5,552 results on '"ciliate"'
Search Results
202. Thermal adaptation in a holobiont accompanied by phenotypic changes in an endosymbiont
- Author
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John P. DeLong and Miranda E. Salsbery
- Subjects
Ciliate ,education.field_of_study ,Paramecium ,biology ,Acclimatization ,Population ,Temperature ,Generalist and specialist species ,biology.organism_classification ,Trade-off ,Adaptation, Physiological ,Holobiont ,Paramecium bursaria ,Evolutionary biology ,Genetics ,Ciliophora ,Adaptation ,Symbiosis ,General Agricultural and Biological Sciences ,education ,Ecology, Evolution, Behavior and Systematics ,Paramecia - Abstract
How and if organisms can adapt to changing temperatures has drastic consequences for the natural world. Thermal adaptation involves finding a match between temperatures permitting growth and the expected temperature distribution of the environment. However, if and how this match is achieved, and how tightly linked species change together, is poorly understood. Paramecium bursaria is a ciliate that has a tight physiological interaction with endosymbiotic green algae (zoochlorellae). We subjected a wild population of P. bursaria to a cold and warm climate (20 and 32℃) for ∼300 generations. We then measured the thermal performance curve (TPC) for intrinsic rate of growth (rmax ) for these evolved lines across temperatures. We also evaluated number and size of the zoochlorellae populations within paramecia cells. TPCs for warm-adapted populations were shallower and broader than TPCs of cold-adapted populations, indicating that the warm populations adapted by moving along a thermal generalist/specialist trade off rather than right-shifting the TPC. Zoochlorellae populations within cold-adapted paramecia had fewer and larger zoochlorellae than hot-adapted paramecia, indicating phenotypic shifts in the endosymbiont accompany thermal adaptation in the host. Our results provide new and novel insight into how species involved in complex interactions will be affected by continuing increasing global temperatures.
- Published
- 2021
203. ' Candidatus Euplotechlamydia quinta,' a novel chlamydia‐like bacterium hosted by the ciliate Euplotes octocarinatus (Ciliophora, Spirotrichea)
- Author
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Ruanlin Wang, Ruijuan Sun, Zhiyun Zhang, Claudia Vannini, Graziano Di Giuseppe, and Aihua Liang
- Subjects
FISH ,chlamydia ,ciliate ,endosymbiont ,Euplotes ,phylogeny ,Microbiology - Abstract
Our knowledge of ciliate endosymbiont diversity greatly expanded over the past decades due to the development of characterization methods for uncultivable bacteria. Chlamydia-like bacteria have been described as symbionts of free-living amoebae and other phylogenetically diverse eukaryotic hosts. In the present work, a systematic survey of the bacterial diversity associated with the ciliate Euplotes octocarinatus strain Zam5b-1 was performed, using metagenomic screening as well as classical full-cycle rRNA approach, and a novel chlamydial symbiont was characterized. The metagenomic screening revealed 16S rRNA gene sequences from Polynucleobacter necessarius, three previously reported accessory symbionts, and a novel chlamydia-like bacterium. Following the full-cycle rRNA approach, we obtained the full-length 16S rRNA gene sequence of this chlamydia-like bacterium and developed probes for diagnostic fluorescence in situ hybridizations. The phylogenetic analysis of the 16S rRNA gene sequences unambiguously places the new bacterium in the family Rhabdochlamydiaceae. This is the first report of chlamydia-like bacterium being found in Euplotes. Based on the obtained data, the bacterium is proposed as a new candidate genus and species: "Candidatus Euplotechlamydia quinta."
- Published
- 2022
204. An Optimized Protocol of Protargol Staining for Ciliated Protozoa.
- Author
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Ji, Daode and Wang, Yunfeng
- Subjects
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CILIATA , *MORPHOLOGY , *TAXONOMY , *PROTOZOA , *PROTISTA - Abstract
Abstract: Protargol staining is a crucial method to reveal the infraciliature of ciliates, which is the most important morphological character for species identification. In the present study, Wilbert's protocol of protargol staining was emended mainly toward the highly happened improper bleaching. Through reciprocal treatments, both insufficient and excessive bleachings were much eliminated from the protargol protocol and the tests performed with four different species of ciliates established that the stainings were considerably improved and more reliable with optimized bleaching. Compared to the original protocol, the optimized method was proved to be more suitable for the groups difficult to stain, and it is also friendlier for the beginners and researchers in related fields. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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205. Interactions between the Newly Described Small‐ and Fast‐Swimming Mixotrophic Dinoflagellate Yihiella yeosuensis and Common Heterotrophic Protists.
- Author
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Jeong, Hae Jin, Kang, Hee Chang, You, Ji Hyun, and Jang, Se Hyeon
- Subjects
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CILIATA , *DINOFLAGELLATES , *INGESTION , *FOOD chains , *PROTISTA - Abstract
Abstract: The mixotroph Yihiella yeosuensis is a small‐ and fast‐swimming dinoflagellate. To investigate its protistan predators, interactions between Y. yeosuensis and 11 heterotrophic protists were explored. No potential predators were able to feed on actively swimming Y. yeosuensis cells, which escaped via rapid jumps, whereas Aduncodinium glandula, Oxyrrhis marina, and Strombidinopsis sp. (approximately 150 μm in cell length) were able to feed on weakly swimming cells that could not jump. Furthermore, Gyrodinium dominans, Luciella masanensis, and Pfiesteria piscicida were able to feed on heat‐killed Yihiella cells, whereas Gyrodinium moestrupii, Noctiluca scintillans, Oblea rotunda, Polykrikos kofoidii, and Strombidium sp. (20 μm) did not feed on them. Thus, the jumping behavior of Y. yeosuensis might be primarily responsible for the observed lack of predation. With increasing Yihiella concentration, the growth rate of O. marina decreased, whereas that of Strombidinopsis did not change. However, with increasing Yihiella concentration (up to 530 ng C/ml), the ingestion rate of Strombidinopsis on Yihiella increased linearly. The highest ingestion rate was 24.1 ng C per predator per d. The low daily carbon acquisition from Yihiella relative to the body carbon content of Strombidinopsis might be responsible for its negligible growth. Thus, Y. yeosuensis might have an advantage over its competitors due to its low mortality rate. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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206. A paradox: rapid evolution rates of germline-limited sequences are associated with conserved patterns of rearrangements in cryptic species of Chilodonella uncinata (Protista, Ciliophora).
- Author
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Zhang, Tengteng, Wang, Chundi, Katz, Laura A., and Gao, Feng
- Abstract
Some of the most extreme genome wide rearrangements are found in ciliates, which are unique in possessing both germline micronucleus and somatic macronucleus in every cell/organism. A series of DNA rearrangement events, including DNA elimination, chromosomal fragmentation, gene unscrambling and alternative processing, happen during macronuclear development. To assess the molecular evolution of macronuclear and germline-limited sequences in different cryptic species of Chilodonella uncinata, we characterized the actin, α-tubulin and β-tubulin genes in the micronucleus and macronucleus genomes of USA-SC2 strain and compared them with other strains (i.e. cryptic species). Three main results are: (i) rearrangement patterns between germline and soma are conserved for each gene among the cryptic species of C. uncinata; (ii) in contrast, the germline-limited regions are highly divergent in sequence and length among the cryptic species; (iii) pointer shifting is frequent among the cryptic species. We speculate that pointer sequences may serve as the buffer between the conserved macronuclear destined sequences and rapidly-evolving internal eliminated sequences. The data combined with previous studies demonstrate the plasticity of gene rearrangement among different groups of ciliates and add to the growing data for the role of genome rearrangements in species differentiation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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207. New record of Epistylis hentscheli (Ciliophora, Peritrichia) as an epibiont of Procambarus (Austrocambarus) sp. (Crustacea, Decapoda) in Chiapas, Mexico.
- Author
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Ramírez-Ballesteros, Mireya, Fernandez-Leborans, Gregorio, and Mayén-Estrada, Rosaura
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CILIATA , *PROCAMBARUS , *EPIBIOSIS , *SPECIES diversity - Abstract
Epibiosis is very common between crustaceans and ciliates where the calcified surface of the crustacean body provides a suitable substrate for ciliate colonization. The aim of this contribution is to provide data about a new record between the epistylid ciliate Epistylis hentscheli Kahl, 1935, and the crayfish Procambarus (Austrocambarus) sp. The distribution of the epistylid on the basibiont body and its cellular/ colonial characteristics were analyzed. Procambarus (Austrocambarus) sp. harbored colonies of E. hentscheli only on the pereiopods. This is the first record of this peritrich ciliate as an epibiont on Crustacea, having been previously found on algae and fish. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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208. The splicing of tiny introns of Paramecium is controlled by MAGO.
- Author
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Contreras, Julia, Begley, Victoria, Marsella, Laura, and Villalobo, Eduardo
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INTRONS , *SPLIT genes , *MESSENGER RNA , *PARAMECIUM , *NUCLEOTIDE sequence - Abstract
The exon junction complex (EJC) is a key element of the splicing machinery. The EJC core is composed of eIF4A3, MAGO, Y14 and MLN51. Few accessory proteins, such as CWC22 or UPF3, bind transiently to the EJC. The EJC has been implicated in the control of the splicing of long introns. To ascertain whether the EJC controls the splicing of short introns, we used Paramecium tetraurelia as a model organism, since it has thousands of very tiny introns. To elucidate whether EJC affects intron splicing in P. tetraurelia , we searched for EJC protein-coding genes, and silenced those genes coding for eIF4A3, MAGO and CWC22. We found that P. tetraurelia likely assembles an active EJC with only three of the core proteins, since MLN51 is lacking. Silencing of eIF4A3 or CWC22 genes, but not that of MAGO, caused lethality. Silencing of the MAGO gene caused either an increase, decrease, or no change in intron retention levels of some intron-containing mRNAs used as reporters. We suggest that a fine-tuning expression of EJC genes is required for steady intron removal in P. tetraurelia . Taking into consideration our results and those published by others, we conclude that the EJC controls splicing independently of the intron size. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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209. Nuclear localization signal targeting to macronucleus and micronucleus in binucleated ciliate Tetrahymena thermophila.
