produce planktonic planula larvae that must select an appropriate habitat to settle and spend the rest of their life, a behaviour that plays a critical role in survival. Here, we report that larvae obtained from a deep-water population of Pseudodiploria strigosa settled more readily under blue light and in the dark, which aligns well with the light field characteristics of their natal habitat. By contrast, larvae of the shallow-water coral Acropora millepora settled in high proportions under blue and green light while settlement was less in the dark. Acropora millepora larvae also showed reduced settlement under red light, which should be abundant at shallow depth. Hypothesizing that this might be a mechanism preventing the larvae from settling on the exposed upwards-facing surfaces, we quantified A. millepora settlement in manipulated light chambers in situ on the reef. While A. millepora larvae naturally preferred settling on vertical rather than exposed horizontal surfaces, swapping the colours of upwards-facing and sideways-facing light fields was sufficient to invert this preference. We also tested if the variation in intrinsic red fluorescence in A. millepora larvae correlates with settlement rates, as has been suggested previously. We observed this correlation only in the absence of light, indicating that larval red fluorescent protein is probably not directly involved in light sensing. Our study reveals previously under-appreciated light-sensory capabilities in coral larvae, which could be an important axis of ecological differentiation between coral species and/or populations.
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25
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Eyal G, Wiedenmann J, Grinblat M, D’Angelo C, Kramarsky-Winter E, Treibitz T, Ben-Zvi O, Shaked Y, Smith TB, Harii S, Denis V, Noyes T, Tamir R, Loya Y. Spectral Diversity and Regulation of Coral Fluorescence in a Mesophotic Reef Habitat in the Red Sea. PLoS One 2015; 10:e0128697. [PMID: 26107282 PMCID: PMC4479885 DOI: 10.1371/journal.pone.0128697] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/29/2015] [Indexed: 11/25/2022] Open
Abstract
The phenomenon of coral fluorescence in mesophotic reefs, although well described for shallow waters, remains largely unstudied. We found that representatives of many scleractinian species are brightly fluorescent at depths of 50–60 m at the Interuniversity Institute for Marine Sciences (IUI) reef in Eilat, Israel. Some of these fluorescent species have distribution maxima at mesophotic depths (40–100 m). Several individuals from these depths displayed yellow or orange-red fluorescence, the latter being essentially absent in corals from the shallowest parts of this reef. We demonstrate experimentally that in some cases the production of fluorescent pigments is independent of the exposure to light; while in others, the fluorescence signature is altered or lost when the animals are kept in darkness. Furthermore, we show that green-to-red photoconversion of fluorescent pigments mediated by short-wavelength light can occur also at depths where ultraviolet wavelengths are absent from the underwater light field. Intraspecific colour polymorphisms regarding the colour of the tissue fluorescence, common among shallow water corals, were also observed for mesophotic species. Our results suggest that fluorescent pigments in mesophotic reefs fulfil a distinct biological function and offer promising application potential for coral-reef monitoring and biomedical imaging.
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Affiliation(s)
- Gal Eyal
- Department of Zoology, Tel-Aviv University, Tel-Aviv, Israel
- The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel
| | - Jörg Wiedenmann
- Coral Reef Laboratory, University of Southampton, NOCS, Southampton, United Kingdom
- Institute for Life Sciences (IFLS), University of Southampton, Southampton, United Kingdom
- * E-mail:
| | - Mila Grinblat
- Department of Zoology, Tel-Aviv University, Tel-Aviv, Israel
| | - Cecilia D’Angelo
- Coral Reef Laboratory, University of Southampton, NOCS, Southampton, United Kingdom
| | | | - Tali Treibitz
- Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Or Ben-Zvi
- Department of Zoology, Tel-Aviv University, Tel-Aviv, Israel
| | - Yonathan Shaked
- The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel
| | - Tyler B. Smith
- Center for Marine and Environmental Studies, University of the Virgin Islands, St. Thomas, United States Virgin Islands, United States of America
| | - Saki Harii
- Tropical Biosphere Research Center, University of the Ryukyus, Motobu, Okinawa, Japan
| | - Vianney Denis
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Tim Noyes
- Bermuda Institute of Ocean Sciences (BIOS), St. George's, Bermuda
| | - Raz Tamir
- The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel
- Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Yossi Loya
- Department of Zoology, Tel-Aviv University, Tel-Aviv, Israel
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Lagorio MG, Cordon GB, Iriel A. Reviewing the relevance of fluorescence in biological systems. Photochem Photobiol Sci 2015; 14:1538-59. [PMID: 26103563 DOI: 10.1039/c5pp00122f] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Fluorescence is emitted by diverse living organisms. The analysis and interpretation of these signals may give information about their physiological state, ways of communication among species and the presence of specific chemicals. In this manuscript we review the state of the art in the research on the fluorescence emitted by plant leaves, fruits, flowers, avians, butterflies, beetles, dragonflies, millipedes, cockroaches, bees, spiders, scorpions and sea organisms and discuss its relevance in nature.
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Affiliation(s)
- M Gabriela Lagorio
- INQUIMAE/D.Q.I.A y Q.F. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
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Hense A, Nienhaus K, Nienhaus GU. Exploring color tuning strategies in red fluorescent proteins. Photochem Photobiol Sci 2015; 14:200-12. [PMID: 25597270 DOI: 10.1039/c4pp00212a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/31/2014] [Indexed: 01/01/2023]
Abstract
Red-emitting fluorescent proteins (RFPs) with fluorescence emission above 600 nm are advantageous for cell and tissue imaging applications for various reasons. Fluorescence from an RFP is well separated from cellular autofluorescence, which is in the green region of the spectrum, and red light is scattered less, which allows thicker specimens to be imaged. Moreover, the phototoxic response of cells is lower for red than blue or green light exposure. Further red-shifted FP variants can be obtained by genetic modifications causing an extension of the conjugated π-electron system of the chromophore, or by placing amino acids near the chromophore that stabilize its excited state or destabilize its ground state. We have selected the tetrameric RFP eqFP611 from Entacmaea quadricolor as a lead structure and discuss several rational design trials to generate RFP variants with improved photochemical properties.
