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Matthew D. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Preferential Plastid Retention by the Acquired Phototroph Mesodinium chamaeleon.
The Journal of eukaryotic microbiology, 2017Co-Authors: Holly V. Moeller, Matthew D. JohnsonAbstract:The ciliate genus Mesodinium contains species that rely to varying degrees on photosynthetic machinery stolen from cryptophyte algal prey. Prey specificity appears to scales inversely with this reliance: The predominantly phototrophic M. major/rubrum species complex exhibits high prey specificity, while the heterotrophic lineages M. pulex and pupula are generalists. Here, we test the hypothesis that the recently described mixotroph M. chamaeleon, which is phylogenetically intermediate between M. major/rubrum and M. pulex/pupula, exhibits intermediate prey preferences. Using a series of feeding and starvation experiments, we demonstrate that M. chamaeleon grazes and retains plastids at rates which often exceed those observed in M. rubrum, and retains plastids from at least five genera of cryptophyte algae. Despite this relative generality, M. chamaeleon exhibits distinct prey preferences, with higher plastid retention, mixotrophic growth rates and efficiencies, and starvation tolerance when offered Storeatula major, a cryptophyte that M. rubrum does not appear to ingest. These results suggest that niche partitioning between the two acquired phototrophs may be mediated by prey identity. M. chamaeleon appears to represent an intermediate step in the transition to strict reliance on acquired Phototrophy, indicating that prey specificity may evolve alongside degree of Phototrophy.
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Acquired Phototrophy stabilises coexistence and shapes intrinsic dynamics of an intraguild predator and its prey.
Ecology letters, 2016Co-Authors: Holly V. Moeller, Matthew D. Johnson, Elina Peltomaa, Michael G. NeubertAbstract:In marine ecosystems, acquired phototrophs - organisms that obtain their photosynthetic ability by hosting endosymbionts or stealing plastids from their prey - are omnipresent. Such taxa function as intraguild predators yet depend on their prey to periodically obtain chloroplasts. We present a new theory for the effects of acquired Phototrophy on community dynamics by analysing a mathematical model of this predator-prey interaction and experimentally verifying its predictions with a laboratory model system. We show that acquired Phototrophy stabilises coexistence, but that the nature of this coexistence exhibits a 'paradox of enrichment': as light increases, the coexistence between the acquired phototroph and its prey transitions from a stable equilibrium to boom-bust cycles whose amplitude increases with light availability. In contrast, heterotrophs and mixotrophic acquired phototrophs (that obtain 95% of carbon from photosynthesis) acquired phototrophs form blooms.
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acquired Phototrophy in mesodinium and dinophysis a review of cellular organization prey selectivity nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Terje Berge, Lasse Tor Nielsen, Per Juel Hansen, Matthew D. Johnson, Kevin J. FlynnAbstract:Abstract Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
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Acquired Phototrophy in Mesodinium and Dinophysis – A review of cellular organization, prey selectivity, nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Per Juel Hansen, Terje Berge, Lasse Tor Nielsen, Matthew D. Johnson, Kevin J. FlynnAbstract:Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
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Acquired Phototrophy in ciliates: a review of cellular interactions and structural adaptations.
The Journal of eukaryotic microbiology, 2011Co-Authors: Matthew D. JohnsonAbstract:Many ciliates acquire the capacity for photosynthesis through stealing plastids or harboring intact endosymbiotic algae. Both phenomena are a form of mixotrophy and are widespread among ciliates. Mixotrophic ciliates may be abundant in freshwater and marine ecosystems, sometimes making substantial contributions toward community primary productivity. While mixotrophic ciliates utilize phagotrophy to capture algal cells, their endomembrane system has evolved to partially bypass typical heterotrophic digestion pathways, enabling metabolic interaction with foreign cells or organelles. Unique adaptations may also be found in certain algal endosymbionts, facilitating establishment of symbiosis and nutritional interactions, while reducing their fitness for survival as free-living cells. Plastid retaining oligotrich ciliates possess little selectivity from which algae they sequester plastids, resulting in unstable kleptoplastids that require frequent ingestion of algal cells to replace them. Mesodinium rubrum ( = Myrionecta rubra) possesses cryptophyte organelles that resemble a reduced endosymbont, and is the only ciliate capable of functional Phototrophy and plastid division. Certain strains of M. rubrum may have a stable association with their cryptophyte organelles, while others need to acquire a cryptophyte nucleus through feeding. This process of stealing a nucleus, termed karyoklepty, was first described in M. rubrum and may be an evolutionary precursor to a stable, reduced endosymbiont, and perhaps eventually a tertiary plastid. The newly described Mesodinium "chamaeleon," however, is less selective of which cryptophyte species it will retain organelles, and appears less capable of sustained Phototrophy. Ciliates likely stem from a phototrophic ancestry, which may explain their propensity to practice acquired Phototrophy.
