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Miyagishima SY. Taming the perils of photosynthesis by eukaryotes: constraints on endosymbiotic evolution in aquatic ecosystems. Commun Biol 2023; 6:1150. [PMID: 37952050 PMCID: PMC10640588 DOI: 10.1038/s42003-023-05544-0] [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: 07/06/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023] Open
Abstract
An ancestral eukaryote acquired photosynthesis by genetically integrating a cyanobacterial endosymbiont as the chloroplast. The chloroplast was then further integrated into many other eukaryotic lineages through secondary endosymbiotic events of unicellular eukaryotic algae. While photosynthesis enables autotrophy, it also generates reactive oxygen species that can cause oxidative stress. To mitigate the stress, photosynthetic eukaryotes employ various mechanisms, including regulating chloroplast light absorption and repairing or removing damaged chloroplasts by sensing light and photosynthetic status. Recent studies have shown that, besides algae and plants with innate chloroplasts, several lineages of numerous unicellular eukaryotes engage in acquired phototrophy by hosting algal endosymbionts or by transiently utilizing chloroplasts sequestrated from algal prey in aquatic ecosystems. In addition, it has become evident that unicellular organisms engaged in acquired phototrophy, as well as those that feed on algae, have also developed mechanisms to cope with photosynthetic oxidative stress. These mechanisms are limited but similar to those employed by algae and plants. Thus, there appear to be constraints on the evolution of those mechanisms, which likely began by incorporating photosynthetic cells before the establishment of chloroplasts by extending preexisting mechanisms to cope with oxidative stress originating from mitochondrial respiration and acquiring new mechanisms.
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Affiliation(s)
- Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
- The Graduate University for Advanced Studies, SOKENDAI, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
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2
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Brown AL, Casarez GA, Moeller HV. Acquired Phototrophy as an Evolutionary Path to Mixotrophy. Am Nat 2023; 202:458-470. [PMID: 37792914 DOI: 10.1086/725918] [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] [Indexed: 10/06/2023]
Abstract
AbstractAcquired photosynthesis transforms genotypically heterotrophic lineages into autotrophs. Transient acquisitions of eukaryotic chloroplasts may provide key evolutionary insight into the endosymbiosis process-the hypothesized mechanism by which eukaryotic cells obtained new functions via organelle retention. Here, we use an eco-evolutionary model to study the environmental conditions under which chloroplast retention is evolutionarily favorable. We focus on kleptoplastidic lineages-which steal functional chloroplasts from their prey-as hypothetical evolutionary intermediates. Our adaptive dynamics analysis reveals a spectrum of evolutionarily stable strategies ranging from phagotrophy to phototrophy to obligate kleptoplasty. Our model suggests that a low-light niche and weak (or absent) trade-offs between chloroplast retention and overall digestive ability favor the evolution of phototrophy. In contrast, when consumers experience strong trade-offs, obligate kleptoplasty emerges as an evolutionary end point. Therefore, the preevolved trade-offs that underlie an evolving lineage's physiology will likely constrain its evolutionary trajectory.
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3
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Millette NC, Gast RJ, Luo JY, Moeller HV, Stamieszkin K, Andersen KH, Brownlee EF, Cohen NR, Duhamel S, Dutkiewicz S, Glibert PM, Johnson MD, Leles SG, Maloney AE, Mcmanus GB, Poulton N, Princiotta SD, Sanders RW, Wilken S. Mixoplankton and mixotrophy: future research priorities. JOURNAL OF PLANKTON RESEARCH 2023; 45:576-596. [PMID: 37483910 PMCID: PMC10361813 DOI: 10.1093/plankt/fbad020] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/14/2023] [Indexed: 07/25/2023]
Abstract
Phago-mixotrophy, the combination of photoautotrophy and phagotrophy in mixoplankton, organisms that can combine both trophic strategies, have gained increasing attention over the past decade. It is now recognized that a substantial number of protistan plankton species engage in phago-mixotrophy to obtain nutrients for growth and reproduction under a range of environmental conditions. Unfortunately, our current understanding of mixoplankton in aquatic systems significantly lags behind our understanding of zooplankton and phytoplankton, limiting our ability to fully comprehend the role of mixoplankton (and phago-mixotrophy) in the plankton food web and biogeochemical cycling. Here, we put forward five research directions that we believe will lead to major advancement in the field: (i) evolution: understanding mixotrophy in the context of the evolutionary transition from phagotrophy to photoautotrophy; (ii) traits and trade-offs: identifying the key traits and trade-offs constraining mixotrophic metabolisms; (iii) biogeography: large-scale patterns of mixoplankton distribution; (iv) biogeochemistry and trophic transfer: understanding mixoplankton as conduits of nutrients and energy; and (v) in situ methods: improving the identification of in situ mixoplankton and their phago-mixotrophic activity.