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Affiliation(s)
- Anika Hense
- Institute of Applied Physics and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany.
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Treibitz T, Neal BP, Kline DI, Beijbom O, Roberts PLD, Mitchell BG, Kriegman D. Wide field-of-view fluorescence imaging of coral reefs. Sci Rep 2015; 5:7694. [PMID: 25582836 PMCID: PMC4291562 DOI: 10.1038/srep07694] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 12/03/2014] [Indexed: 11/09/2022] Open
Abstract
Coral reefs globally are declining rapidly because of both local and global stressors. Improved monitoring tools are urgently needed to understand the changes that are occurring at appropriate temporal and spatial scales. Coral fluorescence imaging tools have the potential to improve both ecological and physiological assessments. Although fluorescence imaging is regularly used for laboratory studies of corals, it has not yet been used for large-scale in situ assessments. Current obstacles to effective underwater fluorescence surveying include limited field-of-view due to low camera sensitivity, the need for nighttime deployment because of ambient light contamination, and the need for custom multispectral narrow band imaging systems to separate the signal into meaningful fluorescence bands. Here we describe the Fluorescence Imaging System (FluorIS), based on a consumer camera modified for greatly increased sensitivity to chlorophyll-a fluorescence, and we show high spectral correlation between acquired images and in situ spectrometer measurements. This system greatly facilitates underwater wide field-of-view fluorophore surveying during both night and day, and potentially enables improvements in semi-automated segmentation of live corals in coral reef photographs and juvenile coral surveys.
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Affiliation(s)
- Tali Treibitz
- The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa 3498838, Israel
| | - Benjamin P Neal
- Catlin Seaview Survey, Global Change Institute, The University of Queensland, St Lucia, QLD, AUS 4072
| | - David I Kline
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - Oscar Beijbom
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Paul L D Roberts
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - B Greg Mitchell
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - David Kriegman
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA 92093, USA
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Moya A, Huisman L, Forêt S, Gattuso JP, Hayward DC, Ball EE, Miller DJ. Rapid acclimation of juvenile corals to CO2-mediated acidification by upregulation of heat shock protein and Bcl-2 genes. Mol Ecol 2015; 24:438-52. [DOI: 10.1111/mec.13021] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/17/2014] [Accepted: 11/20/2014] [Indexed: 01/08/2023]
Affiliation(s)
- A. Moya
- ARC Centre of Excellence for Coral Reef Studies; James Cook University; Townsville Qld 4811 Australia
- Laboratoire d'Océanographie de Villefranche; INSU-CNRS; 181 Chemin du Lazaret 06230 Villefranche-sur-mer France
- Sorbonne Universités; UPMC Univ. Paris 06; Observatoire Océanologique 06230 Villefranche-sur-mer France
| | - L. Huisman
- ARC Centre of Excellence for Coral Reef Studies; James Cook University; Townsville Qld 4811 Australia
- Section of Computational Science; Universiteit van Amsterdam; Science Park 904 1098 XH Amsterdam The Netherlands
| | - S. Forêt
- ARC Centre of Excellence for Coral Reef Studies; James Cook University; Townsville Qld 4811 Australia
- Evolution, Ecology and Genetics; Research School of Biology; Australian National University; Bldg. 46 Canberra ACT 0200 Australia
| | - J.-P. Gattuso
- Laboratoire d'Océanographie de Villefranche; INSU-CNRS; 181 Chemin du Lazaret 06230 Villefranche-sur-mer France
- Sorbonne Universités; UPMC Univ. Paris 06; Observatoire Océanologique 06230 Villefranche-sur-mer France
| | - D. C. Hayward
- Evolution, Ecology and Genetics; Research School of Biology; Australian National University; Bldg. 46 Canberra ACT 0200 Australia
| | - E. E. Ball
- ARC Centre of Excellence for Coral Reef Studies; James Cook University; Townsville Qld 4811 Australia
- Evolution, Ecology and Genetics; Research School of Biology; Australian National University; Bldg. 46 Canberra ACT 0200 Australia
| | - D. J. Miller
- ARC Centre of Excellence for Coral Reef Studies; James Cook University; Townsville Qld 4811 Australia
- School of Pharmacy and Molecular Sciences; James Cook University; Townsville Qld 4811 Australia
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Takahashi-Kariyazono S, Satta Y, Terai Y. Genetic diversity of fluorescent protein genes generated by gene duplication and alternative splicing in reef-building corals. ZOOLOGICAL LETTERS 2015; 1:23. [PMID: 26605068 PMCID: PMC4657232 DOI: 10.1186/s40851-015-0020-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/17/2015] [Indexed: 05/08/2023]
Abstract
INTRODUCTION Reef-building corals (Scleractinia) exhibit various colors, of which fluorescent proteins (FPs) are a major determinant. Gene duplication is considered a major mechanism in the generation of the FP gene family and color diversity. Examining gene duplication events and subsequent evolution may improve our understanding of FP gene family diversity. RESULTS We isolated a novel FP gene family from one individual of Montipora sp., which we named monGFP (GFP gene from Montipora sp.). This gene family consists of at least four genes that produce at least six different cDNA sequences. The sequences were categorized into two types based on the length of cDNA; this difference is attributed to alternative splicing. Although the amino acid sequences were different, the emission spectra of the monGFP variants were nearly identical (518-521 nm). In addition to this gene family, we isolated ten paralogous AdiFP10 (Adi-Fluorescent protein-10 gene from Acropora digitifera) sequences from cDNA of two Acropora species, A. digitifera and A. tenuis. Based on our phylogenetic analysis, five sequences from A. digitifera and four sequences from A. tenuis appeared to be in a different cluster from AdiFP10, suggesting a new FP gene cluster. The FP sequences were likely to have been generated independently in each species or generated by gene duplications in the ancestral lineage of Acropora, followed by extensive gene conversion within each species. CONCLUSION Our results clarify a part of the diversification process of FP genes during the evolutionary history of Montipora and Acropora species. Our analyses of monGFP indicate that FPs translated from different splicing variants and gene copies have evolved without changes in the function of fluorescence, and gene copies have been evolved under purifying selection. On the other hand, AdiFP10 paralogs and other RFP genes in Acropora species may have diversified their functions. Identification of conserved and divergent modes of evolution after the duplication of FP genes may reflect variation in the biological roles of different FPs.
