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Tatsuomi Matsuoka - One of the best experts on this subject based on the ideXlab platform.
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early signaling pathways mediating dormant cyst formation in terrestrial unicellular eukaryote colpoda
Fems Microbiology Letters, 2021Co-Authors: Tatsuomi MatsuokaAbstract:Dormant (resting) cyst formation (Encystment) in unicellular eukaryotes is the process of a large-scale digestion of vegetative cell structures and reconstruction into the dormant form, which is performed by cell signaling pathways accompanied by up- or down-regulation of protein expression, and by posttranslational modification such as phosphorylation. In this review, the author describes the morphogenetic events during Encystment of Colpoda and the early molecular events in the Ca2+/calmodulin-triggered signaling pathways for Encystment, based mainly on our research results of the past 10 years; especially, the author discusses the role of c-AMP dependently phosphorylated proteins (ribosomal P0 protein, ribosomal S5 protein, Rieske iron-sulfur protein, actin and histone H4) and Encystment-dependently upregulated (EF-1α-HSP60, actin-related protein) and downregulated proteins (ATP synthase β-chain). In addition, the roles of AMPK, a key molecule in the signaling pathways leading to Colpoda Encystment, and differentially expressed genes and proteins during Encystment of other ciliates are discussed.
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Identification of differentially expressed water-insoluble proteins in the Encystment process of Colpoda cucullus by two-dimensional electrophoresis and LC-MS/MS analysis.
Journal of Eukaryotic Microbiology, 2013Co-Authors: Yoichiro Sogame, Toshikazu Takeshita, Katsuhiko Kojima, Eiji Kinoshita, Tatsuomi MatsuokaAbstract:In the Encystment process of the ciliate protist Colpoda cucullus, we observed that the cell total protein abundance was reduced at 12 h–1 d after the onset of Encystment induction subsequent to the reduction in mRNA abundance. We analyzed the alteration of the expression levels of water-insoluble proteins by two-dimensional polyacrylamide gel electrophoresis using polyoxyethylene (20) sorbitan monooleate (Tween-80), and we identified proteins whose expression levels were altered in the Encystment process by a liquid chromatography tandem mass spectrometry analysis. The expression level of a 60-kDa protein (p60; heat shock protein 60) was temporarily enhanced and that of a 55-kDa protein (p55; actin) and a 49-kDa protein (p49; actin) was enhanced in the Colpoda Encystment process. In mature cysts, the expression level of p55 and p49 tended to be reduced, whereas the expression level of a 50-kDa protein (p50d; α-tubulin), a 25-kDa protein (p25; α-tubulin) and a 52-kDa protein (p52c; β-tubulin) was enhanced.
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EF-1α and mitochondrial ATP synthase β chain: alteration of their expression in Encystment-induced Colpoda cucullus.
The Journal of eukaryotic microbiology, 2012Co-Authors: Yoichiro Sogame, Toshikazu Takeshita, Katsuhiko Kojima, Eiji Kinoshita, Tatsuomi MatsuokaAbstract:Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the total proteins contained in Encystment-induced Colpoda cucullus showed that a 50-kDa protein (p50) disappeared, whereas the expression of a 49-kDa protein (p49) was enhanced in early phase of morphogenetic transformation into the resting cyst (i.e. 2-5 h after the onset of Encystment induction). Puromycin or actinomycin D inhibited the alteration in the expression of p50 and p49 by the induction of Encystment. These results suggest that the Encystment-specific alteration in expression of these proteins is performed by a transcriptional regulation. Liquid chromatography tandem mass spectrometry analysis revealed that p50 is mitochondrial ATP synthase β chains, and that p49 is elongation factor 1α.