- Author
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Iwamoto, Masaaki, Mori, Chie, Osakada, Hiroko, Koujin, Takako, Hiraoka, Yasushi, and Haraguchi, Tokuko
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TETRAHYMENA thermophila , *NUCLEOLUS , *PROTOZOA , *CELL growth , *CELL proliferation - Abstract
Abstract: Ciliated protozoa possess two morphologically and functionally distinct nuclei: a macronucleus (MAC) and a micronucleus (MIC). The MAC is transcriptionally active and functions in all cellular events. The MIC is transcriptionally inactive during cell growth, but functions in meiotic events to produce progeny nuclei. Thus, these two nuclei must be distinguished by the nuclear proteins required for their distinct functions during cellular events such as cell proliferation and meiosis. To understand the mechanism of the nuclear transport specific to either MAC or MIC, we identified specific nuclear localization signals (NLSs) in two MAC‐ and MIC‐specific nuclear proteins, macronuclear histone H1 and micronuclear linker histone‐like protein (Mlh1), respectively. By expressing GFP‐fused fragments of these proteins in Tetrahymena thermophila cells, two distinct regions in macronuclear histone H1 protein were assigned as independent MAC‐specific NLSs and two distinct regions in Mlh1 protein were assigned as independent MIC‐specific NLSs. These NLSs contain several essential lysine residues responsible for the MAC‐ and MIC‐specific nuclear transport, but neither contains any consensus sequence with known monopartite or bipartite NLSs in other model organisms. Our findings contribute to understanding how specific nuclear targeting is achieved to perform distinct nuclear functions in binucleated ciliates. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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210. Complex life cycle, broad host range and adaptation strategy of the intranuclear Paramecium symbiont Preeria caryophila comb. nov.
- Author
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Potekhin, Alexey, Schweikert, Michael, Nekrasova, Irina, Vitali, Valerio, Schwarzer, Sabine, Anikina, Arina, Kaltz, Oliver, Petroni, Giulio, and Schrallhammer, Martina
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PARAMECIUM , *PARAMECIUM caudatum , *SYMBIOSIS , *PHYLOGENY , *HABITATS , *PHYSIOLOGY - Abstract
Holospora and related bacteria are a group of obligate Paramecium symbionts. Characteristic features are their infectivity, the presence of two distinct morphotypes, and usually a strict specialization for a single Paramecium species as host and for a nuclear compartment (either somatic or generative nucleus) for reproduction. Holospora caryophila steps out of line, naturally occurring in Paramecium biaurelia and Paramecium caudatum. This study addresses the phylogenetic relationship among H. caryophila and other Holospora species based on 16S rRNA gene sequence comparison analyzing the type strain and seven new macronuclear symbionts. Key aspects of Holospora physiology such as infectivity, symbiosis establishment and host range were determined by comprehensive infection assays. Detailed morphological investigations and sequence-based phylogeny confirmed a high similarity between the type strain of H. caryophila and the novel strains. Surprisingly, they are only distantly related to other Holospora species suggesting that they belong to a new genus within the family Holosporaceae, here described as Preeria caryophila comb. nov. Adding to this phylogenetic distance, we also observed a much broader host range, comprising at least eleven Paramecium species. As these potential host species exhibit substantial differences in frequency of sexual processes, P. caryophila demonstrates which adaptations are crucial for macronuclear symbionts facing regular destruction of their habitat. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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211. SURVEY OF INDUSTRIAL WASTEWATER TREATMENT PERFORMANCE WITH BIOLOGICAL MONITORING OF PROTOZOA IN THE INDUSTRIAL PARK OF ABADAN.
- Author
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Bay, Abotaleb, Sadeghi, Mahdi, Rahimzade, Hadi, and Behnampour, Nasser
- Abstract
Industrial wastewater is of particular importance. In most wastewater treatments, physicochemical parameters are used to determine the performances which are costly while protozoa can be used as less expensive biological indicators to determine the efficiency of the treatment plant. The purpose of this study was to investigate the relationship between protozoa and physic-chemical characteristics of the Abadan wastewater treatment industry. Samples were collected from wastewater stabilization ponds in the Abadan industrial park. A total of 66 samples for biochemical and chemical tests and protozoa counts were taken. The sites of sampling were influent of sewage and effluent from maturation pond. For the parameters from influent, first 300 mL of samples was collected in depths of 0.1, 0.35 and 1 m and then mixed to provide a composite sample. 300 mL sample was directly taken from the effluent. The results of this study indicate that there is a positive relationship between the number and population percentage of amoeba and mastigophora (flagellate) with BOD and COD, whereas is the negative relationship between sticking ciliates with BOD and COD. Furthermore there is a positive relation between DO, the percentage, number of ciliates and amoeba population and there is a correlation, with flagellate population. Increase of flagellate numbers is indicative of high effluent Kjeldahl nitrogen. There was also an increase of input TSS and amoeba population percentage and a reduction of free ciliates numbers. The type and abundance of protozoa in industrial wastewater treatment following biological methods is an indicator of the system performance and effluent quality. This study shows the use of biological indicators can be used for monitoring as a much cheaper alternative resulting in a better economy. It is also a good indicator for the detection of toxic materials entering the plant or refinery and also its organic load shocks. [ABSTRACT FROM AUTHOR]
- Published
- 2018
212. The remembrance of the things past: Conserved signalling pathways link protozoa to mammalian nervous system.
- Author
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Plattner, Helmut and Verkhratsky, Alexei
- Abstract
The aim of the present article is to analyse the evolutionary links between protozoa and neuronal and neurosecretory cells. To this effect we employ functional and topological data available for ciliates, in particular for Paramecium . Of note, much less data are available for choanoflagellates, the progenitors of metazoans, which currently are in the focus of metazoan genomic data mining. Key molecular players are found from the base to the highest levels of eukaryote evolution, including neurones and neurosecretory cells. Several common fundamental mechanisms, such as SNARE proteins and assembly of exocytosis sites, GTPases, Ca 2+ -sensors, voltage-gated Ca 2+ -influx channels and their inhibition by the forming Ca 2+ /calmodulin complex are conserved, albeit with different subcellular channel localisation, from protozoans to man. Similarly, Ca 2+ -release channels represented by InsP 3 receptors and putative precursors of ryanodine receptors, which all emerged in protozoa, serve for focal intracellular Ca 2+ signalling from ciliates to mammalian neuronal cells, eventually in conjunction with store-operated Ca 2+ -influx. Restriction of Ca 2+ signals by high capacity/low affinity Ca 2+ -binding proteins is maintained throughout the evolutionary tree although the proteins involved differ between the taxa. Phosphatase 2B/calcineurin appears to be involved in signalling and in membrane recycling throughout evolution. Most impressive example of evolutionary conservation is the sub-second dynamics of exocytosis-endocytosis coupling in Paramecium cells, with similar kinetics in neuronal and neurosecretory systems. Numerous cell surface receptors and channels that emerge in protozoa operate in the human nervous system, whereas a variety of cell adhesion molecules are newly “invented” during evolution, enabled by an increase in gene numbers, alternative splice forms and transcription factors. Thereby, important regulatory and signalling molecules are retained as a protozoan heritage. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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213. Identification and molecular characterization of two Cu/Zn-SODs and Mn-SOD in the marine ciliate Euplotes crassus: Modulation of enzyme activity and transcripts in response to copper and cadmium.
- Author
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Kim, Ji-Soo, Kim, Hokyun, Yim, Bora, Rhee, Jae-Sung, Won, Eun-Ji, and Lee, Young-Mi
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SUPEROXIDE dismutase , *CILIATA , *PHYSIOLOGICAL effects of copper , *GENETIC transcription , *ENZYME activation , *OXIDATIVE stress , *PROTOZOA genetics , *GENETICS - Abstract
The superoxide dismutase (SOD) family is a first line antioxidant enzyme group involved in transformation of the superoxide anion (O 2 − ) into hydrogen peroxide (H 2 O 2 ) and O 2 . SOD gene expression patterns and enzyme activities therefore have a role as molecular biomarkers in evaluating the oxidative stress status of aquatic organisms. However, antioxidant enzyme systems are yet to be fully explored in the marine ciliates. In this study, we identified and characterized two types of Cu/Zn SODs (Ec-Cu/ZnSOD1 and Ec-Cu/ZnSOD2) and Ec-Mn SOD in the marine ciliate Euplotes crassus . Subsequently, SOD activity and transcriptional modulation of the relevant genes were investigated after the exposure to Cd and Cu for 8 h. All Ec-SODs showed conserved domains and metal binding sites on their active sites. Total SOD activity was induced at 1 h after exposure to Cd (125 and 1000 μg/L), and showed a marginal increase at 1-h exposure to Cu (10 and 100 μg/L). However, SOD activity was maintained at a steady level under Cd and decreased under Cu exposure conditions at 3 h and 8 h. mRNA expression of both the Ec-Cu/Zn-SOD s and Mn-SOD were remarkably elevated after the exposure to Cd (250–1000 μg/L, maximum 4-fold, p < 0.05) and, in particular, Cu (25–100 μg/L, maximum > 20-fold, p < 0.05), in a concentration – dependent manner. These findings suggest that Ec-SODs may be actively involved in cellular protection against metal – mediated oxidative stress. This study is therefore helpful in understanding the molecular responses for metal toxicity in the ciliates. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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214. Toxicity of Chlorpyrifos and Dimethoate to the Ciliate <italic>Urostyla grandis</italic>, with Notes on Their Effects on Cell Ultrastructure.