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Affiliation(s)
- Shiho Takahashi-Kariyazono
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Japan
| | - Yoko Satta
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Japan
| | - Yohey Terai
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Japan
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Gittins JR, D'Angelo C, Oswald F, Edwards RJ, Wiedenmann J. Fluorescent protein-mediated colour polymorphism in reef corals: multicopy genes extend the adaptation/acclimatization potential to variable light environments. Mol Ecol 2015; 24:453-65. [PMID: 25496144 PMCID: PMC4949654 DOI: 10.1111/mec.13041] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 12/05/2014] [Accepted: 12/09/2014] [Indexed: 01/22/2023]
Abstract
The genomic framework that enables corals to adjust to unfavourable conditions is crucial for coral reef survival in a rapidly changing climate. We have explored the striking intraspecific variability in the expression of coral pigments from the green fluorescent protein (GFP) family to elucidate the genomic basis for the plasticity of stress responses among reef corals. We show that multicopy genes can greatly increase the dynamic range over which corals can modulate transcript levels in response to the light environment. Using the red fluorescent protein amilFP597 in the coral Acropora millepora as a model, we demonstrate that its expression increases with light intensity, but both the minimal and maximal gene transcript levels vary markedly among colour morphs. The pigment concentration in the tissue of different morphs is strongly correlated with the number of gene copies with a particular promoter type. These findings indicate that colour polymorphism in reef corals can be caused by the environmentally regulated expression of multicopy genes. High-level expression of amilFP597 is correlated with reduced photodamage of zooxanthellae under acute light stress, supporting a photoprotective function of this pigment. The cluster of light-regulated pigment genes can enable corals to invest either in expensive high-level pigmentation, offering benefits under light stress, or to rely on low tissue pigment concentrations and use the conserved resources for other purposes, which is preferable in less light-exposed environments. The genomic framework described here allows corals to pursue different strategies to succeed in habitats with highly variable light stress levels. In summary, our results suggest that the intraspecific plasticity of reef corals' stress responses is larger than previously thought.
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Affiliation(s)
- John R. Gittins
- Coral Reef Laboratory, Ocean and Earth ScienceNational Oceanography CentreUniversity of SouthamptonWaterfront CampusSouthamptonSO14 3ZHUK
| | - Cecilia D'Angelo
- Coral Reef Laboratory, Ocean and Earth ScienceNational Oceanography CentreUniversity of SouthamptonWaterfront CampusSouthamptonSO14 3ZHUK
| | - Franz Oswald
- Department of Internal Medicine IUniversity Medical Center Ulm89081UlmGermany
| | - Richard J. Edwards
- School of Biotechnology and Biomolecular SciencesThe University of New South WalesSydneyNSW2052Australia
- Centre for Biological SciencesUniversity of SouthamptonHighfield CampusSouthamptonSO17 1BJUK
- Institute for Life SciencesUniversity of SouthamptonHighfield CampusSouthamptonSO17 1BJUK
| | - Jörg Wiedenmann
- Coral Reef Laboratory, Ocean and Earth ScienceNational Oceanography CentreUniversity of SouthamptonWaterfront CampusSouthamptonSO14 3ZHUK
- Institute for Life SciencesUniversity of SouthamptonHighfield CampusSouthamptonSO17 1BJUK
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Grover R, Ferrier-Pagès C, Maguer JF, Ezzat L, Fine M. Nitrogen fixation in the mucus of Red Sea corals. ACTA ACUST UNITED AC 2014; 217:3962-3. [PMID: 25278474 DOI: 10.1242/jeb.111591] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Scleractinian corals are essential constituents of tropical reef ecological diversity. They live in close association with diazotrophs [dinitrogen (N2)-fixing microbes], which can fix high rates of N2. Whether corals benefit from this extrinsic nitrogen source is still under debate. Until now, N2 fixation rates have been indirectly estimated using the acetylene reduction assay, which does not permit assessment of the amount of nitrogen incorporated into the different compartments of the coral holobiont. In the present study, the (15)N2 technique was applied for the first time on three Red Sea coral species. Significant (15)N enrichment was measured in particles released by corals to the surrounding seawater. N2 fixation rates were species specific and as high as 1.6-2 ng N day(-1) l(-1). However, no significant enrichment was measured in the symbiotic dinoflagellates or the coral host tissues, suggesting that corals do not benefit from diazotrophic N2 fixation.