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culture age intracellular ca 2 concentration and protein phosphorylation in Encystment induced colpoda cucullus
Indian Journal of Microbiology, 2012Co-Authors: Yoichiro Sogame, Tatsuomi MatsuokaAbstract:In Colpoda cucullus, intracellular Ca2+ mediates the Encystment induction and protein phosphorylation that occur just prior to morphogenetic transformation into the resting form. When rapidly growing cells were stimulated to encyst, Encystment was not readily induced, and the protein phosphorylation level was lower. On the other hand, in post-growing cells stimulated to encyst, the Encystment rate and protein phosphorylation level were elevated. These results suggest that protein phosphorylation is closely linked to Encystment induction. Why, then, are the protein phosphorylation level and Encystment rate difficult to elevate in the rapidly growing cells? Fura 2 ratiometry showed that the intracellular Ca2+ concentration (F340/F380 ratio) was raised in rapidly growing cells as well as in post-growing cells when the cells were stimulated to encyst. It is presumed that the Ca2+-mediated signal transduction pathways for protein phosphorylation and Encystment may be triggered in rapidly growing cells, but downstream certain steps may be suppressed by certain intracellular components.
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Emergence of the Terrestrial Ciliate Colpoda cucullus from a Resting Cyst: Rupture of the Cyst Wall by Active Expansion of an Excystment Vacuole
2012Co-Authors: Ryoji Funadani, Yasutaka Suetomo, Tatsuomi MatsuokaAbstract:The first sign of excysting Colpoda cucullus cells is the initiation of the pulsation of a contractile vacuole, which is then replaced by a non-pulsating vacuole (excystment vacuole) that continues to expand and finally ruptures the outermost cyst wall (ectocyst) due to inner pressure. A ciliate surrounded by flexible membranes (endocyst) thus emerges. The osmolarity of the excysting cells is estimated to be 140 mOsm L−1 from the relationship between the frequency of contractile vacuole pulsation and the external sucrose concentration. Both the expansion of the excystment vacuole and the emergence of ciliates occurred even when the cysts were immersed in hypertonic medium. In hypotonic medium containing sodium azide (NaN3, a cytochrome c oxidase inhibitor), the contractile vacuole of vegetative cells stopped pulsating and gradually expanded, causing cells to burst. When C. cucullus was induced to encyst in a hypotonic medium containing NaN3, the expansion of the excystment vacuoles was inhibited. These results suggest that the active uptake of water may be responsible for the expansion of the excystment vacuole required for the ectocyst to rupture. Key words: Colpoda, excystment, excystment vacuole, emergence Resting cyst formation (Encystment) and sporulation are common survival strategies in terrestrial unicellular organisms. In the terrestrial ciliate Colpoda cucullus, the formation of resting cysts that are resistant to drying and t
Nagore Sampedro - One of the best experts on this subject based on the ideXlab platform.
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life cycle alternations in alexandrium minutum natural populations from the nw mediterranean sea
Harmful Algae, 2012Co-Authors: Silvia Angles, Esther Garces, Albert Rene, Nagore SampedroAbstract:Abstract Life-cycle transitions play a key role in the bloom dynamics of many dinoflagellates. In this study, in situ excystment and Encystment were monitored during recurrent Alexandrium minutum blooms in Arenys de Mar harbor (NW Mediterranean Sea) from October 2005 to May 2008. In addition, the dynamics of vegetative cells in the water column and resting cysts in the sediments were assessed. Excystment occurred continuously during the period studied. The excystment fluxes and the estimated excystment percentages indicated a pattern of alternating reduced and active excystment periods. From July to November, excystment percentages were A. minutum population underwent active excystment, with excystment percentages of 0.3–45.7%. Periods of active excystment coincided with increases in irradiance and water temperature, conditions also favorable for bloom development. During vegetative cell blooms, resting cyst formation coincided with periods marked by vegetative cell abundances in the water column of >2 × 10 3 cells l −1 . Resting cyst fluxes were higher when the abundance of vegetative cells in the overlying water column was greater. The excystment and Encystment processes overlapped for 2 months during the extended blooms, indicating that newly formed resting cysts had overcome the mandatory dormancy period and were capable of germinating within the same bloom in which they were produced. Resting cysts in the surface sediment were rapidly depleted during periods of active excystment, but their production, although involving only a small fraction of the vegetative population, more than compensated for their loss. These results are discussed with respect to the role of frequent life-stage switches in determining the population dynamics and the maintenance of A. minutum blooms.