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Affiliation(s)
| | - Rebecca J Gast
- Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543, USA
| | - Jessica Y Luo
- NOAA Geophysical Fluid Dynamics Laboratory, 201 Forrestal Rd., Princeton, NJ 08540, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, 1120 Noble Hall, Santa Barbara, CA 93106, USA
| | - Karen Stamieszkin
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Dr., East Boothbay, ME 04544, USA
| | - Ken H Andersen
- Center for Ocean Life, Natl. Inst. of Aquatic Resources, Technical University of Denmark, Kemitorvet, Bygning 202, Kongens Lyngby 2840, Denmark
| | - Emily F Brownlee
- Department of Biology, St. Mary’s College of Maryland, 18952 E. Fisher Road, St. Mary’s City, MD 20686, USA
| | - Natalie R Cohen
- Skidaway Institute of Oceanography, University of Georgia, 10 Ocean Science Circle, Savannah, GA 31411, USA
| | - Solange Duhamel
- Department of Molecular and Cellular Biology, The University of Arizona, 1007 E Lowell Street, Tucson, AZ 85721, USA
| | - Stephanie Dutkiewicz
- Center for Global Change Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02874, USA
| | - Patricia M Glibert
- Horn Point Laboratory, University of Maryland Center for Environmental Science, 2020 Horns Point Rd, Cambridge, MD 21613, USA
| | - Matthew D Johnson
- Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543, USA
| | - Suzana G Leles
- Department of Marine and Environmental Biology, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089, USA
| | - Ashley E Maloney
- Geosciences Department, Princeton University, Guyot Hall, Princeton, NJ 08544, USA
| | - George B Mcmanus
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Rd., Groton, CT 06340, USA
| | - Nicole Poulton
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Dr., East Boothbay, ME 04544, USA
| | - Sarah D Princiotta
- Biology Department, Pennsylvania State University, Schuylkill Campus, 200 University Drive, Schuylkill Haven, PA 17972, USA
| | - Robert W Sanders
- Department of Biology, Temple University, 1900 N. 12th St., Philadelphia, PA 19122, USA
| | - Susanne Wilken
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
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4
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Moeller HV, Johnson MD. Mesodinium. Curr Biol 2023; 33:R249-R250. [PMID: 37040701 DOI: 10.1016/j.cub.2023.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
In this Quick guide, Holly Moeller and Matthew Johnson introduce Mesodinium, a genus of algae with a propensity for 'stealing' photosynthetic machinery from its prey.
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Affiliation(s)
- Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
| | - Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02540, USA
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Paight C, Johnson MD, Lasek-Nesselquist E, Moeller HV. Cascading effects of prey identity on gene expression in a kleptoplastidic ciliate. J Eukaryot Microbiol 2023; 70:e12940. [PMID: 35975609 PMCID: PMC10087830 DOI: 10.1111/jeu.12940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 07/14/2022] [Accepted: 08/05/2022] [Indexed: 01/13/2023]
Abstract
Kleptoplastidic, or chloroplast stealing, lineages transiently retain functional photosynthetic machinery from algal prey. This machinery, and its photosynthetic outputs, must be integrated into the host's metabolism, but the details of this integration are poorly understood. Here, we study this metabolic integration in the ciliate Mesodinium chamaeleon, a coastal marine species capable of retaining chloroplasts from at least six distinct genera of cryptophyte algae. To assess the effects of feeding history on ciliate physiology and gene expression, we acclimated M. chamaeleon to four different types of prey and contrasted well-fed and starved treatments. Consistent with previous physiological work on the ciliate, we found that starved ciliates had lower chlorophyll content, photosynthetic rates, and growth rates than their well-fed counterparts. However, ciliate gene expression mirrored prey phylogenetic relationships rather than physiological status, suggesting that, even as M. chamaeleon cells were starved of prey, their overarching regulatory systems remained tuned to the prey type to which they had been acclimated. Collectively, our results indicate a surprising degree of prey-specific host transcriptional adjustments, implying varied integration of prey metabolic potential into many aspects of ciliate physiology.