Kevin J. Flynn - One of the best experts on this subject based on the ideXlab platform.
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Oceanic protists with different forms of acquired Phototrophy display contrasting biogeographies and abundance
Proceedings. Biological sciences, 2017Co-Authors: Suzanne Leles, Robert W. Sanders, Kevin J. Flynn, Per Juel Hansen, Diane K. Stoecker, Aditee Mitra, Albert Calbet, George B. Mcmanus, David A. Caron, Fabrice NotAbstract:This first comprehensive analysis of the global biogeography of marine protistan plankton with acquired Phototrophy shows these mixotrophic organisms to be ubiquitous and abundant; however, their biogeography differs markedly between different functional groups. These mixotrophs, lacking a constitutive capacity for photosynthesis (i.e. non-constitutive mixotrophs, NCMs), acquire their phototrophic potential through either integration of prey-plastids or through endosymbiotic associations with photosynthetic microbes. Analysis of field data reveals that 40–60% of plankton traditionally labelled as (non-phototrophic) microzooplankton are actually NCMs, employing acquired Phototrophy in addition to phagotrophy. Specialist NCMs acquire chloroplasts or endosymbionts from specific prey, while generalist NCMs obtain chloroplasts from a variety of prey. These contrasting functional types of NCMs exhibit distinct seasonal and spatial global distribution patterns. Mixotrophs reliant on ‘stolen’ chloroplasts, controlled by prey diversity and abundance, dominate in high-biomass areas. Mixotrophs harbouring intact symbionts are present in all waters and dominate particularly in oligotrophic open ocean systems. The contrasting temporal and spatial patterns of distribution of different mixotroph functional types across the oceanic provinces, as revealed in this study, challenges traditional interpretations of marine food web structures. Mixotrophs with acquired Phototrophy (NCMs) warrant greater recognition in marine research.
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Modeling plankton mixotrophy: A mechanistic model consistent with the shuter-type biochemical approach
Frontiers in Ecology and Evolution, 2017Co-Authors: Caroline Ghyoot, Kevin J. Flynn, Aditee Mitra, Christiane Lancelot, Nathalie GypensAbstract:Mixotrophy, i.e., the ability to combine Phototrophy and phagotrophy in one organism, is now recognized to be widespread among photic-zone protists and to potentially modify the structure and functioning of planktonic ecosystems. However, few biogeochemical/ecological models explicitly include this mode of nutrition, owing to the large diversity of observed mixotrophic types, the few data allowing the parameterization of physiological processes, and the need to make the addition of mixotrophy into existing ecosystem models as simple as possible. We here propose and discuss a flexible model that depicts the main observed behaviors of mixotrophy in microplankton. A first model version describes constitutive mixotrophy (the organism photosynthesizes by use of its own chloroplasts). This model version offers two possible configurations, allowing the description of constitutive mixotrophs (CMs) that favor either Phototrophy or heterotrophy. A second version describes non-constitutive mixotrophy (the organism performs Phototrophy by use of chloroplasts acquired from its prey). The model variants were described so as to be consistent with a plankton conceptualization in which the biomass is divided into separate components on the basis of their biochemical function (Shuter-approach; Shuter, 1979). The two model variants of mixotrophy can easily be implemented in ecological models that adopt the Shuter-approach, such as the MIRO model (Lancelot et al., 2005), and address the challenges associated with modelling mixotrophy.