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relationship between vegetative cells and cyst production during alexandrium minutum bloom in arenys de mar harbour nw mediterranean
Journal of Plankton Research, 2004Co-Authors: Esther Garces, Rosa Isabel Figueroa, Isabel Bravo, Magda Vila, Mercedes Maso, Nagore SampedroAbstract:A recurrent Alexandrium minutum bloom in the Arenys de Mar harbour (Catalan coast, North Western Mediterranean) was monitored in order to establish the relationship between vegetative cells and cyst production. The bloom lasted from January 21 to February 24, 2002 and reached cell concentrations of up to 47 � 10 6 cell L � 1 . Two aspects related to the resting cysts deposition were studied: (i) production of resting cysts during the bloom period (by means of sediment traps) and (ii) distribution of resting cysts in the sediment after the bloom (May 2002). Cyst formation in Arenys clearly started in a period with high vegetative cell densities in the water column. Once production was initiated Encystment fluxes remained constant for two weeks, and covering the periods of maintenance and decline of the bloom. High cyst fluxes (up to 6000 cysts cm � 2 day � 1 ) were quantified as a result of the high vegetative cell concentration. Moreover, Encystment occurring in less than 1% of the total population indicates that mostof the cellsare not involved in resting cysts formation. A comparison of the resting cyst flux values obtained from the sediment traps and the resting cyst concentrations in surface sediment (628‐3270 cysts cm � 3 ) three months later, revealed that the number of cysts in the sediment decreased during that time. The studies of excystment showed a high germination percentage (91%) and germling viability (100%). These data, together with the resting cyst distribution in the sediment, are important in assessing the role of resting cysts in the bloom dynamics of A. minutum in confined waters.
Juan Carlos Gutiérrez - One of the best experts on this subject based on the ideXlab platform.
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macronuclear dna demethylation is involved in the Encystment process of the ciliate colpoda inflata
Cell Biology International, 1994Co-Authors: Gemma Palacios, Ana Martingonzalez, Juan Carlos GutiérrezAbstract:Ciliate Encystment is an eukaryotic cell differentiation process which involves a specific gene expression, to form the resting stage. In this study, we investigate, for first time, the DNA methylation pattern changes during Encystment in the ciliate Colpoda inflata, and the 5-azacytidine effect on growing cells and Encystment. Results indicate that 5-methylcytosine is present in macronuclear DNA of this ciliate and the 5-azacytidine treatment induces Encystment in growth conditions. From restriction enzyme digestion and 5-azacytidine experiments, we conclude that a specific DNA demethylation is probably involved in the Encystment gene expression of this ciliate.
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regular articlemacronuclear dna demethylation is involved in the Encystment process of the ciliate colpoda inflata
Cell Biology International, 1994Co-Authors: Gemma Palacios, Ana Martingonzalez, Juan Carlos GutiérrezAbstract:Ciliate Encystment is an eukaryotic cell differentiation process which involves a specific gene expression, to form the resting stage. In this study, we investigate, for first time, the DNA methylation pattern changes during Encystment in the ciliate Colpoda inflata, and the 5-azacytidine effect on growing cells and Encystment. Results indicate that 5-methylcytosine is present in macronuclear DNA of this ciliate and the 5-azacytidine treatment induces Encystment in growth conditions. From restriction enzyme digestion and 5-azacytidine experiments, we conclude that a specific DNA demethylation is probably involved in the Encystment gene expression of this ciliate.
