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Helgoe J, Davy SK, Weis VM, Rodriguez-Lanetty M. Triggers, cascades, and endpoints: connecting the dots of coral bleaching mechanisms. Biol Rev Camb Philos Soc 2024; 99:715-752. [PMID: 38217089 DOI: 10.1111/brv.13042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/15/2024]
Abstract
The intracellular coral-dinoflagellate symbiosis is the engine that underpins the success of coral reefs, one of the most diverse ecosystems on the planet. However, the breakdown of the symbiosis and the loss of the microalgal symbiont (i.e. coral bleaching) due to environmental changes are resulting in the rapid degradation of coral reefs globally. There is an urgent need to understand the cellular physiology of coral bleaching at the mechanistic level to help develop solutions to mitigate the coral reef crisis. Here, at an unprecedented scope, we present novel models that integrate putative mechanisms of coral bleaching within a common framework according to the triggers (initiators of bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, e.g. photoinhibition, unfolded protein response, nitric oxide), and endpoints (mechanisms of symbiont loss, e.g. apoptosis, necrosis, exocytosis/vomocytosis). The models are supported by direct evidence from cnidarian systems, and indirectly through comparative evolutionary analyses from non-cnidarian systems. With this approach, new putative mechanisms have been established within and between cascades initiated by different bleaching triggers. In particular, the models provide new insights into the poorly understood connections between bleaching cascades and endpoints and highlight the role of a new mechanism of symbiont loss, i.e. 'symbiolysosomal digestion', which is different from symbiophagy. This review also increases the approachability of bleaching physiology for specialists and non-specialists by mapping the vast landscape of bleaching mechanisms in an atlas of comprehensible and detailed mechanistic models. We then discuss major knowledge gaps and how future research may improve the understanding of the connections between the diverse cascade of cellular pathways and the mechanisms of symbiont loss (endpoints).
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Affiliation(s)
- Joshua Helgoe
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 2701 SW Campus Way, 2403 Cordley Hall, Corvallis, OR, USA
| | - Mauricio Rodriguez-Lanetty
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
- Department of Biological Sciences, Biomolecular Sciences Institute, Florida International University, 11200 SW 8th Street, Miami, FL, USA
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2
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Xiao Y, Gao L, Li Z. Unique high-temperature tolerance mechanisms of zoochlorellae Symbiochlorum hainanensis derived from scleractinian coral Porites lutea. mBio 2024; 15:e0278023. [PMID: 38385710 DOI: 10.1128/mbio.02780-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024] Open
Abstract
Global warming is a key issue that causes coral bleaching mainly because of the thermosensitivity of zooxanthellae. Compared with the well-studied zooxanthellae Symbiodiniaceae in coral holobionts, we rarely know about other coral symbiotic algae, let alone their thermal tolerance. In this study, a zoochlorellae, Symbiochlorum hainanensis, isolated from the coral Porites lutea, was proven to have a threshold temperature of 38°C. Meanwhile, unique high-temperature tolerance mechanisms were suggested by integrated transcriptomics and real-time quantitative PCR, physiological and biochemical analyses, and electron microscopy observation. Under heat stress, S. hainanensis shared some similar response strategies with zooxanthellae Effrenium sp., such as increased ascorbate peroxidase, glutathione peroxidase, superoxide dismutase activities and chlorophyll a, thiamine, and thiamine phosphate contents. In particular, more chloroplast internal layered structure, increased CAT activity, enhanced selenate reduction, and thylakoid assembly pathways were highlighted for S. hainanensis's high-temperature tolerance. Notably, it is the first time to reveal a whole selenate reduction pathway from SeO42- to Se2- and its contribution to the high-temperature tolerance of S. hainanensis. These unique mechanisms, including antioxidation and maintaining photosynthesis homeostasis, efficiently ensure the high-temperature tolerance of S. hainanensis than Effrenium sp. Compared with the thermosensitivity of coral symbiotic zooxanthellae Symbiodiniaceae, this study provides novel insights into the high-temperature tolerance mechanisms of coral symbiotic zoochlorellae S. hainanensis, which will contribute to corals' survival in the warming oceans caused by global climate change. IMPORTANCE The increasing ocean temperature above 31°C-32°C might trigger a breakdown of the coral-Symbiodiniaceae symbioses or coral bleaching because of the thermosensitivity of Symbiodiniaceae; therefore, the exploration of alternative coral symbiotic algae with high-temperature tolerance is important for the corals' protection under warming oceans. This study proves that zoochlorellae Symbiochlorum hainanensis can tolerate 38°C, which is the highest temperature tolerance known for coral symbiotic algae to date, with unique high-temperature tolerance mechanisms. Particularly, for the first time, an internal selenium antioxidant mechanism of coral symbiotic S. hainanensis to high temperature was suggested.
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Affiliation(s)
- Yilin Xiao
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Luyao Gao
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhiyong Li
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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3
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Han T, Liao X, Guo Z, Chen JY, He C, Lu Z. Deciphering temporal gene expression dynamics in multiple coral species exposed to heat stress: Implications for predicting resilience. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169021. [PMID: 38061659 DOI: 10.1016/j.scitotenv.2023.169021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/21/2023] [Accepted: 11/29/2023] [Indexed: 01/18/2024]
Abstract
Coral reefs are facing unprecedented threats due to global climate change, particularly elevated sea surface temperatures causing coral bleaching. Understanding coral responses at the molecular level is crucial for predicting their resilience and developing effective conservation strategies. In this study, we conducted a comprehensive gene expression analysis of four coral species to investigate their long-term molecular response to heat stress. We identified distinct gene expression patterns among the coral species, with laminar corals exhibiting a stronger response compared to branching corals. Heat shock proteins (HSPs) showed an overall decreasing expression trend, indicating the high energy cost associated with sustaining elevated HSP levels during prolonged heat stress. Peroxidases and oxidoreductases involved in oxidative stress response demonstrated significant upregulation, highlighting their role in maintaining cellular redox balance. Differential expression of genes related to calcium homeostasis and bioluminescence suggested distinct mechanisms for coping with heat stress among the coral species. Furthermore, the impact of heat stress on coral biomineralization varied, with downregulation of carbonic anhydrase and skeletal organic matrix proteins indicating reduced capacity for biomineralization in the later stages of heat stress. Our findings provide insights into the molecular mechanisms underlying coral responses to heat stress and highlight the importance of considering species-specific responses in assessing coral resilience. The identified biomarkers may serve as indicators of heat stress and contribute to early detection of coral bleaching events. These findings contribute to our understanding of coral resilience and provide a basis for future research aimed at enhancing coral survival in the face of climate change.
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Affiliation(s)
- Tingyu Han
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Xin Liao
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Beihai 536000, China
| | - Zhuojun Guo
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - J-Y Chen
- Nanjing Institute of Paleontology and Geology, Nanjing 210008, China
| | - Chunpeng He
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
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4
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Rosic N, Thornber C. Biotechnological Potential of Macroalgae during Seasonal Blooms for Sustainable Production of UV-Absorbing Compounds. Mar Drugs 2023; 21:633. [PMID: 38132954 PMCID: PMC10744652 DOI: 10.3390/md21120633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
Marine macroalgae (seaweeds) are important primary global producers, with a wide distribution in oceans around the world from polar to tropical regions. Most of these species are exposed to variable environmental conditions, such as abiotic (e.g., light irradiance, temperature variations, nutrient availability, salinity levels) and biotic factors (e.g., grazing and pathogen exposure). As a result, macroalgae developed numerous important strategies to increase their adaptability, including synthesizing secondary metabolites, which have promising biotechnological applications, such as UV-absorbing Mycosporine-Like Amino Acid (MAAs). MAAs are small, water-soluble, UV-absorbing compounds that are commonly found in many marine organisms and are characterized by promising antioxidative, anti-inflammatory and photoprotective properties. However, the widespread use of MAAs by humans is often restricted by their limited bioavailability, limited success in heterologous expression systems, and low quantities recovered from the natural environment. In contrast, bloom-forming macroalgal species from all three major macroalgal clades (Chlorophyta, Phaeophyceae, and Rhodophyta) occasionally form algal blooms, resulting in a rapid increase in algal abundance and high biomass production. This review focuses on the bloom-forming species capable of producing pharmacologically important compounds, including MAAs, and the application of proteomics in facilitating macroalgal use in overcoming current environmental and biotechnological challenges.
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Affiliation(s)
- Nedeljka Rosic
- Faculty of Health, Southern Cross University, Gold Coast, QLD 4225, Australia
- Marine Ecology Research Centre, Southern Cross University, Lismore, NSW 2480, Australia
| | - Carol Thornber
- Department of Natural Resources Science, University of Rhode Island, 120 Flagg Road, Kingston, RI 02881, USA;
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Ishibashi H, Minamide S, Takeuchi I. Expression analyses of stress-responsive genes in the hermatypic coral Acropora tenuis and its symbiotic dinoflagellates after exposure to the herbicide Diuron. MARINE LIFE SCIENCE & TECHNOLOGY 2023; 5:289-299. [PMID: 37637253 PMCID: PMC10449730 DOI: 10.1007/s42995-023-00183-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 05/31/2023] [Indexed: 08/29/2023]
Abstract
Diuron is one of the most frequently applied herbicides in sugarcane farming in southern Japan, and Australia. In addition, it is used as a booster substance in copper-based antifouling paints. Due to these various uses, Diuron is released into the marine environment; however, little information is available on gene expression in corals and their symbiotic algae exposed to Diuron. We investigated the effects of Diuron on stress-responsive gene expression in the hermatypic coral Acropora tenuis and its symbiotic dinoflagellates. After seven days of exposure to 1 µg/L and 10 µg/L Diuron, no significant changes in the body colour of corals were observed. However, quantitative reverse transcription-polymerase chain reaction analyses revealed that the expression levels of stress-responsive genes, such as heat shock protein 90 (HSP90), HSP70, and calreticulin (CALR), were significantly downregulated in corals exposed to 10 µg/L of Diuron for seven days. Moreover, aquaglyceroporin was significantly downregulated in corals exposed to environmentally relevant concentrations of 1 µg/L Diuron. In contrast, no such effects were observed on the expression levels of other stress-responsive genes, such as oxidative stress-responsive proteins, methionine adenosyltransferase, and green/red fluorescent proteins. Diuron exposure had no significant effect on the expression levels of HSP90, HSP70, or HSP40 in the symbiotic dinoflagellates. These results suggest that stress-responsive genes, such as HSPs, respond differently to Diuron in corals and their symbiotic dinoflagellates and that A. tenuis HSPs and CALRs may be useful molecular biomarkers for predicting stress responses induced by the herbicide Diuron. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-023-00183-0.
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Affiliation(s)
- Hiroshi Ishibashi
- Graduate School of Agriculture, Ehime University, Matsuyama, Ehime 790-8566 Japan
- Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, Matsuyama, Ehime 790-8566 Japan
| | - Seigo Minamide
- Graduate School of Agriculture, Ehime University, Matsuyama, Ehime 790-8566 Japan
| | - Ichiro Takeuchi
- Graduate School of Agriculture, Ehime University, Matsuyama, Ehime 790-8566 Japan
- Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, Matsuyama, Ehime 790-8566 Japan
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6
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Beavers KM, Van Buren EW, Rossin AM, Emery MA, Veglia AJ, Karrick CE, MacKnight NJ, Dimos BA, Meiling SS, Smith TB, Apprill A, Muller EM, Holstein DM, Correa AMS, Brandt ME, Mydlarz LD. Stony coral tissue loss disease induces transcriptional signatures of in situ degradation of dysfunctional Symbiodiniaceae. Nat Commun 2023; 14:2915. [PMID: 37217477 DOI: 10.1038/s41467-023-38612-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 05/10/2023] [Indexed: 05/24/2023] Open
Abstract
Stony coral tissue loss disease (SCTLD), one of the most pervasive and virulent coral diseases on record, affects over 22 species of reef-building coral and is decimating reefs throughout the Caribbean. To understand how different coral species and their algal symbionts (family Symbiodiniaceae) respond to this disease, we examine the gene expression profiles of colonies of five species of coral from a SCTLD transmission experiment. The included species vary in their purported susceptibilities to SCTLD, and we use this to inform gene expression analyses of both the coral animal and their Symbiodiniaceae. We identify orthologous coral genes exhibiting lineage-specific differences in expression that correlate to disease susceptibility, as well as genes that are differentially expressed in all coral species in response to SCTLD infection. We find that SCTLD infection induces increased expression of rab7, an established marker of in situ degradation of dysfunctional Symbiodiniaceae, in all coral species accompanied by genus-level shifts in Symbiodiniaceae photosystem and metabolism gene expression. Overall, our results indicate that SCTLD infection induces symbiophagy across coral species and that the severity of disease is influenced by Symbiodiniaceae identity.
