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Sample records for ciliate tetrahymena thermophila

  1. Experimental identification and analysis of macronuclear non-coding RNAs from the ciliate Tetrahymena thermophila

    DEFF Research Database (Denmark)

    Andersen, Kasper Langebjerg; Nielsen, Henrik

    2012-01-01

    The ciliate Tetrahymena thermophila is an important eukaryotic model organism that has been used in pioneering studies of general phenomena, such as ribozymes, telomeres, chromatin structure and genome reorganization. Recent work has shown that Tetrahymena has many classes of small RNA molecules ...

  2. Effect of salt and urban water samples on bacterivory by the ciliate, Tetrahymena thermophila

    Energy Technology Data Exchange (ETDEWEB)

    St Denis, C.H.; Pinheiro, M.D.O.; Power, M.E. [Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1 (Canada); Bols, Niels C., E-mail: ncbols@uwaterloo.c [Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1 (Canada)

    2010-02-15

    The effect of road salt on the eating of bacteria or bacterivory by the ciliate, Tetrahymena thermophila, was followed in non-nutrient Osterhout's solution with Escherichia coli expressing green fluorescent protein. Bacterivory was impaired at between 0.025 and 0.050% w/v but the ciliates appeared to have normal morphologies and motilities, whereas at above 0.1%, bacterivory was blocked and many ciliates died. By contrast, E. coli remained viable, suggesting salt could alter predator-prey relationships in microbial communities. In nutrient medium, salt was not toxic and the ciliates grew. After growth in salt, ciliates consumed bacteria in 0.2% salt, indicating the salt acclimation of bacterivory. Bacteria and ciliates were added to urban creek samples to compare their capacity to support exogenous bacterivory. Even though samples were collected weekly for a year and be expected to have fluctuating salt levels as a result of deicing, all creek samples supported a similar level of bacterivory. - Road salt at some concentrations inhibits bacterivory by ciliates, and thus potentially could alter the microbial food web.

  3. Purification and partial characterization of glyceraldehyde-3-phosphate dehydrogenase from the ciliate Tetrahymena thermophila

    Institute of Scientific and Technical Information of China (English)

    Nadia Errafiy; Abdelaziz Soukri

    2012-01-01

    In the present study,we purified the glycolytic enzymeglyceraldehyde-3-phosphate dehydrogenase (GAPDH)which is involved in cellular energy production and has important housekeeping functions,from the ciliate Tetrahymena thermophila using a three-step procedure.The enzyme was purified ~68 folds by ammonium sulfate precipitation,followed by two steps of column chromatography (DEAE-cellulose and Mono-S).The purified enzyme is a homotetramer with a molecular weight of ~120 kDa.Isoelectric focusing analysis showed the presence of only one basic GAPDH isoform with an isoelectric point of 8.8.Western blot analysis showed a single 32-kDa band corresponding to the enzyme subunit using a monospecific polyclonal antibody against the T.thermophila GAPDH.The maximum of enzyme activity occurred at pH 8.0 and at 30-35℃.The apparent Km values for both NAD+ and D-glyceraldehyde-3-phosphate were 0.102±0.012 and 0.360 + 0.018 mM,respectively.The maximal velocity (Vmax) was 39.40 + 2.95 U/mg.The T.thermophila GAPDH is inhibited by oxidative and nitrosative stress reagents.

  4. Macronuclear genome sequence of the ciliate Tetrahymena thermophila, a model eukaryote.

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    Jonathan A Eisen

    2006-09-01

    Full Text Available The ciliate Tetrahymena thermophila is a model organism for molecular and cellular biology. Like other ciliates, this species has separate germline and soma functions that are embodied by distinct nuclei within a single cell. The germline-like micronucleus (MIC has its genome held in reserve for sexual reproduction. The soma-like macronucleus (MAC, which possesses a genome processed from that of the MIC, is the center of gene expression and does not directly contribute DNA to sexual progeny. We report here the shotgun sequencing, assembly, and analysis of the MAC genome of T. thermophila, which is approximately 104 Mb in length and composed of approximately 225 chromosomes. Overall, the gene set is robust, with more than 27,000 predicted protein-coding genes, 15,000 of which have strong matches to genes in other organisms. The functional diversity encoded by these genes is substantial and reflects the complexity of processes required for a free-living, predatory, single-celled organism. This is highlighted by the abundance of lineage-specific duplications of genes with predicted roles in sensing and responding to environmental conditions (e.g., kinases, using diverse resources (e.g., proteases and transporters, and generating structural complexity (e.g., kinesins and dyneins. In contrast to the other lineages of alveolates (apicomplexans and dinoflagellates, no compelling evidence could be found for plastid-derived genes in the genome. UGA, the only T. thermophila stop codon, is used in some genes to encode selenocysteine, thus making this organism the first known with the potential to translate all 64 codons in nuclear genes into amino acids. We present genomic evidence supporting the hypothesis that the excision of DNA from the MIC to generate the MAC specifically targets foreign DNA as a form of genome self-defense. The combination of the genome sequence, the functional diversity encoded therein, and the presence of some pathways missing from

  5. A P450 gene associated with robust resistance to DDT in ciliated protozoan, Tetrahymena thermophila by efficient degradation.