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Affiliation(s)
- Christopher Paight
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Erica Lasek-Nesselquist
- Wadsworth Center, NYSDOH, Albany, New York, USA.,Department of Biomedical Sciences, State University of New York at Albany School of Public Health, Rensselaer, New York, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, USA
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6
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Moeller HV, Hsu V, Lepori-Bui M, Mesrop LY, Chinn C, Johnson MD. Prey type constrains growth and photosynthetic capacity of the kleptoplastidic ciliate Mesodinium chamaeleon (Ciliophora). JOURNAL OF PHYCOLOGY 2021; 57:916-930. [PMID: 33454988 DOI: 10.1111/jpy.13131] [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: 08/21/2020] [Revised: 12/18/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
Kleptoplastidic, or chloroplast-stealing, lineages offer insight into the process of acquiring photosynthesis. By quantifying the ability of these organisms to retain and use photosynthetic machinery from their prey, we can understand how intermediaries on the endosymbiosis pathway might have evolved regulatory and maintenance mechanisms. Here, we focus on a mixotrophic kleptoplastidic ciliate, Mesodinium chamaeleon, noteworthy for its ability to retain functional chloroplasts from at least half a dozen cryptophyte algal genera. We contrasted the performance of kleptoplastids from blue-green and red cryptophyte prey as a function of light level and feeding history. Our experiments showed that starved M. chamaeleon cells are able to maintain photosynthetic function for at least 2 weeks and that M. chamaeleon containing red plastids lost chlorophyll and electron transport capacity faster than those containing blue-green plastids. However, likely due to increased pigment content and photosynthetic rates in red plastids, M. chamaeleon had higher growth rates and more prolonged growth when feeding on red cryptophytes. For example, M. chamaeleon grew rapidly and extensively when fed the blue-green cryptophyte Chroomonas mesostigmatica, but this growth appeared to hinge on high levels of feeding supporting photosynthetic activity. In contrast, even starved M. chamaeleon containing red plastids from Rhodomonas salina could achieve high photosynthetic rates and extensive growth. Our findings show that plastid origin impacts the maintenance and magnitude of photosynthetic activity, though whether this is due to variation in ciliate control or gradual loss of plastid function in ingested prey cells remains unknown.
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Affiliation(s)
- Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California - Santa Barbara, Santa Barbara, California, 93106, USA
| | - Veronica Hsu
- Department of Ecology, Evolution, and Marine Biology, University of California - Santa Barbara, Santa Barbara, California, 93106, USA
| | - Michelle Lepori-Bui
- Department of Ecology, Evolution, and Marine Biology, University of California - Santa Barbara, Santa Barbara, California, 93106, USA
| | - Lisa Y Mesrop
- Department of Ecology, Evolution, and Marine Biology, University of California - Santa Barbara, Santa Barbara, California, 93106, USA
| | - Cara Chinn
- Department of Ecology, Evolution, and Marine Biology, University of California - Santa Barbara, Santa Barbara, California, 93106, USA
| | - Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA
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Drumm K, Norlin A, Kim M, Altenburger A, Juel Hansen P. Physiological Responses of Mesodinium major to Irradiance, Prey Concentration and Prey Starvation. J Eukaryot Microbiol 2021; 68:e12854. [PMID: 33866638 DOI: 10.1111/jeu.12854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/31/2021] [Indexed: 11/30/2022]
Abstract
Ciliates within the Mesodinium rubrum/Mesodinium major species complex harbor chloroplasts and other cell organelles from specific cryptophyte species. Mesodinium major was recently described, and new studies indicate that blooms of M. major are just as common as blooms of M. rubrum. Despite this, the physiology of M. major has never been studied and compared to M. rubrum. In this study, growth, food uptake, chlorophyll a and photosynthesis were measured at six different irradiances, when fed the cryptophyte, Teleaulax amphioxeia. The results show that the light compensation point for growth of M. major was significantly higher than for M. rubrum. Inorganic carbon uptake via photosynthesis contributed by far most of total carbon uptake at most irradiances, similar to M. rubrum. Mesodinium major cells contain ~four times as many chloroplast as M. rubrum leading to up to ~four times higher rates of photosynthesis. The responses of M. major to prey starvation and refeeding were also studied. Mesodinium major was well adapted to prey starvation, and 51 d without prey did not lead to mortality. Mesodinium major quickly recovered from prey starvation when refed, due to high ingestion rates of > 150 prey/predator/d.
