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Kazumi Matsuoka - One of the best experts on this subject based on the ideXlab platform.
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cyst theca relationship and phylogenetic position of impagidinium caspienense incubated from caspian sea surface sediments relation to Gonyaulax baltica and evidence for heterospory within gonyaulacoid dinoflagellates
Journal of Eukaryotic Microbiology, 2017Co-Authors: Kenneth Neil Mertens, Yoshihito Takano, Siamak Bagheri, Vera Pospelova, Anna J. Pieńkowski, Suzanne A.g. Leroy, Kazumi MatsuokaAbstract:We investigate the cyst-theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single-cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. (2002). The ability of this species to belong to two types of cyst-based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by Gonyaulax baltica, which provides evidence for heterospory in this species. The affiliation to Gonyaulax baltica demonstrates that Impagidinium caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other gonyaulacoid species is also documented: Impagidinium pallidum, Ataxiodinium choane, Pyxidinopsis psilata, Spiniferites belerius, and Spiniferites ramosus. The LSU and SSU rDNA based phylogenies suggest that the genera Impagidinium and Spiniferites are not monophyletic, and that Pyxidinopsis psilata and Ataxiodinium choane are close to Gonyaulax verior and Gonyaulax polygramma, respectively. In addition, this study accentuates the importance of cyst morphology in the classification of the Gonyaulacales. This article is protected by copyright. All rights reserved.
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Cyst‐Theca Relationship and Phylogenetic Position of Impagidinium caspienense Incubated from Caspian Sea Surface Sediments: Relation to Gonyaulax baltica and Evidence for Heterospory within Gonyaulacoid Dinoflagellates
Journal of Eukaryotic Microbiology, 2017Co-Authors: Kenneth Neil Mertens, Yoshihito Takano, Siamak Bagheri, Vera Pospelova, Anna J. Pieńkowski, Suzanne A.g. Leroy, Kazumi MatsuokaAbstract:We investigate the cyst-theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single-cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. (2002). The ability of this species to belong to two types of cyst-based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by Gonyaulax baltica, which provides evidence for heterospory in this species. The affiliation to Gonyaulax baltica demonstrates that Impagidinium caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other gonyaulacoid species is also documented: Impagidinium pallidum, Ataxiodinium choane, Pyxidinopsis psilata, Spiniferites belerius, and Spiniferites ramosus. The LSU and SSU rDNA based phylogenies suggest that the genera Impagidinium and Spiniferites are not monophyletic, and that Pyxidinopsis psilata and Ataxiodinium choane are close to Gonyaulax verior and Gonyaulax polygramma, respectively. In addition, this study accentuates the importance of cyst morphology in the classification of the Gonyaulacales. This article is protected by copyright. All rights reserved.
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relationship between the dinoflagellate cyst spiniferites pachydermus and Gonyaulax ellegaardiae sp nov from izmir bay turkey and molecular characterization
Journal of Phycology, 2015Co-Authors: Kenneth Neil Mertens, Yoshihito Takano, Hilal Aydin, Serdar Uzar, Aika Yamaguchi, Kazumi MatsuokaAbstract:Here, we established the cyst-motile stage relation-ship for Spiniferites pachydermus through incubation of cysts with a characteristically microreticulate/perforate surface isolated from Izmir Bay in the eastern Aegean Sea of the eastern Mediterranean. The morphology of the motile stage was similar to Gonyaulax spinifera but had a different size, overhang, displacement and reticulations. Based on the distinct morphology of the cyst and morphological differences in motile cells, we assigned S. pachydermus from Izmir Bay to the new species Gonyaulax ellegaardiae. We elucidate the phylogenetic relationship of G. ellegaardiae through large and small subunit ribosomal DNA and show that it forms a clade with other species that belong to the G. spinifera complex.
Kenneth Neil Mertens - One of the best experts on this subject based on the ideXlab platform.