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Affiliation(s)
- Kelsey M Beavers
- Biology Department, University of Texas at Arlington, Arlington, TX, USA
| | - Emily W Van Buren
- Biology Department, University of Texas at Arlington, Arlington, TX, USA
| | - Ashley M Rossin
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Madison A Emery
- Biology Department, University of Texas at Arlington, Arlington, TX, USA
| | - Alex J Veglia
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Carly E Karrick
- Department of BioSciences, Rice University, Houston, TX, USA
| | | | - Bradford A Dimos
- Biology Department, University of Texas at Arlington, Arlington, TX, USA
| | - Sonora S Meiling
- Center for Marine and Environmental Studies, University of the Virgin Islands, St. Thomas, USVI, USA
| | - Tyler B Smith
- Center for Marine and Environmental Studies, University of the Virgin Islands, St. Thomas, USVI, USA
| | - Amy Apprill
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | | | - Daniel M Holstein
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA
| | | | - Marilyn E Brandt
- Center for Marine and Environmental Studies, University of the Virgin Islands, St. Thomas, USVI, USA
| | - Laura D Mydlarz
- Biology Department, University of Texas at Arlington, Arlington, TX, USA.
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7
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Oakley CA, Newson GI, Peng L, Davy SK. The Symbiodinium Proteome Response to Thermal and Nutrient Stresses. PLANT & CELL PHYSIOLOGY 2023; 64:433-447. [PMID: 36565060 PMCID: PMC10109209 DOI: 10.1093/pcp/pcac175] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/18/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Coral bleaching is primarily caused by high sea surface temperatures, and nutrient enrichment of reefs is associated with lower resilience to thermal stress and ecological degradation. Excess inorganic nitrogen relative to phosphate has been proposed to sensitize corals to thermal bleaching. We assessed the physiological and proteomic responses of cultures of the dinoflagellate coral symbiont Symbiodinium microadriaticum to elevated temperature under low-nutrient, high-nutrient and phosphate-limited conditions. Elevated temperature induced reductions of many chloroplast proteins, particularly the light-harvesting complexes, and simultaneously increased the abundance of many chaperone proteins. Proteomes were similar when the N:P ratio was near the Redfield ratio, regardless of absolute N and P concentrations, but were strongly affected by phosphate limitation. Very high N:P inhibited Symbiodinium cell division while increasing the abundance of chloroplast proteins. The proteome response to phosphate limitation was greater than that to elevated temperature, as measured by the number of differentially abundant proteins. Increased physiological sensitivity to high temperatures under high nutrients or imbalanced N:P ratios was not apparent; however, oxidative stress response proteins were enriched among proteins responding to thermal stress under imbalanced N:P ratios. These data provide a detailed catalog of the effects of high temperatures and nutrients on a coral symbiont proteome.
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Affiliation(s)
| | - Grace I Newson
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - Lifeng Peng
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
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8
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Hernández Elizárraga VH, Olguín-López N, Hernández-Matehuala R, Caballero-Pérez J, Ibarra-Alvarado C, Rojas-Molina A. Transcriptomic differences between bleached and unbleached hydrozoan Millepora complanata following the 2015-2016 ENSO in the Mexican Caribbean. PeerJ 2023; 11:e14626. [PMID: 36691486 PMCID: PMC9864129 DOI: 10.7717/peerj.14626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 12/02/2022] [Indexed: 01/19/2023] Open
Abstract
The 2015-2016 El Niño-southern oscillation or "ENSO" caused many M. complanata colonies that live in the Mexican Caribbean to experience extensive bleaching. The purpose of this work was to analyze the effect of bleaching on the cellular response of M. complanata, employing a transcriptomic approach with RNA-seq. As expected, bleached specimens contained a significantly lower chlorophyll content than unbleached hydrocorals. The presence of algae of the genera Durusdinium and Cladocopium was only found in tissues of unbleached M. complanata, which could be associated to the greater resistance that these colonies exhibited during bleaching. We found that 299 genes were differentially expressed in M. complanata bleached colonies following the 2015-2016 ENSO in the Mexican Caribbean. The differential expression analysis of bleached M. complanata specimens evidenced enriched terms for functional categories, such as ribosome, RNA polymerase and basal transcription factors, chaperone, oxidoreductase, among others. Our results suggest that the heat-shock response mechanisms displayed by M. complanata include: an up-regulation of endogenous antioxidant defenses; a higher expression of heat stress response genes; up-regulation of transcription-related genes, higher expression of genes associated to transport processes, inter alia. This study constitutes the first differential gene expression analysis of the molecular response of a reef-forming hydrozoan during bleaching.
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Affiliation(s)
| | - Norma Olguín-López
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, México
| | - Rosalina Hernández-Matehuala
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, México
| | | | - César Ibarra-Alvarado
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, México
| | - Alejandra Rojas-Molina
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, México
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9
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Multi-Omics Profiling Reveals Resource Allocation and Acclimation Strategies to Temperature Changes in a Marine Dinoflagellate. Appl Environ Microbiol 2022; 88:e0121322. [PMID: 35976001 PMCID: PMC9469709 DOI: 10.1128/aem.01213-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Temperature is a critical environmental factor that affects the cell growth of dinoflagellates and bloom formation. To date, the molecular mechanisms underlying the physiological responses to temperature variations are poorly understood. Here, we applied quantitative proteomic and untargeted metabolomic approaches to investigate protein and metabolite expression profiles of a bloom-forming dinoflagellate Prorocentrum shikokuense at different temperatures. Of the four temperatures (19, 22, 25, and 28°C) investigated, P. shikokuense at 25°C exhibited the maximal cell growth rate and maximum quantum efficiency of photosystem II (Fv/Fm) value. The levels of particulate organic carbon (POC) and nitrogen (PON) decreased with increasing temperature, while the POC/PON ratio increased and peaked at 25°C. Proteomic analysis showed proteins related to photoreaction, light harvesting, and protein homeostasis were highly expressed at 28°C when cells were under moderate heat stress. Metabolomic analysis further confirmed reallocated amino acids and soluble sugars at this temperature. Both omic analyses showed glutathione metabolism that scavenges the excess reactive oxygen species, and transcription and lipid biosynthesis that compensate for the low translation efficiency and plasma membrane fluidity were largely upregulated at suboptimal temperature. Higher accumulations of glutathione, glutarate semialdehyde, and 5-KETE at 19°C implied their important roles in low-temperature acclimation. The strikingly active nitrate reduction and nitrogen flux into asparagine, glutamine, and aspartic acid at 19°C indicated these three amino acids may serve as nitrogen storage pools and help cells cope with low temperature. Our study provides insights into the effects of temperature on dinoflagellate resource allocation and advances our knowledge of dinoflagellate bloom formation in marine environments. IMPORTANCE Marine phytoplankton is one of the most important nodes in global biogeochemical cycle. Deciphering temperature-associated marine phytoplankton cell stoichiometric changes and the underlying molecular mechanisms are therefore of great ecological concerns. However, knowledge of how phytoplankton adjust the cell stoichiometry to sustain growth under temperature changes is still lacking. This study investigates the variations of protein and metabolite profiles in a marine dinoflagellate across temperatures at which the field blooms usually occur and highlights the temperature-dependent molecular traits and key metabolites that may be associated with rapid cell growth and temperature stress acclimation.
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10
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Al-Hammady MA, Silva TF, Hussein HN, Saxena G, Modolo LV, Belasy MB, Westphal H, Farag MA. How do algae endosymbionts mediate for their coral host fitness under heat stress? A comprehensive mechanistic overview. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Nitschke MR, Rosset SL, Oakley CA, Gardner SG, Camp EF, Suggett DJ, Davy SK. The diversity and ecology of Symbiodiniaceae: A traits-based review. ADVANCES IN MARINE BIOLOGY 2022; 92:55-127. [PMID: 36208879 DOI: 10.1016/bs.amb.2022.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Among the most successful microeukaryotes to form mutualisms with animals are dinoflagellates in the family Symbiodiniaceae. These photosynthetic symbioses drive significant primary production and are responsible for the formation of coral reef ecosystems but are particularly sensitive when environmental conditions become extreme. Annual episodes of widespread coral bleaching (disassociation of the mutualistic partnership) and mortality are forecasted from the year 2060 under current trends of ocean warming. However, host cnidarians and dinoflagellate symbionts display exceptional genetic and functional diversity, and meaningful predictions of the future that embrace this biological complexity are difficult to make. A recent move to trait-based biology (and an understanding of how traits are shaped by the environment) has been adopted to move past this problem. The aim of this review is to: (1) provide an overview of the major cnidarian lineages that are symbiotic with Symbiodiniaceae; (2) summarise the symbiodiniacean genera associated with cnidarians with reference to recent changes in taxonomy and systematics; (3) examine the knowledge gaps in Symbiodiniaceae life history from a trait-based perspective; (4) review Symbiodiniaceae trait variation along three abiotic gradients (light, nutrients, and temperature); and (5) provide recommendations for future research of Symbiodiniaceae traits. We anticipate that a detailed understanding of traits will further reveal basic knowledge of the evolution and functional diversity of these mutualisms, as well as enhance future efforts to model stability and change in ecosystems dependent on cnidarian-dinoflagellate organisms.
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Affiliation(s)
- Matthew R Nitschke
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand; Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia.
| | - Sabrina L Rosset
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Stephanie G Gardner
- Center for Marine Science and Innovation, University of New South Wales Sydney, Kensington, NSW, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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12
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Rosic N. Genome Mining as an Alternative Way for Screening the Marine Organisms for Their Potential to Produce UV-Absorbing Mycosporine-like Amino Acid. Mar Drugs 2022; 20:md20080478. [PMID: 35892946 PMCID: PMC9394291 DOI: 10.3390/md20080478] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/21/2022] [Accepted: 07/21/2022] [Indexed: 12/10/2022] Open
Abstract
Mycosporine-like amino acids (MAAs) are small molecules with robust ultraviolet (UV)-absorbing capacities and a huge potential to be used as an environmentally friendly natural sunscreen. MAAs, temperature, and light-stable compounds demonstrate powerful photoprotective capacities and the ability to capture light in the UV-A and UV-B ranges without the production of damaging free radicals. The biotechnological uses of these secondary metabolites have been often limited by the small quantities restored from natural resources, variation in MAA expression profiles, and limited success in heterologous expression systems. Overcoming these obstacles requires a better understanding of MAA biosynthesis and its regulatory processes. MAAs are produced to a certain extent via a four-enzyme pathway, including genes encoding enzymes dehydroquinate synthase, enzyme O-methyltransferase, adenosine triphosphate grasp, and a nonribosomal peptide synthetase. However, there are substantial genetic discrepancies in the MAA genetic pathway in different species, suggesting further complexity of this pathway that is yet to be fully explored. In recent years, the application of genome-mining approaches allowed the identification of biosynthetic gene clusters (BGCs) that resulted in the discovery of many new compounds from unconventional sources. This review explores the use of novel genomics tools for linking BGCs and secondary metabolites based on the available omics data, including MAAs, and evaluates the potential of using novel genome-mining tools to reveal a cryptic potential for new bioproduct screening approaches and unrevealing new MAA producers.