- Author
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Mu, Weijie, Warren, Alan, Pan, Xuming, and Ying, Chen
- Abstract
Chlorpyrifos and dimethoate are overused agricultural pesticides that can trigger trophic cascades, resulting in toxicity to both terrestrial and aquatic organisms as well as altered ecosystems. In previous studies, substantial attention has been given to the effects of pesticides on vertebrate species and, to a lesser extent, species of zooplankton. The present study was designed to show that the fission time effective concentration in ciliates is a potential aquatic detection index for environmental monitoring. The ciliate
Urostyla grandis was treated with doses of chlorpyrifos and dimethoate. After exposed to the pesticides, theLC 50 (i.e. , concentration that killed 50% of the ciliate cells within 24 h) values were 0.029 mg L−1 for chlorpyrifos and 0.0685 mg L−1 for dimethoate. The fission time effective concentrations after 168 h of exposure were 0.0075-0.0093 mg L−1 for chlorpyrifos and 0.2640-0.2750 mg L−1 for dimethoate. These results show that the fission time effective concentration is lower than theLC 50 value in ciliates, indicating that fission time effective concentration is more suitable than theLC 50 value for environmental monitoring using ciliates. The effects of chlorpyrifos and dimethoate on ciliate cell ultrastructures included agglutination of chromatin in the macronucleus, protruded and discontinuous macronuclear and micronuclear membranes, loss of integrity of mitochondrial membranes and contents, and abscission and deformation of the adoral zone of membranelles. [ABSTRACT FROM AUTHOR]- Published
- 2018
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215. New discoveries of the genus Thuricola Kent, 1881 (Ciliophora, Peritrichia, Vaginicolidae), with descriptions of three poorly known species from China.
- Author
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Borong LU, Daode JI, Yalan SHENG, Weibo SONG, Xiaozhong HU, Xiangrui CHEN, and AL-RASHEID, Khaled A. S.
- Subjects
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CILIATA , *PERITRICHA , *RECOMBINANT DNA , *COLONIAL animals (Marine invertebrates) , *MOLECULAR phylogeny , *MORPHOLOGY - Abstract
Members of the genus Thuricola are a highly specialized group of peritrichous ciliates possessing a protective barrel-shaped lorica. The genus presents many difficulties in terms of species separation and definition, and in this context the present study investigates three species by protargol staining and analyses of SSU rDNA sequences. Based on their morphologic characteristics and biotope, they were identified as three poorly known forms in Thuricola, namely T. obconica Kahl, 1933, T. kellicottiana (Stokes, 1887) Kahl 1935 and T. folliculata Kent, 1881, respectively. T. obconica is characterized by possessing curved lorica and a single valve in vivo. T. kellicottiana is distinguished by two valves with a spine on the main valve, and a generally long internal stalk upon which the zooids sit. T. folliculata also has two valves but lacks a spine. The ciliature of the three species are basically similar. The main features are characterized as follows: infundibular polykineties 1-3 (P1-3) are relatively long and composed of three rows each; P1 bends twice and comprises three equally long rows; P2 ends near the second bend of P1 with all rows exhibiting a staggered arrangement; P3 converges with P1 at adstomal end, its row 1 at least twice as long as the other two rows; epistomial membranes 1 and 2 are present. Silverline system in Vorticella-pattern. Phylogenetic analyses indicate that the three ciliates in this study cluster together within one of the two major sub-clades within the Vaginicolidae. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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216. Characterisation of the intracellular protozoan MPX in Scottish mussels, Mytilus edulis Linnaeus, 1758.
- Author
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Fichi, G., Carboni, S., Bron, J.E., Ireland, J., Leaver, M.J., and Paladini, G.
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MYTILUS edulis , *CILIATA , *RIBOSOMAL RNA , *BIVALVES , *NECROSIS - Abstract
Ciliates have been reported as pathogens of many species of economically important bivalves. Mussel protozoan X (MPX), is an uncharacterised intracellular ciliate of mussels and has been widely reported in Mytilus spp . around the world. In order to characterise this ciliate, Mytilus edulis samples were collected from a site on the West coast of Scotland, and four different fixatives for histological examination were tested. Fresh preparations of mussel digestive glands were also examined by laser scanning confocal microscopy. Intracellular ciliates were prepared by laser capture microdissection and partial sequences of small subunit ribosomal RNA gene and of large subunit ribosomal RNA gene were generated, using Phyllopharyngea primers. Methacarn solution proved to be the best fixative for both histological and molecular characterisation. The morphological and molecular investigations confirmed that this ciliate belongs to the class Phyllopharyngea, order Rhynchodida. However, this organism does not belong to any known family, genus or species, therefore, a new description is necessary, following further morphological analyses. Most mussel samples containing MPX displayed mild to moderate infections, with no signs of necrosis or haemocytic response, although a single sample displayed a severe infection (∼10 3 ciliates per section). The localisation of this ciliate in tissues other than the digestive gland, the presence of necrosis in infected tissue of the most severely infected mussel and the binary fission of this ciliate have been observed here for the first time. We also report the first observation of the live ciliate isolated from tissue. Although MPX remains of unknown significance to the mussel industry, tools and protocols described here will be useful in further characterising these and other ciliates (subclass Rhynchodia) known as pathogens for bivalves. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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217. Biomechanics of Tetrahymena escaping from a dead end.
- Author
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Takuji Ishikawa and Kenji Kikuchi
- Subjects
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BIOMECHANICS , *TETRAHYMENA thermophila , *MICROORGANISMS , *HYDRODYNAMICS , *LUBRICATION & lubricants - Abstract
Understanding the behaviours of swimming microorganisms in various environments is important for understanding cell distribution and growth in nature and industry. However, cell behaviour in complex geometries is largely unknown. In this study, we used Tetrahymena thermophila as a model microorganism and experimentally investigated cell behaviour between two flat plates with a small angle. In this configuration, the geometry provided a 'dead end' line where the two flat plates made contact. The results showed that cells tended to escape from the dead end line more by hydrodynamics than by a biological reaction. In the case of hydrodynamic escape, the cell trajectories were symmetric as they swam to and from the dead end line. Near the dead end line, T. thermophila cells were compressed between the two flat plates while cilia kept beating with reduced frequency; those cells again showed symmetric trajectories, although the swimming velocity decreased. These behaviours were well reproduced by our computational model based on biomechanics. The mechanism of hydrodynamic escape can be understood in terms of the torque balance induced by lubrication flow. We therefore conclude that a cell's escape from the dead end was assisted by hydrodynamics. These findings pave the way for understanding cell behaviour and distribution in complex geometries. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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218. Morphology and Phylogeny of a New Species of Anaerobic Ciliate, Trimyema finlayi n. sp., with Endosymbiotic Methanogens.
- Author
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Lewis, William H., Sendra, Kacper M., Embley, T. Martin, and Esteban, Genoveva F.
- Subjects
ANAEROBIC protozoa ,CILIATA ,PHYLOGENY - Abstract
Many anaerobic ciliated protozoa contain organelles of mitochondrial ancestry called hydrogenosomes. These organelles generate molecular hydrogen that is consumed by methanogenic Archaea, living in endosymbiosis within many of these ciliates. Here we describe a new species of anaerobic ciliate, Trimyema finlayi n. sp., by using silver impregnation and microscopy to conduct a detailed morphometric analysis. Comparisons with previously published morphological data for this species, as well as the closely related species, Trimyema compressum, demonstrated that despite them being similar, both the mean cell size and the mean number of somatic kineties are lower for T. finlayi than for T. compressum, which suggests that they are distinct species. This was also supported by analysis of the 18S rRNA genes from these ciliates, the sequences of which are 97.5% identical (6 substitutions, 1479 compared bases), and in phylogenetic analyses these sequences grouped with other 18S rRNA genes sequenced from previous isolates of the same respective species. Together these data provide strong evidence that T. finlayi is a novel species of Trimyema, within the class Plagiopylea. Various microscopic techniques demonstrated that T. finlayi n. sp. contains polymorphic endosymbiotic methanogens, and analysis of the endosymbionts' 16S rRNA gene showed that they belong to the genus Methanocorpusculum, which was confirmed using fluorescence in situ hybridization with specific probes. Despite the degree of similarity and close relationship between these ciliates, T. compressum contains endosymbiotic methanogens from a different genus, Methanobrevibacter. In phylogenetic analyses of 16S rRNA genes, the Methanocorpusculum endosymbiont of T. finlayi n. sp. grouped with sequences from Methanomicrobia, including the endosymbiont of an earlier isolate of the same species, 'Trimyema sp.,' which was sampled approximately 22 years earlier, at a distant (~400 km) geographical location. Identification of the same endosymbiont species in the two separate isolates of T. finlayi n. sp. provides evidence for spatial and temporal stability of the Methanocorpusculum- T. finlayi n. sp. endosymbiosis. T. finlayi n. sp. and T. compressum provide an example of two closely related anaerobic ciliates that have endosymbionts from different methanogen genera, suggesting that the endosymbionts have not co-speciated with their hosts. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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219. More than the "Killer Trait": Infection with the Bacterial Endosymbiont Caedibacter taeniospiralis Causes Transcriptomic Modulation in Paramecium Host.