    Science.gov (United States)

    Feng, Lifang; Fu, Chengjie; Yuan, Dongxia; Miao, Wei

    2014-04-01

    Analysis of metabolic mechanisms of dichlorodiphenyltrichloroethane (DDT) accumulation and degradation in microorganisms, which could be used to reduce its hazard to higher organisms at the higher in the food chain, have not been investigated. Robust resistance to DDT (grows well in 256 mg/L DDT) and a surprising ability to degrade DDT (more than 70% DDT within 4h) were found in the ciliated protozoan Tetrahymena thermophila. A P450 gene (CYP5013C2) was found to respond specifically to DDT treatment. In the presence of 256 mg/L DDT, cells with overexpressing CYP5013C2 (p450-OE) grew faster and degraded DDT more efficiently than wild-type (WT) cells, while cells with CYP5013C2 partially knocked down (p450-KD) grew slower and exhibited reduced ability to degrade DDT compared to WT cells. Both dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) were detected in cells after exposure to DDT, and the concentration of DDD in the p450-OE strain gradually decreased from 0.5 to 4h. Thus, we argue that this P450 gene (CYP5013C2), by efficiently degrading DDT to DDD, is associated with robust resistance to DDT in Tetrahymena, and that a strain overexpressing this gene has the potential to serve as bioreactor that degrades environmental DDT.

  6. Genome-wide identification and evolution of ATP-binding cassette transporters in the ciliate Tetrahymena thermophila: A case of functional divergence in a multigene family

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    Yuan Dongxia

    2010-10-01

    Full Text Available Abstract Background In eukaryotes, ABC transporters that utilize the energy of ATP hydrolysis to expel cellular substrates into the environment are responsible for most of the efflux from cells. Many members of the superfamily of ABC transporters have been linked with resistance to multiple drugs or toxins. Owing to their medical and toxicological importance, members of the ABC superfamily have been studied in several model organisms and warrant examination in newly sequenced genomes. Results A total of 165 ABC transporter genes, constituting a highly expanded superfamily relative to its size in other eukaryotes, were identified in the macronuclear genome of the ciliate Tetrahymena thermophila. Based on ortholog comparisons, phylogenetic topologies and intron characterizations, each highly expanded ABC transporter family of T. thermophila was classified into several distinct groups, and hypotheses about their evolutionary relationships are presented. A comprehensive microarray analysis revealed divergent expression patterns among the members of the ABC transporter superfamily during different states of physiology and development. Many of the relatively recently formed duplicate pairs within individual ABC transporter families exhibit significantly different expression patterns. Further analysis showed that multiple mechanisms have led to functional divergence that is responsible for the preservation of duplicated genes. Conclusion Gene duplications have resulted in an extensive expansion of the superfamily of ABC transporters in the Tetrahymena genome, making it the largest example of its kind reported in any organism to date. Multiple independent duplications and subsequent divergence contributed to the formation of different families of ABC transporter genes. Many of the members within a gene family exhibit different expression patterns. The combination of gene duplication followed by both sequence divergence and acquisition of new patterns of

  7. Spliceosomal small nuclear RNAs of Tetrahymena thermophila and some possible snRNA-snRNA base-pairing interactions

    DEFF Research Database (Denmark)

    Orum, H; Nielsen, Henrik; Engberg, J

    1991-01-01

    We have identified and characterized the full set of spliceosomal small nuclear RNAs (snRNAs; U1, U2, U4, U5 and U6) from the ciliated protozoan Tetrahymena thermophila. With the exception of U4 snRNA, the sizes of the T. thermophila snRNAs are closely similar to their metazoan homologues. The T...

  8. Rapid biotransformation of arsenic by a model protozoan Tetrahymena thermophila

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    Yin Xixiang [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); State Key Lab of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhang Yongyu; Yang Jun [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Zhu Yongguan, E-mail: ygzhu@rcees.ac.cn [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); State Key Lab of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)

    2011-04-15

    Arsenic biomethylation and biovolatilization are thought to be two important metabolic pathways in aquatic and soil environments. Tetrahymena thermophila is a genus of free-living ciliated protozoan that is widely distributed in freshwater environments around the world. In this study, we studied arsenic accumulation, speciation, efflux, methylation and volatilization in this unicellular eukaryote exposed to various concentrations of arsenate. Our results show that T. thermophila accumulated 187 mg.kg{sup -1} dry weight of arsenic when exposed to 40 {mu}M for 48 h, with MMAs(V) (monomethylarsenate) and DMAs(V) (dimethylarsenate) as the dominant species, accounting for 66% of the total arsenic. Meanwhile, arsenate, arsenite, MMAs(V) and DMAs(V) were detected in the culture medium; the last three were released by the cells. The production of volatile arsenic increased with increasing external As(V) concentrations and exposure time. To our knowledge, this is the first study on arsenic metabolism, particularly biomethylation and biovolatilization, in protozoa. - Tetrahymena thermophila can rapidly methylate arsenic, and produce volatile arsenicals.