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Identification of Precystic Stages and Encystment Kinetics Analysis of Colpoda inflata by Using an Immunofluorescent Method
The Journal of Eukaryotic Microbiology, 1994Co-Authors: Laura Benítez, Ana Martín-gonzález, Juan Carlos GutiérrezAbstract:The application of an immunocytochemical method to identify precystic stages and to analyse the Encystment kinetics, by using a polyclonal antiserum against isolated cyst walls from the ciliate Colpoda inflata, is reported for the first time. Three different precystic phases were chosen on the basis of morphological changes and degree of cyst wall formation. By using this procedure a better identification of mature resting cysts with regard to precystic cells or young cysts is provided. An average consensus Encystment kinetics of C. inflata, by using an accumulated class frequency analysis, is reported.Supplementary key words. Colpoda inflata, cyst wall, Encystment kinetics, immunofluorescence method
Esther Garces - One of the best experts on this subject based on the ideXlab platform.
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life cycle alternations in alexandrium minutum natural populations from the nw mediterranean sea
Harmful Algae, 2012Co-Authors: Silvia Angles, Esther Garces, Albert Rene, Nagore SampedroAbstract:Abstract Life-cycle transitions play a key role in the bloom dynamics of many dinoflagellates. In this study, in situ excystment and Encystment were monitored during recurrent Alexandrium minutum blooms in Arenys de Mar harbor (NW Mediterranean Sea) from October 2005 to May 2008. In addition, the dynamics of vegetative cells in the water column and resting cysts in the sediments were assessed. Excystment occurred continuously during the period studied. The excystment fluxes and the estimated excystment percentages indicated a pattern of alternating reduced and active excystment periods. From July to November, excystment percentages were A. minutum population underwent active excystment, with excystment percentages of 0.3–45.7%. Periods of active excystment coincided with increases in irradiance and water temperature, conditions also favorable for bloom development. During vegetative cell blooms, resting cyst formation coincided with periods marked by vegetative cell abundances in the water column of >2 × 10 3 cells l −1 . Resting cyst fluxes were higher when the abundance of vegetative cells in the overlying water column was greater. The excystment and Encystment processes overlapped for 2 months during the extended blooms, indicating that newly formed resting cysts had overcome the mandatory dormancy period and were capable of germinating within the same bloom in which they were produced. Resting cysts in the surface sediment were rapidly depleted during periods of active excystment, but their production, although involving only a small fraction of the vegetative population, more than compensated for their loss. These results are discussed with respect to the role of frequent life-stage switches in determining the population dynamics and the maintenance of A. minutum blooms.
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effects of nutritional factors and different parental crosses on the Encystment and excystment of alexandrium catenella dinophyceae in culture
Phycologia, 2005Co-Authors: Rosa Isabel Figueroa, Isabel Bravo, Esther GarcesAbstract:Abstract Alexandrium catenella is a cyst-forming dinoflagellate causative of paralytic shellfish poisoning. Strain and nutritional factors affecting cyst formation and germination in this species were studied in cultures of several clonal crosses. Sexual reproduction was monitored and the effect of nutrients on sexual stages was proved because planozygotes isolated in medium with no phosphates added encysted in lower percentages than those placed in media with no nitrates added or in replete conditions, where the highest Encystment was achieved. However, other unknown factors prevented Encystment, because, even in replete conditions, some planozygotes were unable to encyst. Dormancy period of cysts ranged from 5 to 65 days at 24°C. A progressive germination inside this time interval was recorded for cysts from all six clonal crosses employed, and therefore, identified as a species characteristic. This gradual germination was modulated by nutrient levels in both Encystment and excystment media: (1) cysts f...