- Author
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Grosser, Katrin, Ramasamy, Pathmanaban, Amirabad, Azim Dehghani, Schulz, Marcel H., Gasparoni, Gilles, Simon, Martin, and Schrallhammer, Martina
- Subjects
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ENDOSYMBIOSIS , *TRANSCRIPTOMES , *PARAMECIUM , *PROTEIN structure , *COMPARATIVE genomics - Abstract
Endosymbiosis is a widespread phenomenon and hosts of bacterial endosymbionts can be found all-over the eukaryotic tree of life. Likely, this evolutionary success is connected to the altered phenotype arising from a symbiotic association. The potential variety of symbiont's contributions to new characteristics or abilities of host organisms are largely unstudied. Addressing this aspect, we focused on an obligate bacterial endosymbiont that confers an intraspecific killer phenotype to its host. The symbiosis between Paramecium tetraurelia and Caedibacter taeniospiralis, living in the host's cytoplasm, enables the infected paramecia to release Caedibacter symbionts, which can simultaneously produce a peculiar protein structure and a toxin. The ingestion of bacteria that harbor both components leads to the death of symbiont-free congeners. Thus, the symbiosis provides Caedibacter-infected cells a competitive advantage, the "killer trait." We characterized the adaptive gene expression patterns in symbiont-harboring Paramecium as a second symbiosis-derived aspect next to the killer phenotype. Comparative transcriptomics of infected P. tetraurelia and genetically identical symbiont-free cells confirmed altered gene expression in the symbiont-bearing line. Our results show up-regulation of specific metabolic and heat shock genes whereas down-regulated genes were involved in signaling pathways and cell cycle regulation. Functional analyses to validate the transcriptomics results demonstrated that the symbiont increases host density hence providing a fitness advantage. Comparative transcriptomics shows gene expression modulation of a ciliate caused by its bacterial endosymbiont thus revealing new adaptive advantages of the symbiosis. Caedibacter taeniospiralis apparently increases its host fitness via manipulation of metabolic pathways and cell cycle control. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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220. Reconsideration of the systematics of Peniculida (Protista, Ciliophora) based on SSU rRNA gene sequences and new morphological features of Marituja and Disematostoma.
- Author
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Xu, Yuan, Gao, Feng, and Fan, Xinpeng
- Subjects
- *
EUKARYOTES , *PROTISTA , *AQUATIC ecology , *RIBOSOMAL RNA , *PHYLOGENY - Abstract
Ciliated protists are unicellular eukaryotes that play important roles in aquatic ecosystems. One of the major tasks of ciliate taxonomy is to re-evaluate the systematic confusing taxa using modern methods. In the present study, two peniculid ciliates, Marituja cf. caudata and Disematostoma minor collected from east China, were studied using a multi-method approach. New morphological observations supplied additional information for species identification and systematic revision of the order Peniculida. The small subunit ribosomal RNA gene sequences of M. cf. caudata, D. minor, and Frontonia terricola were characterized for the first time and provided new insights into the phylogeny of Peniculida. The family Stokesiidae Roque, 1961, was expanded to include the genera Disematostoma and Marituja in addition to its type genus Stokesia, since the three genera formed a well-supported clade in the phylogenetic analyses. The diagnosis of Stokesiidae was improved to include the newly recognized synapomorphies, i.e., barren kinetosomes on the dorsal side, a ciliated dorsal suture, and the somatic ciliature that can be recognized as transversely oriented circles. Additionally, the systematic relationships of the genera and families of Peniculida were hypothesized. We argue that more diversified morphological features should be considered when assessing diagnostic traits for ciliate taxa during systematic revisions. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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221. Phylogeny of the families Zoothamniidae and Epistylididae (Protozoa: Ciliophora: Peritrichia) based on analyses of three rRNA-coding regions.
- Author
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Zhuang, Yuan, Clamp, John C., Yi, Zhenzhen, and Ji, Daode
- Subjects
- *
PERITRICHA , *MICROORGANISM phylogeny , *HABITATS , *VORTICELLIDAE , *MICROBIAL genetics , *MICROBIAL evolution - Abstract
Peritrichs are a major group of ciliates with worldwide distribution, and they play important roles in many habitats. Intrafamilial phylogeny of some peritrichs was investigated using information from three genes, which provided more robust interpretations than single-gene analyses. Sixty-seven new sequences including SSU rDNA, ITS1-5.8S-ITS2 and LSU rDNA were aligned with available sequences in GenBank to infer phylogenetic relationships within the families Zoothamniidae and Epistylididae. Results reveal the following relationships: (1) Epistylididae is polyphyletic, consisting of two clades that nest within the Zoothamniidae as part of the crown clade of peritrichs (order Vorticellida) and a third one that is part of the basal clade of peritrichs (order Opercularida); (2) Epistylis elongata falls within one of the clades of Zoothamnium rather than with congeners; (3) Zoothamnium is probably paraphyletic, consisting of three divergent clades, with the genera Myoschiston and Zoothamnopsis intermingled with species of Zoothamnium . The following evolutionary hypotheses can be inferred from these results: (1) the contractile stalk of Zoothamnium is plesiomorphic. (2) Myoschiston, Zoothamnopsis and clade II of Epistylididae are derived from the Zoothamnium morphotype by partial or incomplete development of the spasmoneme that forms the contractile center of the stalk around which the rigid cortex is secreted. (3) Clade I of the Epistylididae, which are primarily colonial forms that appear never to have evolved a spasmoneme of any sort, may represent the ancestral morphotype of peritrichs. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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222. Balantidium grimi n. sp. (Ciliophora, Litostomatea), a new species inhabiting the rectum of the frog Quasipaa spinosa from Lishui, China.
- Author
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Zhao, Weishan, Li, Can, Zhang, Dong, Wang, Runqiu, Zheng, Yingzhen, Zou, Hong, Li, Wenxiang, Wu, Shangong, Wang, Guitang, and Li, Ming
- Abstract
Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
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223. Transcriptional profiling of antioxidant defense system and heat shock protein ( Hsp) families in the cadmium- and copper-exposed marine ciliate Euplotes crassu.
- Author
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Kim, Bo-Mi, Rhee, Jae-Sung, Choi, Ik-Young, and Lee, Young-Mi
- Abstract
To understand the transcriptional response of antioxidant defense system and heat shock protein ( Hsp) families of the marine ciliate Euplotes crassus, we analyzed the transcriptome profile using RNA-seq technology after exposure to cadmium (Cd) and copper (Cu). De novo sequence assembly produced 61,240 unigenes with 21,330 BLAST hits and showed high sequence orthology with transcriptomes of other ciliates. Gene annotation and gene ontology (GO) comparison revealed that E. crassus expressed highly diversified but conserved stress-responsive gene families of the antioxidant defense system and Hsps. After waterborne exposure to 250 μg/L of Cd and 25 μg/L of Cu, transcriptional responses of the gene families were significantly modulated, suggesting that even the unicellular E. crassus has a conserved molecular defense mechanism, such as modulating mRNA expression, for homeostasis. These transcriptional responses make E. crassus a potential model for understanding the molecular response of single cell ciliates to heavy metal contamination. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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- View/download PDF
224. Interactions between the voracious heterotrophic nanoflagellate Katablepharis japonica and common heterotrophic protists.
- Author
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So Jin Kim, Hae Jin Jeong, Se Hyeon Jang, Sung Yeon Lee, and Tae Gyu Park
- Subjects
- *
DINOFLAGELLATES , *PROTISTA , *RED tide , *PREDATION , *ANIMAL species - Abstract
Recently, the heterotrophic nanoflagellate Katablepharis japonica has been reported to feed on diverse red-tide species and contribute to the decline of red tides. However, if there are effective predators feeding on K. japonica, its effect on red tide dynamics may be reduced. To investigate potential effective protist predators of K. japonica, feeding by the engulfment-feeding heterotrophic dinoflagellates (HTDs) Oxyrrhis marina, Gyrodinium dominans, Gyrodinium moestrupii, Polykrikos kofoidii, and Noctiluca scintillans, the peduncle-feeding HTDs Luciella masanensis and Pfiesteria piscicida, the pallium-feeding HTD Oblea rotunda, and the naked ciliates Strombidium sp. (approximately 20 μm in cell length), Pelagostrobilidium sp., and Miamiensis sp. on K. japonica was explored. We found that none of these heterotrophic protists fed on actively swimming cells of K. japonica. However, O. marina, G. dominans, L. masanensis, and P. piscicida were able to feed on heat-killed K. japonica. Thus, actively swimming behavior of K. japonica may affect feeding by these heterotrophic protists on K. japonica. To the contrary, K. japonica was able to feed on O. marina, P. kofoidii, O. rotunda, Miamiensis sp., Pelagostrobilidium sp., and Strombidium sp. However, the specific growth rates of O. marina did not differ significantly among nine different K. japonica concentrations. Thus, K. japonica may not affect growth of O. marina. Our findings suggest that the effect of predation by heterotrophic protists on K. japonica might be negligible, and thus, the effect of grazing by K. japonica on populations of red-tide species may not be reduced by mortality due to predation by protists. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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225. Packaging of Mycobacterium smegmatis bacteria into fecal pellets by the ciliate Tetrahymena pyriformis.
- Author
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Denoncourt, Alix M., Paquet, Valérie E., and Charette, Steve J.
- Subjects
- *
MYCOBACTERIUM smegmatis , *TETRAHYMENA pyriformis , *PROTOZOA - Abstract
Mycobacteria are widespread microorganisms that live in various environments, including man-made water systems where they cohabit with protozoa. Environmental mycobacterial species give rise to many opportunistic human infections and can infect phagocytic protozoa. Protozoa such as amoebae and ciliates feeding on bacteria can sometimes get rid of non-digestible or pathogenic material by packaging it into secreted fecal pellets. Usually, packaged bacteria are still viable and are protected against chemical and physical stresses. We report here that mycobacteria can be packaged into pellets by ciliates. The model bacterium Mycobacterium smegmatis survived digestion in food vacuoles of the ciliate Tetrahymena pyriformis and was included in expelled fecal pellets. LIVE/DEAD® staining confirmed that packaged M. smegmatis cells preserved their viability through the process. Scanning and transmission electron microscopy revealed that bacteria are packaged in undefined filamentous and/or laminar substances and that just a thin layer of material seemed to keep the pellet contents in a spherical shape. These results imply that packaging of bacteria is more common than expected, and merits further study to understand its role in persistence and dissemination of pathogens in the environment. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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226. Novel Specificity of IDO Enzyme Involved in the Biosynthesis of Mating Pheromone in the Ciliate Blepharisma stoltei.