  9. The fenestrin antigen in submembrane skeleton of the ciliate Tetrahymena thermophila is proposed as a marker of cell polarity during cell division and in oral replacement.

    Science.gov (United States)

    Kaczanowska, Janina; Joachimiak, Ewa; Kiersnowska, Mauryla; Krzywicka, Anna; Golinska, Krystyna; Kaczanowski, Andrzej

    2003-07-01

    Tetrahymena thermophila cells have two types of polarized morphogenesis: divisional morphogenesis and oral reorganization (OR). The aim of this research is the analysis of cortical patterns of immunostaining during cell division and in OR using previously characterized antibodies against fenestrin and epiplasm B proteins. During cell division, the anarchic field of basal body proliferation of the new developing oral apparatus (AF) showed concomitant strong binding of the fenestrin antigen and withdrawal of a signal of the epiplasm B antigen. At a specific stage, the fenestrin antigen also appeared as a character of the anterior cortex pole, with a co-localized decrease in the detected epiplasm B antigen. The fenestrin antigen also showed a polarity of duplicating basal bodies in ciliary rows. Indirect immunofluorescence and immunogold labeling experiments were performed in the absence and presence of an inhibitor of activity of serine/threonine kinases, 6-dimethylaminopurine (6-DMAP) as an inducer of the oral replacement process. In the presence of 6-DMAP, one class of cells started OR, and some others were trapped and affected in cell division. Both types of cells showed an instability of oral structures and formed enlarged primordial oral fields. These anarchic fields (AFs) bind the fenestrin antigen, with disappearance of epiplasmic antigen staining. Only one protein (about 64 kDa) is detected in western blots by the anti-fenestrin antibody and it accumulated in 6-DMAP-treated cells that are involved in uncompleted morphogenetic activity. At a defined stage of oral development, both during cell division and in OR, the fenestrin antigen served as a marker of polarity of the cell of the anterior pole character.

  10. Cloning and characterization of the gene encoding the highly expressed ribosomal protein l3 of the ciliated protozoan Tetrahymena thermophila. Evidence for differential codon usage in highly expressed genes

    DEFF Research Database (Denmark)

    Larsen, L K; Andreasen, P H; Dreisig, H

    1999-01-01

    We have cloned and characterized the cDNA and the macronuclear genomic copy of the highly conserved ribosomal protein (r-protein) L3 of Tetrahymena thermophila. The r-protein L3 is encoded by a single copy gene interrupted by one intron. The organization of the promoter region exhibits features...

  11. Structure of the germline genome of Tetrahymena thermophila and relationship to the massively rearranged somatic genome.

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    Hamilton, Eileen P; Kapusta, Aurélie; Huvos, Piroska E; Bidwell, Shelby L; Zafar, Nikhat; Tang, Haibao; Hadjithomas, Michalis; Krishnakumar, Vivek; Badger, Jonathan H; Caler, Elisabet V; Russ, Carsten; Zeng, Qiandong; Fan, Lin; Levin, Joshua Z; Shea, Terrance; Young, Sarah K; Hegarty, Ryan; Daza, Riza; Gujja, Sharvari; Wortman, Jennifer R; Birren, Bruce W; Nusbaum, Chad; Thomas, Jainy; Carey, Clayton M; Pritham, Ellen J; Feschotte, Cédric; Noto, Tomoko; Mochizuki, Kazufumi; Papazyan, Romeo; Taverna, Sean D; Dear, Paul H; Cassidy-Hanley, Donna M; Xiong, Jie; Miao, Wei; Orias, Eduardo; Coyne, Robert S

    2016-11-28

    The germline genome of the binucleated ciliate Tetrahymena thermophila undergoes programmed chromosome breakage and massive DNA elimination to generate the somatic genome. Here, we present a complete sequence assembly of the germline genome and analyze multiple features of its structure and its relationship to the somatic genome, shedding light on the mechanisms of genome rearrangement as well as the evolutionary history of this remarkable germline/soma differentiation. Our results strengthen the notion that a complex, dynamic, and ongoing interplay between mobile DNA elements and the host genome have shaped Tetrahymena chromosome structure, locally and globally. Non-standard outcomes of rearrangement events, including the generation of short-lived somatic chromosomes and excision of DNA interrupting protein-coding regions, may represent novel forms of developmental gene regulation. We also compare Tetrahymena's germline/soma differentiation to that of other characterized ciliates, illustrating the wide diversity of adaptations that have occurred within this phylum.

  12. Rate of phenotypic assortment in Tetrahymena thermophila.

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    Doerder, F P; Deak, J C; Lief, J H

    1992-01-01

    During vegetative, asexual reproduction in heterozygous Tetrahymena thermophila, the macronucleus divides amitotically to produce clonal lineages that express either one or the other allele but not both. Because such phenotypic assortment has been described for every locus studied, its mechanism has important implications concerning the development and structure of the macronucleus. The primary tools to study assortment are Rf, the rate at which subclones come to express a single allele stably, and the output ratio, the ratio of assortee classes. Because Rf is related to the number of assorting units, a constant Rf for all loci suggests that all genes are maintained at the same copy number. Output ratios reflect the input ratio of assorting units, with a 1:1 output ratio implying equal numbers of alleles at the end of macronuclear development. Because different outcomes would suggest a different macronuclear structure, it is crucial that these parameters be accurately measured. Although published Rf values are similar for all loci measured, there has been no commonly accepted form of presentation and analysis. Here we examine the experimental determination of Rf. First, we use computer simulation to describe how the variability inherent in the assortment process affects experimental determination of Rf. Second, we describe a simple method of plotting assortment data that permits the uniform calculation of Rf, and we describe how to measure Rf accurately in instances when it is possible to score only the recessive allele. Using this method to produce truly comparable Rfs for all published data, we find that most, if not all, loci assort at Rfs consistent with approximately 45 assorting units, as has been asserted.