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Should Gonyaulax hyalina and Gonyaulax fragilis (Dinophyceae) remain two different taxa
Phycologia, 2019Co-Authors: M. Consuelo Carbonell-moore, Kenneth Neil MertensAbstract:Escalera et al. (2018. Phycologia 57: 453–464) concluded that Gonyaulax hyalina and G. fragilis were the same species. Here, the morphologies of G. hyalina and G. fragilis were restudied in field s...
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cyst theca relationship and phylogenetic position of impagidinium caspienense incubated from caspian sea surface sediments relation to Gonyaulax baltica and evidence for heterospory within gonyaulacoid dinoflagellates
Journal of Eukaryotic Microbiology, 2017Co-Authors: Kenneth Neil Mertens, Yoshihito Takano, Siamak Bagheri, Vera Pospelova, Anna J. Pieńkowski, Suzanne A.g. Leroy, Kazumi MatsuokaAbstract:We investigate the cyst-theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single-cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. (2002). The ability of this species to belong to two types of cyst-based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by Gonyaulax baltica, which provides evidence for heterospory in this species. The affiliation to Gonyaulax baltica demonstrates that Impagidinium caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other gonyaulacoid species is also documented: Impagidinium pallidum, Ataxiodinium choane, Pyxidinopsis psilata, Spiniferites belerius, and Spiniferites ramosus. The LSU and SSU rDNA based phylogenies suggest that the genera Impagidinium and Spiniferites are not monophyletic, and that Pyxidinopsis psilata and Ataxiodinium choane are close to Gonyaulax verior and Gonyaulax polygramma, respectively. In addition, this study accentuates the importance of cyst morphology in the classification of the Gonyaulacales. This article is protected by copyright. All rights reserved.
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Cyst‐Theca Relationship and Phylogenetic Position of Impagidinium caspienense Incubated from Caspian Sea Surface Sediments: Relation to Gonyaulax baltica and Evidence for Heterospory within Gonyaulacoid Dinoflagellates
Journal of Eukaryotic Microbiology, 2017Co-Authors: Kenneth Neil Mertens, Yoshihito Takano, Siamak Bagheri, Vera Pospelova, Anna J. Pieńkowski, Suzanne A.g. Leroy, Kazumi MatsuokaAbstract:We investigate the cyst-theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single-cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. (2002). The ability of this species to belong to two types of cyst-based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by Gonyaulax baltica, which provides evidence for heterospory in this species. The affiliation to Gonyaulax baltica demonstrates that Impagidinium caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other gonyaulacoid species is also documented: Impagidinium pallidum, Ataxiodinium choane, Pyxidinopsis psilata, Spiniferites belerius, and Spiniferites ramosus. The LSU and SSU rDNA based phylogenies suggest that the genera Impagidinium and Spiniferites are not monophyletic, and that Pyxidinopsis psilata and Ataxiodinium choane are close to Gonyaulax verior and Gonyaulax polygramma, respectively. In addition, this study accentuates the importance of cyst morphology in the classification of the Gonyaulacales. This article is protected by copyright. All rights reserved.
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relationship between the dinoflagellate cyst spiniferites pachydermus and Gonyaulax ellegaardiae sp nov from izmir bay turkey and molecular characterization
Journal of Phycology, 2015Co-Authors: Kenneth Neil Mertens, Yoshihito Takano, Hilal Aydin, Serdar Uzar, Aika Yamaguchi, Kazumi MatsuokaAbstract:Here, we established the cyst-motile stage relation-ship for Spiniferites pachydermus through incubation of cysts with a characteristically microreticulate/perforate surface isolated from Izmir Bay in the eastern Aegean Sea of the eastern Mediterranean. The morphology of the motile stage was similar to Gonyaulax spinifera but had a different size, overhang, displacement and reticulations. Based on the distinct morphology of the cyst and morphological differences in motile cells, we assigned S. pachydermus from Izmir Bay to the new species Gonyaulax ellegaardiae. We elucidate the phylogenetic relationship of G. ellegaardiae through large and small subunit ribosomal DNA and show that it forms a clade with other species that belong to the G. spinifera complex.