- Author
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Sugiura, Mayumi, Yuasa, Hajime J., and Harumoto, Terue
- Subjects
BLEPHARISMA ,PHEROMONES ,INDOLEAMINE 2,3-dioxygenase ,TRYPTOPHAN metabolism ,BACTERIAL conjugation - Abstract
Mating pheromones (gamone 1 and gamone 2) in the ciliate Blepharisma are biologically active substances that trigger sexual reproduction (conjugation) under starvation conditions. Gamone 1 is a glycoprotein secreted by type I cells, and gamone 2 is a tryptophan (Trp)-derivative compound secreted by type II cells. Both gamones stimulate complementary mating type cells to promote each gamone production and induce pair formation. To elucidate the biosynthetic pathway of gamone 2, we investigated the enzymes involved in the pathway and the specificity of the enzymes. An RNA-seq analysis revealed that Blepharisma stoltei (Heterotrichea) possesses four indoleamine 2,3-dioxygenase ( IDO ) genes showing distinct expression patterns. Along with results from real-time PCR, these findings demonstrated that each IDO gene has different expression patterns that depend on the cellular conditions. Expression of IDO-I was correlated with the intensity of gamone 2 expression, and the recombinant IDO-I protein showed catalytic activity for 5-hydroxy-L-Trp (5-HTP) but very weak activity for L-Trp. Our results indicate that IDO-I is an enzyme evolutionary specialized to gamone 2 production in Blepharisma , and that the biosynthetic pathway for gamone 2 uses 5-HTP as an intermediate. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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227. Molecular characterization of ABC transporters in marine ciliate, Euplotes crassus: Identification and response to cadmium and benzo[a]pyrene.
- Author
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Kim, Hokyun, Yim, Bora, Kim, Jisoo, Kim, Haeyeon, and Lee, Young-Mi
- Subjects
ATP-binding cassette transporters ,XENOBIOTICS ,CADMIUM ,BENZOPYRENE ,EFFLUX (Microbiology) - Abstract
ATP-binding cassette (ABC) transporters participate in transporting various substances, including xenobiotics, in or out of cells. However, their genetic information and function in ciliates remain still unclear. In this study, we sequenced and characterized two ABC transporter genes ( EcABCB and EcABCC ), and investigated the effect of cadmium (Cd) and benzo[ a ]pyrene (B[ a ]P) on their function and gene expression, using efflux assay and real-time reverse transcription-polymerase chain reaction (qRT-PCR), respectively, in the marine ciliate, Euplotes crassus . Sequencing analysis and efflux assay showed that EcABCB and EcABCC are typical ABC transporters, possessing conserved function. Exposure to Cd (≥ 5 mg/L) and B[ a ]P (≥ 50.5 μg/L) enhanced accumulation of a substrate. A significant increase in the expression of EcABCB and EcABC mRNA was observed at lower concentration in response to Cd and B[ a ]P. Our findings indicate that Cd and B[ a ]P could inhibit the efflux function of ABC transporters, leading to cellular toxicity in the ciliate. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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228. Distribution of Abundant and Active Planktonic Ciliates in Coastal and Slope Waters Off New England.
- Author
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Tucker, Sarah J., McManus, George B., Katz, Laura A., and Grattepanche, Jean-David
- Subjects
CILIATA ,DNA analysis ,MICROBIAL communities - Abstract
Despite their important role of linking microbial and classic marine food webs, data on biogeographical patterns of microbial eukaryotic grazers are limited, and even fewer studies have used molecular tools to assess active (i.e., those expressing genes) community members. Marine ciliate diversity is believed to be greatest at the chlorophyll maximum, where there is an abundance of autotrophic prey, and is often assumed to decline with depth. Here, we assess the abundant (DNA) and active (RNA) marine ciliate communities throughout the water column at two stations off the New England coast (Northwest Atlantic)--a coastal station 43 kmfromshore (40mdepth) and a slope station 135 km off shore (1,000m). We analyze ciliate communities using a DNA fingerprinting technique, Denaturing Gradient Gel Electrophoresis (DGGE), which captures patterns of abundant community members. We compare estimates of ciliate communities from SSU-rDNA (abundant) and SSU-rRNA (active) and find complex patterns throughout the water column, including many active lineages below the photic zone. Our analyses reveal (1) a number of widely-distributed taxa that are both abundant and active; (2) considerable heterogeneity in patterns of presence/absence of taxa in offshore samples taken 50m apart throughout the water column; and (3) three distinct ciliate assemblages based on position from shore and depth. Analysis of active (RNA) taxa uncovers biodiversity hidden to traditional DNA-based approaches (e.g., clone library, rDNA amplicon studies). [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
229. Coupling of phytoplankton and ciliate biomasses to environmental factors along the north coast of Sfax (Tunisia, Eastern Mediterranean Sea).
- Author
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Rekik, Amira, Elloumi, Jannet, Drira, Zaher, Maalej, Sami, and Ayadi, Habib
- Subjects
BIOMASS ,PHYTOPLANKTON ,DIATOMS ,DINOFLAGELLATES ,GREEN algae - Abstract
The phytoplankton and ciliate biomasses coupled with environmental factors were investigated in 15 transects in north coasts of Sfax (Tunisia, Eastern Mediterranean Sea) in July 2007. The phytoplankton biomass was dominated by Bacillariophyceae (89.66%), followed by Dinophyceae (10.07%), Coccolithophorideae (0.96%), Cyanobacteriae (0.21%), Chlorophyceae (0.03%) and Euglenophyceae (0.01%). Coscinodiscus sp. (93.26%) was the most abundant species of Bacillariophyceae group and associated with a high nutrient availability. Ciliate biomass was highly variable, with a large dominance of Spirotrichea, up to 96.2%. Biomass followed distinct patterns because of differences in the observed organism biovolumes. The spatial distribution of the ciliates biomass seems to be dependent on environmental factors and probably on their capacity to exploit a wide range of food resources including phytoplankton. The pollution generated by the phosphate-treating manufactory influenced the spatial phytoplankton and ciliate community's distribution and their diversity along the north coast of Sfax. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
230. Grazing by microzooplankton and copepods on the microbial food web in spring in the southern Yellow Sea, China
- Author
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Zhao, Yuan, Dong, Yi, Li, Haibo, Lin, Shiquan, Huang, Lingfeng, Xiao, Tian, Gregori, Gerald, Zhao, Li, and Zhang, Wuchang
- Published
- 2020
- Full Text
- View/download PDF
231. Characteristics of maltose transport system in the endosymbiont Chlorella variabilis of Paramecium bursaria
- Author
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Nobutaka Imamura, Fumio Takahashi, Masahiro Kasahara, and Aika Shibata
- Subjects
Chlorella variabilis ,Ciliate ,Maltose transport ,Paramecium bursaria ,Symbiosis ,biology ,Botany ,Green algae ,Plant Science ,Aquatic Science ,biology.organism_classification ,Agricultural and Biological Sciences (miscellaneous) - Published
- 2021
232. Environmental association of heterotrophic micro-eukaryotes in the varying biogeochemical regimes of the Arabian Sea, resolved via high-throughput sequencing
- Author
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Mangesh Gauns, Alexandra Stock, Syed Wajih Ahmad Naqvi, and Priya Brata Das
- Subjects
Ciliate ,Chlorophyll a ,Biogeochemical cycle ,biology ,Ecology ,fungi ,Pelagic zone ,Aquatic Science ,Oxygen minimum zone ,biology.organism_classification ,Salinity ,chemistry.chemical_compound ,chemistry ,Canonical correspondence analysis ,Environmental science ,Flagellate ,Ecology, Evolution, Behavior and Systematics - Abstract
The diverse physicochemical conditions prevailing in the Arabian Sea are expected to result in marked spatial variations in heterotrophic flagellate (HF) and ciliate communities. Here, we report the environmental association of heterotrophic micro-eukaryotes, particularly the heterotrophic flagellates and ciliates, based on 18S rRNA gene survey in the region. High-throughput next-generation sequencing, using the V4 eukaryotic-specific primer, was employed to study the composition of these communities associated with low-O2 waters in both coastal and offshore settings. Canonical correspondence analysis (CCA) revealed a preference of the heterotrophic flagellates for nitrate- and nitrite-rich zones. Notably, the heterotrophic nanoflagellate genus Monosiga showed a strong positive correlation with NO3−, which suggests its potential denitrifying capability. Shannon’s entropy analysis revealed a higher HF diversity in the hypoxic waters of the open ocean (depth 103 m), whereas ciliates were more diverse at oxygenated coastal stations. The estuarine waters exhibited a low diversity of both ciliates and flagellates. The UPGMA clusters of heterotrophic flagellates and ciliates in suboxic waters of the open ocean oxygen minimum zone were distinct from those found at other sites. Overall, CCA revealed the important relationship between nitrite, nitrate, salinity and chlorophyll a, which could be important factors for the partitioning of different ecological niches for specific HF and ciliate communities in the Arabian Sea. The community of heterotrophic protists that can adapt to varying biogeochemical regimes has been identified.
- Published
- 2021
233. Prey type constrains growth and photosynthetic capacity of the kleptoplastidic ciliate Mesodinium chamaeleon (Ciliophora)
- Author
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Cara Chinn, Matthew D. Johnson, Holly V. Moeller, Veronica Hsu, Lisa Y. Mesrop, and Michelle Lepori-Bui
- Subjects
0106 biological sciences ,Ciliate ,Chloroplasts ,Endosymbiosis ,010604 marine biology & hydrobiology ,Mesodinium chamaeleon ,food and beverages ,Plant Science ,Aquatic Science ,Biology ,Photosynthesis ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Photosynthetic capacity ,Chloroplast ,Botany ,Plastids ,Ciliophora ,Plastid ,Kleptoplasty ,Cryptophyta ,Phylogeny - 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.