  13. Transcriptome analysis of the model protozoan, Tetrahymena thermophila, using Deep RNA sequencing.

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    Jie Xiong

    Full Text Available BACKGROUND: The ciliated protozoan Tetrahymena thermophila is a well-studied single-celled eukaryote model organism for cellular and molecular biology. However, the lack of extensive T. thermophila cDNA libraries or a large expressed sequence tag (EST database limited the quality of the original genome annotation. METHODOLOGY/PRINCIPAL FINDINGS: This RNA-seq study describes the first deep sequencing analysis of the T. thermophila transcriptome during the three major stages of the life cycle: growth, starvation and conjugation. Uniquely mapped reads covered more than 96% of the 24,725 predicted gene models in the somatic genome. More than 1,000 new transcribed regions were identified. The great dynamic range of RNA-seq allowed detection of a nearly six order-of-magnitude range of measurable gene expression orchestrated by this cell. RNA-seq also allowed the first prediction of transcript untranslated regions (UTRs and an updated (larger size estimate of the T. thermophila transcriptome: 57 Mb, or about 55% of the somatic genome. Our study identified nearly 1,500 alternative splicing (AS events distributed over 5.2% of T. thermophila genes. This percentage represents a two order-of-magnitude increase over previous EST-based estimates in Tetrahymena. Evidence of stage-specific regulation of alternative splicing was also obtained. Finally, our study allowed us to completely confirm about 26.8% of the genes originally predicted by the gene finder, to correct coding sequence boundaries and intron-exon junctions for about a third, and to reassign microarray probes and correct earlier microarray data. CONCLUSIONS/SIGNIFICANCE: RNA-seq data significantly improve the genome annotation and provide a fully comprehensive view of the global transcriptome of T. thermophila. To our knowledge, 5.2% of T. thermophila genes with AS is the highest percentage of genes showing AS reported in a unicellular eukaryote. Tetrahymena thus becomes an excellent unicellular

  14. Netrin-1 Peptide Is a Chemorepellent in Tetrahymena thermophila

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    Heather Kuruvilla

    2016-01-01

    Full Text Available Netrin-1 is a highly conserved, pleiotropic signaling molecule that can serve as a neuronal chemorepellent during vertebrate development. In vertebrates, chemorepellent signaling is mediated through the tyrosine kinase, src-1, and the tyrosine phosphatase, shp-2. Tetrahymena thermophila has been used as a model system for chemorepellent signaling because its avoidance response is easily characterized under a light microscope. Our experiments showed that netrin-1 peptide is a chemorepellent in T. thermophila at micromolar concentrations. T. thermophila adapts to netrin-1 over a time course of about 10 minutes. Netrin-adapted cells still avoid GTP, PACAP-38, and nociceptin, suggesting that netrin does not use the same signaling machinery as any of these other repellents. Avoidance of netrin-1 peptide was effectively eliminated by the addition of the tyrosine kinase inhibitor, genistein, to the assay buffer; however, immunostaining using an anti-phosphotyrosine antibody showed similar fluorescence levels in control and netrin-1 exposed cells, suggesting that tyrosine phosphorylation is not required for signaling to occur. In addition, ELISA indicates that a netrin-like peptide is present in both whole cell extract and secreted protein obtained from Tetrahymena thermophila. Further study will be required in order to fully elucidate the signaling mechanism of netrin-1 peptide in this organism.

  15. E2fl1 is a meiosis-specific transcription factor in the protist Tetrahymena thermophila.

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    Zhang, Jing; Tian, Miao; Yan, Guan-Xiong; Shodhan, Anura; Miao, Wei

    2017-01-02

    Members of the E2F family of transcription factors have been reported to regulate the expression of genes involved in cell cycle control, DNA replication, and DNA repair in multicellular eukaryotes. Here, E2FL1, a meiosis-specific E2F transcription factor gene, was identified in the model ciliate Tetrahymena thermophila. Loss of this gene resulted in meiotic arrest prior to anaphase I. The cytological experiments revealed that the meiotic homologous pairing was not affected in the absence of E2FL1, but the paired homologous chromosomes did not separate and assumed a peculiar tandem arrangement. This is the first time that an E2F family member has been shown to regulate meiotic events. Moreover, BrdU incorporation showed that DSB processing during meiosis was abnormal upon the deletion of E2FL1. Transcriptome sequencing analysis revealed that E2FL1 knockout decreased the expression of genes involved in DNA replication and DNA repair in T. thermophila, suggesting that the function of E2F is highly conserved in eukaryotes. In addition, E2FL1 deletion inhibited the expression of related homologous chromosome segregation genes in T. thermophila. The result may explain the meiotic arrest phenotype at anaphase I. Finally, by searching for E2F DNA-binding motifs in the entire T. thermophila genome, we identified 714 genes containing at least one E2F DNA-binding motif; of these, 235 downregulated represent putative E2FL1 target genes.