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Affiliation(s)
- Nedeljka Rosic
- Faculty of Health, Southern Cross University, Gold Coast, QLD 4225, Australia;
- Marine Ecology Research Centre, Southern Cross University, Lismore, NSW 2480, Australia
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13
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Endosymbiotic Symbiodinium clades occurrence and influence on coral growth and resilience during stress. Symbiosis 2022. [DOI: 10.1007/s13199-022-00846-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Yuyama I, Higuchi T, Mezaki T, Tashiro H, Ikeo K. Metatranscriptomic Analysis of Corals Inoculated With Tolerant and Non-Tolerant Symbiont Exposed to High Temperature and Light Stress. Front Physiol 2022; 13:806171. [PMID: 35480050 PMCID: PMC9037784 DOI: 10.3389/fphys.2022.806171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/17/2022] [Indexed: 11/13/2022] Open
Abstract
Algal symbionts of corals can influence host stress resistance; for example, in the Pacific Ocean, whereas Cladocopium (C-type) is generally dominant in corals, Durusdinium (D-type) is found in more heat-resistant corals. Thus, the presence of D-type symbiont likely increases coral heat tolerance, and this symbiotic relationship potentially provides a hint to increase the stress tolerance of coral–algal symbioses. In this study, transcriptome profiles of Cladocopium- and Durusdinium-harboring Acropora solitaryensis (C-coral and D-coral, respectively) and algal photosystem functioning (Fv/Fm) under bleaching conditions (high temperature and light stress) were compared. Stress treatment caused algal photoinhibition that the Fv/Fm value of Symbiodiniaceae was immediately reduced. The transcriptome analysis of corals revealed that genes involved in the following processes were detected: endoplasmic reticulum (ER) stress, mitophagy, apoptosis, endocytosis, metabolic processes (acetyl-CoA, chitin metabolic processes, etc.), and the PI3K-AKT pathway were upregulated, while DNA replication and the calcium signaling pathway were downregulated in both C- and D-corals. These results suggest that unrepaired DNA and protein damages were accumulated in corals under high temperature and light stress. Additionally, some differentially expressed genes (DEGs) were specific to C- or D-corals, which includes genes involved in transient receptor potential (TRP) channels and vitamin B metabolic processes. Algal transcriptome analysis showed the increased expression of gene encoding photosystem and molecular chaperone especially in D-type symbiont. The transcriptome data imply a possible difference in the stress reactions on C-type and D-type symbionts. The results reveal the basic process of coral heat/light stress response and symbiont-type-specific coral transcriptional responses, which provides a perspective on the mechanisms that cause differences in coral stress tolerance.
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Affiliation(s)
- Ikuko Yuyama
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
- *Correspondence: Ikuko Yuyama
| | - Tomihiko Higuchi
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
| | - Takuma Mezaki
- Kuroshio Biological Research Foundation, Otsuki, Japan
| | - Hisako Tashiro
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Japan
| | - Kazuho Ikeo
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Japan
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15
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Yusof NA, Masnoddin M, Charles J, Thien YQ, Nasib FN, Wong CMVL, Abdul Murad AM, Mahadi NM, Bharudin I. Can heat shock protein 70 (HSP70) serve as biomarkers in Antarctica for future ocean acidification, warming and salinity stress? Polar Biol 2022. [DOI: 10.1007/s00300-022-03006-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AbstractThe Antarctic Peninsula is one of the fastest-warming places on Earth. Elevated sea water temperatures cause glacier and sea ice melting. When icebergs melt into the ocean, it “freshens” the saltwater around them, reducing its salinity. The oceans absorb excess anthropogenic carbon dioxide (CO2) causing decline in ocean pH, a process known as ocean acidification. Many marine organisms are specifically affected by ocean warming, freshening and acidification. Due to the sensitivity of Antarctica to global warming, using biomarkers is the best way for scientists to predict more accurately future climate change and provide useful information or ecological risk assessments. The 70-kilodalton (kDa) heat shock protein (HSP70) chaperones have been used as biomarkers of stress in temperate and tropical environments. The induction of the HSP70 genes (Hsp70) that alter intracellular proteins in living organisms is a signal triggered by environmental temperature changes. Induction of Hsp70 has been observed both in eukaryotes and in prokaryotes as response to environmental stressors including increased and decreased temperature, salinity, pH and the combined effects of changes in temperature, acidification and salinity stress. Generally, HSP70s play critical roles in numerous complex processes of metabolism; their synthesis can usually be increased or decreased during stressful conditions. However, there is a question as to whether HSP70s may serve as excellent biomarkers in the Antarctic considering the long residence time of Antarctic organisms in a cold polar environment which appears to have greatly modified the response of heat responding transcriptional systems. This review provides insight into the vital roles of HSP70 that make them ideal candidates as biomarkers for identifying resistance and resilience in response to abiotic stressors associated with climate change, which are the effects of ocean warming, freshening and acidification in Antarctic organisms.
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16
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Reichert J, Tirpitz V, Anand R, Bach K, Knopp J, Schubert P, Wilke T, Ziegler M. Interactive effects of microplastic pollution and heat stress on reef-building corals. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 290:118010. [PMID: 34488160 DOI: 10.1016/j.envpol.2021.118010] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/30/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
Plastic pollution is an emerging stressor that increases pressure on ecosystems such as coral reefs that are already challenged by climate change. However, the effects of plastic pollution in combination with global warming are largely unknown. Thus, the goal of this study was to determine the cumulative effects of microplastic pollution with that of global warming on reef-building coral species and to compare the severity of both stressors. For this, we conducted a series of three controlled laboratory experiments and exposed a broad range of coral species (Acropora muricata, Montipora digitata, Porites lutea, Pocillopora verrucosa, and Stylophora pistillata) to microplastic particles in a range of concentrations (2.5-2500 particles L-1) and mixtures (from different industrial sectors) at ambient temperatures and in combination with heat stress. We show that microplastic can occasionally have both aggravating or mitigating effects on the corals' thermal tolerance. In comparison to heat stress, however, microplastic constitutes a minor stressor. While heat stress led to decreased photosynthetic efficiency of algal symbionts, and increased bleaching, tissue necrosis, and mortality, treatment with microplastic particles had only minor effects on the physiology and health of the tested coral species at ambient temperatures. These findings underline that while efforts to reduce plastic pollution should continue, they should not replace more urgent efforts to halt global warming, which are immediately needed to preserve remaining coral reef ecosystems.
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Affiliation(s)
- Jessica Reichert
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany
| | - Vanessa Tirpitz
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany
| | - Rajshree Anand
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany
| | - Katharina Bach
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany
| | - Jonas Knopp
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany
| | - Patrick Schubert
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany
| | - Thomas Wilke
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany
| | - Maren Ziegler
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany.
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17
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Rivera HE, Davies SW. Symbiosis maintenance in the facultative coral, Oculina arbuscula, relies on nitrogen cycling, cell cycle modulation, and immunity. Sci Rep 2021; 11:21226. [PMID: 34707162 PMCID: PMC8551165 DOI: 10.1038/s41598-021-00697-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/11/2021] [Indexed: 12/24/2022] Open
Abstract
Symbiosis with unicellular algae in the family Symbiodiniaceae is common across tropical marine invertebrates. Reef-building corals offer a clear example of cellular dysfunction leading to a dysbiosis that disrupts entire ecosystems in a process termed coral bleaching. Due to their obligate symbiotic relationship, understanding the molecular underpinnings that sustain this symbiosis in tropical reef-building corals is challenging, as any aposymbiotic state is inherently coupled with severe physiological stress. Here, we leverage the subtropical, facultatively symbiotic and calcifying coral Oculina arbuscula to investigate gene expression differences between aposymbiotic and symbiotic branches within the same colonies under baseline conditions. We further compare gene ontology (GO) and KOG enrichment in gene expression patterns from O. arbuscula with prior work in the sea anemone Exaiptasia pallida (Aiptasia) and the salamander Ambystoma maculatum-both of which exhibit endophotosymbiosis with unicellular algae. We identify nitrogen cycling, cell cycle control, and immune responses as key pathways involved in the maintenance of symbiosis under baseline conditions. Understanding the mechanisms that sustain a healthy symbiosis between corals and Symbiodiniaceae algae is of urgent importance given the vulnerability of these partnerships to changing environmental conditions and their role in the continued functioning of critical and highly diverse marine ecosystems.
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Affiliation(s)
- H E Rivera
- Department of Biology, Boston University, Boston, MA, USA.
| | - S W Davies
- Department of Biology, Boston University, Boston, MA, USA.
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18
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Expression Patterns of the Heat Shock Protein 90 (Hsp90) Gene Suggest Its Possible Involvement in Maintaining the Dormancy of Dinoflagellate Resting Cysts. Int J Mol Sci 2021; 22:ijms222011054. [PMID: 34681714 PMCID: PMC8538777 DOI: 10.3390/ijms222011054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/05/2021] [Accepted: 10/08/2021] [Indexed: 11/21/2022] Open
Abstract
Heat shock protein 90 (Hsp90) is a highly conserved molecular chaperone functioning in cellular structural folding and conformational integrity maintenance and thus plays vital roles in a variety of biological processes. However, many aspects of these functions and processes remain to be fully elucidated, particularly for non-model organisms. Dinoflagellates are a group of eukaryotes that are exceedingly important in primary production and are responsible for the most harmful algal blooms (HABs) in aquatic ecosystems. The success of dinoflagellates in dominating the plankton community is undoubtedly pertinent to their remarkable adaptive strategies, characteristic of resting cyst production and broad tolerance to stresses of temperature and others. Therefore, this study was conducted to examine the putative roles of Hsp90 in the acclimation to temperature stress and life stage alterations of dinoflagellates. Firstly, we isolated the full-length cDNA of an Hsp90 gene (StHsp90) via RACE from the cosmopolitan HAB species Scrippsiella trochoidea and tracked its transcriptions in response to varied scenarios via real-time qPCR. The results indicated that StHsp90 displayed significant mRNA augment patterns, escalating during 180-min treatments, when the cells were exposed to elevated and lowered temperatures. Secondly, we observed prominently elevated StHsp90 transcriptions in the cysts that were stored at the cold and dark conditions compared to those in newly formed resting cysts and vegetative cells. Finally, and perhaps most importantly, we identified 29 entries of Hsp90-encoding genes with complete coding regions from a dinoflagellate-specific environmental cDNA library generated from marine sediment assemblages. The observed active transcription of these genes in sediment-buried resting cysts was fully supported by the qPCR results for the cold-stored resting cysts of S. trochoidea. Hsp90s expressions in both laboratory-raised and field-collected cysts collectively highlighted the possible involvement and engagement of Hsp90 chaperones in the resting stage persistence of dinoflagellates.
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19
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Broad scale proteomic analysis of heat-destabilised symbiosis in the hard coral Acropora millepora. Sci Rep 2021; 11:19061. [PMID: 34561509 PMCID: PMC8463592 DOI: 10.1038/s41598-021-98548-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 09/07/2021] [Indexed: 02/07/2023] Open
Abstract
Coral reefs across the globe are threatened by warming oceans. The last few years have seen the worst mass coral bleaching events recorded, with more than one quarter of all reefs irreversibly impacted. Considering the widespread devastation, we need to increase our efforts to understanding the physiological and metabolic shifts underlying the breakdown of this important symbiotic ecosystem. Here, we investigated the proteome (PRIDE accession # PXD011668) of both host and symbionts of the reef-building coral Acropora millepora exposed to ambient (~ 28 °C) and elevated temperature (~ 32 °C for 2 days, following a five-day incremental increase) and explored associated biomolecular changes in the symbiont, with the aim of gaining new insights into the mechanisms underpinning the collapse of the coral symbiosis. We identified 1,230 unique proteins (774 host and 456 symbiont) in the control and thermally stressed corals, of which 107 significantly increased and 125 decreased in abundance under elevated temperature relative to the control. Proteins involved in oxidative stress and proteolysis constituted 29% of the host proteins that increased in abundance, with evidence of impairment to endoplasmic reticulum and cytoskeletal regulation proteins. In the symbiont, we detected a decrease in proteins responsible for photosynthesis and energy production (33% of proteins decreased in abundance), yet minimal signs of oxidative stress or proteolysis. Lipid stores increased > twofold despite reduction in photosynthesis, suggesting reduced translocation of carbon to the host. There were significant changes in proteins related to symbiotic state, including proteins linked to nitrogen metabolism in the host and the V-ATPase (-0.6 fold change) known to control symbiosome acidity. These results highlight key differences in host and symbiont proteomic adjustments under elevated temperature and identify two key proteins directly involved in bilateral nutrient exchange as potential indicators of symbiosis breakdown.
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20
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Curran A, Barnard S. What is the role of zooxanthellae during coral bleaching? Review of zooxanthellae and their response to environmental stress. S AFR J SCI 2021. [DOI: 10.17159/sajs.2021/8369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Coral reefs are diverse and productive but sensitive ecosystems. Due to the impact of climate change, these organisms are in danger of dying out, mainly through the process of coral bleaching, which is the process by which zooxanthellae (algal endosymbionts) are expelled from their respective coral hosts, causing the coral to lose colour and become white. Coral bleaching has been linked to increases in sea surface temperatures as well as an increase in light intensity. We reviewed the different zooxanthellae taxa and their ecological traits, as well as the information available on the protective mechanisms present in zooxanthellae cells when they experience environmental stress conditions, such as temperature fluctuations, specifically concentrating on heat shock proteins and their response to antioxidant stress. The eight clades (A–H) previously recognised were reorganised into seven existing genera. Different zooxanthellae taxa exhibit different ecological traits such as their photosynthetic stress responses to light and temperature. Zooxanthellae have the ability to regulate the number and type of heat shock proteins (Hsps) they produce during a heat response. They can also regulate the host’s respective Hsps. Antioxidant responses that can prevent coral hosts from expelling the zooxanthellae, can be found both within exposed coral tissue and the zooxanthellae cells. Despite the lower likelihood of bleaching in South African coral reefs, genetic engineering presents a useful tool to understand and adapt traits within zooxanthellae genotypes to help mitigate coral bleaching in the future.