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Affiliation(s)
- Kirstine Drumm
- Department of Biology, University of Copenhagen, Helsingør, 3000, Denmark
- Department of Bioscience, University of Aarhus, Roskilde, 4000, Denmark
| | - Andreas Norlin
- Department of Biology, University of Copenhagen, Helsingør, 3000, Denmark
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, CF10 3AT, United Kingdom
| | - Miran Kim
- Department of Biology, University of Copenhagen, Helsingør, 3000, Denmark
- Honam National Institute of Biological Resources, Gohadoan-gil, Mokpo-si, Jeollanam-do, 58762, Korea
| | - Andreas Altenburger
- The Arctic University Museum of Norway, UiT - the Arctic University of Norway, Tromsø, 9037, Norway
| | - Per Juel Hansen
- Department of Biology, University of Copenhagen, Helsingør, 3000, Denmark
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Zhang S, Xia X, Ke Y, Song S, Shen Z, Cheung S, Liu H. Population dynamics and interactions of Noctiluca scintillans and Mesodinium rubrum during their successive blooms in a subtropical coastal water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:142349. [PMID: 33032128 DOI: 10.1016/j.scitotenv.2020.142349] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/09/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
A time series field survey were conducted in Port Shelter, a subtropical coastal water in NW Pacific, beginning before the onset of a chain of Noctiluca scintillans and/or Mesodinium rubrum blooms, and ending after the blooms had declined. At the first mixed bloom stage, seed of N. scintillans and the consequent outbreak of both N. scintillans and M. rubrum were largely due to the physical forcing. Plenty food supply and their different feeding habits supported N. scintillans and M. rubrum to bloom massively and concomitantly. Following that, there was a small N. scintillans bloom followed by a small crest of M. rubrum. Their initiation and scale were mainly affected by limited food supply and/or the inferior food source. Sudden change of wind from mild northeast wind to strong southeast wind might contribute to the termination of N. scintillans bloom. Finally, physical accumulation was the most important driving factors of the formation and dispersal of the third and largest bloom of N. scintillans. Formation of these bloom events may involve vertical migration and/or the concentrating mechanism of M. rubrum and N. scintillans. Meanwhile, biotic interactions such as mutual supportive relationship between N. scintillans and M. rubrum, and O. hongkongense fed on the progametes of N. scintillans, as well as other abiotic factors like seawater temperature and rainfall, also play important roles in this series of bloom events. Our findings have important implications for coastal zones worldwide, which are affected recurrently by these two ubiquitous red tide-forming species.
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Affiliation(s)
- Shuwen Zhang
- Guangdong Provincial Key Laboratory of Healthy and Safe Aquaculture, College of Life Science, South China Normal University, West 55 of Zhongshan Avenue, Guangzhou 510631, PR China
| | - Xiaomin Xia
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, PR China; Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, PR China
| | - Ying Ke
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region
| | - Shuqun Song
- Key Lab of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, PR China
| | - Zhuo Shen
- Institute of Microbial Ecology and Matter Cycle, School of Marine Sciences, Sun Yat-sen University, Zhuhai, PR China
| | - Shunyan Cheung
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region
| | - Hongbin Liu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region; Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region.