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acquired Phototrophy in mesodinium and dinophysis a review of cellular organization prey selectivity nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Terje Berge, Lasse Tor Nielsen, Per Juel Hansen, Matthew D. Johnson, Kevin J. FlynnAbstract:Abstract Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
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Acquired Phototrophy in Mesodinium and Dinophysis – A review of cellular organization, prey selectivity, nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Per Juel Hansen, Terje Berge, Lasse Tor Nielsen, Matthew D. Johnson, Kevin J. FlynnAbstract:Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
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Prey selection and rejection by a microflagellate; implications for the study and operation of microbial food webs
Journal of Experimental Marine Biology and Ecology, 1996Co-Authors: Kevin J. Flynn, Keith Davidson, Alex CunninghamAbstract:Abstract In a series of experiments, measurements were made of both numbers and biovolumes of the phototrophs Dunaliella primolecta (Butcher) (7.6 μm diameter), Isochrysis galbana (Parke) (4.5 μm), and Micromonas pusilla (Butcher) (1.5 μm), together with the phagotrophic dinoflagellate Oxyrrhis marina (Dujardin) (typically 16–20 μm). This enabled the calculation of the ‘equivalent encounter distance’ (l eq ), which gives a measure of the distance an average sized predator would have to swim in order to encounter a biovolume of prey equal to its own cell volume. If predation of a given prey type continues when its l eq is greater than that of an alternative prey item, then the predator is deemed to be demonstrating a preference for the former item. When confronted with all three phototrophs, Oxyrrhis selected Dunaliella first but, despite the 25-fold difference in cell volume, showed no preference for Isochrysis over Micromonas. Oxyrrhis may also reject Isochrysis on occasion, an event which seems to be associated particularly with elevated C:N ratios in the phototroph. Oxyrrhis has been seen to exhibit cannibalism when in the presence of Isochrysis biovolumes (biomass concentrations) an order of magnitude above that of Oxyrrhis . Such plasticity in prey selection makes it very difficult to predict the outcome of predator-prey interactions, especially where (as between Dunaliella and Isochrysis ) there are also growth interactions between the prey species. It also suggests that results obtained from short term studies of predation-kinetics, or in studies conducted under conditions such as in steady-state cultures and in continuous darkness, should not be generalised to more realistic environmental conditions.
Per Juel Hansen - One of the best experts on this subject based on the ideXlab platform.
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Oceanic protists with different forms of acquired Phototrophy display contrasting biogeographies and abundance
Proceedings. Biological sciences, 2017Co-Authors: Suzanne Leles, Robert W. Sanders, Kevin J. Flynn, Per Juel Hansen, Diane K. Stoecker, Aditee Mitra, Albert Calbet, George B. Mcmanus, David A. Caron, Fabrice NotAbstract:This first comprehensive analysis of the global biogeography of marine protistan plankton with acquired Phototrophy shows these mixotrophic organisms to be ubiquitous and abundant; however, their biogeography differs markedly between different functional groups. These mixotrophs, lacking a constitutive capacity for photosynthesis (i.e. non-constitutive mixotrophs, NCMs), acquire their phototrophic potential through either integration of prey-plastids or through endosymbiotic associations with photosynthetic microbes. Analysis of field data reveals that 40–60% of plankton traditionally labelled as (non-phototrophic) microzooplankton are actually NCMs, employing acquired Phototrophy in addition to phagotrophy. Specialist NCMs acquire chloroplasts or endosymbionts from specific prey, while generalist NCMs obtain chloroplasts from a variety of prey. These contrasting functional types of NCMs exhibit distinct seasonal and spatial global distribution patterns. Mixotrophs reliant on ‘stolen’ chloroplasts, controlled by prey diversity and abundance, dominate in high-biomass areas. Mixotrophs harbouring intact symbionts are present in all waters and dominate particularly in oligotrophic open ocean systems. The contrasting temporal and spatial patterns of distribution of different mixotroph functional types across the oceanic provinces, as revealed in this study, challenges traditional interpretations of marine food web structures. Mixotrophs with acquired Phototrophy (NCMs) warrant greater recognition in marine research.
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acquired Phototrophy in mesodinium and dinophysis a review of cellular organization prey selectivity nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Terje Berge, Lasse Tor Nielsen, Per Juel Hansen, Matthew D. Johnson, Kevin J. FlynnAbstract:Abstract Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
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Acquired Phototrophy in Mesodinium and Dinophysis – A review of cellular organization, prey selectivity, nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Per Juel Hansen, Terje Berge, Lasse Tor Nielsen, Matthew D. Johnson, Kevin J. FlynnAbstract:Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
Lasse Tor Nielsen - One of the best experts on this subject based on the ideXlab platform.