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Affiliation(s)
- Anuschka Curran
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Sandra Barnard
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
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21
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Selmoni O, Lecellier G, Magalon H, Vigliola L, Oury N, Benzoni F, Peignon C, Joost S, Berteaux-Lecellier V. Seascape genomics reveals candidate molecular targets of heat stress adaptation in three coral species. Mol Ecol 2021; 30:1892-1906. [PMID: 33619812 PMCID: PMC8252710 DOI: 10.1111/mec.15857] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 02/02/2021] [Accepted: 02/16/2021] [Indexed: 12/14/2022]
Abstract
Anomalous heat waves are causing a major decline of hard corals around the world and threatening the persistence of coral reefs. There are, however, reefs that have been exposed to recurrent thermal stress over the years and whose corals appear to have been tolerant against heat. One of the mechanisms that could explain this phenomenon is local adaptation, but the underlying molecular mechanisms are poorly known. In this work, we applied a seascape genomics approach to study heat stress adaptation in three coral species of New Caledonia (southwestern Pacific) and to uncover the molecular actors potentially involved. We used remote sensing data to characterize the environmental trends across the reef system, and sampled corals living at the most contrasted sites. These samples underwent next generation sequencing to reveal single nucleotide polymorphisms (SNPs), frequencies of which were associated with heat stress gradients. As these SNPs might underpin an adaptive role, we characterized the functional roles of the genes located in their genomic region. In each of the studied species, we found heat stress-associated SNPs located in proximity of genes involved in pathways well known to contribute to the cellular responses against heat, such as protein folding, oxidative stress homeostasis, inflammatory and apoptotic pathways, and DNA damage-repair. In some cases, the same candidate molecular targets of heat stress adaptation recurred among species. Together, these results underline the relevance and the power of the seascape genomics approach for the discovery of adaptive traits that could allow corals to persist across wider thermal ranges.
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Affiliation(s)
- Oliver Selmoni
- Laboratory of Geographic Information Systems (LASIG, School of Architecture, Civil and Environmental Engineering (ENAC, Ecole Polytechnique Fédérale de Lausanne (EPFL, Lausanne, Switzerland.,UMR250/9220, ENTROPIE IRD-CNRS-Ifremer-UNC-UR, Labex CORAIL, Nouméa, France
| | - Gaël Lecellier
- UMR250/9220, ENTROPIE IRD-CNRS-Ifremer-UNC-UR, Labex CORAIL, Nouméa, France.,Université Paris-Saclay, UVSQ, Versailles, France
| | - Hélène Magalon
- UMR250/9220, ENTROPIE IRD-CNRS-Ifremer-UNC-UR, Labex CORAIL, St Denis de la Réunion, France
| | - Laurent Vigliola
- UMR250/9220, ENTROPIE IRD-CNRS-Ifremer-UNC-UR, Labex CORAIL, Nouméa, France
| | - Nicolas Oury
- UMR250/9220, ENTROPIE IRD-CNRS-Ifremer-UNC-UR, Labex CORAIL, St Denis de la Réunion, France
| | - Francesca Benzoni
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Christophe Peignon
- UMR250/9220, ENTROPIE IRD-CNRS-Ifremer-UNC-UR, Labex CORAIL, Nouméa, France
| | - Stéphane Joost
- Laboratory of Geographic Information Systems (LASIG, School of Architecture, Civil and Environmental Engineering (ENAC, Ecole Polytechnique Fédérale de Lausanne (EPFL, Lausanne, Switzerland
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22
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Shitaoka R, Ishibashi H, Takeuchi I. Thermal tolerance of the hermatypic coral Acropora tenuis elucidated by RGB analysis and expression of heat shock proteins in coral and symbiotic dinoflagellates. MARINE POLLUTION BULLETIN 2021; 162:111812. [PMID: 33213856 DOI: 10.1016/j.marpolbul.2020.111812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 06/11/2023]
Abstract
Increased seawater temperature has resulted in mass coral bleaching events globally. Acropora tenuis, the dominant hermatypic coral species in southern Japan, was exposed to four temperature treatments [28 °C, 30 °C, 32 °C, and >32 (=33.3 °C)] for 7 d. The coral colour was converted to R (red), G (green), and B (blue) values, each ranging from 0 (darkest) to 255 (brightest). RGB values exposed to 28 °C and 30 °C decreased slightly, whereas those exposed to 32 °C increased significantly after day 3-6, and those exposed to 33.3 °C changed to white within 2 d. Quantitative RT-PCR analysis revealed no significant changes in heat shock proteins in Acropora and symbiotic dinoflagellates at 28 °C and 30 °C after a 7 d exposure. Our findings revealed that 30 °C, higher than the mean temperature of the warmest month in southern Japan, was an inhabitable temperature for A. tenuis.
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Affiliation(s)
- Rin Shitaoka
- Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Hiroshi Ishibashi
- Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Ichiro Takeuchi
- Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
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23
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Zhang E, Wu S, Cai W, Zeng J, Li J, Li G, Liu J. Validation of superior reference genes for qRT-PCR and Western blot analyses in marine Emiliania huxleyi-virus model system. J Appl Microbiol 2020; 131:257-271. [PMID: 33275816 DOI: 10.1111/jam.14958] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/19/2020] [Accepted: 11/29/2020] [Indexed: 11/30/2022]
Abstract
AIMS To search for a set of reference genes for reliable gene expression analysis in the globally important marine coccolithophore Emiliania huxleyi-virus model system. METHODS AND RESULTS Fifteen housekeeping genes (CDKA, CYP15, EFG3, POLAI, RPL30, RPL13, SAMS, COX1, GPB1-2, HSP90, TUA, TUB, UBA1, CAM3 and GAPDH) were evaluated for their stability as potential reference genes for qRT-PCR using ΔCt, geNorm, NormFinder, Bestkeeper and RefFinder software. CDKA, TUA and TUB genes were tested as loading controls for Western blot in the same sample panel. Additionally, target genes associated with cell apoptosis, that is metacaspase genes, were applied to validate the selection of reference genes. The analysis results demonstrated that putative housekeeping genes exhibited significant variations in both mRNA and protein content during virus infection. After a comprehensive analysis with all the algorithms, CDKA and GAPDH were recommended as the most stable reference genes for E huxleyi virus (EhV) infection treatments. For Western blot, significant variation was seen for TUA and TUB, whereas CDKA was stably expressed, consistent with the results of qRT-PCR. CONCLUSIONS CDKA and GAPDH are the best choice for gene and protein expression analysis than the other candidate reference genes under EhV infection conditions. SIGNIFICANCE AND IMPACT OF THE STUDY The stable internal control genes identified in this work will help to improve the accuracy and reliability of gene expression analysis and gain insight into complex E. huxleyi-EhV interaction regulatory networks.
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Affiliation(s)
- E Zhang
- College of Food and Bioengineering, Jimei University, Xiamen, China
| | - S Wu
- College of Food and Bioengineering, Jimei University, Xiamen, China
| | - W Cai
- College of Food and Bioengineering, Jimei University, Xiamen, China
| | - J Zeng
- College of Food and Bioengineering, Jimei University, Xiamen, China
| | - J Li
- College of Food and Bioengineering, Jimei University, Xiamen, China
| | - G Li
- College of Food and Bioengineering, Jimei University, Xiamen, China
| | - J Liu
- College of Food and Bioengineering, Jimei University, Xiamen, China
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24
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Reduced thermal tolerance in a coral carrying CRISPR-induced mutations in the gene for a heat-shock transcription factor. Proc Natl Acad Sci U S A 2020; 117:28899-28905. [PMID: 33168726 DOI: 10.1073/pnas.1920779117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Reef-building corals are keystone species that are threatened by anthropogenic stresses including climate change. To investigate corals' responses to stress and other aspects of their biology, numerous genomic and transcriptomic studies have been performed, generating many hypotheses about the roles of particular genes and molecular pathways. However, it has not generally been possible to test these hypotheses rigorously because of the lack of genetic tools for corals or closely related cnidarians. CRISPR technology seems likely to alleviate this problem. Indeed, we show here that microinjection of single-guide RNA/Cas9 ribonucleoprotein complexes into fertilized eggs of the coral Acropora millepora can produce a sufficiently high frequency of mutations to detect a clear phenotype in the injected generation. Based in part on experiments in a sea-anemone model system, we targeted the gene encoding Heat Shock Transcription Factor 1 (HSF1) and obtained larvae in which >90% of the gene copies were mutant. The mutant larvae survived well at 27 °C but died rapidly at 34 °C, a temperature that did not produce detectable mortality over the duration of the experiment in wild-type (WT) larvae or larvae injected with Cas9 alone. We conclude that HSF1 function (presumably its induction of genes in response to heat stress) plays an important protective role in corals. More broadly, we conclude that CRISPR mutagenesis in corals should allow wide-ranging and rigorous tests of gene function in both larval and adult corals.
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25
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Abassi S, Wang H, Ki JS. Molecular cloning of heat shock protein 70 and HOP from the freshwater green algae Closterium ehrenbergii and their responses to stress. Cell Stress Chaperones 2020; 25:1117-1123. [PMID: 32794097 PMCID: PMC7591666 DOI: 10.1007/s12192-020-01143-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/07/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022] Open
Abstract
Heat shock proteins (HSPs) and HSP70-HSP90 organizing proteins (HOPs) are related, and they function together to maintain cellular homeostasis and respond to stress. In the present study, we reported the first molecular characteristics of HSP70 (designated as CeHSP70) and HOP (designated as CeHOP) genes from the freshwater green algae Closterium ehrenbergii and examined the changes in their expression profiles under heat stress and toxic chemicals treatment. CeHSP70 presented the conserved motif patterns and EEVD domain specific to cytosolic HSP70; CeHOP contained a typical domain of TPR repeats. Real-time PCR analysis showed that thermal stress considerably up-regulated both CeHOP and CeHSP70. In addition, the genes were significantly induced by CuCl2, CuSO4, and NiSO4, but not by K2Cr2O7, herbicide, and endocrine disrupting chemicals. These results suggest that CeHOP and CeHSP70 function together and play a role in responses to specific stressors and indicate their possible use as sensitive specific biomarkers in risk assessments.
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Affiliation(s)
- Sofia Abassi
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea.
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26
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Paknejad H, Hosseini Shekarabi SP, Shamsaie Mehrgan M, Hajimoradloo A, Khorshidi Z, Rastegari S. Dietary peppermint (Mentha piperita) powder affects growth performance, hematological indices, skin mucosal immune parameters, and expression of growth and stress-related genes in Caspian roach (Rutilus caspicus). FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:1883-1895. [PMID: 32592128 DOI: 10.1007/s10695-020-00839-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
Peppermint is a popular herbal medicine due to its several pharmaceutical applications. In this study, peppermint powder was used as a feed additive to evaluate growth performance, hematological parameters, protein profile of skin mucus, and immune parameters, as well as growth hormone (GH), insulin-like growth factor (IGF), and 70 kDa heat shock protein (HSP70) gene expression in Caspian roach (Rutilus caspicus). The fingerlings (average weight of 2.40 ± 0.12 g) were fed with diet containing 0 (control), 2, 3, and 4 g/kg peppermint for 8 weeks. The addition of peppermint significantly enhanced the growth parameters and decreased the food conversion ratio. Hematological indices of fish fed with peppermint-supplemented diets were significantly different from the control group (P < 0.05). Soluble protein, alkaline phosphatase, and lysozyme enzyme activity in mucus samples showed an incremental trend by increasing the peppermint levels in the diet. Evaluation of mucosal immunity indicated a remarkable difference between the protein profile in treatments fed with peppermint-supplemented diets and the control group. A new protein band (approximately 27 kDa) was also found in the skin mucus of fish fed with the diet containing 4 g/kg peppermint, and the highest band density was observed in this treatment. The highest IGF and GH gene expression were observed in 4 g/kg peppermint treatment. There was a significant difference in HSP70 expression between the fish fed with peppermint powder and the control group (P < 0.05). Overall, the results showed that dietary oral administration of peppermint at 4 g/kg of feed can act as a growth promoter and immunostimulant.