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Lemley DA, Adams JB, Rishworth GM, Purdie DA. Harmful algal blooms of Heterosigma akashiwo and environmental features regulate Mesodinium cf. rubrum abundance in eutrophic conditions. HARMFUL ALGAE 2020; 100:101943. [PMID: 33298364 DOI: 10.1016/j.hal.2020.101943] [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: 05/05/2020] [Revised: 10/29/2020] [Accepted: 11/05/2020] [Indexed: 06/12/2023]
Abstract
Functional drivers of phytoplankton that can potentially form harmful algal blooms (HABs) are important to understand given the increased prevalence of anthropogenic modification and pressure on coastal habitats. However, teasing these drivers apart from other influences is problematic in natural systems, while laboratory assessments often fail to replicate relevant natural conditions. One such potential bloom-forming species complex highlighted globally is Mesodinium cf. rubrum, a planktonic ciliate. This species occurs persistently in the Sundays Estuary in South Africa yet has never been observed to "bloom" (> 1,000 cell.ml-1). Modified by artificial nutrient-rich baseflow conditions, the Sundays Estuary provides a unique Southern Hemisphere case study to identify the autecological drivers of this ciliate due to artificial seasonally "controlled" abiotic environmental conditions. This study utilised a three-year monitoring dataset (899 samples) to assess the drivers of M. cf. rubrum using a generalised modelling approach. Key abiotic variables that influenced population abundance were season and salinity, with M. cf. rubrum populations peaking in summer and spring and preferring polyhaline salinity regions (>18) with pronounced water column salinity stratification, especially in warmer months. This was reflected in the diel vertical migration (DVM) behaviour of this species, demonstrating its ability to utilise the optimal daylight photosynthetic surface conditions and high-nutrient bottom waters at night. The only phytoplankton groups clearly associated with M. cf. rubrum were Raphidophyceae and Cryptophyceae. Although M. cf. rubrum reflects a niche overlap with the dominant HAB-forming phytoplankton in the estuary (the raphidophyte, Heterosigma akashiwo), its reduced competitive abilities restrict its abundance. In contrast, the mixotrophic foraging behaviour of M. cf. rubrum exerts a top-down control on cryptophyte prey abundance, yet, the limited availability of these prey resources (mean < 300 cells ml-1) seemingly inhibits the formation of red-water accumulations. Hydrodynamic variability is necessary to ensure that no single phytoplankton HAB-forming taxa outcompetes the rest. These results confirm aspects of the autecology of M. cf. rubrum related to salinity associations and DVM behaviour and contribute to a global understanding of managing HABs in estuaries.
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Affiliation(s)
- Daniel A Lemley
- Botany Department, Nelson Mandela University, Port Elizabeth 6031, South Africa; DSI/NRF Research Chair in Shallow Water Ecosystems, Institute for Coastal and Marine Research (CMR), Nelson Mandela University, Port Elizabeth 6031, South Africa.
| | - Janine B Adams
- Botany Department, Nelson Mandela University, Port Elizabeth 6031, South Africa; DSI/NRF Research Chair in Shallow Water Ecosystems, Institute for Coastal and Marine Research (CMR), Nelson Mandela University, Port Elizabeth 6031, South Africa.
| | - Gavin M Rishworth
- DSI/NRF Research Chair in Shallow Water Ecosystems, Institute for Coastal and Marine Research (CMR), Nelson Mandela University, Port Elizabeth 6031, South Africa; Zoology Department, Nelson Mandela University, Port Elizabeth 6031, South Africa.
| | - Duncan A Purdie
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, United Kingdom.
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Lasek-Nesselquist E, Johnson MD. A Phylogenomic Approach to Clarifying the Relationship of Mesodinium within the Ciliophora: A Case Study in the Complexity of Mixed-Species Transcriptome Analyses. Genome Biol Evol 2019; 11:3218-3232. [PMID: 31665294 PMCID: PMC6859813 DOI: 10.1093/gbe/evz233] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2019] [Indexed: 11/25/2022] Open
Abstract
Recent high-throughput sequencing endeavors have yielded multigene/protein phylogenies that confidently resolve several inter- and intra-class relationships within the phylum Ciliophora. We leverage the massive sequencing efforts from the Marine Microbial Eukaryote Transcriptome Sequencing Project, other SRA submissions, and available genome data with our own sequencing efforts to determine the phylogenetic position of Mesodinium and to generate the most taxonomically rich phylogenomic ciliate tree to date. Regardless of the data mining strategy, the multiprotein data set, or the molecular models of evolution employed, we consistently recovered the same well-supported relationships among ciliate classes, confirming many of the higher-level relationships previously identified. Mesodinium always formed a monophyletic group with members of the Litostomatea, with mixotrophic species of Mesodinium-M. rubrum, M. major, and M. chamaeleon-being more closely related to each other than to the heterotrophic member, M. pulex. The well-supported position of Mesodinium as sister to other litostomes contrasts with previous molecular analyses including those from phylogenomic studies that exploited the same transcriptomic databases. These topological discrepancies illustrate the need for caution when mining mixed-species transcriptomes and indicate that identifying ciliate sequences among prey contamination-particularly for Mesodinium species where expression from stolen prey nuclei appears to dominate-requires thorough and iterative vetting with phylogenies that incorporate sequences from a large outgroup of prey.