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Affiliation(s)
- Renaud Grover
- Centre Scientifique de Monaco, Avenue Saint-Martin, MC-98000, Monaco
| | | | - Jean-François Maguer
- Laboratoire de l'Environnement Marin (LEMAR), UMR 6539, UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer, Place Nicolas Copernic, F-29280 Plouzané, France
| | - Leila Ezzat
- Centre Scientifique de Monaco, Avenue Saint-Martin, MC-98000, Monaco
| | - Maoz Fine
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel The Interuniversity Institute for Marine Science, 88000 Eilat, Israel
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Nienhaus K, Nienhaus GU. Fluorescent proteins for live-cell imaging with super-resolution. Chem Soc Rev 2014; 43:1088-106. [PMID: 24056711 DOI: 10.1039/c3cs60171d] [Citation(s) in RCA: 256] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fluorescent proteins (FPs) from the GFP family have become indispensable as marker tools for imaging live cells, tissues and entire organisms. A wide variety of these proteins have been isolated from natural sources and engineered to optimize their properties as genetically encoded markers. Here we review recent developments in this field. A special focus is placed on photoactivatable FPs, for which the fluorescence emission can be controlled by light irradiation at specific wavelengths. They enable regional optical marking in pulse-chase experiments on live cells and tissues, and they are essential marker tools for live-cell optical imaging with super-resolution. Photoconvertible FPs, which can be activated irreversibly via a photo-induced chemical reaction that either turns on their emission or changes their emission wavelength, are excellent markers for localization-based super-resolution microscopy (e.g., PALM). Patterned illumination microscopy (e.g., RESOLFT), however, requires markers that can be reversibly photoactivated many times. Photoswitchable FPs can be toggled repeatedly between a fluorescent and a non-fluorescent state by means of a light-induced chromophore isomerization coupled to a protonation reaction. We discuss the mechanistic origins of the effect and illustrate how photoswitchable FPs are employed in RESOLFT imaging. For this purpose, special FP variants with low switching fatigue have been introduced in recent years. Despite nearly two decades of FP engineering by many laboratories, there is still room for further improvement of these important markers for live cell imaging.
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Affiliation(s)
- Karin Nienhaus
- Institute of Applied Physics and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straβe 1, 76131 Karlsruhe, Germany
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Roth MS. The engine of the reef: photobiology of the coral-algal symbiosis. Front Microbiol 2014; 5:422. [PMID: 25202301 PMCID: PMC4141621 DOI: 10.3389/fmicb.2014.00422] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 07/25/2014] [Indexed: 01/09/2023] Open
Abstract
Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology, and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral-algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral-algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral-algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral-algal symbiosis, and recent advances in the field. Studies integrating physiology with the developing "omics" fields will provide new insights into the coral-algal symbiosis. Greater physiological and ecological understanding of the coral-algal symbiosis is needed for protection and conservation of coral reefs.
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Affiliation(s)
- Melissa S. Roth
- Department of Plant and Microbial Biology, University of California BerkeleyBerkeley, CA, USA
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Matsumura K, Qian PY. Larval vision contributes to gregarious settlement in barnacles: adult red fluorescence as a possible visual signal. J Exp Biol 2014; 217:743-50. [DOI: 10.1242/jeb.096990] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Gregarious settlement, an essential behavior for many barnacle species that can only reproduce by mating with a nearby barnacle, has long been thought to rely on larval ability to recognize chemical signals from conspecifics during settlement. However, the cyprid, the settlement stage larva in barnacles, has one pair of compound eyes that appear only at the late nauplius VI and cyprid stages, but the function(s) of these eyes remains unknown. Here we show that cyprids of the intertidal barnacle Balanus (=Amphibalanus) amphitrite can locate adult barnacles even in the absence of chemical cues, and prefer to settle around them probably via larval sense of vision. We also show that the cyprids can discriminate color and preferred to settle on red surfaces. Moreover, we found that shells of adult B. amphitrite emit red auto-fluorescence and the adult extracts with the fluorescence as a visual signal attracted cyprid larvae to settle around it. We propose that the perception of specific visual signals can be involved in behavior of zooplankton including marine invertebrate larvae, and that barnacle auto-fluorescence may be a specific signal involved in gregarious larval settlement.
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Affiliation(s)
- Kiyotaka Matsumura
- KAUST Global Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong
| | - Pei-Yuan Qian
- KAUST Global Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong
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Zawada DG, Mazel CH. Fluorescence-based classification of Caribbean coral reef organisms and substrates. PLoS One 2014; 9:e84570. [PMID: 24482676 PMCID: PMC3903367 DOI: 10.1371/journal.pone.0084570] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 11/25/2013] [Indexed: 11/19/2022] Open
Abstract
A diverse group of coral reef organisms, representing several phyla, possess fluorescent pigments. We investigated the potential of using the characteristic fluorescence emission spectra of these pigments to enable unsupervised, optical classification of coral reef habitats. We compiled a library of characteristic fluorescence spectra through in situ and laboratory measurements from a variety of specimens throughout the Caribbean. Because fluorescent pigments are not species-specific, the spectral library is organized in terms of 15 functional groups. We investigated the spectral separability of the functional groups in terms of the number of wavebands required to distinguish between them, using the similarity measures Spectral Angle Mapper (SAM), Spectral Information Divergence (SID), SID-SAM mixed measure, and Mahalanobis distance. This set of measures represents geometric, stochastic, joint geometric-stochastic, and statistical approaches to classifying spectra. Our hyperspectral fluorescence data were used to generate sets of 4-, 6-, and 8-waveband spectra, including random variations in relative signal amplitude, spectral peak shifts, and water-column attenuation. Each set consisted of 2 different band definitions: ‘optimally-picked’ and ‘evenly-spaced.’ The optimally-picked wavebands were chosen to coincide with as many peaks as possible in the functional group spectra. Reference libraries were formed from half of the spectra in each set and used for training purposes. Average classification accuracies ranged from 76.3% for SAM with 4 evenly-spaced wavebands to 93.8% for Mahalanobis distance with 8 evenly-spaced wavebands. The Mahalanobis distance consistently outperformed the other measures. In a second test, empirically-measured spectra were classified using the same reference libraries and the Mahalanobis distance for just the 8 evenly-spaced waveband case. Average classification accuracies were 84% and 87%, corresponding to the extremes in modeled water-column attenuation. The classification results from both tests indicate that a high degree of separability among the 15 fluorescent-spectra functional groups is possible using only a modest number of spectral bands.