  16. Structural organization of the genes encoding the small nuclear RNAs U1 to U6 of Tetrahymena thermophila is very similar to that of plant small nuclear RNA genes

    DEFF Research Database (Denmark)

    Orum, H; Nielsen, Henrik; Engberg, J

    1992-01-01

    We report the sequences of the genes encoding the small nuclear RNAs (snRNAs) U1 to U6 of the ciliate Tetrahymena thermophila. The genes of the individual snRNAs exist in two to six slightly different copies per haploid genome. Sequence analyses of the gene-flanking regions indicate that there ar......We report the sequences of the genes encoding the small nuclear RNAs (snRNAs) U1 to U6 of the ciliate Tetrahymena thermophila. The genes of the individual snRNAs exist in two to six slightly different copies per haploid genome. Sequence analyses of the gene-flanking regions indicate...

  17. Microcalorimetric investigation of the toxic action of berberine on Tetrahymena thermophila BF(5).

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    Kong, Weijun; Li, Zulun; Xiao, Xiaohe; Zhao, Yanling

    2010-10-01

    Tetrahymena thermophila (T. thermophila) BF(5) produces heat through growth and metabolism. By microcalorimetry, the power-time curves of the metabolism of T. thermophila BF(5) at 28 °C were measured and some quantitative parameters were obtained from these curves. Then the action of berberine on this microbe was investigated. Furthermore, the minimum inhibitory concentration (MIC) of berberine against T. thermophila BF(5) growth was obtained by tube dilution method. Berberine of different concentrations had various actions on T. thermophila BF(5) growth: a low concentration (25 μg/ml) of berberine began to inhibit the growth of T. thermophila BF(5) and a high concentration (450 μg/ml) of berberine completely inhibited T. thermophila BF(5) growth. The toxic action of berberine could also be expressed as half-inhibitory concentration IC(50), i.e., 50% effective in this inhibition. The value of IC(50) was 175.60 μg/ml, while the MIC of this compound against T. thermophila BF(5) was 20.76 mg/ml. Berberine has strong toxic action on T. thermophila BF(5) growth. The microcalorimetric method for the assay of toxic action is quantitative, inexpensive and versatile.

  18. Staurosporine-induced cell death in Tetrahymena thermophila has mixed characteristics of both apoptotic and autophagic degeneration

    DEFF Research Database (Denmark)

    Christensen, S T; Chemnitz, J; Straarup, E M;

    1998-01-01

    phosphorylation of the PKC-specific substrate, myelin basic protein fragment 4-14. Our results show that cell death in the presence of staurosporine is associated with morphological and ultrastructural changes similar to both apoptosis and autophagic degeneration, but these in turn can be postponed or prevented......Staurosporine blocks signal transduction associated with cell survival, proliferation and chemosensory behaviour in the ciliated protozoan, Tetrahymena thermophila. Staurosporine inhibits cell proliferation and in vivo protein phosphorylation induced by phorbol ester. It also reduces the in vitro...... by 8-bromo-cyclic GMP, protoporphyrin IX, hemin or actinomycin D, although phorbol ester and insulin were ineffective. The results support the notion that staurosporine-induced cell death is an active process, associated with and/or requiring de novo RNA synthesis....

  19. Effects of protein kinase C activators and staurosporine on protein kinase activity, cell survival, and proliferation in Tetrahymena thermophila

    DEFF Research Database (Denmark)

    Straarup, EM; Schousboe, P; Hansen, HQ;

    1997-01-01

    with either PMA or OAG, or at 2,500 cells ml-1. At 500 cells ml-1 PMA induced the in vivo phosphorylation of at least six proteins. The myelin basic protein fragment 4-14 was phosphorylated in vitro in crude extracts of a culture of 250,000 cells ml-1. Both the in vivo and the in vitro phosphorylation were......Autocrine factors prevent cell death in the ciliate Tetrahymena thermophila, a unicellular eukaryote, in a chemically defined medium. At certain growth conditions these factors are released at a sufficient concentration by > 500 cells ml-1 to support cell survival and proliferation. The protein...... kinase C activators phorbol 12-myristate 13-acetate (PMA) or 1-oleyl 2-acetate glycerol (OAG) when added to 250 cells ml-1 supported cell survival and proliferation. In the presence of the serine and threonine kinase inhibitor staurosporine the cells died both at 250 cells ml-1 in cultures supplemented...