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Affiliation(s)
| | - Matthew D Johnson
- Biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
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11
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Kim M, Park MG. Unveiling the hidden genetic diversity and chloroplast type of marine benthic ciliate Mesodinium species. Sci Rep 2019; 9:14081. [PMID: 31575940 PMCID: PMC6773952 DOI: 10.1038/s41598-019-50659-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/23/2019] [Indexed: 12/12/2022] Open
Abstract
Ciliate Mesodinium species are commonly distributed in diverse aquatic systems worldwide. Among Mesodinium species, M. rubrum is closely associated with microbial food webs and red tide formation and is known to acquire chloroplasts from its cryptophyte prey for use in photosynthesis. For these reasons, Mesodinium has long received much attention in terms of ecophysiology and chloroplast evolution. Mesodinium cells are easily identifiable from other organisms owing to their unique morphology comprising two hemispheres, but a clear distinction among species is difficult under a microscope. Recent taxonomic studies of Mesodinium have been conducted largely in parallel with molecular sequence analysis, and the results have shown that the best-known planktonic M. rubrum in fact comprises eight genetic clades of a M. rubrum/M. major complex. However, unlike the planktonic Mesodinium species, little is known of the genetic diversity of benthic Mesodinium species, and to our knowledge, the present study is the first to explore this. A total of ten genetic clades, including two clades composed of M. chamaeleon and M. coatsi, were found in marine sandy sediments, eight of which were clades newly discovered through this study. We report the updated phylogenetic relationship within the genus Mesodinium comprising heterotrophic/mixotrophic as well as planktonic/benthic species. Furthermore, we unveiled the wide variety of chloroplasts of benthic Mesodinium, which were related to the green cryptophyte Chroomonas/Hemiselmis and the red cryptophyte Rhodomonas/Storeatula/Teleaulax groups.
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Affiliation(s)
- Miran Kim
- Research Institute for Basic Science, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Myung Gil Park
- LOHABE, Department of Oceanography, Chonnam National University, Gwangju, 61186, Republic of Korea.
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Kim M, Kang M, Park MG. Growth and Chloroplast Replacement of the Benthic Mixotrophic Ciliate Mesodinium coatsi. J Eukaryot Microbiol 2019; 66:625-636. [PMID: 30561091 PMCID: PMC6766864 DOI: 10.1111/jeu.12709] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 09/27/2018] [Accepted: 12/06/2018] [Indexed: 01/14/2023]
Abstract
While the ecophysiology of planktonic Mesodinium rubrum species complex has been relatively well studied, very little is known about that of benthic Mesodinium species. In this study, we examined the growth response of the benthic ciliate Mesodinium coatsi to different cryptophyte prey using an established culture of this species. M. coatsi was able to ingest all of the offered cryptophyte prey types, but not all cryptophytes supported its positive, sustained growth. While M. coatsi achieved sustained growth on all of the phycocyanin‐containing Chroomonas spp. it was offered, it showed different growth responses to the phycoerythrin‐containing cryptophytes Rhodomonas spp., Storeatula sp., and Teleaulax amphioxeia. M. coatsi was able to easily replace previously ingested prey chloroplasts with newly ingested ones within 4 d, irrespective of prey type, if cryptophyte prey were available. Once retained, the ingested prey chloroplasts seemed to be photosynthetically active. When fed, M. coatsi was capable of heterotrophic growth in darkness, but its growth was enhanced significantly in the light (14:10 h light:dark cycle), suggesting that photosynthesis by ingested prey chloroplast leads to a significant increase in the growth of M. coatsi. Our results expand the knowledge of autecology and ecophysiology of the benthic M. coatsi.