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Affiliation(s)
- David G. Zawada
- United States Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida, United States of America
- * E-mail:
| | - Charles H. Mazel
- Physical Sciences Incorporated, Andover, Massachusetts, United States of America
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37
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Haas AF, Smith JE, Thompson M, Deheyn DD. Effects of reduced dissolved oxygen concentrations on physiology and fluorescence of hermatypic corals and benthic algae. PeerJ 2014; 2:e235. [PMID: 24482757 PMCID: PMC3898309 DOI: 10.7717/peerj.235] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 12/11/2013] [Indexed: 01/22/2023] Open
Abstract
While shifts from coral to seaweed dominance have become increasingly common on coral reefs and factors triggering these shifts successively identified, the primary mechanisms involved in coral-algae interactions remain unclear. Amongst various potential mechanisms, algal exudates can mediate increases in microbial activity, leading to localized hypoxic conditions which may cause coral mortality in the direct vicinity. Most of the processes likely causing such algal exudate induced coral mortality have been quantified (e.g., labile organic matter release, increased microbial metabolism, decreased dissolved oxygen availability), yet little is known about how reduced dissolved oxygen concentrations affect competitive dynamics between seaweeds and corals. The goals of this study were to investigate the effects of different levels of oxygen including hypoxic conditions on a common hermatypic coral Acropora yongei and the common green alga Bryopsis pennata. Specifically, we examined how photosynthetic oxygen production, dark and daylight adapted quantum yield, intensity and anatomical distribution of the coral innate fluorescence, and visual estimates of health varied with differing background oxygen conditions. Our results showed that the algae were significantly more tolerant to extremely low oxygen concentrations (2–4 mg L−1) than corals. Furthermore corals could tolerate reduced oxygen concentrations, but only until a given threshold determined by a combination of exposure time and concentration. Exceeding this threshold led to rapid loss of coral tissue and mortality. This study concludes that hypoxia may indeed play a significant role, or in some cases may even be the main cause, for coral tissue loss during coral-algae interaction processes.
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Affiliation(s)
- Andreas F Haas
- Department of Biology, San Diego State University , United States ; Scripps Institution of Oceanography, University of California , San Diego , United States
| | - Jennifer E Smith
- Scripps Institution of Oceanography, University of California , San Diego , United States
| | - Melissa Thompson
- Scripps Institution of Oceanography, University of California , San Diego , United States
| | - Dimitri D Deheyn
- Scripps Institution of Oceanography, University of California , San Diego , United States
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Anderson DA, Armstrong RA, Weil E. Hyperspectral sensing of disease stress in the Caribbean reef-building coral, Orbicella faveolata - perspectives for the field of coral disease monitoring. PLoS One 2013; 8:e81478. [PMID: 24324697 PMCID: PMC3852271 DOI: 10.1371/journal.pone.0081478] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 10/21/2013] [Indexed: 11/29/2022] Open
Abstract
The effectiveness of management plans developed for responding to coral disease outbreaks is limited due to the lack of rapid methods of disease diagnosis. In order to fulfill current management guidelines for responding to coral disease outbreaks, alternative methods that significantly reduce response time must be developed. Hyperspectral sensing has been used by various groups to characterize the spectral signatures unique to asymptomatic and bleached corals. The 2010 combined bleaching and Caribbean yellow band disease outbreak in Puerto Rico provided a unique opportunity to investigate the spectral signatures associated with bleached and Caribbean yellow band-diseased colonies of Orbicella faveolata for the first time. Using derivative and cluster analyses of hyperspectral reflectance data, the present study demonstrates the proof of concept that spectral signatures can be used to differentiate between coral disease states. This method enhanced predominant visual methods of diagnosis by distinguishing between different asymptomatic conditions that are identical in field observations and photographic records. The ability to identify disease-affected tissue before lesions become visible could greatly reduce response times to coral disease outbreaks in monitoring efforts. Finally, spectral signatures associated with the poorly understood Caribbean yellow band disease are presented to guide future research on the role of pigments in the etiology.