  20. The bifunctional dihydrofolate reductase thymidylate synthase of Tetrahymena thermophila provides a tool for molecular and biotechnology applications

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    Tiedtke Arno

    2006-03-01

    Full Text Available Abstract Background Dihydrofolate reductase (DHFR and thymidylate synthase (TS are crucial enzymes in DNA synthesis. In alveolata both enzymes are expressed as one bifunctional enzyme. Results Loss of this essential enzyme activities after successful allelic assortment of knock out alleles yields an auxotrophic marker in ciliates. Here the cloning, characterisation and functional analysis of Tetrahymena thermophila's DHFR-TS is presented. A first aspect of the presented work relates to destruction of DHFR-TS enzyme function in an alveolate thereby causing an auxotrophy for thymidine. A second aspect is to knock in an expression cassette encoding for a foreign gene with subsequent expression of the target protein. Conclusion This system avoids the use of antibiotics or other drugs and therefore is of high interest for biotechnological applications.

  1. Recombination and Assortment in the Macronucleus of TETRAHYMENA THERMOPHILA: A Theoretical Study by Computer Simulation

    OpenAIRE

    Doerder, F. P.; Diblasi, S. L.

    1984-01-01

    The compound nature of the macronucleus of Tetrahymena thermophila presents multiple opportunities for recombination between genes on the same macronuclear chromosome. Such recombinants should be detectable through their assortment at subsequent amitotic macronuclear divisions. Thus, a macronucleus that is initially AB/ab should produce recombinant assortees of the genotypes Ab/aB. Computer simulation shows that, when the recombination frequency is two or fewer times per cell cycle, recombin...

  2. Tetrahymena thermophila acidic ribosomal protein L37 contains an archaebacterial type of C-terminus

    DEFF Research Database (Denmark)

    Hansen, T S; Andreasen, P H; Dreisig, H;

    1991-01-01

    We have cloned and characterized a Tetrahymena thermophila macronuclear gene (L37) encoding the acidic ribosomal protein (A-protein) L37. The gene contains a single intron located in the 3'-part of the coding region. Two major and three minor transcription start points (tsp) were mapped 39 to 63...... nucleotides upstream from the translational start codon. The uppermost tsp mapped to the first T in a putative T. thermophila RNA polymerase II initiator element, TATAA. The coding region of L37 predicts a protein of 109 amino acid (aa) residues. A substantial part of the deduced aa sequence was verified...... by protein sequencing. The T. thermophila L37 clearly belongs to the P1-type family of eukaryotic A-proteins, but the C-terminal region has the hallmarks of archaebacterial A-proteins....

  3. The dynamics of filamentous structures in the apical band, oral crescent, fission line and the postoral meridional filament in Tetrahymena thermophila revealed by monoclonal antibody 12G9.

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    Jerka-Dziadosz, M; Strzyewska-Jówko, I; Wojsa-Lugowska, U; Krawczyńska, W; Krzywicka, A

    2001-05-01

    The ciliate Tetrahymena thermophila possesses a multitude of cytoskeletal structures whose differentiation is related to the basal bodies - the main mediators of the cortical pattern. This investigation deals with immunolocalization using light and electron microscopy of filaments labeled by the monoclonal antibody 12G9, which in other ciliates identifies filaments involved in transmission of cellular polarities and marks cell meridians with the highest morphogenetic potential. In Tetrahymena interphase cells, mAb 12G9 localizes to the sites of basal bodies and to the striated ciliary rootlets, to the apical band of filaments and to the fine fibrillar oral crescent. We followed the sequence of development of these structures during divisional morphogenesis. The labeling of the maternal oral crescent disappears in pre-metaphase cells and reappears during anaphase, concomitantly with differentiation of the new structure in the posterior daughter cell. In the posterior daughter cell, the new apical band originates as small clusters of filaments located at the base of the anterior basal bodies of the apical basal body couplets during early anaphase. The differentiation of the band is completed in the final stages of cytokinesis and in the young post-dividing cell. The maternal band is reorganized earlier, simultaneously with the oral structure. The mAb 12G9 identifies two transient structures present only in dividing cells. One is a medial structure demarcating the two daughter cells during metaphase and anaphase, and defining the new anterior border of the posterior daughter cell. The other is a post-oral meridional filament marking the stomatogenic meridian in postmetaphase cells. Comparative analysis of immunolocalization of transient filaments labeled with mAb12G9 in Tetrahymena and other ciliates indicates that this antibody identifies a protein bound to filamentous structures, which might play a role in relying polarities of cortical domains and could be a part

  4. Identification and characterization of a putative telomere end-binding protein from Tetrahymena thermophila.

    OpenAIRE

    1995-01-01

    Telomeric DNA of Tetrahymena thermophila consists of a long stretch of (TTGGGG)n double-stranded repeats with a single-stranded (TTGGGG)2 3' overhang at the end of the chromosome. We have identified and characterized a protein that specifically binds to a synthetic telomeric substrate consisting of duplex DNA and the 3' telomeric repeat overhang. This protein is called TEP (telomere end-binding protein). A change from G to A in the third position of the TTGGGG overhang repeat converts the sub...