- Published
- 2021
234. Swimming behavior of cryptophyte prey affects prey preference of the ambush-feeding ciliate Mesodinium rubrum
- Author
-
Houshuo Jiang and Matthew D. Johnson
- Subjects
0106 biological sciences ,Ciliate ,0303 health sciences ,010604 marine biology & hydrobiology ,Mesodinium rubrum ,Zoology ,Aquatic Science ,Biology ,biology.organism_classification ,01 natural sciences ,Preference ,Predation ,03 medical and health sciences ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology - Abstract
The mixotrophic ciliate Mesodinium rubrum is an ambush feeder relying on cryptophyte prey motility for prey encounter and perception; therefore, cryptophyte species-specific swimming behaviors affect M. rubrum’s prey preference. Here, a high-speed microscale imaging system was used to quantify the swimming behaviors of 3 cryptophyte species (Teleaulax amphioxeia, Storeatula major, and Guillardia theta) and to conduct quantitative microvideography of M. rubrum-T. amphioxeia predator-prey interaction. T. amphioxeia, a preferred prey of M. rubrum, swam at path-averaged speeds of 155 ± 73 µm s-1 along rather straight paths. In contrast, S. major regularly tumbled slowly downward or upward at 64 ± 16 µm s-1, while G. theta moved slowly in looped/curved trajectories at 57 ± 15 µm s-1; neither supports M. rubrum growth. Only while motionlessly sinking passively did M. rubrum detect and initiate an attack on swimming T. amphioxeia at reaction distances of 8.2 ± 8.2 µm. It seemed that M. rubrum needed to use oral tentacles to initially poke T. amphioxeia’s ventral posterior part and subsequently poke the prey multiple times in a short duration to compromise the prey’s escape ability, presumably by discharging extrusomes into the prey. T. amphioxeia also responded to nearby predators by switching to tumbling similar to S. major in normal swimming, suggesting an effective anti-predator defense behavior that prevents M. rubrum from accurately poking the prey’s ventral posterior part. T. amphioxeia swimming at significantly higher speeds leads to sufficiently high prey encounters and hydrodynamic signals for M. rubrum, thereby partially explaining M. rubrum’s ability to select T. amphioxeia prey.
- Published
- 2021
235. Establishment of loop-mediated isothermal amplification assay for detection of parasitic ciliate Ichthyophthirius multifiliis in cyprinid fish
- Author
-
Surachai Pikulkaew and Panyisa Potibut
- Subjects
Ciliate ,General Veterinary ,Ichthyophthirius multifiliis ,Loop-mediated isothermal amplification ,%22">Fish ,Animal Science and Zoology ,Biology ,biology.organism_classification ,Agricultural and Biological Sciences (miscellaneous) ,Microbiology - Abstract
The objective of this research was to establish loop-mediated isothermal amplifications (LAMP) that could be used to detect parasitic ciliate Ichthyophthirius multifiliis (I. multifiliis) in freshwater cyprinid fish. Primers were developed from the distinguishing fragments of 18S ribosomal RNA of I. multifiliis and the LAMP test was then used to evaluate and optimize various concentrations of chemicals, time and temperature. The results indicated that LAMP required 1.6 μM of FIP primers and BIP primers, 0.2 μM of F3 and B3, 2 mM of Mg2+, 1 M of Betaine, and 0.6 mM of dNTP. This assay was able to detect parasite DNA within a 40 min period of incubation and at a constant optimal temperature of 64oC. The positive sample appeared as a clear ladder like pattern on gel electrophoresis, while a yellowish green color appeared with SYBR Green I under ultraviolet light with the use of a heating block. The LAMP test was determined to be more sensitive than conventional PCR in the detection of I. multifiliis. In conclusion, we have presented a sensitive and specific rapid detection system for I. multifiliis based on isothermal DNA amplification. Importantly, this system could then be employed as an alternative and effective diagnostic method in place of other molecular techniques.
- Published
- 2021
236. The macronuclear genome of anaerobic ciliate Entodinium caudatum reveals its biological features adapted to the distinct rumen environment
- Author
-
Tansol Park, Jeffrey L. Firkins, Zhongtang Yu, Saranga Wijeratne, and Tea Meulia
- Subjects
0106 biological sciences ,Ciliate ,Genetics ,0303 health sciences ,Rumen ,biology ,Macronucleus ,Sequence assembly ,Sequence Analysis, DNA ,biology.organism_classification ,01 natural sciences ,Genome ,03 medical and health sciences ,Minion ,Horizontal gene transfer ,Proteome ,Animals ,Carbohydrate Metabolism ,Anaerobiosis ,Ciliophora ,030304 developmental biology ,010606 plant biology & botany - Abstract
Entodinium caudatum is an anaerobic binucleated ciliate representing the most dominant protozoal species in the rumen. However, its biological features are largely unknown due to the inability to establish an axenic culture. In this study, we primally sequenced its macronucleus (MAC) genome to aid the understanding of its metabolism, physiology, ecology. We isolated the MAC of E. caudatum strain MZG-1 and sequenced the MAC genome using Illumina MiSeq, MinION, and PacBio RSII systems. De novo assembly of the MiSeq sequence reads followed with subsequent scaffolding with MinION and PacBio reads resulted in a draft MAC genome about 117 Mbp. A large number of carbohydrate-active enzymes were likely acquired through horizontal gene transfer. About 8.74% of the E. caudatum predicted proteome was predicted as proteases. The MAC genome of E. caudatum will help better understand its important roles in rumen carbohydrate metabolism, and interaction with other members of the rumen microbiome.
- Published
- 2021
237. New observations on the large hemidiscoid diatomPalmerina ostenfeldiiand its symbiotic ciliateVaginicola collariformasp. nov.from subtropical Australian waters
- Author
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Anthony J. Richardson, Lucy Whittock, Julian Uribe-Palomino, Romain Gastineau, Gustaaf M. Hallegraeff, and Nicholas M. Wade
- Subjects
0106 biological sciences ,Ciliate ,0303 health sciences ,biology ,010604 marine biology & hydrobiology ,fungi ,Zoology ,Aquatic Science ,biology.organism_classification ,01 natural sciences ,03 medical and health sciences ,Peritrich ,Diatom ,Genus ,Taxonomy (biology) ,Epiphyte ,Bay ,030304 developmental biology ,Tintinnid - Abstract
The large hemi-discoid diatom Palmerina ostenfeldii was common in subtropical Moreton Bay, Australia, following a flood in January 2011. All diatom cells exhibited diagnostic subapical folds settled by loricate peritrich ciliates, but which readily abandoned stressed diatom cells. We characterized both diatoms and ciliates by morphological and molecular analyses, including careful video observations on non-preserved cells immediately after collection. The fold in the diatom cell wall comprises a narrow shelf upon which the ciliates attach (on average seven per fold, and similar for the two folds of a single diatom cell) but without penetrating the diatom wall itself. Folds were fully developed in newly formed internal valves, indicating that the ciliates play no role in their morphogenesis. SSU rRNA sequences of P. ostenfeldii from Moreton Bay (with ciliates) differed by 25 bp (1.5%) from those of P. hardmaniana from Texas (without ciliates), but surprisingly rbcL chloroplast sequences for both diatom species were indistinguishable. The ciliate species epiphytic on P. ostenfeldii, previously referred to as the cold-water tintinnid Amphorella borealis could not be assigned to any known species. We formally describe it here as Vaginicola collariforma sp. nov. within the crown clade of peritrichs which also includes the closely related genus Cothurnia (but distinguished as having an external stalk). Beating of the peritrich oral cilia was observed to drive rotational movement of the large discoid diatoms as in a ferris wheel. The observed diatom-ciliate symbiosis may represent a unique evolutionary adaptation in which the ciliate is host-specific and attaches in a specific locality on the host cell.
- Published
- 2021
238. STORM imaging reveals the spatial arrangement of transition zone components and IFT particles at the ciliary base in Tetrahymena
- Author
-
Zhu Zhou, Jarema Malicki, Natalia A. Bulgakova, Dorota Wloga, Khodor S. Hazime, and Ewa Joachimiak
- Subjects
Protozoan Proteins/metabolism ,Mutation/genetics ,Science ,Protozoan Proteins ,Tetrahymena/metabolism ,Article ,Imaging ,Ciliopathies/genetics ,Cilia/metabolism ,Intraflagellar transport ,DOCK ,Developmental biology ,Genetics ,Sequencing ,Humans ,Cilia ,Ciliary membrane ,Bardet-Biedl Syndrome ,Biological models ,Flagella/metabolism ,Ciliate ,Microscopy ,Multidisciplinary ,biology ,Ciliogenesis ,Chemistry ,Cilium ,Compartment (ship) ,Biological techniques ,Tetrahymena ,Biological Transport ,Bardet-Biedl Syndrome/metabolism ,biology.organism_classification ,Ciliopathies ,Computational biology and bioinformatics ,Flagella ,Mutation ,Biophysics ,Medicine ,sense organs ,Ciliary base ,Software ,Microscopy/methods - Abstract
The base of the cilium comprising the transition zone (TZ) and transition fibers (TF) acts as a selecting gate to regulate the intraflagellar transport (IFT)-dependent trafficking of proteins to and from cilia. Before entering the ciliary compartment, IFT complexes and transported cargoes accumulate at or near the base of the cilium. The spatial organization of IFT proteins at the cilia base is key for understanding cilia formation and function. Using stochastic optical reconstruction microscopy (STORM) and computational averaging, we show that seven TZ, nine IFT, three Bardet–Biedl syndrome (BBS), and one centrosomal protein, form 9-clustered rings at the cilium base of a ciliate Tetrahymena thermophila. In the axial dimension, analyzed TZ proteins localize to a narrow region of about 30 nm while IFT proteins dock approximately 80 nm proximal to TZ. Moreover, the IFT-A subcomplex is positioned peripheral to the IFT-B subcomplex and the investigated BBS proteins localize near the ciliary membrane. The positioning of the HA-tagged N- and C-termini of the selected proteins enabled the prediction of the spatial orientation of protein particles and likely cargo interaction sites. Based on the obtained data, we built a comprehensive 3D-model showing the arrangement of the investigated ciliary proteins.