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Affiliation(s)
- David A. Anderson
- Department of Marine Sciences, University of Puerto Rico, Mayagüez, Mayagüez, Puerto Rico
- * E-mail:
| | - Roy A. Armstrong
- Department of Marine Sciences, University of Puerto Rico, Mayagüez, Mayagüez, Puerto Rico
| | - Ernesto Weil
- Department of Marine Sciences, University of Puerto Rico, Mayagüez, Mayagüez, Puerto Rico
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Hume B, D'Angelo C, Burt J, Baker AC, Riegl B, Wiedenmann J. Corals from the Persian/Arabian Gulf as models for thermotolerant reef-builders: prevalence of clade C3 Symbiodinium, host fluorescence and ex situ temperature tolerance. MARINE POLLUTION BULLETIN 2013; 72:313-22. [PMID: 23352079 DOI: 10.1016/j.marpolbul.2012.11.032] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 11/09/2012] [Accepted: 11/17/2012] [Indexed: 05/03/2023]
Abstract
Corals in the Arabian/Persian Gulf endure summer temperatures of up to 36°C, making them ideal subjects to study the mechanisms underlying thermal tolerance. Unexpectedly, we found the "generalist" Symbiodinium clade C3 to be the prevalent symbiont among seven coral species from Abu Dhabi (UAE) waters. Moreover, C3 represented the only dominant symbiont type in Porites spp. from this region. The "thermotolerant" symbionts D1a and C15 were not encountered, indicating that the association with these symbionts cannot be the sole reason for the heat tolerance of Gulf corals. The association of Porites lobata with specific symbiont types (C3 vs. C15) in samples from habitats with very different temperature regimes (Abu Dhabi vs. Fiji) remained unaffected by laboratory culture. During temperature stress experiments specimens from both locations strongly downregulated green fluorescent protein (GFP)-like pigments. However, the Abu Dhabi samples were less prone to bleaching and showed lower mortality.
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Affiliation(s)
- B Hume
- National Oceanography Centre, Southampton (NOCS), University of Southampton, European Way, SO143ZH Southampton, UK
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40
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Fluorescent epibiotic microbial community on the carapace of a Bahamian ostracod. Arch Microbiol 2013; 195:595-604. [PMID: 23861150 DOI: 10.1007/s00203-013-0911-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 06/19/2013] [Accepted: 06/26/2013] [Indexed: 10/26/2022]
Abstract
Ostracods collected from shallow coral reefs in the Bahamas were found to exhibit blue light-stimulated orange fluorescence at night. Fluorescent spectra revealed the presence of orange fluorescence with a maximum emission at ~595 nm on the carapace of these ostracods, while scanning electron microscopy revealed a morphologically diverse microbial community covering the entire carapace of these ostracods. Pyrosequencing and cyanobacterial-specific 16S rRNA sequencing reveals that this epibiont community is highly diverse and highly variable between individual ostracods. Many species of Cyanobacteria in the orders Oscillatoriales and Chroococcales, as well as other Proteobacteria and diatom chloroplast sequences, were identified using the cyanobacterial-specific primers. While no fluorescent proteins or phycoerythrin were detected in these ostracods, it is possible that the observed orange fluorescence is the result of carotenoid fluorescence from Cyanobacteria. The microbial consortium forms an epibiotic biofilm on the carapace of these ostracods whose functions are unknown.
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Responses to high seawater temperatures in zooxanthellate octocorals. PLoS One 2013; 8:e54989. [PMID: 23405104 PMCID: PMC3566138 DOI: 10.1371/journal.pone.0054989] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 12/21/2012] [Indexed: 11/19/2022] Open
Abstract
Increases in Sea Surface Temperatures (SSTs) as a result of global warming have caused reef-building scleractinian corals to bleach worldwide, a result of the loss of obligate endosymbiotic zooxanthellae. Since the 1980's, bleaching severity and frequency has increased, in some cases causing mass mortality of corals. Earlier experiments have demonstrated that zooxanthellae in scleractinian corals from three families from the Great Barrier Reef, Australia (Faviidae, Poritidae, and Acroporidae) are more sensitive to heat stress than their hosts, exhibiting differential symptoms of programmed cell death - apoptosis and necrosis. Most zooxanthellar phylotypes are dying during expulsion upon release from the host. The host corals appear to be adapted or exapted to the heat increases. We attempt to determine whether this adaptation/exaptation occurs in octocorals by examining the heat-sensitivities of zooxanthellae and their host octocoral alcyonacean soft corals - Sarcophyton ehrenbergi (Alcyoniidae), Sinularia lochmodes (Alcyoniidae), and Xenia elongata (Xeniidae), species from two different families. The soft coral holobionts were subjected to experimental seawater temperatures of 28, 30, 32, 34, and 36°C for 48 hrs. Host and zooxanthellar cells were examined for viability, apoptosis, and necrosis (in hospite and expelled) using transmission electron microscopy (TEM), fluorescent microscopy (FM), and flow cytometry (FC). As experimental temperatures increased, zooxanthellae generally exhibited apoptotic and necrotic symptoms at lower temperatures than host cells and were expelled. Responses varied species-specifically. Soft coral hosts were adapted/exapted to higher seawater temperatures than their zooxanthellae. As with the scleractinians, the zooxanthellae appear to be the limiting factor for survival of the holobiont in the groups tested, in this region. These limits have now been shown to operate in six species within five families and two orders of the Cnidaria in the western Pacific. We hypothesize that this relationship may have taxonomic implications for other obligate zooxanthellate cnidarians subject to bleaching.