John Woodland Hastings - One of the best experts on this subject based on the ideXlab platform.
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Inhibitors of Serine/Threonine Phosphoprotein Phosphatases Alter Circadian Properties in Gonyaulax polyedra
Plant physiology, 1996Co-Authors: James Comolli, Walter Taylor, Jalees Rehman, John Woodland HastingsAbstract:Protein serine/threonine phosphatases were implicated in the regulation of circadian rhythmicity in the marine dinoflagellate Gonyaulax polyedra based on the effects of three inhibitors specific for protein phosphatases 1 and 2A (okadaic acid, calyculin A, and cantharidin). Chronic exposure to okadaic acid resulted in a significant period lengthening, as measured by the bioluminescent glow rhythm, whereas cantharidin and calyculin A caused large phase delays but no persistent effect on period. Short pulses of the phosphatase inhibitors resulted in phase delays that were greatest near subjective dawn. Unlike 6-dimethylaminopurine, a protein kinase inhibitor, okadaic acid, calyculin A, and cantharidin did not block light-induced phase shifts. The inhibitors tested also increased radiolabeled phosphate incorporation into Gonyaulax proteins in vivo and blocked protein phosphatase 1 and 2A activities in Gonyaulax extracts. This study indicates that protein dephosphorylation catalyzed by protein serine/threonine phosphatases is necessary for proper functioning of the circadian system.
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inhibitors of serine threonine phosphoprotein phosphatases alter circadian properties in Gonyaulax polyedra
Plant Physiology, 1996Co-Authors: James Comolli, Walter Taylor, Jalees Rehman, John Woodland HastingsAbstract:Protein serine/threonine phosphatases were implicated in the regulation of circadian rhythmicity in the marine dinoflagellate Gonyaulax polyedra based on the effects of three inhibitors specific for protein phosphatases 1 and 2A (okadaic acid, calyculin A, and cantharidin). Chronic exposure to okadaic acid resulted in a significant period lengthening, as measured by the bioluminescent glow rhythm, whereas cantharidin and calyculin A caused large phase delays but no persistent effect on period. Short pulses of the phosphatase inhibitors resulted in phase delays that were greatest near subjective dawn. Unlike 6-dimethylaminopurine, a protein kinase inhibitor, okadaic acid, calyculin A, and cantharidin did not block light-induced phase shifts. The inhibitors tested also increased radiolabeled phosphate incorporation into Gonyaulax proteins in vivo and blocked protein phosphatase 1 and 2A activities in Gonyaulax extracts. This study indicates that protein dephosphorylation catalyzed by protein serine/threonine phosphatases is necessary for proper functioning of the circadian system.
Till Roenneberg - One of the best experts on this subject based on the ideXlab platform.
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Extracellular pH is under circadian control in Gonyaulax polyedra and forms a metabolic feedback loop.
Chronobiology international, 2004Co-Authors: Brigitte Eisensamer, Till RoennebergAbstract:This study investigates the relationship between the circadian clock and metabolism based on recordings of the extracellular pH in cultures of the marine dinoflagellate, Gonyaulax polyedra. In light-dark cycles, pH of the medium rises during the light phase and declines in the dark. The amplitude of this pH-rhythm correlates with light intensity, indicating photosynthesis (and respiration) as the driving force. The recorded extracellular pH changes probably reflect the need to control intracellular pH in spite of pH-modifying reactions. The daily pH-changes are under control of the circadian clock because they continue to oscillate with a circa-24 h period in constant light, albeit with a smaller amplitude. Similar to other circadian output rhythms, the pH rhythm depends (amplitude and phase) on nitrate levels in the medium. Both the bioluminescence and the pH rhythm can also be shifted by extracellular pH-changes although Gonyaulax is rarely exposed to significant pH changes in its marine ecosystems (except for highly dense algal blooms). Because intracellular proton levels are both affecting circadian input and output they form a feedback loop with the Gonyaulax circadian system indicating complex interactions between metabolism and the circadian clock.