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Affiliation(s)
- Hammed Paknejad
- Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | | | - Mehdi Shamsaie Mehrgan
- Department of Fisheries Science, Science and Research Branch, Islamic Azad University, Tehran, Iran.
| | - Abdolmajid Hajimoradloo
- Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Zohre Khorshidi
- Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Soheila Rastegari
- Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
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Differential Dynamics of the Ruminal Microbiome of Jersey Cows in a Heat Stress Environment. Animals (Basel) 2020; 10:ani10071127. [PMID: 32630754 PMCID: PMC7401637 DOI: 10.3390/ani10071127] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/25/2022] Open
Abstract
Simple Summary Recently, it has become apparent that the microbiome is essential to health and affects practically every aspect of physiology. The rumen contains highly dense and diverse microbial communities, which can impact health through their composition, diversity, and assembly. Nevertheless, the diversity and function of rumen microbes have not been fully described. Therefore, this study aims to identify differences in the functional attributes and metabolites of rumen microbiota to heat stress by metagenomics and metabolomics analyses. We observed differences in biological changes, as well as changes in rumen metabolites and metabolic pathways depending on the breed of cow. In addition, significant changes in rumen bacterial taxa and functional gene abundance were observed. Overall, the findings of this study improve our understanding of heat-vulnerable ruminal bacteria and related genes. Abstract The microbial community within the rumen can be changed and shaped by heat stress. Accumulating data have suggested that different breeds of dairy cows have differential heat stress resistance; however, the underlying mechanism by which nonanimal factors contribute to heat stress are yet to be understood. This study is designed to determine changes in the rumen microbiome of Holstein and Jersey cows to normal and heat stress conditions. Under heat stress conditions, Holstein cows had a significantly higher respiration rate than Jersey cows. Heat stress increased the rectal temperature of Holstein but not Jersey cows. In the Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, Jersey cows had a significantly higher proportion of genes associated with energy metabolism in the normal condition than that with other treatments. Linear discriminant analysis effect size (LEfSe) results identified six taxa as distinguishing taxa between normal and heat stress conditions in Holstein cows; in Jersey cows, 29 such taxa were identified. Changes in the rumen bacterial taxa were more sensitive to heat stress in Jersey cows than in Holstein cows, suggesting that the rumen mechanism is different in both breeds in adapting to heat stress. Collectively, distinct changes in rumen bacterial taxa and functional gene abundance in Jersey cows may be associated with better adaptation ability to heat stress.
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Sun F, Yang H, Wang G, Shi Q. Combination Analysis of Metatranscriptome and Metagenome Reveal the Composition and Functional Response of Coral Symbionts to Bleaching During an El Niño Event. Front Microbiol 2020; 11:448. [PMID: 32265879 PMCID: PMC7104784 DOI: 10.3389/fmicb.2020.00448] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 03/02/2020] [Indexed: 01/12/2023] Open
Abstract
With the abnormal rise in ocean temperatures globally in recent years, coral bleaching is becoming common and serious. However, the response mechanisms and processes of coral symbionts to bleaching are not well understood. In this study, metagenomics and metatranscriptomics were used to explore the composition of coral symbionts and their functions in response to coral bleaching. All four bleaching coral species displayed a significant reduction of the abundance and function of Dinophyceae-like eukaryotes at the DNA and RNA levels. However, different species of bleaching coral have their own characteristic symbiotic components. Bleaching Acropora tenuis and Goniastrea minuta corals exhibited a very high abundance of prokaryotes and associated gene functions, especially for opportunistic bacteria. In contrast, algae and fungi were identified as the main microbial associate components and had relatively high RNA abundance in bleaching Pocillopora verrucosa and Pocillopora meandrina. Different coral species, whether unbleached or bleaching, have the same symbiotic taxa that perform the same biological functions in vivo. Different stages of bleaching, or transitional states, were identified by different genome content and functional gene abundance among bleaching corals. These stages should be considered in future coral bleaching studies to accurately determine symbiont structure and function. An implicit hypothesis is that there is a causal relationship between the stability of eukaryotic communities and coral bleaching.
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Affiliation(s)
- Fulin Sun
- South China Sea Institute of Oceanology, Institute of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China.,State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,Daya Bay Marine Biology Research Station, Chinese Academy of Sciences, Shenzhen, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Hongqiang Yang
- South China Sea Institute of Oceanology, Institute of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China.,Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,Nansha Marine Ecological and Environmental Research Station, Chinese Academy of Sciences, Sansha, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Guan Wang
- South China Sea Institute of Oceanology, Institute of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China.,Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Qi Shi
- South China Sea Institute of Oceanology, Institute of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China.,Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
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29
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Chakravarti LJ, Buerger P, Levin RA, van Oppen MJH. Gene regulation underpinning increased thermal tolerance in a laboratory-evolved coral photosymbiont. Mol Ecol 2020; 29:1684-1703. [PMID: 32268445 DOI: 10.1111/mec.15432] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 03/07/2020] [Accepted: 03/16/2020] [Indexed: 12/12/2022]
Abstract
Small increases in ocean temperature can disrupt the obligate symbiosis between corals and dinoflagellate microalgae, resulting in coral bleaching. Little is known about the genes that drive the physiological and bleaching response of algal symbionts to elevated temperature. Moreover, many studies to-date have compared highly divergent strains, making it challenging to accredit specific genes to contrasting traits. Here, we compare transcriptional responses at ambient (27°C) and bleaching-relevant (31°C) temperatures in a monoclonal, wild-type (WT) strain of Symbiodiniaceae to those of a selected-strain (SS), derived from the same monoclonal culture and experimentally evolved to elevated temperature over 80 generations (2.5 years). Thousands of genes were differentially expressed at a log fold-change of >8 between the WT and SS over a 35 days temperature treatment period. At 31°C, WT cells exhibited a temporally unstable transcriptomic response upregulating genes involved in the universal stress response such as molecular chaperoning, protein repair, protein degradation and DNA repair. Comparatively, SS cells exhibited a temporally stable transcriptomic response and downregulated many stress response genes that were upregulated by the WT. Among the most highly upregulated genes in the SS at 31°C were algal transcription factors and a gene probably of bacterial origin that encodes a type II secretion system protein, suggesting interactions with bacteria may contribute to the increased thermal tolerance of the SS. Genes and functional pathways conferring thermal tolerance in the SS could be targeted in future genetic engineering experiments designed to develop thermally resilient algal symbionts for use in coral restoration and conservation.
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Affiliation(s)
- Leela J Chakravarti
- Australian Institute of Marine Science, Townsville MC, Qld, Australia.,AIMS@JCU, Australian Institute of Marine Science, College of Marine and Environmental Sciences, James Cook University, Townsville, Qld, Australia.,College of Marine and Environmental Sciences, James Cook University, Townsville, Qld, Australia.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, Australia
| | - Patrick Buerger
- CSIRO, Land & Water, Canberra, ACT, Australia.,School of BioSciences, University of Melbourne, Parkville, Vic, Australia
| | | | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville MC, Qld, Australia.,School of BioSciences, University of Melbourne, Parkville, Vic, Australia
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Kamei M, Takayama K, Ishibashi H, Takeuchi I. Effects of ecologically relevant concentrations of Irgarol 1051 in tropical to subtropical coastal seawater on hermatypic coral Acropora tenuis and its symbiotic dinoflagellates. MARINE POLLUTION BULLETIN 2020; 150:110734. [PMID: 31910516 DOI: 10.1016/j.marpolbul.2019.110734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
The effects of ecologically relevant concentrations of Irgarol 1051, a representative PSII herbicide, on hermatypic corals were studied in the laboratory. The colour and chlorophyll fluorescence of Acropora tenuis were examined following exposure to around ambient concentrations of Irgarol 1051 (20 ng/L and 200 ng/L) for 7 days. While the colour of corals was stable throughout the experiment at both concentrations, the maximum effective quantum yield (ΔF/Fm') of symbiotic dinoflagellates decreased with increasing Irgarol 1051 concentration (day 7: 8%, 20 ng/L; 37%, 200 ng/L). The expression of heat shock protein (HSP) 70 and 90 in symbiotic dinoflagellates was upregulated after 7 days exposure to both Irgarol concentrations, whereas HSP90 in coral was not upregulated. The findings of the present study suggest that the threshold of chlorophyll fluorescence and HSP expression in symbiotic dinoflagellates is lower than 20 ng/L, which is around ecologically relevant concentrations in tropical to subtropical waters.
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Affiliation(s)
- Misato Kamei
- Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Kotaro Takayama
- Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan
| | - Hiroshi Ishibashi
- Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Ichiro Takeuchi
- Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
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Cheng D, Liu H, Zhang H, Tan K, Ye T, Ma H, Li S, Zheng H. Effects of thermal stress on mortality and HSP90 expression levels in the noble scallops Chlamys nobilis with different total carotenoid content. Cell Stress Chaperones 2020; 25:105-117. [PMID: 31768900 PMCID: PMC6985358 DOI: 10.1007/s12192-019-01052-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 11/04/2019] [Accepted: 11/10/2019] [Indexed: 12/21/2022] Open
Abstract
The noble scallop Chlamys nobilis is an economically important marine bivalve cultivated in the southern sea of China since the 1980s. Unfortunately, mass mortality of this scallop species often occurs in summer. The present study was conducted to investigate whether the expression of heat shock protein 90 (HSP90) and level of carotenoids could enhance high-temperature stress resistance in scallop. First, the HSP90 homolog of C. nobilis (designated CnHSP90) was identified and cloned. The complete cDNA sequence of CnHSP90 was 2631 bp, including a 2181-bp open reading frame (ORF) encoding a 726 amino acid polypeptide with five HSP90 family signatures, and sharing high homology with members of the HSP90 family. CnHSP90 was ubiquitously expressed in all examined tissues including the intestine, kidney, adductor, mantle, gill, and gonad, with the highest in the gonad. Golden and brown scallops, which contain significantly different total carotenoid content (TCC), were subjected to acute thermal challenge, and the LTE50 (semi-lethal temperature at 36 h heat shock) and LTI50 (semi-lethal time after heat shock) as well as the correlation between CnHSP90 gene expression and TCC were determined. The LTE50 of golden scallop (32.14 °C) was higher than that of brown scallops (31.19 °C), with longer LTI50 at all tested temperatures, indicating that golden scallops were more resistant to thermal stress than brown scallops. Similarly, the mRNA expression levels of CnHSP90 in gill of golden scallops were significantly higher (P < 0.05) than that of brown scallops at 6, 12, 24, and 36 h, with a strong positive correlation between CnHSP90 expression level and TCC. This suggests that both carotenoids and HSP90 levels could improve thermal resistance in the noble scallops.
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Affiliation(s)
- Dewei Cheng
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Hongxing Liu
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Hongkuan Zhang
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Karsoon Tan
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Ting Ye
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Hongyu Ma
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Shengkang Li
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Huaiping Zheng
- Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China.
- Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China.
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China.
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Ishii Y, Maruyama S, Takahashi H, Aihara Y, Yamaguchi T, Yamaguchi K, Shigenobu S, Kawata M, Ueno N, Minagawa J. Global Shifts in Gene Expression Profiles Accompanied with Environmental Changes in Cnidarian-Dinoflagellate Endosymbiosis. G3 (BETHESDA, MD.) 2019; 9:2337-2347. [PMID: 31097480 PMCID: PMC6643889 DOI: 10.1534/g3.118.201012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 05/15/2019] [Indexed: 12/13/2022]
Abstract
Stable endosymbiotic relationships between cnidarian animals and dinoflagellate algae are vital for sustaining coral reef ecosystems. Recent studies have shown that elevated seawater temperatures can cause the collapse of their endosymbiosis, known as 'bleaching', and result in mass mortality. However, the molecular interplay between temperature responses and symbiotic states still remains unclear. To identify candidate genes relevant to the symbiotic stability, we performed transcriptomic analyses under multiple conditions using the symbiotic and apo-symbiotic (symbiont free) Exaiptasia diaphana, an emerging model sea anemone. Gene expression patterns showed that large parts of differentially expressed genes in response to heat stress were specific to the symbiotic state, suggesting that the host sea anemone could react to environmental changes in a symbiotic state-dependent manner. Comparative analysis of expression profiles under multiple conditions highlighted candidate genes potentially important in the symbiotic state transition under heat-induced bleaching. Many of these genes were functionally associated with carbohydrate and protein metabolisms in lysosomes. Symbiont algal genes differentially expressed in hospite encode proteins related to heat shock response, calcium signaling, organellar protein transport, and sugar metabolism. Our data suggest that heat stress alters gene expression in both the hosts and symbionts. In particular, heat stress may affect the lysosome-mediated degradation and transportation of substrates such as carbohydrates through the symbiosome (phagosome-derived organelle harboring symbiont) membrane, which potentially might attenuate the stability of symbiosis and lead to bleaching-associated symbiotic state transition.