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42
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Hyperspectral Distinction of Two Caribbean Shallow-Water Corals Based on Their Pigments and Corresponding Reflectance. REMOTE SENSING 2012. [DOI: 10.3390/rs4123813] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Palmer CV, Graham E, Baird AH. Immunity through early development of coral larvae. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2012; 38:395-399. [PMID: 22885633 DOI: 10.1016/j.dci.2012.07.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 07/16/2012] [Accepted: 07/22/2012] [Indexed: 06/01/2023]
Abstract
As a determinant of survival, immunity is likely to be significant in enabling coral larvae to disperse and successfully recruit, however, whether reef-building coral larvae have immune defenses is unknown. We investigated the potential presence and variation in immunity in the lecithotrophic larvae of Acropora tenuis through larval development. Enzymes indicative of tyrosinase and laccase-type melanin-synthesis were quantified, and the concentration of three coral fluorescent proteins was measured over six developmental stages; egg, embryo, motile planula, planula post-exposure to crustose coralline algae (CCA; settlement cue), settled, settled post-exposure to Symbiodinium (endosymbiont). Both types of melanin-synthesis pathways and the three fluorescent proteins were present in A. tenuis throughout development. Laccase-type activity and red fluorescence increased following exposure of planula to CCA, whereas tyrosinase-type activity and cyan fluorescence increased following settlement. No change was detected in the measured parameters following exposure to Symbiodinium. This study is the first to document coral larval immune responses and suggests the melanin-synthesis pathways have disparate roles-the laccase-type potentially non-immunological and the tyrosinase-type in cytotoxic defense. Our results indicate that corals have the potential to resist infection from the earliest life history phase.
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Affiliation(s)
- C V Palmer
- School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia.
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Wangpraseurt D, Larkum AWD, Ralph PJ, Kühl M. Light gradients and optical microniches in coral tissues. Front Microbiol 2012; 3:316. [PMID: 22969755 PMCID: PMC3427877 DOI: 10.3389/fmicb.2012.00316] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 08/13/2012] [Indexed: 11/13/2022] Open
Abstract
Light quantity and quality are among the most important factors determining the physiology and stress response of zooxanthellate corals. Yet, almost nothing is known about the light field that Symbiodinium experiences within their coral host, and the basic optical properties of coral tissue are unknown. We used scalar irradiance microprobes to characterize vertical and lateral light gradients within and across tissues of several coral species. Our results revealed the presence of steep light gradients with photosynthetically available radiation decreasing by about one order of magnitude from the tissue surface to the coral skeleton. Surface scalar irradiance was consistently higher over polyp tissue than over coenosarc tissue in faviid corals. Coral bleaching increased surface scalar irradiance by ~150% (between 500 and 700 nm) relative to a healthy coral. Photosynthesis peaked around 300 μm within the tissue, which corresponded to a zone exhibiting strongest depletion of scalar irradiance. Deeper coral tissue layers, e.g., ~1000 μm into aboral polyp tissues, harbor optical microniches, where only ~10% of the incident irradiance remains. We conclude that the optical microenvironment of corals exhibits strong lateral and vertical gradients of scalar irradiance, which are affected by both tissue and skeleton optical properties. Our results imply that zooxanthellae populations inhabit a strongly heterogeneous light environment and highlight the presence of different optical microniches in corals; an important finding for understanding the photobiology, stress response, as well as the phenotypic and genotypic plasticity of coral symbionts.
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Affiliation(s)
- Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, Department of Environmental Sciences, University of Technology Sydney Sydney, NSW, Australia
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Salih A. Screening reef corals for novel GFP-type fluorescent proteins by confocal imaging. Methods Mol Biol 2012; 872:217-33. [PMID: 22700414 DOI: 10.1007/978-1-61779-797-2_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The discovery of multicolored fluorescent proteins (FPs), in reef corals, that are close relatives of the green fluorescent protein (GFP) has led to what is now viewed as the second GFP revolution. Numerous GFP-type proteins, termed "reef FPs," have been cloned from reef organisms and many possess new colors, novel molecular characteristics, protein chemistry and many display unusual photophysical properties. Although some FPs have certain disadvantageous properties, such as the tendency to oligomerize or have slow maturation rates, reef FPs have been developed into versatile probes for cell biology and imaging applications. Screening of natural sources for novel GFP-type proteins continues to be valuable due to the need to expand the range of spectral colors, brightness, monomeric or dimeric states, faster maturation states, and photoactivity. Confocal imaging, coupled with microspectral detection, provides a rapid technique for in vivo characterization of FPs with desirable spectral and photoactive properties.
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Affiliation(s)
- Anya Salih
- Confocal Bio-Imaging Facility (CBIF), School of Science and Health, University of Western Sydney, Sydney, NSW, Australia.
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Development of gene expression markers of acute heat-light stress in reef-building corals of the genus Porites. PLoS One 2011; 6:e26914. [PMID: 22046408 PMCID: PMC3202587 DOI: 10.1371/journal.pone.0026914] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 10/06/2011] [Indexed: 12/02/2022] Open
Abstract
Coral reefs are declining worldwide due to increased incidence of climate-induced coral bleaching, which will have widespread biodiversity and economic impacts. A simple method to measure the sub-bleaching level of heat-light stress experienced by corals would greatly inform reef management practices by making it possible to assess the distribution of bleaching risks among individual reef sites. Gene expression analysis based on quantitative PCR (qPCR) can be used as a diagnostic tool to determine coral condition in situ. We evaluated the expression of 13 candidate genes during heat-light stress in a common Caribbean coral Porites astreoides, and observed strong and consistent changes in gene expression in two independent experiments. Furthermore, we found that the apparent return to baseline expression levels during a recovery phase was rapid, despite visible signs of colony bleaching. We show that the response to acute heat-light stress in P. astreoides can be monitored by measuring the difference in expression of only two genes: Hsp16 and actin. We demonstrate that this assay discriminates between corals sampled from two field sites experiencing different temperatures. We also show that the assay is applicable to an Indo-Pacific congener, P. lobata, and therefore could potentially be used to diagnose acute heat-light stress on coral reefs worldwide.