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The flavo-enzyme xanthine oxidase is under circadian control in the marine alga Gonyaulax
Die Naturwissenschaften, 2002Co-Authors: Tzu-shing Deng, Till RoennebergAbstract:The activity of xanthine oxidoreductases (xanthine oxidase, XO, EC 1.2.3.2 and xanthine dehydrogenase, XDH, EC 1.1.1.204) in partially purified extracts of Gonyaulax polyedra was measured over 24 h both in a light:dark cycle and in constant light. This is the first demonstration of xanthine oxidoreductase in a unicellular alga. The activity of the O2-dependent form (XO) was found to be 15 times higher in light than in darkness. The same time-of-day specific differences persisted in constant light, demonstrating a control of XO by the circadian clock. In contrast, the activity of the NAD-dependent form (XDH) is not under circadian control. Because pharmacological inhibition of XO also blocks the effect of blue light on the Gonyaulax circadian clock, the possible relationship between XO and light reception in this unicellular alga will be discussed.
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Photobiology of the Gonyaulax circadian system. II. Allopurinol inhibits blue-light effects
Planta, 1997Co-Authors: Tzu-shing Deng, Till RoennebergAbstract:Light is the main environmental signal (zeitgeber) for practically all circadian systems, but little is known about the transduction mechanisms by which light signals reach the circadian oscillator. To identify components involved in the circadian light transduction pathway in the unicellular alga Gonyaulax polyedra Stein, we assayed inhibitors of pigment synthesis and of flavo-enzymes for their effects on circadian properties such as phase and period. We found that allopurinol, an inhibitor of xanthine oxidoreductase, specifically inhibits the period and phase effects mediated by the blue-light-sensitive input pathway, while the other light input of the Gonyaulax circadian system, that is sensitive to both red and blue light, appears to be unaffected.
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Several clocks may simplify the circadian system of Gonyaulax.
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas, 1996Co-Authors: David Morse, P. Markovic, Till RoennebergAbstract:The circadian system of Gonyaulax involves at least two pacemaking oscillators. These oscillators have been shown to be distinct at the physiological level by an examination of their rhythmic periods under different conditions, their phase response to pulses of light and darkness and their ability to compensate the rhythms for changes in temperature. It is also known that Gonyaulax can restrict synthesis of different proteins to at least three different times of day. We suggest that the two known oscillators may each control synthesis of a differently timed class of proteins.
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Light-Induced Phase Responses in Gonyaulax Are Drastically Altered by Creatine:
Journal of biological rhythms, 1994Co-Authors: Till Roenneberg, Walter TaylorAbstract:The mammalian phosphagen creatine has been shown to shorten the circadian period (τ) of the bioluminescence rhythm in the marine alga Gonyaulax polyedra from 23 to 18 hr. The studies described here concern the interactive effects of creatine and light, mainly on the bioluminescence rhythm. We have found that the τ-shortening effect of creatine is greater in blue light, suggesting that it acts on a blue-sensitive light input pathway. In addition, creatine affects the phase response mechanism in Gonyaulax, which is also known to be mainly blue-sensitive. The responses to 4-hr light pulses are dramatically increased under the influence of creatine. The unusual phase response curve (PRC) of the Gonyaulax circadian system, which has no phase delays in the early night, is changed in the presence of creatine to a more typical type 0 PRC, with delays of up to 12 hr. Creatine also amplifies the cells' phototactic response, suggesting that the blue-sensitive light input pathway is shared by the phase-shifting mecha...
David Morse - One of the best experts on this subject based on the ideXlab platform.