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Affiliation(s)
- Yuu Ishii
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | | | - Hiroki Takahashi
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Yusuke Aihara
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Takeshi Yamaguchi
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Katsushi Yamaguchi
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Shuji Shigenobu
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Masakado Kawata
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Naoto Ueno
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Jun Minagawa
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Aichi, Japan
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Hernández-Elizárraga VH, Olguín-López N, Hernández-Matehuala R, Ocharán-Mercado A, Cruz-Hernández A, Guevara-González RG, Caballero-Pérez J, Ibarra-Alvarado C, Sánchez-Rodríguez J, Rojas-Molina A. Comparative Analysis of the Soluble Proteome and the Cytolytic Activity of Unbleached and Bleached Millepora complanata ("Fire Coral") from the Mexican Caribbean. Mar Drugs 2019; 17:md17070393. [PMID: 31277227 PMCID: PMC6669453 DOI: 10.3390/md17070393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/25/2019] [Accepted: 06/28/2019] [Indexed: 01/24/2023] Open
Abstract
Coral bleaching caused by global warming has resulted in massive damage to coral reefs worldwide. Studies addressing the consequences of elevated temperature have focused on organisms of the class Anthozoa, and up to now, there is little information regarding the mechanisms by which reef forming Hydrozoans face thermal stress. In this study, we carried out a comparative analysis of the soluble proteome and the cytolytic activity of unbleached and bleached Millepora complanata ("fire coral") that inhabited reef colonies exposed to the 2015-2016 El Niño-Southern Oscillation in the Mexican Caribbean. A differential proteomic response involving proteins implicated in key cellular processes, such as glycolysis, DNA repair, stress response, calcium homeostasis, exocytosis, and cytoskeleton organization was found in bleached hydrocorals. Four of the proteins, whose levels increased in bleached specimens, displayed sequence similarity to a phospholipase A2, an astacin-like metalloprotease, and two pore forming toxins. However, a protein, which displayed sequence similarity to a calcium-independent phospholipase A2, showed lower levels in bleached cnidarians. Accordingly, the hemolytic effect of the soluble proteome of bleached hydrocorals was significantly higher, whereas the phospholipase A2 activity was significantly reduced. Our results suggest that bleached M. complanata is capable of increasing its toxins production in order to balance the lack of nutrients supplied by its symbionts.
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Affiliation(s)
- Víctor Hugo Hernández-Elizárraga
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Norma Olguín-López
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Rosalina Hernández-Matehuala
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Andrea Ocharán-Mercado
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Andrés Cruz-Hernández
- Laboratorio de Biología Molecular. Escuela de Agronomía, Universidad de La Salle Bajío, Av. Universidad 15 602, Colonia Lomas del Campestre, C.P. 37150 León, Guanajuato, México
| | - Ramón Gerardo Guevara-González
- C.A Ingeniería de Biosistemas, Facultad de Ingeniería-Campus Amazcala, Universidad Autónoma de Querétaro, Carr. Chichimequillas-Amazcala Km. 1, S/N, C.P. 76265 Amazcala, El Marqués, Querétaro, México
| | - Juan Caballero-Pérez
- Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - César Ibarra-Alvarado
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Judith Sánchez-Rodríguez
- Unidad Académica de Sistemas Arrecifales Puerto Morelos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Prolongación Niños Héroes S/N, Puerto Morelos, C.P. 77580 Quintana Roo, México
| | - Alejandra Rojas-Molina
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México.
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34
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Di Natale M, Bennici C, Biondo G, Masullo T, Monastero C, Tagliavia M, Torri M, Costa S, Ragusa MA, Cuttitta A, Nicosia A. Aberrant gene expression profiles in Mediterranean sea urchin reproductive tissues after metal exposures. CHEMOSPHERE 2019; 216:48-58. [PMID: 30359916 DOI: 10.1016/j.chemosphere.2018.10.137] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/12/2018] [Accepted: 10/18/2018] [Indexed: 06/08/2023]
Abstract
Marine organisms are simultaneously exposed to numerous pollutants, among which metals probably represent the most abundant in marine environments. In order to evaluate the effects of metal exposure at molecular level in reproductive tissues, we profiled the sea urchin transcriptional response after non-lethal exposures using pathway-focused mRNA expression analyses. Herein, we show that exposures to relatively high concentrations of both essential and toxic metals hugely affected the gonadic expression of several genes involved in stress-response, detoxification, transcriptional and post-transcriptional regulation, without significant changes in gonadosomatic indices. Even though treatments did not result in reproductive tissues visible alterations, metal exposures negatively affected the main mechanisms of stress-response, detoxification and survival of adult P. lividus. Additionally, transcriptional changes observed in P. lividus gonads may cause altered gametogenesis and maintenance of heritable aberrant epigenetic effects. This study leads to the conclusion that exposures to metals, as usually occurs in polluted coastal areas, may affect sea urchin gametogenesis, thus supporting the hypothesis that parental exposure to environmental stressors affects the phenotype of the offspring.
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Affiliation(s)
- Marilena Di Natale
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Carmelo Bennici
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Girolama Biondo
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Tiziana Masullo
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Calogera Monastero
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Marcello Tagliavia
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Marco Torri
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Salvatore Costa
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, Ed. 16, 90128, Palermo, Sicily, Italy.
| | - Maria Antonietta Ragusa
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, Ed. 16, 90128, Palermo, Sicily, Italy.
| | - Angela Cuttitta
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
| | - Aldo Nicosia
- National Research Council-Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino (IAS-CNR), Laboratory of Molecular Ecology and Biotechnology, Detached Unit of Capo Granitola, Via del mare, 91021, Torretta Granitola (TP), Sicily, Italy.
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Knyazev NA, Pechkovskaya SA, Skarlato SO, Telesh IV, Filatova NA. The Impact of Temperature Stress on DNA and RNA Synthesis in Potentially Toxic Dinoflagellates Prorocentrum minimum. J EVOL BIOCHEM PHYS+ 2018. [DOI: 10.1134/s002209301805006x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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A differential k-mer analysis pipeline for comparing RNA-Seq transcriptome and meta-transcriptome datasets without a reference. Funct Integr Genomics 2018; 19:363-371. [PMID: 30483906 DOI: 10.1007/s10142-018-0647-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/08/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
Abstract
Next-generation DNA sequencing technologies, such as RNA-Seq, currently dominate genome-wide gene expression studies. A standard approach to analyse this data requires mapping sequence reads to a reference and counting the number of reads which map to each gene. However, for many transcriptome studies, a suitable reference genome is unavailable, especially for meta-transcriptome studies which assay gene expression from mixed populations of organisms. Where a reference is unavailable, it is possible to generate a reference by the de novo assembly of the sequence reads. However, the high cost of generating high-coverage data for de novo assembly hinders this approach and more importantly the accurate assembly of such data is challenging, especially for meta-transcriptome data, and resulting assemblies frequently suffer from collapsed regions or chimeric sequences. As an alternative to the standard reference mapping approach, we have developed a k-mer-based analysis pipeline (DiffKAP) to identify differentially expressed reads between RNA-Seq datasets without the requirement for a reference. We compared the DiffKAP approach with the traditional Tophat/Cuffdiff method using RNA-Seq data from soybean, which has a suitable reference genome. We subsequently examined differential gene expression for a coral meta-transcriptome where no reference is available, and validated the results using qRT-PCR. We conclude that DiffKAP is an accurate method to study differential gene expression in complex meta-transcriptomes without the requirement of a reference genome.
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Ishibashi H, Minamide S, Takeuchi I. Identification and characterization of heat shock protein 90 (HSP90) in the hard coral Acropora tenuis in response to Irgarol 1051. MARINE POLLUTION BULLETIN 2018; 133:773-780. [PMID: 30041376 DOI: 10.1016/j.marpolbul.2018.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/24/2017] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
To elucidate the effects of the herbicide Irgarol 1051 on the gene expression of heat shock protein 90 (HSP90) in hard corals, we isolated a full-length cDNA encoding HSP90 from Acropora tenuis, which has a deduced open reading frame of 732-amino acid residues with a predicted molecular mass of 84.5 kDa. The amino acid sequence of A. tenuis HSP90 showed a high degree of similarity with the hermatypic-coral HSP90 families. After a 7-d exposure to 1 or 10 μg/L of Irgarol, the body colours of corals in the 10 μg/L treatment group were significantly whiter (bleached), whereas no such effects were observed in the corals in the 1 μg/L treatment group. However, the expression level of coral HSP90 was significantly downregulated after exposure to both 1 and 10 μg/L Irgarol. These results suggest that A. tenuis HSP90 may be a useful molecular biomarker to predict bleaching caused by herbicides.
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Affiliation(s)
- Hiroshi Ishibashi
- Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Seigo Minamide
- Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Ichiro Takeuchi
- Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center of Advanced Technology for the Environment, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
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38
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Xu B, Lian S, Li SZ, Guo JR, Wang JF, Wang D, Zhang LP, Yang HM. GABAB receptor mediate hippocampal neuroinflammation in adolescent male and female mice after cold expose. Brain Res Bull 2018; 142:163-175. [PMID: 30031816 DOI: 10.1016/j.brainresbull.2018.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 07/04/2018] [Accepted: 07/17/2018] [Indexed: 12/12/2022]
Abstract
Stress induces many non-specific inflammatory responses in the mouse brain, especially during adolescence. Although the impact of stress on the brain has long been reported, the effects of cold stress on hippocampal neuroinflammation in adolescent mice are not well understood; furthermore, whether these effects are gender specific are also not well established. Adolescent male and female C57BL/6 mice were exposed to 4 °C temperatures for 12 h, after which behavior was assessed using the open field test. Using western blotting and immunohistochemistry we also assessed glial cell numbers and microglial activation, as well as inflammatory cytokine levels and related protein expression levels. We found that in mice subjected to cold stress: 1) There were significant behavioral changes; 2) neuronal nuclei densities were smaller and total cell numbers were significantly decreased; 3) nuclear factor (NF)-κB and phosphorylated AKT were upregulated; 4) pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-α were also upregulated; and 5) microglia were activated, while glial fibrillary acid protein and ionized calcium-binding adapter molecule 1 protein expression increased. Taken together, these results indicate that cold stress induces pro-inflammatory cytokine upregulation that leads to neuroinflammation and neuronal apoptosis in the hippocampi of adolescent mice. We believe that these effects are influenced by a GABAB/Rap1B/AKT/NF-κB pathway. Finally, male mice were more sensitive to the effects of cold stress than were female mice.
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Affiliation(s)
- Bin Xu
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China
| | - Shuai Lian
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China
| | - Shi-Ze Li
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China
| | - Jing-Ru Guo
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China
| | - Jian-Fa Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China
| | - Di Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China
| | - Li-Ping Zhang
- College of Food Science, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China.
| | - Huan-Min Yang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163319, PR China.
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39
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Nielsen DA, Petrou K, Gates RD. Coral bleaching from a single cell perspective. THE ISME JOURNAL 2018; 12:1558-1567. [PMID: 29463894 PMCID: PMC5955907 DOI: 10.1038/s41396-018-0080-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 01/18/2018] [Accepted: 01/26/2018] [Indexed: 01/03/2023]
Abstract
Ocean warming is resulting in increased occurrence of mass coral bleaching; a response in which the intracellular algal endosymbionts (Symbiodinium sp.) are expelled from the coral host due to physiological stress. This detrimental process is often attributed to overproduction of reactive oxygen species (ROS) that leak out of the endosymbionts and causes damage to the host cell, though direct evidence validating this link is limited. Here, for the first time, we used confocal microscopy and fluorescent dyes to investigate if endosymbiont ROS production significantly and predictably affects physiological parameters in its host cell. Heat treatment resulted in a 60% reduction in coral symbiont density, a ~70% increase in median endosymbiont ROS and a small reduction in photosystem efficiency (FV/FM, 11%), indicating absence of severe light stress. Notably, no other physiological parameters were affected in either endosymbionts or host cells, including reduced glutathione and ROS-induced lipid peroxidation. Taken together, the increase in endosymbiont ROS could not be linked to physiological damage in either partner, suggesting that oxidative stress is unlikely to have been the driver for symbiont expulsion in this study.