- Published
- 2021
239. Single-cell transcriptome reveals cell division-regulated hub genes in the unicellular eukaryote Paramecium.
- Author
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Yang, Juan, Wang, Zhenyuan, Wang, Chundi, Tang, Danxu, Zang, Zihan, Stover, Naomi A., Chen, Xiao, and Li, Lifang
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PROTEOLYSIS ,TUBULINS ,CELL cycle ,CHROMOSOME segregation ,PARAMECIUM ,CELL division ,EXTRACELLULAR matrix proteins - Abstract
[Display omitted] The transition from growth to division during the cell cycle encompasses numerous conserved processes such as large-scale DNA replication and protein synthesis. In ciliate cells, asexual cell division is accompanied by additional cellular changes including amitotic nuclear division, extensive ciliogenesis, and trichocyst replication. However, the molecular mechanisms underlying these processes remain elusive. In this study, we present single-cell gene expression profiles of Paramecium cf. multimicronucleatum cells undergoing cell division. Our results reveal that the most up-regulated genes in dividing cells compared to growing cells are associated with 1) cell cycle signaling pathways including transcription, DNA replication, chromosome segregation and protein degradation; 2) microtubule proteins and tubulin glycylases which are essential for ciliogenesis, nuclei separation and structural differentiation signaling; and 3) trichocyst matrix proteins involved in trichocyst synthesis and reproduction. Furthermore, weighted gene co-expression network analysis identified hub genes that may play crucial roles during cell division. Our findings provide insights into cell cycle regulators, microtubules and trichocyst matrix proteins that may exert influence on this process in ciliates. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
240. Protists at the plant-bacterial interface: Impacts and prospective applications.
- Author
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Triplett, Lindsay R., Taerum, Stephen J., and Patel, Ravikumar R.
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- *
PROTISTA , *PREDATION , *SUSTAINABILITY , *MICROBIAL inoculants , *PLANT diseases , *MICROBIAL growth , *RHIZOBACTERIA - Abstract
Protists are nonfungal eukaryotes that represent a vastly diverse component of plant microbial communities. Predatory protists provide plant microbiome ecosystems with nutrient recycling, culling and dispersal of the bacterial community, and selection and activation of microbial biocontrol or growth promoting traits, all functions important for plant health. Here, we briefly review protist interactions with bacteria in the rhizosphere, following topics discussed at the 12th Japan-US Seminar in Plant Pathology. We discuss how understanding of the specificity and signaling mechanisms of predator-prey interactions at the plant interface could be used to develop novel products and strategies for sustainable crop production. • Protist predators are a diverse and ubiquitous part of the plant microbiome, but are functionally poorly understood. • Predators shape the rhizosphere by cycling nutrients, selecting for or activating bacterial defense, or protecting bacteria. • Understanding of protist-bacterial associations could improve discovery, delivery, and efficacy of microbial inoculants. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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241. The hidden genomic diversity of ciliated protists revealed by single-cell genome sequencing
- Author
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Chen, Wenbing, Zuo, Changling, Wang, Chundi, Zhang, Tengteng, Lyu, Liping, Qiao, Yu, Zhao, Fangqing, and Miao, Miao
- Published
- 2021
- Full Text
- View/download PDF
242. ВПЛИВ ПРЕПАРАТУ ФАГОМАСТ НА ЖИТТЄДІЯЛЬНІСТЬ ІНФУЗОРІЙ ТА СЛИЗОВУ ОБОЛОНКУ ОЧЕЙ КРОЛИКІВ
- Subjects
бактеріофаговий препарат Фагомаст ,Tetrachymena pyriformis ,інфузорія ,подразнююча дія ,irritating effect ,toxicity ,ciliate ,токсичність ,bacteriophage drug Fagomast - Abstract
Phage therapy is an alternative in the treatment of bacterial infections caused by antibiotic-resistant strains of bacteria, including mastitis in cows. Bacteriophage-based drugs for the treatment of mastitis in cows shall comply with the standards usually applied to pharmaceutical products. The aim of the work is to investigate the effect of the phage drug Fagomast on the vital activity of the ciliate Tetrachymena pyriformis and its possible irritating effect on the mucous membrane of the eyes of rabbits. For this purpose, a certified museum strain of the ciliate Tetrachymena pyriformis WH-14 has been used in accordance with generally accepted recommendations. To sterile test tubes with drug solutions has been added 0.05 ml of a 72-hour ciliate culture. After 0.5, 1 and 96 hours microscopy has been performed: the number of ciliates in the Goryaev chamber has been counted and their mobility has been determined. Each dilution of the drug has been studied in triplicate. Evaluation of the harmful (irritating) effect of phage drug solutions on the mucous membrane of the eyes of rabbits has been performed in accordance with all bioethical standards of animal handling. Each concentration of the drug has been instilled 2-3 drops into the conjunctival sac of one eye of the rabbit, and the other eye has been served as a control. The drug has been applied twice a day for 5 days. According to the results of research, it has been found that at the concentration of phages from 104 to 109 PFU/ml in the drug there is no change in motor activity and pathological abnormalities in the cells of ciliates. When determining the local irritating effect of Fagomast on the mucous membranes of the eyes of a rabbit, no visible changes have been observed both for the applying of the drug in the amount of phage parts of 104 PFU/ml and at the maximum content of 109 PFU/ml. Therefore, toxicological studies have shown that the bacteriophage-based drug Fagomast developed by us for the treatment of mastitis in cows can be recommended for further production tests., Фаготерапія є альтернативою в лікуванні бактеріальних інфекцій, спричинених антибіотикорезистентними штамами бактерій, в тому числі і маститу у корів. Препарати на основі бактеріофагів для лікування корів за маститу мають відповідати нормам, які, зазвичай, застосовуються до фармацевтичних продуктів. Метою роботи було дослідити вплив фагового препарату Фагомаст на життєдіяльність інфузорії Tetrachymena pyriformis та його можливу подразнюючу дію на слизову оболонку очей кроликів. Для цього використано паспортизований музейний штам інфузорії Tetrachymena pyriformis WH-14 відповідно до загальноприйнятих рекомендацій. Оцінку шкідливої (подразнюючої) дії розчинів фагового препарату на слизові оболонки ока кролика здійснювали з дотриманням всіх біоетичних норм поводження з тваринами. Встановлено, за концентрації фагів від 104 до 109 БУО/мл у препараті зміни рухової активності та патологічних відхилень у клітинах інфузорій не було. При визначенні місцевої подразнюючої дії Фагомасту на слизових оболонках очей кролика видимих змін не спостерігали, як за внесення препарату за кількості фагових частин 104 БУО/мл, так і за максимального вмісту 109 БУО/мл. Отже, проведені токсикологічні дослідження показали, що розроблений нами препарат на основі бактеріофагів Фагомаст для лікування корів за маститу можна рекомендувати для подальших виробничих випробувань
- Published
- 2022
243. Colchicine-induced degeneration of the micronucleus during conjugation in Tetrahymena
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Pin-Fang Chen, Sita Singhal, Daniel Bushyhead, Sarabeth Broder-Fingert, and Jason Wolfe
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Apoptosis ,Autophagy ,Ciliate ,Nuclear morphogenesis ,Meiosis ,Micronucleus ,Tetrahymena ,Science ,Biology (General) ,QH301-705.5 - Abstract
One of the most dramatic examples of nuclear morphogenesis occurs during conjugation in Tetrahymena when the micronucleus elongates to a size longer than the cell itself. After contraction to a spherical shape, the nucleus moves directly to chromosome separation in the first meiotic division. Here we investigate the consequences of interrupting the elongation process. Colchicine, a microtubule inhibitor, caused retraction of elongated structures. With time, cells began to lose their micronuclei, and by five hours more than half of the paired cells had at least one cell missing a micronucleus. After reversing the colchicine block, existing micronuclei did not undergo elongation again, nor did meiosis occur. These observations indicate that micronuclear elongation is critical to subsequent meiotic division. Further, nuclear elimination occurs, which could be due to meiotic failure or possibly a problem downstream from meiosis. An analysis of the process of colchicine-induced micronuclear degeneration indicated that it was regulated by a caspase-dependent mechanism, characteristic of apoptosis, and then resorbed by a lysosome-dependent autophagic mechanism. Amicronucleate cells failed to grow when returned to nutrient medium, likely because of a lesion in the post-conjugation reconstruction of a functioning oral apparatus. The ease by which a large number of nuclei are induced to “self-destruct” may make this system useful in investigating the link between colchicine treatment and nuclear death in Tetrahymena, and in investigating how nuclear death could be regulated in living cells more generally. Finally, we note that this phenomenon might relate to the evolution of amicronucleate species of Tetrahymena.
- Published
- 2014
- Full Text
- View/download PDF
244. Interactions between common heterotrophic protists and the dinoflagellate Tripos furca: implication on the long duration of its red tides in the South Sea of Korea in 2020
- Author
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Yeong Du Yoo, Ji Hyun You, Hae Jin Jeong, Jin Hee Ok, Moo Joon Lee, Se Hee Eom, Hee Chang Kang, Sung Yeon Lee, An Suk Lim, and Sang Ah Park
- Subjects
Ciliate ,food.ingredient ,Red tide ,Furca ,Heterotroph ,Dinoflagellate ,Plant Science ,Aquatic Science ,Biology ,biology.organism_classification ,Algal bloom ,Oceanography ,food ,Short duration ,Ecology, Evolution, Behavior and Systematics ,Cambridge Mathematical Tripos - Published
- 2021
245. Spring Distribution of Ciliate Plankton in the Southeastern Yellow Sea in 2019
- Author
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Jung Min Choi, Hyung-Ku Kang, Dong Han Choi, Young-Ok Kim, Jae Hoon Noh, and Kyung-Hee Oh
- Subjects
0106 biological sciences ,Ciliate ,010504 meteorology & atmospheric sciences ,biology ,010604 marine biology & hydrobiology ,Plankton ,Oceanography ,Spatial distribution ,biology.organism_classification ,01 natural sciences ,Salinity ,Abundance (ecology) ,Nanophytoplankton ,Environmental science ,Picoplankton ,Surface water ,0105 earth and related environmental sciences - Abstract
As planktonic ciliates have been recognized as important players in marine microbial food webs, relevant studies have been conducted in the western coastal waters of the Yellow Sea. However, little is known about ciliate distributions from the eastern coast of the Yellow Sea near the Korean Peninsula. A spring cruise in April 2019 was carried out to investigate vertical and horizontal distributions of ciliate plankton at 18 stations that form three zonal sections in the eastern area. Biological (picoplankton, nanophytoplankton, and mesozooplankton) and hydrological (water temperature and salinity) environments were also analyzed to understand relationships between the ciliate distributions and the environments. High abundance (ca. 2400 cells L−1) of a large ciliate species, Laboea strobila, was observed at the surface water of Stn. 37–5. Abundance peak of large (> 50 μm) ciliates coincided with the peak of mesozooplankton abundance. Spatial distribution of the large ciliates was associated with nanophytoplankton distribution while a smaller (20–50 μm) ciliate group was associated with picoplankton distribution. Therefore, the spring distribution of ciliate plankton in the southeastern coast of the Yellow Sea indicates that food size for the ciliates is one of the important factors controlling ciliate compositions as well as their abundances. Further investigations need to be carried out to understand seasonal differences of ciliate distributions in the eastern Yellow Sea.