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Affiliation(s)
- Miran Kim
- Research Institute for Basic Science, Chonnam National University, Gwangju, 61186, Korea
| | - Misun Kang
- LOHABE, Department of Oceanography, Chonnam National University, Gwangju, 61186, Korea
| | - Myung Gil Park
- LOHABE, Department of Oceanography, Chonnam National University, Gwangju, 61186, Korea
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Nishitani G, Yamaguchi M. Seasonal succession of ciliate Mesodinium spp. with red, green, or mixed plastids and their association with cryptophyte prey. Sci Rep 2018; 8:17189. [PMID: 30464297 PMCID: PMC6249236 DOI: 10.1038/s41598-018-35629-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 11/07/2018] [Indexed: 11/09/2022] Open
Abstract
Mesodinium spp. are commonly found in marine and brackish waters, and several species are known to contain red, green, or both plastids that originate from cryptophyte prey. We observed the seasonal succession of Mesodinium spp. in a Japanese brackish lake, and we analysed the origin and diversity of the various coloured plastids within the cells of Mesodinium spp. using a newly developed primer set that specifically targets the cryptophyte nuclear 18S rRNA gene. Mesodinium rubrum isolated from the lake contained only red plastids originating from cryptophyte Teleaulax amphioxeia. We identified novel Mesodinium sp. that contained only green plastids or both red and green plastids originating from cryptophytes Hemiselmis sp. and Teleaulax acuta. Although the morphology of the newly identified Mesodinium sp. was indistinguishable from that of M. rubrum under normal light microscopy, phylogenetic analysis placed this species between the M. rubrum/major species complex and a well-supported lineage of M. chamaeleon and M. coatsi. Close associations were observed in cryptophyte species composition within cells of Mesodinium spp. and in ambient water samples. The appearance of suitable cryptophyte prey is probably a trigger for succession of Mesodinium spp., and the subsequent abundance of Mesodinium spp. appears to be influenced by water temperature and dissolved inorganic nutrients.
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Affiliation(s)
- Goh Nishitani
- Graduate School of Agricultural Science, Tohoku University, Aoba 468-1, Aramaki, Aoba-ku, Sendai, 980-0845, Japan.
| | - Mineo Yamaguchi
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan.
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Inorganic carbon and nitrogen assimilation in cellular compartments of a benthic kleptoplastic foraminifer. Sci Rep 2018; 8:10140. [PMID: 29973634 PMCID: PMC6031614 DOI: 10.1038/s41598-018-28455-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/20/2018] [Indexed: 11/08/2022] Open
Abstract
Haynesina germanica, an ubiquitous benthic foraminifer in intertidal mudflats, has the remarkable ability to isolate, sequester, and use chloroplasts from microalgae. The photosynthetic functionality of these kleptoplasts has been demonstrated by measuring photosystem II quantum efficiency and O2 production rates, but the precise role of the kleptoplasts in foraminiferal metabolism is poorly understood. Thus, the mechanism and dynamics of C and N assimilation and translocation from the kleptoplasts to the foraminiferal host requires study. The objective of this study was to investigate, using correlated TEM and NanoSIMS imaging, the assimilation of inorganic C and N (here ammonium, NH4+) in individuals of a kleptoplastic benthic foraminiferal species. H. germanica specimens were incubated for 20 h in artificial seawater enriched with H13CO3- and 15NH4+ during a light/dark cycle. All specimens (n = 12) incorporated 13C into their endoplasm stored primarily in the form of lipid droplets. A control incubation in darkness resulted in no 13C-uptake, strongly suggesting that photosynthesis is the process dominating inorganic C assimilation. Ammonium assimilation was observed both with and without light, with diffuse 15N-enrichment throughout the cytoplasm and distinct 15N-hotspots in fibrillar vesicles, electron-opaque bodies, tubulin paracrystals, bacterial associates, and, rarely and at moderate levels, in kleptoplasts. The latter observation might indicate that the kleptoplasts are involved in N assimilation. However, the higher N assimilation observed in the foraminiferal endoplasm incubated without light suggests that another cytoplasmic pathway is dominant, at least in darkness. This study clearly shows the advantage provided by the kleptoplasts as an additional source of carbon and provides observations of ammonium uptake by the foraminiferal cell.
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