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Peridinin-Chlorophyll a-Protein Is not Implicated in the Photosynthesis Rhythm of the Dinoflagellate Gonyaulax despite Circadian Regulation of its Translation
Biological Rhythm Research, 2001Co-Authors: Raffael Jovine, P. Markovic, David MorseAbstract:The levels of peridinin-chlorophyll a -protein (PCP) mRNA, apoprotein and protein bound with peridinin (holoprotein) were measured as a function of circadian time in the dinoflagellate Gonyaulax polyedra to test involvement of this protein in the circadian oxygen evolution rhythm. This involvement was suggested by previous work showing that synthesis of PCP was rhythmic in vivo and in phase with the three-fold rhythm of oxygen evolution. However, Gonyaulax contains six PCP isoforms, only one of which was previously examined. In this report, we extend our analysis to two additional isoforms to encompass roughly 90% of the total cellular PCP. We confirm that synthesis of two additional PCP isoforms is rhythmic in vivo and show that this regulation appears to occur at a translational level as found for two other regulated proteins in this organism. However, PCP is unlikely to be implicated in the oxygen evolution rhythm since both PCP protein levels and the amount of chromophore (OD480) bound to protein (OD2...
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The phylogeny of glyceraldehyde-3-phosphate dehydrogenase indicates lateral gene transfer from cryptomonads to dinoflagellates.
Journal of molecular evolution, 1998Co-Authors: Thomas F. Fagan, J. Woodland Hastings, David MorseAbstract:Sequence analysis of two nuclear-encoded glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes isolated from the dinoflagellate Gonyaulax polyedra distinguishes them as cytosolic and chloroplastic forms of the enzyme. Distance analysis of the cytosolic sequence shows the Gonyaulax gene branching early within the cytosolic clade, consistent with other analyses. However, the plastid sequence forms a monophyletic group with the plastid isoforms of cryptomonads, within an otherwise cytosolic clade, distinct from all other plastid GAPDHs. This is attributed to lateral gene transfer from an ancestral cryptomonad to a dinoflagellate, providing the first example of genetic exchange accompanying symbiotic associations between the two, which are common in present day cells.
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CHARACTERIZATION AND MOLECULAR PHYLOGENYOF A PROTEIN KINASE cDNA FROM THE DINOFLAGELLATE Gonyaulax (DINOPHYCEAE)1
Journal of Phycology, 1997Co-Authors: Patrick Salois, David MorseAbstract:Degenerate primers corresponding to conserved protein kinase motifs were used to amplify potential kinase DNA fragments from a Gonyaulax polyedra Stein cDNA library using PCR. One PCR fragment, potentially encoding a CAMP-dependent protein kinase, was used as a probe to isolate a near full-length cDNA from the library. The nucleic acid sequence of the entire cDNA clone had a high homology to the catalytic subunit of cAMP-dependent protein kinase (cAPK subfamily and affiliated members. Northern blot analysis showed that the corresponding mRNA had a size (about 1.4 kb) and a relative high abundance consistent with a cAPK homologue. Southern blot analysis showed that while there are roughly 30 copies of the kinase gene per genome, the pattern of restriction fragments is inconsistent with the hypothesis of a large gene family. Phylogenetic analyses comparing the deduced amino acid sequence from the Gonyaulax cDNA with other cAPK sequences place Gonyaulax close to the slime mold Dictyostelium discoideum. This is the first phylogenetic analysis of dinoflagellates based on protein sequence, and the results are in agreement with similar analyses based on rRNA sequences.
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Several clocks may simplify the circadian system of Gonyaulax.
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas, 1996Co-Authors: David Morse, P. Markovic, Till RoennebergAbstract:The circadian system of Gonyaulax involves at least two pacemaking oscillators. These oscillators have been shown to be distinct at the physiological level by an examination of their rhythmic periods under different conditions, their phase response to pulses of light and darkness and their ability to compensate the rhythms for changes in temperature. It is also known that Gonyaulax can restrict synthesis of different proteins to at least three different times of day. We suggest that the two known oscillators may each control synthesis of a differently timed class of proteins.
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The polypeptide components of scintillons, the bioluminescence organelles of the dinoflagellate Gonyaulax polyedra
Biochemistry and cell biology = Biochimie et biologie cellulaire, 1993Co-Authors: Michel Desjardins, David MorseAbstract:Scintillons, the bioluminescence organelles of Gonyaulax polyedra, were purified by isopycnic density gradient centrifugation until only low levels of contaminating chloroplasts and mitochondria we...