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Trophic strategies of unicellular plankton
The American Naturalist, 2017Co-Authors: Subhendu Chakraborty, Lasse Tor Nielsen, Ken Haste AndersenAbstract:AbstractUnicellular plankton employ trophic strategies ranging from pure photoautotrophs over mixotrophy to obligate heterotrophs (phagotrophs), with cell sizes from 10−8 to 1 μg C. A full understanding of how trophic strategy and cell size depend on resource environment and predation is lacking. To this end, we develop and calibrate a trait-based model for unicellular planktonic organisms characterized by four traits: cell size and investments in Phototrophy, nutrient uptake, and phagotrophy. We use the model to predict how optimal trophic strategies depend on cell size under various environmental conditions, including seasonal succession. We identify two mixotrophic strategies: generalist mixotrophs investing in all three investment traits and obligate mixotrophs investing only in Phototrophy and phagotrophy. We formulate two conjectures: (1) most cells are limited by organic carbon; however, small unicellulars are colimited by organic carbon and nutrients, and only large photoautotrophs and smaller mix...
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acquired Phototrophy in mesodinium and dinophysis a review of cellular organization prey selectivity nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Terje Berge, Lasse Tor Nielsen, Per Juel Hansen, Matthew D. Johnson, Kevin J. FlynnAbstract:Abstract Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
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Acquired Phototrophy in Mesodinium and Dinophysis – A review of cellular organization, prey selectivity, nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Per Juel Hansen, Terje Berge, Lasse Tor Nielsen, Matthew D. Johnson, Kevin J. FlynnAbstract:Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
Terje Berge - One of the best experts on this subject based on the ideXlab platform.
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acquired Phototrophy in mesodinium and dinophysis a review of cellular organization prey selectivity nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Terje Berge, Lasse Tor Nielsen, Per Juel Hansen, Matthew D. Johnson, Kevin J. FlynnAbstract:Abstract Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
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Acquired Phototrophy in Mesodinium and Dinophysis – A review of cellular organization, prey selectivity, nutrient uptake and bioenergetics
Harmful Algae, 2013Co-Authors: Per Juel Hansen, Terje Berge, Lasse Tor Nielsen, Matthew D. Johnson, Kevin J. FlynnAbstract:Acquired Phototrophy, i.e. the use of chloroplasts from ingested prey, can be found among some species of dinoflagellates and ciliates. The best studied examples of this phenomenon in these groups are within the ciliate genus Mesodinium and the dinoflagellate genus Dinophysis, both ecologically important genera with a worldwide distribution. Mesodinium species differ considerably in their carbon metabolism. Some species rely almost exclusively on food uptake, while other species rely mostly on photosynthesis. In Mesodinium with acquired Phototrophy, a number of prey organelles in addition to chloroplasts may be retained, and the host ciliate has considerable control over the acquired chloroplasts; Mesodinium rubrum is capable of dividing its acquired chloroplasts and can also photoacclimate. In Dinophysis spp., the contents of ciliate prey are sucked out, but only the chloroplasts are retained from the ingested prey. Some chloroplast house-keeping genes have been found in the nucleus of Dinophysis and some preliminary evidence suggests that Dinophysis may be capable for photoacclimation. Both genera have been claimed to take up inorganic nutrients, including NO3−, indicating that processes beyond photosynthesis have been acquired. M. rubrum seems to depend upon prey species within the Teleaulax/Plagioselmis/Geminigera clade of marine cryptophytes. Up until now, Dinophysis species have only been maintained cultured on M. rubrum as food, but other ciliates may also be ingested. Dinophysis spp. and M. rubrum are obligate mixotrophs, depending upon both prey and light for sustained growth. However, while M. rubrum only needs to ingest 1–2% of its carbon demand per day to attain maximum growth, Dinophysis spp. need to obtain about half of their carbon demand from ingestion for maximum growth. Both Mesodinium and Dinophysis spp. can survive for months in the light without food. The potential role for modeling in exploring the complex balance of Phototrophy and phago-heterotrophy, and its ecological implications for the mixotroph and their prey, is discussed.