  5. Microcalorimetric Investigation of Toxic Effects of Three Injectable Solubilizing Excipients on Tetrahymena thermophila BF5 Growth

    Institute of Scientific and Technical Information of China (English)

    Yan Dan; Zhang Shaofeng; Han Yumei; Yang Ming; Qi Yun; Xiao Xiaohe

    2011-01-01

    Using microcalorimetry, thermal metabolic curves of Tetrahymena thermophila BF5 (T. thermophila BF5) growth at 28 ℃ affected by three injectable solubilizing excipients (ISE) including tween 80, hydroxypro-pyl-β-cyclodextrin (HP-β-CD) and poloxamer 188 were measured. Meanwhile, the toxicifies of three ISE were evaluated by dynamic parameters of thermal metabolic curves. In addition, the irritative effects of the ISE on myoblast L6 cells were investigated to show their cytotoxicities by biochemical method. The results indicated that the effects of the ISE on T. the rmophila BF5 varied for different ISE. 5% inhibition concentration values (IC5) of the ISE were 1.33, 1.83 and 1.64 mg/mL for tween 80, HP-β-CD and poloxamer 188, respectively. By the principal component analysis (PCA), the total quantity of heat (Q), growth rate constant (k) and second maximum power (P2) were selected as the main characteristic parameters to present their toxicities, there were good linear relationships between Q, k, P2 and concentrations c, suggesting that the toxicities of the ISE on T. thermophila BF5 were closely linked to their concentrations. The results of creatine kinase (CK) bioassay of myoblast L6 cells indicated that the sequence of irritative effects of the ISE was HP-β-CD

  6. Recombination and assortment in the macronucleus of Tetrahymena thermophila: a theoretical study by computer simulation.

    Science.gov (United States)

    Doerder, F P; Diblasi, S L

    1984-12-01

    The compound nature of the macronucleus of Tetrahymena thermophila presents multiple opportunities for recombination between genes on the same macronuclear chromosome. Such recombinants should be detectable through their assortment at subsequent amitotic macronuclear divisions. Thus, a macronucleus that is initially AB/ab should produce recombinant assortees of the genotypes Ab/aB. Computer simulation shows that, when the recombination frequency is two or fewer times per cell cycle, recombinant assortees are produced at experimentally measurable frequencies of less than 40%. At higher recombination frequencies, linked genes appear to assort independently. The simulations also show that recombination during macronuclear development can be distinguished from recombination in subsequent cell cycles only if the first appearance of recombinant assortees is 100 or more fissions after conjugation. The use of macronuclear recombination and assortment as a means of mapping macronuclear genes is severely constrained by the large variances in assortment outcomes; with experimentally small sample sizes, such mapping is impossible.

  7. Bioaccumulation of Multiwall Carbon Nanotubes in Tetrahymena thermophila by Direct Feeding or Trophic Transfer.

    Science.gov (United States)

    Mortimer, Monika; Petersen, Elijah J; Buchholz, Bruce A; Orias, Eduardo; Holden, Patricia A

    2016-08-16

    Consumer goods contain multiwall carbon nanotubes (MWCNTs) that could be released during product life cycles into the environment, where their effects are uncertain. Here, we assessed MWCNT bioaccumulation in the protozoan Tetrahymena thermophila via trophic transfer from bacterial prey (Pseudomonas aeruginosa) versus direct uptake from growth media. The experiments were conducted using (14)C-labeled MWCNT ((14)C-MWCNT) doses at or below 1 mg/L, which proved subtoxic since there were no adverse effects on the growth of the test organisms. A novel contribution of this study was the demonstration of the ability to quantify MWCNT bioaccumulation at low (sub μg/kg) concentrations accomplished by employing accelerator mass spectrometry (AMS). After the treatments with MWCNTs at nominal concentrations of 0.01 mg/L and 1 mg/L, P. aeruginosa adsorbed considerable amounts of MWCNTs: (0.18 ± 0.04) μg/mg and (21.9 ± 4.2) μg/mg bacterial dry mass, respectively. At the administered MWCNT dose of 0.3 mg/L, T. thermophila accumulated up to (0.86 ± 0.3) μg/mg and (3.4 ± 1.1) μg/mg dry mass by trophic transfer and direct uptake, respectively. Although MWCNTs did not biomagnify in the microbial food chain, MWCNTs bioaccumulated in the protozoan populations regardless of the feeding regime, which could make MWCNTs bioavailable for organisms at higher trophic levels.

  8. In vivo synthesis of nano-selenium by Tetrahymena thermophila SB210.

    Science.gov (United States)

    Cui, Yin-Hua; Li, Ling-Li; Zhou, Nan-Qing; Liu, Jing-Hua; Huang, Qing; Wang, Hui-Juan; Tian, Jie; Yu, Han-Qing

    2016-12-01

    Nano-selenium has a great potential to be used in chemical, biological, medical and environmental fields. Biological methods for nano-selenium synthesis have attracted wide interests, because they can be operated at ambient temperature and pressure without complicated equipments. In this work, a protozoa, Tetrahymena thermophila (T. thermophila) SB210, was used to in vivo synthesize nano-selenium. The biosynthesized nano-selenium was characterized using transmission electron microscopy, energy dispersive X-ray spectroscopy and Raman spectroscopy. The synthesized amorphous spherical selenium nanoparticles had diameters of 50-500nm with the coexistence of irregular nano-selenium. The expressions of glutathione (GSH) synthesis related gene glutathione synthase, cysteine-rich protein metallothionein related gene metallothionein-1 and [2Fe-2S] cluster-binding protein related gene were up-regulated in the nano-selenium producing group. Also, the subsequent GSH detection and in vitro synthesis experimental results suggest the three proteins were likely to be involved in the nano-selenium synthesis process.