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Affiliation(s)
| | - Katherina Petrou
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology at the University of Hawai'i at Manoa, Hawai'i, USA
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40
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Morse D, Tse SPK, Lo SCL. Exploring dinoflagellate biology with high-throughput proteomics. HARMFUL ALGAE 2018; 75:16-26. [PMID: 29778222 DOI: 10.1016/j.hal.2018.03.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 06/08/2023]
Abstract
Dinoflagellates are notorious for their ability to form the harmful algal blooms known as "red tides," yet the mechanisms underlying bloom formation remain poorly understood. Despite recent advances in nucleic acid sequencing, which have generated transcriptomes from a wide range of species exposed to a variety of different conditions, measuring changes in RNA levels have not generally produced great insight into dinoflagellate cell biology or environmental physiology, nor do we have a thorough grasp on the molecular events underpinning bloom formation. Not only is the transcriptomic response of dinoflagellates to environmental change generally muted, but there is a markedly low degree of congruency between mRNA expression and protein expression in dinoflagellates. Herein we discuss the application of high-throughput proteomics to the study of dinoflagellate biology. By profiling the cellular protein complement (the proteome) instead of mRNA (the transcriptome), the biomolecular events that underlie the changes of phenotypes can be more readily evaluated, as proteins directly determine the structure and the function of the cell. Recent advances in proteomics have seen this technique become a high-throughput method that is now able to provide a perspective different from the more commonly employed nucleic acid sequencing. We suggest that the time is ripe to exploit these new technologies in addressing the many mysteries of dinoflagellate biology, such as how the symbiotic dinoflagellate inhabiting reef corals acclimate to increases in temperature, as well as how harmful algal blooms are initiated at the sub-cellular level. Furthermore, as dinoflagellates are not the only eukaryotes that demonstrate muted transcriptional responses, the techniques addressed within this review are amenable to a wide array of organisms.
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Affiliation(s)
- David Morse
- Institut de Recherche en biologie Végétale, Département de Sciences Biologiques, Université de Montréal, Canada.
| | - Sirius P K Tse
- Shenzhen Key Laboratory of Food Biological Safety Control, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
| | - Samuel C L Lo
- Shenzhen Key Laboratory of Food Biological Safety Control, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
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Xiang T, Jinkerson RE, Clowez S, Tran C, Krediet CJ, Onishi M, Cleves PA, Pringle JR, Grossman AR. Glucose-Induced Trophic Shift in an Endosymbiont Dinoflagellate with Physiological and Molecular Consequences. PLANT PHYSIOLOGY 2018; 176:1793-1807. [PMID: 29217594 PMCID: PMC5813547 DOI: 10.1104/pp.17.01572] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/04/2017] [Indexed: 05/12/2023]
Abstract
Interactions between the dinoflagellate endosymbiont Symbiodinium and its cnidarian hosts (e.g. corals, sea anemones) are the foundation of coral-reef ecosystems. Carbon flow between the partners is a hallmark of this mutualism, but the mechanisms governing this flow and its impact on symbiosis remain poorly understood. We showed previously that although Symbiodinium strain SSB01 can grow photoautotrophically, it can grow mixotrophically or heterotrophically when supplied with Glc, a metabolite normally transferred from the alga to its host. Here we show that Glc supplementation of SSB01 cultures causes a loss of pigmentation and photosynthetic activity, disorganization of thylakoid membranes, accumulation of lipid bodies, and alterations of cell-surface morphology. We used global transcriptome analyses to determine if these physiological changes were correlated with changes in gene expression. Glc-supplemented cells exhibited a marked reduction in levels of plastid transcripts encoding photosynthetic proteins, although most nuclear-encoded transcripts (including those for proteins involved in lipid synthesis and formation of the extracellular matrix) exhibited little change in their abundances. However, the altered carbon metabolism in Glc-supplemented cells was correlated with modest alterations (approximately 2x) in the levels of some nuclear-encoded transcripts for sugar transporters. Finally, Glc-bleached SSB01 cells appeared unable to efficiently populate anemone larvae. Together, these results suggest links between energy metabolism and cellular physiology, morphology, and symbiotic interactions. However, the results also show that in contrast to many other organisms, Symbiodinium can undergo dramatic physiological changes that are not reflected by major changes in the abundances of nuclear-encoded transcripts and thus presumably reflect posttranscriptional regulatory processes.
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Affiliation(s)
- Tingting Xiang
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Robert E Jinkerson
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521
| | - Sophie Clowez
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Cawa Tran
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305
- Department of Biological Sciences, California State University, Chico, California 95929
| | - Cory J Krediet
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305
- Eckerd College, Department of Marine Science, St. Petersburg, Florida 33711
| | - Masayuki Onishi
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305
| | - Phillip A Cleves
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305
| | - John R Pringle
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305
| | - Arthur R Grossman
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
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42
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Wietheger A, Starzak DE, Gould KS, Davy SK. Differential ROS Generation in Response to Stress in Symbiodinium spp. THE BIOLOGICAL BULLETIN 2018; 234:11-21. [PMID: 29694799 DOI: 10.1086/696977] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Oxidative stress inside cells occurs when the production of reactive oxygen species (ROS) is no longer efficiently counterbalanced by the generation of antioxidants. In this study, we measured the intracellular production of ROS, including hydrogen peroxide (H2O2), superoxide (O2-), and singlet oxygen (1O2), in cultured dinoflagellates of the genus Symbiodinium under thermal and oxidative stress. ROS tagged with fluorescent probes were measured by flow cytometry. Dissimilar Symbiodinium internal transcribed spacer 2 (ITS2) clades or phylotypes (A1, B2, E, F1) produced ROS in different quantities in response to stress. For example, when comparing the control (26 °C) to the high-temperature treatment (35 °C), Symbiodinium E showed no change in the intracellular concentrations of any of the ROS; but phylotype A1 displayed a 10-fold increase in the overall ROS concentration and a 4-fold increase in O2-. Under oxidative stress, when 8 mmol l-1 H2O2 was added to the cells, these same two Symbiodinium phylotypes increased their overall concentrations of ROS, but only Symbiodinium E showed an increase in the concentrations of O2- (2×) and 1O2 (3×). Therefore, not only were the stress responses of the various Symbiodinium phylotypes different but also the responses of individual phylotypes to thermal and oxidative stress were different in terms of ROS production. Variation in the quality and quantity of ROS generation and its implications for subsequent antioxidant production suggest that different stress mechanisms are at play. While our experiments were done under laboratory conditions that did not necessarily mirror ecological ones, these results provide new insight into processes inside Symbiodinium cells during stress events and add new explanations for a phylotype's susceptibility to stress.
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Key Words
- 1O2, singlet oxygen
- APX, ascorbate peroxidase
- CAT, catalase
- DMSO, dimethyl sulfoxide
- H2DCF-DA, 2′,7′-dichlorodihydrofluorescein diacetate
- ITS2, internal transcribed spacer 2
- NPQ, non-photochemical quenching
- O2−, superoxide
- OEC, oxygen-evolving complex
- OH•, hydroxyl radical
- PSI/II, photosystem I/II
- ROS, reactive oxygen species
- SOD, superoxide dismutase
- SOG, singlet oxygen sensor green
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Xiang XL, Jiang RM, Chen YY, Ge YL, Wen XL, Xi YL. Regulation of heat shock protein 70 (Hsp70) levels in the bdelloid rotifer Rotaria rotatoria under temperature stress. Isr J Ecol Evol 2017. [DOI: 10.1163/22244662-06301001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The bdelloid rotifer is an important component of freshwater zooplankton, exhibiting the features of parthenogenesis and anhydrobiotic capability. Heat shock proteins (Hsps), acting as molecular chaperones, are a highly conserved, ubiquitously expressed family of stress response proteins. In this study, the thermal optimums for heat-shock response and the levels of Hsp70 in Rotaria rotatoria (bdelloid rotifer) under different stress conditions were evaluated using survival assays and western blotting with fluorescent detection. The results showed that: (1) The survivorship in R. rotatoria were 100% throughout the temperature range of 12°C to 40°C, and the population growth rate reached its culmination at 28°C, suggesting the retardation of growth and reproduction at the other temperatures; (2) While stressed under 40°C, the levels of Hsp70 in R. rotatoria increased significantly over time, correlating with the duration of the stress; (3) As responses to different temperatures, the synthesis of Hsp70 could be induced significantly in R. rotatoria under both of high (40°C) and low (16°C) temperatures; (4) After removal of the thermal stress and recovery at 28°C, the levels of Hsp70 continued to rise for a period of time, peaked at 12 h, and then slowly declined with the extension of recovery duration, until there is no significant difference of Hsp70 levels. Summarily, with the fluctuations of stress duration and temperature, the rotifers could adapt to the environments sensitively by regulating the synthesis of Hsp70.
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Affiliation(s)
- Xian-Ling Xiang
- a College of Life Sciences, Anhui Normal University, Wuhu 241000, Anhui, P.R. China
- b Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province, Wuhu 241000, Anhui, P.R. China
| | - Rui-Ming Jiang
- a College of Life Sciences, Anhui Normal University, Wuhu 241000, Anhui, P.R. China
| | - Ying-Ying Chen
- a College of Life Sciences, Anhui Normal University, Wuhu 241000, Anhui, P.R. China
| | - Ya-Li Ge
- a College of Life Sciences, Anhui Normal University, Wuhu 241000, Anhui, P.R. China
- b Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province, Wuhu 241000, Anhui, P.R. China
| | - Xin-Li Wen
- a College of Life Sciences, Anhui Normal University, Wuhu 241000, Anhui, P.R. China
- b Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province, Wuhu 241000, Anhui, P.R. China
| | - Yi-Long Xi
- a College of Life Sciences, Anhui Normal University, Wuhu 241000, Anhui, P.R. China
- b Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province, Wuhu 241000, Anhui, P.R. China
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44
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Ellison MA, Ferrier MD, Carney SL. Salinity stress results in differential Hsp70 expression in the Exaiptasia pallida and Symbiodinium symbiosis. MARINE ENVIRONMENTAL RESEARCH 2017; 132:63-67. [PMID: 29108677 DOI: 10.1016/j.marenvres.2017.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/08/2017] [Accepted: 10/13/2017] [Indexed: 06/07/2023]
Abstract
Abiotic factors affect cnidarian-algal symbiosis and, if severe enough, can result in bleaching. Increased temperature and light are well characterized causes of bleaching, but other factors like salinity can also stress the holobiont. In cnidarian-dinoflagellate systems, the expression of host genes, including heat shock protein 70 (Hsp70), changes due to thermal and light stress. In this experiment, we characterized to what extent salinity stress affects Hsp70 expression in the holobiont by simultaneously measuring host and symbiont Hsp70 expression in response to up to 8 h of hypo- and hypersaline conditions in the sea anemone Exaiptasia pallida and its intracellular symbiont Symbiodinium minutum. We show that E. pallida Hsp70 expression increases (6-11-fold) at high salinities whereas Symbiodinium Hsp70 expression shows little change (1.4-2.6-fold). These data suggest that cnidarian Hsp70 response is similar across multiple abiotic stressors further validating the Hsp70 gene as a biomarker for abiotic stress.
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Affiliation(s)
- Mitchell A Ellison
- Hood College, Department of Biology, 401 Rosemont Avenue, Frederick, MD 21701, USA
| | - M Drew Ferrier
- Hood College, Department of Biology, 401 Rosemont Avenue, Frederick, MD 21701, USA
| | - Susan L Carney
- Hood College, Department of Biology, 401 Rosemont Avenue, Frederick, MD 21701, USA.