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relationship between vegetative cells and cyst production during alexandrium minutum bloom in arenys de mar harbour nw mediterranean
Journal of Plankton Research, 2004Co-Authors: Esther Garces, Rosa Isabel Figueroa, Isabel Bravo, Magda Vila, Mercedes Maso, Nagore SampedroAbstract:A recurrent Alexandrium minutum bloom in the Arenys de Mar harbour (Catalan coast, North Western Mediterranean) was monitored in order to establish the relationship between vegetative cells and cyst production. The bloom lasted from January 21 to February 24, 2002 and reached cell concentrations of up to 47 � 10 6 cell L � 1 . Two aspects related to the resting cysts deposition were studied: (i) production of resting cysts during the bloom period (by means of sediment traps) and (ii) distribution of resting cysts in the sediment after the bloom (May 2002). Cyst formation in Arenys clearly started in a period with high vegetative cell densities in the water column. Once production was initiated Encystment fluxes remained constant for two weeks, and covering the periods of maintenance and decline of the bloom. High cyst fluxes (up to 6000 cysts cm � 2 day � 1 ) were quantified as a result of the high vegetative cell concentration. Moreover, Encystment occurring in less than 1% of the total population indicates that mostof the cellsare not involved in resting cysts formation. A comparison of the resting cyst flux values obtained from the sediment traps and the resting cyst concentrations in surface sediment (628‐3270 cysts cm � 3 ) three months later, revealed that the number of cysts in the sediment decreased during that time. The studies of excystment showed a high germination percentage (91%) and germling viability (100%). These data, together with the resting cyst distribution in the sediment, are important in assessing the role of resting cysts in the bloom dynamics of A. minutum in confined waters.
Rosa Isabel Figueroa - One of the best experts on this subject based on the ideXlab platform.
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effects of nutritional factors and different parental crosses on the Encystment and excystment of alexandrium catenella dinophyceae in culture
Phycologia, 2005Co-Authors: Rosa Isabel Figueroa, Isabel Bravo, Esther GarcesAbstract:Abstract Alexandrium catenella is a cyst-forming dinoflagellate causative of paralytic shellfish poisoning. Strain and nutritional factors affecting cyst formation and germination in this species were studied in cultures of several clonal crosses. Sexual reproduction was monitored and the effect of nutrients on sexual stages was proved because planozygotes isolated in medium with no phosphates added encysted in lower percentages than those placed in media with no nitrates added or in replete conditions, where the highest Encystment was achieved. However, other unknown factors prevented Encystment, because, even in replete conditions, some planozygotes were unable to encyst. Dormancy period of cysts ranged from 5 to 65 days at 24°C. A progressive germination inside this time interval was recorded for cysts from all six clonal crosses employed, and therefore, identified as a species characteristic. This gradual germination was modulated by nutrient levels in both Encystment and excystment media: (1) cysts f...
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relationship between vegetative cells and cyst production during alexandrium minutum bloom in arenys de mar harbour nw mediterranean
Journal of Plankton Research, 2004Co-Authors: Esther Garces, Rosa Isabel Figueroa, Isabel Bravo, Magda Vila, Mercedes Maso, Nagore SampedroAbstract:A recurrent Alexandrium minutum bloom in the Arenys de Mar harbour (Catalan coast, North Western Mediterranean) was monitored in order to establish the relationship between vegetative cells and cyst production. The bloom lasted from January 21 to February 24, 2002 and reached cell concentrations of up to 47 � 10 6 cell L � 1 . Two aspects related to the resting cysts deposition were studied: (i) production of resting cysts during the bloom period (by means of sediment traps) and (ii) distribution of resting cysts in the sediment after the bloom (May 2002). Cyst formation in Arenys clearly started in a period with high vegetative cell densities in the water column. Once production was initiated Encystment fluxes remained constant for two weeks, and covering the periods of maintenance and decline of the bloom. High cyst fluxes (up to 6000 cysts cm � 2 day � 1 ) were quantified as a result of the high vegetative cell concentration. Moreover, Encystment occurring in less than 1% of the total population indicates that mostof the cellsare not involved in resting cysts formation. A comparison of the resting cyst flux values obtained from the sediment traps and the resting cyst concentrations in surface sediment (628‐3270 cysts cm � 3 ) three months later, revealed that the number of cysts in the sediment decreased during that time. The studies of excystment showed a high germination percentage (91%) and germling viability (100%). These data, together with the resting cyst distribution in the sediment, are important in assessing the role of resting cysts in the bloom dynamics of A. minutum in confined waters.