- Published
- 2021
246. Shulin packages axonemal outer dynein arms for ciliary targeting
- Author
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Andrew P. Carter, Ferdos Abid Ali, G.R. Mali, Juri Rappsilber, Jérôme Boulanger, Clinton K. Lau, Jonathan D. Howe, Farida Begum, Mark Skehel, and Zhuo A. Chen
- Subjects
Models, Molecular ,Cytoplasm ,Protein Conformation ,Movement ,Dynein ,Protozoan Proteins ,Plasma protein binding ,Flagellum ,Microtubules ,Article ,Tetrahymena thermophila ,Protein Domains ,Ciliogenesis ,Image Processing, Computer-Assisted ,Cilia ,Ciliate ,Multidisciplinary ,biology ,Chemistry ,Cilium ,Cryoelectron Microscopy ,Tetrahymena ,Axonemal Dyneins ,biology.organism_classification ,Cell biology ,Gene Knockdown Techniques ,Protein Binding - Abstract
Ciliary motors locked closed by Shulin Motile cilia and flagella are vital cellular organelles with functions that include setting up the left-right body axis, clearing airways of mucus, and driving single-cell movements. Cilia beating is powered by arrays of dynein motors, the key force generators being the outer dynein arm (ODA) complexes. Using the protozoan Tetrahymena , Mali et al. identified a factor, which they name Shulin, that binds newly synthesized ODAs. Cryo–electron microscopy revealed how Shulin locks the dynein motors together by shutting off motor activity and facilitating delivery of ODAs from the cytoplasm to their final position in the cilia. Science , this issue p. 910
- Published
- 2021
247. Morphology, phylogenetics and pathology of 'red sore disease' (coinfection by Epistylis cf. wuhanensis and Aeromonas hydrophila ) on sportfishes from reservoirs in the South‐Eastern United States
- Author
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Stephen A. Bullard and Steven P. Ksepka
- Subjects
Ciliate ,biology ,Veterinary (miscellaneous) ,Aquatic Science ,biology.organism_classification ,medicine.disease ,DNA gyrase ,Microbiology ,Aeromonas hydrophila ,Epistylis ,Phylogenetics ,medicine ,Ribosomal DNA ,Pathogen ,Epizootic - Abstract
The aetiological agents of red sore disease (RSD) reportedly comprise a taxonomically ambiguous stalked ciliate (a species of Epistylis) and Aeromonas hydrophila. The taxonomic identity of each pathogen remains provisional: using supra-specific morphological features for the ciliate and culture-based methods that cannot delineate bacterial strain. On 7 and 9 November 2017 and 28 May 2020, biologists and anglers reported a local epizootic (Hiwassee and Chattahoochee river basins; Georgia) wherein some moribund fish presented RSD-like lesions. The ciliates were assigned to Epistylis by morphology. The ciliate is regarded as Epistylis cf wuhanensis, as nucleotide sequences from its small subunit ribosomal DNA were identical to those of Epistylis wuhanensis. The bacterium was identified as Aeromonas hydrophila by phenotypic markers and nucleotide sequences from the DNA gyrase subunit B; our sequences comprised 3 strains and phylogenetically were recovered sister to strains of Eurasian origin. Histological sections of lesions revealed effacement or partial deterioration of the epithelium covering scales, scale loss, haemorrhaging, necrosis, oedema, and extensive inflammatory infiltrate in the dermis. This is the first nucleotide sequence information for the symbionts implicated in RSD.
- Published
- 2021
248. Relative contributions of disparate animal vectors to the development of freshwater ciliate communities
- Author
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Carolina Leite Guimarães Durán, Luiz Felipe Machado Velho, Bianca Ramos Meira, Felipe Rafael de Oliveira, Fernando Miranda Lansac-Tôha, Crislaine Cochak, and Jean Ricardo Simões Vitule
- Subjects
0106 biological sciences ,Ciliate ,biology ,010604 marine biology & hydrobiology ,Zoology ,Aquatic Science ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Animal groups ,Propagule ,Abundance (ecology) ,Biological dispersal ,Vector (molecular biology) ,Species richness - Abstract
Here, we evaluate the role of two disparate animal groups, amphibians and odonates, in the dispersal of ciliates. We performed a 33-day outdoor experiment from July to August 2018 with four treatments: (i) a control, with only wind action; (ii) a treatment with the addition from propagules of odonates; (iii) a treatment with propagules from amphibians; and (iv) a treatment with the addition of propagules from both animals. We recorded 54 species of ciliates from 11 groups, with Peritrichia the most representative. Species richness and abundance increased markedly after the 12th day. The species composition of the ciliate species showed differences between treatments within each time period, as well as between the different treatments throughout the experiment. As expected, our results not only evidenced that the dispersal of ciliate protists was improved when mediated by biological vectors, but also demonstrated that the impact depends on the animal vector, and that the effect is even more relevant when propagules are carried by both animal vectors. Our findings support the importance of animal vectors in the dispersal and structuring of ciliates, and highlight the potential differences in the effectiveness of amphibians and odonates for the dispersal of this group.
- Published
- 2021
249. Characterization of a green Stentor with symbiotic algae growing in an extremely oligotrophic environment and storing large amounts of starch granules in its cytoplasm
- Author
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Yuuji Tsukii, Toshinobu Suzaki, Terue Harumoto, and Ryo Hoshina
- Subjects
0106 biological sciences ,0301 basic medicine ,Cytoplasm ,Starch ,Science ,Carbohydrates ,Chlorella ,Bursaria ,010603 evolutionary biology ,01 natural sciences ,Article ,Microbial ecology ,03 medical and health sciences ,chemistry.chemical_compound ,Algae ,Japan ,Botany ,Ciliophora ,Ponds ,Symbiosis ,Taxonomy ,Ciliate ,Multidisciplinary ,biology ,Endosymbiosis ,fungi ,Biodiversity ,biology.organism_classification ,Adaptation, Physiological ,Staining ,Phylogenetics ,030104 developmental biology ,Paramecium bursaria ,chemistry ,Wetlands ,Medicine - Abstract
The genus Stentor is a relatively well-known ciliate owing to its lucid trumpet shape. Stentor pyriformis represents a green, short, and fat Stentor, but it is a little-known species. We investigated 124 ponds and wetlands in Japan and confirmed the presence of S. pyriformis at 23 locations. All these ponds were noticeably oligotrophic. With the improvement of oligotrophic culture conditions, we succeeded in long-term cultivation of three strains of S. pyriformis. The cytoplasm of S. piriformis contains a large number of 1–3 μm refractive granules that turn brown by Lugol’s staining. The granules also show a typical Maltese-cross pattern by polarization microscopy, strongly suggesting that the granules are made of amylopectin-rich starch. By analyzing the algal rDNA, it was found that all S. pyriformis symbionts investigated in this study were Chlorella variabilis. This species is known as the symbiont of Paramecium bursaria and is physiologically specialized for endosymbiosis. Genetic discrepancies between C. variabilis of S. pyriformis and P. bursaria may indicate that algal sharing was an old incident. Having symbiotic algae and storing carbohydrate granules in the cytoplasm is considered a powerful strategy for this ciliate to withstand oligotrophic and cold winter environments in highland bogs.
- Published
- 2021
250. Ciliate microzooplankton from the Northeastern Gulf of Mexico
- Author
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Luciana F. Santoferrara, Richard A. Snyder, Joseph A. Moss, Wade H. Jeffrey, and Marie Head
- Subjects
0106 biological sciences ,0301 basic medicine ,Ciliate ,Ecology ,biology ,010604 marine biology & hydrobiology ,Aquatic Science ,Oceanography ,biology.organism_classification ,01 natural sciences ,03 medical and health sciences ,030104 developmental biology ,Ecology, Evolution, Behavior and Systematics - Abstract
Microzooplankton mediate a critical juncture of autotrophic and heterotrophic microbial production in the water column. Taxonomic and ecological work on this group has been substantial, yet few reports exist for the offshore waters of the Gulf of Mexico (GOM). This report focuses on protists in the phylum Ciliophora collected at stations spanning the continental shelf in the northeastern GOM. We hypothesized that patterns of spatial distribution across the region would be west–east along the coast, rather than north–south coastal to offshore, reflecting major freshwater sources. Samples were obtained by 10 µm plankton net for microscopy and by filtration of seawater for DNA extraction and ciliate-specific clone sequencing. Microscopy and molecular analysis recovered 46 and 156 taxa, respectively. Some visually identified taxa were missing from the sequence analysis and sequences from unknown species dominated molecular results. Differences were apparent with both dominant and rare taxa between February and July sampling and across a trophic gradient from coastal influenced stations to those more representative of the offshore environment. This report provides new data on ciliate microzooplankton richness and distribution in the GOM and adds to our understanding of microzooplankton diversity in the ocean.
- Published
- 2021
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