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45
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Macrander JC, Dimond JL, Bingham BL, Reitzel AM. Transcriptome sequencing and characterization of Symbiodinium muscatinei and Elliptochloris marina, symbionts found within the aggregating sea anemone Anthopleura elegantissima. Mar Genomics 2017; 37:82-91. [PMID: 28888836 DOI: 10.1016/j.margen.2017.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 08/26/2017] [Accepted: 08/27/2017] [Indexed: 12/20/2022]
Abstract
There is a growing body of literature using transcriptomic data to study how tropical cnidarians and their photosynthetic endosymbionts respond to environmental stressors and participate in metabolic exchange. Despite these efforts, our understanding of how essential genes function to facilitate symbiosis establishment and maintenance remains limited. The inclusion of taxonomically and ecologically diverse endosymbionts will enhance our understanding of these interactions. Here we characterize the transcriptomes of two very different symbionts found within the temperate sea anemone Anthopleura elegantissima: the chlorophyte Elliptochloris marina and the dinoflagellate Symbiodinium muscatinei. We use a multi-level approach to assess the diversity of genes found across S. muscatinei and E. marina transcriptomes, and compare their overall protein domains with other dinoflagellates and chlorophytes. Our analysis identified several genes that are potentially involved in mitigating stress response (e.g., heat shock proteins pathways for mediating reactive oxygen species) and metabolic exchange (e.g., ion transporters). Finally, we show that S. muscatinei and other Symbiodinium strains are equipped with a high salt peridinin-chl-protein (HSPCP) gene previously identified only in free-living dinoflagellates. The addition of these transcriptomes to the cnidarian-symbiont molecular toolkit will aid in understanding how these vitally important symbiotic relationships are established and maintained across a variety of environmental conditions.
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Affiliation(s)
- Jason C Macrander
- Department of Biological Sciences, University of North Carolina, Charlotte, 9201 University City Blvd, Charlotte, NC 28223, USA.
| | - James L Dimond
- Shannon Point Marine Center, Western Washington University, 1900 Shannon Point Road, Anacortes, WA 98221, USA
| | - Brian L Bingham
- Shannon Point Marine Center, Western Washington University, 1900 Shannon Point Road, Anacortes, WA 98221, USA; Department of Environmental Sciences, Western Washington University, 516 High Street, Bellingham, WA 98225, USA
| | - Adam M Reitzel
- Department of Biological Sciences, University of North Carolina, Charlotte, 9201 University City Blvd, Charlotte, NC 28223, USA
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46
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Sparrow L, Momigliano P, Russ GR, Heimann K. Effects of temperature, salinity and composition of the dinoflagellate assemblage on the growth of Gambierdiscus carpenteri isolated from the Great Barrier Reef. HARMFUL ALGAE 2017; 65:52-60. [PMID: 28526119 DOI: 10.1016/j.hal.2017.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/07/2017] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
Increases in reported incidence of ciguatera fish poisoning (hereafter ciguatera) have been linked to warmer sea temperatures that are known to trigger coral bleaching events. The drivers that trigger blooms of ciguatera-causing dinoflagellates on the Great Barrier Reef (GBR) are poorly understood. This study investigated the effects of increased temperatures and lowered salinities, often associated with environmental disturbance events, on the population growth of two strains of the potentially ciguatera-causing dinoflagellate, Gambierdiscus carpenteri (NQAIF116 and NQAIF380). Both strains were isolated from the central GBR with NQAIF116 being an inshore strain and NQAIF380 an isolate from a stable environment of a large coral reef aquarium exhibit in ReefHQ, Townsville, Australia. Species of Gambierdiscus are often found as part of a mixed assemblage of benthic toxic dinoflagellates on macroalgal substrates. The effect of assemblage structure of dinoflagellates on the growth of Gambierdiscus populations has, however, not been explored. The study, therefore investigated the growth of G. carpenteri within mixed assemblages of benthic dinoflagellates. Population growth was monitored over a period of 28days under three salinities (16, 26 and 36) and three temperature (24, 28 and 34°C) conditions in a fully crossed experimental design. Temperature and salinity had a significant effect on population growth. Strain NQAIF380 exhibited significantly higher growth at 28°C compared to strain NQAIF116, which had highest growth at 24°C. When strain NQAIF116 was co-cultured with the benthic dinoflagellates, Prorocentrum lima and Ostreopsis sp., inhibitory effects on population growth were observed at a salinity of 36. In contrast, growth stimulation of G. carpenteri (strain NQAIF116) was observed at a salinity of 26 and particularly at 16 when co-cultured with Ostreopsis-dominated assemblages. Range expansion of ciguatera-causing dinoflagellates could lead to higher frequency of reported ciguatera illness in populated temperate Australian regions, outside the tropical range of the GBR. Therefore, the findings on salinity and temperature tolerance of two strains of G. carpenteri indicates potential adaptability to different local environmental conditions. These are baseline data for future investigations into the potential southward range expansion of ciguatera-causing dinoflagellates originating from the GBR.
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Affiliation(s)
- Leanne Sparrow
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; Centre of Sustainable Tropical Fisheries & Aquaculture, James Cook University, Townsville, QLD 4811, Australia.
| | - Paolo Momigliano
- Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Garry R Russ
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Kirsten Heimann
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; Centre of Sustainable Tropical Fisheries & Aquaculture, James Cook University, Townsville, QLD 4811, Australia
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Traylor-Knowles N, Rose NH, Sheets EA, Palumbi SR. Early Transcriptional Responses during Heat Stress in the Coral Acropora hyacinthus. THE BIOLOGICAL BULLETIN 2017; 232:91-100. [PMID: 28654330 DOI: 10.1086/692717] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Corals respond to heat pulses that cause bleaching with massive transcriptional change, but the immediate responses to stress that lead up to these shifts have never been detailed. Understanding these early signals could be important for identifying the regulatory mechanisms responsible for bleaching and how these mechanisms vary between more and less resilient corals. Using RNA sequencing (RNAseq) and sampling every 30 minutes during a short-term heat shock, we found that components of the transcriptome were significantly upregulated within 90 min and after a temperature increase of +2 °C. The developmental transcription factor, Krüppel-like factor 7, was highly expressed within 60 min, and stress-related transcription factors such as Elk-3 were highly expressed starting at 240 min. The sets of genes enriched for early transcriptional response to heat stress included heat shock proteins, small GTPases, and proteasome genes. Retrovirus-related Pol polyproteins from transposons were significantly expressed throughout the whole experiment. Lastly, we propose a model for early transcriptional regulation of protein degradation and cell adhesion response that may ultimately lead to the bleaching and stress response.
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48
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Salas BH, Haslun JA, Strychar KB, Ostrom PH, Cervino JM. Site-specific variation in gene expression from Symbiodinium spp. associated with offshore and inshore Porites astreoides in the lower Florida Keys is lost with bleaching and disease stress. PLoS One 2017; 12:e0173350. [PMID: 28355291 PMCID: PMC5371298 DOI: 10.1371/journal.pone.0173350] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 02/20/2017] [Indexed: 11/18/2022] Open
Abstract
Scleractinian coral are experiencing unprecedented rates of mortality due to increases in sea surface temperatures in response to global climate change. Some coral species however, survive high temperature events due to a reduced susceptibility to bleaching. We investigated the relationship between bleaching susceptibility and expression of five metabolically related genes of Symbiodinium spp. from the coral Porites astreoides originating from an inshore and offshore reef in the Florida Keys. The acclimatization potential of Symbiodinium spp. to changing temperature regimes was also measured via a two-year reciprocal transplant between the sites. Offshore coral fragments displayed significantly higher expression in Symbiodinium spp. genes PCNA, SCP2, G3PDH, PCP and psaE than their inshore counterparts (p<0.05), a pattern consistent with increased bleaching susceptibility in offshore corals. Additionally, gene expression patterns in Symbiodinium spp. from site of origin were conserved throughout the two-year reciprocal transplant, indicating acclimatization did not occur within this multi-season time frame. Further, laboratory experiments were used to investigate the influence of acute high temperature (32°C for eight hours) and disease (lipopolysaccharide of Serratia marcescens) on the five metabolically related symbiont genes from the same offshore and inshore P. astreoides fragments. Gene expression did not differ between reef fragments, or as a consequence of acute exposure to heat or heat and disease, contrasting to results found in the field. Gene expression reported here indicates functional variation in populations of Symbiodinium spp. associated with P. astreoides in the Florida Keys, and is likely a result of localized adaptation. However, gene expression patterns observed in the lab imply that functional variation in zooxanthellae observed under conditions of chronic moderate stress is lost under the acute extreme conditions studied here.
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Affiliation(s)
- Briana Hauff Salas
- University of Texas School of Medicine, San Antonio, TX, United States of America
| | - Joshua A Haslun
- Michigan State University, Department of Integrative Biology, East Lansing, MI, United States of America
| | - Kevin B Strychar
- Annis Water Resources Institute-Grand Valley State University, Muskegon, MI, United States of America
| | - Peggy H Ostrom
- Michigan State University, Department of Integrative Biology, East Lansing, MI, United States of America
| | - James M Cervino
- Woods Hole Oceanographic Institute, Department of Marine Chemistry & Geochemistry, Woods Hole, MA, United States of America
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49
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Kumar R, Ghosh M, Kumar N, Balhara AK, Gupta M, Sharma RK, Singh I. Polymorphism in 5′ untranslated region of heat-shock protein 70 gene as marker of post-partum anoestrus in Murrah buffaloes. Reprod Domest Anim 2017; 52:505-512. [DOI: 10.1111/rda.12941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/10/2017] [Indexed: 12/25/2022]
Affiliation(s)
- R Kumar
- Central Institute for Research on Buffaloes; Hisar Haryana India
| | - M Ghosh
- Department of Veterinary Biochemistry; Ranchi Veterinary College; Birsa Agricultural University; Kanke Ranchi Jharkhand India
| | - N Kumar
- Department of Chemistry and Biochemistry; College of Basic Sciences and Humanities; CCSHAU; Hisar Haryana India
| | - AK Balhara
- Central Institute for Research on Buffaloes; Hisar Haryana India
| | - M Gupta
- Department of Veterinary Physiology & Biochemistry; Lala Lajpat Rai University of Veterinary and Animal Sciences; Hisar Haryana India
| | - RK Sharma
- Central Institute for Research on Buffaloes; Hisar Haryana India
| | - I Singh
- Central Institute for Research on Buffaloes; Hisar Haryana India
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50
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Gierz SL, Forêt S, Leggat W. Transcriptomic Analysis of Thermally Stressed Symbiodinium Reveals Differential Expression of Stress and Metabolism Genes. FRONTIERS IN PLANT SCIENCE 2017; 8:271. [PMID: 28293249 PMCID: PMC5328969 DOI: 10.3389/fpls.2017.00271] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/14/2017] [Indexed: 05/29/2023]
Abstract
Endosymbioses between dinoflagellate algae (Symbiodinium sp.) and scleractinian coral species form the foundation of coral reef ecosystems. The coral symbiosis is highly susceptible to elevated temperatures, resulting in coral bleaching, where the algal symbiont is released from host cells. This experiment aimed to determine the transcriptional changes in cultured Symbiodinium, to better understand the response of cellular mechanisms under future temperature conditions. Cultures were exposed to elevated temperatures (average 31°C) or control conditions (24.5°C) for a period of 28 days. Whole transcriptome sequencing of Symbiodinium cells on days 4, 19, and 28 were used to identify differentially expressed genes under thermal stress. A large number of genes representing 37.01% of the transcriptome (∼23,654 unique genes, FDR < 0.05) with differential expression were detected at no less than one of the time points. Consistent with previous studies of Symbiodinium gene expression, fold changes across the transcriptome were low, with 92.49% differentially expressed genes at ≤2-fold change. The transcriptional response included differential expression of genes encoding stress response components such as the antioxidant network and molecular chaperones, cellular components such as core photosynthesis machinery, integral light-harvesting protein complexes and enzymes such as fatty acid desaturases. Differential expression of genes encoding glyoxylate cycle enzymes were also found, representing the first report of this in Symbiodinium. As photosynthate transfer from Symbiodinium to coral hosts provides up to 90% of a coral's daily energy requirements, the implications of altered metabolic processes from exposure to thermal stress found in this study on coral-Symbiodinium associations are unknown and should be considered when assessing the stability of the symbiotic relationship under future climate conditions.
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Affiliation(s)
- Sarah L. Gierz
- College of Public Health, Medical and Veterinary Sciences, James Cook University, TownsvilleQLD, Australia
- Comparative Genomics Centre, James Cook University, TownsvilleQLD, Australia
| | - Sylvain Forêt
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, TownsvilleQLD, Australia
- Evolution, Ecology and Genetics, Research School of Biology, Australian National University, CanberraACT, Australia
| | - William Leggat
- College of Public Health, Medical and Veterinary Sciences, James Cook University, TownsvilleQLD, Australia
- Comparative Genomics Centre, James Cook University, TownsvilleQLD, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, TownsvilleQLD, Australia
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