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Kenkel CD, Traylor MR, Wiedenmann J, Salih A, Matz MV. Fluorescence of coral larvae predicts their settlement response to crustose coralline algae and reflects stress. Proc Biol Sci 2011; 278:2691-7. [PMID: 21270034 PMCID: PMC3136821 DOI: 10.1098/rspb.2010.2344] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 01/06/2011] [Indexed: 11/13/2022] Open
Abstract
Multi-coloured homologues of the green fluorescent protein generate some of the most striking visual phenomena in the ocean. Despite their natural prominence in reef-building corals and widespread use in biotechnology, their biological role remains obscure. Here, we experimented with larvae of Acropora millepora to determine what can be learned about a coral larva or recruit from its fluorescent colour. We performed 12 crosses between seven A. millepora colonies representing differing fluorescence phenotypes, the larvae of which were exposed to a natural settlement cue (crustose coralline algae) and heat-light stress. Parental effects explained 18 per cent of variation in colour and 47 per cent of variation in settlement. The colour of the larval family emerged as a predictor of the settlement success: redder families were significantly less responsive to the provided settlement cue (p = 0.006). This relationship was owing to a correlation between parental effects on settlement and colour (r(2) = 0.587, p = 0.045). We also observed pronounced (16%) decline in settlement rate, as well as subtle (2%), but a statistically significant decrease in red fluorescence, as a consequence of heat-light stress exposure. Variation in settlement propensity in A. millepora is largely owing to additive genetic effects, and is thought to reflect variation in dispersal potential. Our results suggest an optical signature to discriminate between long- and short-range dispersing genotypes, as well as to evaluate stress. Further research in this direction may lead to the development of field applications to trace changes in coral life history and physiology caused by global warming.
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Affiliation(s)
- C. D. Kenkel
- Integrative Biology Section, University of Texas at Austin, Austin, TX, USA
| | - M. R. Traylor
- Integrative Biology Section, University of Texas at Austin, Austin, TX, USA
| | - J. Wiedenmann
- National Oceanography Centre, University of Southampton, Southampton, UK
| | - A. Salih
- School of Natural Sciences, University of Western Sydney, Penrith, New South Wales 1797, Australia
| | - M. V. Matz
- Integrative Biology Section, University of Texas at Austin, Austin, TX, USA
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Wiedenmann J, Gayda S, Adam V, Oswald F, Nienhaus K, Bourgeois D, Nienhaus GU. From EosFP to mIrisFP: structure-based development of advanced photoactivatable marker proteins of the GFP-family. JOURNAL OF BIOPHOTONICS 2011; 4:377-90. [PMID: 21319305 DOI: 10.1002/jbio.201000122] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 01/25/2011] [Accepted: 01/26/2011] [Indexed: 05/11/2023]
Abstract
Fluorescent proteins from the GFP family have become indispensable imaging tools in life sciences research. In recent years, a wide variety of these proteins were discovered in non-bioluminescent anthozoa. Some of them feature exciting new properties, including the possibility to change their fluorescence quantum yield and/or color by irradiating with light of specific wavelengths. These photoactivatable fluorescent proteins enable many interesting applications including pulse-chase experiments and super-resolution imaging. In this review, we discuss the development of advanced variants, using a structure-function based, molecular biophysics approach, of the photoactivatable fluorescent protein EosFP, which can be photoconverted from green to red fluorescence by ~400 nm light. A variety of applications are presented that demonstrate the versatility of these marker proteins in live-cell imaging.
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Affiliation(s)
- Jörg Wiedenmann
- National Oceanography Centre, University of Southampton, Southampton SO143ZH, UK
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Aglyamova GV, Hunt ME, Modi CK, Matz MV. Multi-colored homologs of the green fluorescent protein from hydromedusa Obelia sp. Photochem Photobiol Sci 2011; 10:1303-9. [PMID: 21614405 DOI: 10.1039/c1pp05068k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The presence of green fluorescent protein (GFP) within the bioluminescent system of Obelia (Cnidaria, Hydrozoa, Campanulariidae) was inferred shortly after the discovery of GFP in Aequorea. Despite the enormous success of Aequorea GFP as a genetically encoded fluorescent label, Obelia GFP thus far has been defeating attempts to clone it from the hydroid life cycle stage. Here, we report cloning of three GFP-like fluorescent proteins (FPs) from Obelia medusa, representing cyan, green, and yellow spectral types. Such color diversity has never been detected outside class Anthozoa, suggesting a more general function for multi-colored fluorescence in cnidarians than has been previously hypothesized. An unusual property of the new FPs is the formation of large soluble complexes of well-defined sizes and molecular weights, corresponding to up to 128 individual polypeptides. This aligns well with the earlier observation that luminescence in Obelia, unlike in Aequorea, is localized within subcellular granules, which prompts further inquiry into the self-assembly properties of the new FPs and their interactions with the photoprotein. The discovery of Obelia FPs fills the four-decade-old gap in the knowledge of cnidarian bioluminescence and provides experimental material to further investigate the details of its molecular mechanism.
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Affiliation(s)
- Galina V Aglyamova
- Integrative Biology Section, University of Texas at Austin, 1 University station C0930, Austin, Texas 78712, USA
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50
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Nienhaus GU, Nienhaus K, Wiedenmann J. Structure–Function Relationships in Fluorescent Marker Proteins of the Green Fluorescent Protein Family. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/4243_2011_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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