  9. Identification, modeling, and characterization studies of Tetrahymena thermophila myosin FERM domains suggests a conserved core fold but functional differences.

    Science.gov (United States)

    Martin, Che L; Singh, Shaneen M

    2015-11-01

    Myosins (MYO) define a superfamily of motor proteins which facilitate movement along cytoskeletal actin filaments in an ATP-dependent manner. To date, over 30 classes of myosin have been defined that vary in their roles and distribution across different taxa. The multidomain tail of myosin is responsible for the observed functional differences in different myosin classes facilitating differential binding to different cargos. One domain found in this region, the FERM domain, is found in several diverse proteins and is involved in many biological functions ranging from cell adhesion and actin-driven cytoskeleton assembly to cell signaling. Recently, new classes of unconventional myosin have been identified in Tetrahymena thermophila. In this study, we have identified, modeled, and characterized eight FERM domains from the unconventional T. thermophila myosins as their complete functional MyTH4-FERM cassettes. Our results reveal notable sequence, structural, and electrostatic differences between T. thermophila and other characterized FERM domains. Specifically, T. thermophila FERM domains contain helical inserts or extensions, which contribute to significant differences in surface electrostatic profiles of T. thermophila myosin FERMs when compared to the conventional FERM domains. Analyses of the modeled domains reveal differences in key functional residues as well as phosphoinositide-binding signatures and affinities. The work presented here broadens the scope of our understanding of myosin classes and their inherent functions, and provides a platform for experimentalists to design rational experimental studies to test the functional roles for T. thermophila myosins.

  10. The key role of CYC2 during meiosis in Tetrahymena thermophila.

    Science.gov (United States)

    Xu, Qianlan; Wang, Ruoyu; Ghanam, A R; Yan, Guanxiong; Miao, Wei; Song, Xiaoyuan

    2016-04-01

    Meiotic recombination is carried out through a specialized pathway for the formation and repair of DNA double-strand breaks (DSBs) made by the Spo11 protein. The present study shed light on the functional role of cyclin, CYC2, in Tetrahymena thermophila which has transcriptionally high expression level during meiosis process. Knocking out the CYC2 gene results in arrest of meiotic conjugation process at 2.5-3.5 h after conjugation initiation, before the meiosis division starts, and in company with the absence of DSBs. To investigate the underlying mechanism of this phenomenon, a complete transcriptome profile was performed between wild-type strain and CYC2 knock-out strain. Functional analysis of RNA-Seq results identifies related differentially expressed genes (DEGs) including SPO11 and these DEGs are enriched in DNA repair/mismatch repair (MMR) terms in homologous recombination (HR), which indicates that CYC2 could play a crucial role in meiosis by regulating SPO11 and participating in HR.

  11. Several RNase T2 enzymes function in induced tRNA and rRNA turnover in the ciliate Tetrahymena

    DEFF Research Database (Denmark)

    Andersen, Kasper Langebjerg; Collins, Kathleen

    2012-01-01

    RNase T2 enzymes are produced by a wide range of organisms and have been implicated to function in diverse cellular processes, including stress-induced anticodon loop cleavage of mature tRNAs to generate tRNA halves. Here we describe a family of eight RNase T2 genes (RNT2A-RNT2H) in the ciliate...... Tetrahymena thermophila. We constructed strains lacking individual or combinations of these RNT2 genes that were viable but had distinct cellular and molecular phenotypes. In strains lacking only one Rnt2 protein or lacking a subfamily of three catalytically inactive Rnt2 proteins, starvation-induced tRNA...... fragments continued to accumulate, with only a minor change in fragment profile in one strain. We therefore generated strains lacking pairwise combinations of the top three candidates for Rnt2 tRNases. Each of these strains showed a distinct starvation-specific profile of tRNA and rRNA fragment accumulation...

  12. Identification of differentially expressed genes in Tetrahymena thermophila in response to dichlorodiphenyltrichloroethane (DDT) by suppression subtractive hybridization.

    Science.gov (United States)

    Miao, Wei; Yu, Ting; Orias, Eduardo; Wan, Mingliang; Fu, Chenjie

    2006-06-01

    The insecticide dichlorodiphenyltrichloroethane (DDT) is persistent in the environment, and continues to cause health problems. Tetrahymena has potential as a model organism for assaying low levels of DDT and for analysing the mechanisms of its toxicity. We constructed the suppression subtractive hybridization library of T. thermophila exposed to DDT, and screened out 90 Expressed Sequence Tags whose expressions were significantly up- or downregulated with DDT treatment. From this, a series of important genes related to the DDT metabolism and detoxification were discovered, such as P450 gene, glutathione S-transferase gene and sterol carrier protein 2 gene. Furthermore, their expressions under different concentrations of DDT treatment were detected by real-time fluorescent quantitative PCR. The results show that Tetrahymena is a relevant and useful model organism for detecting DDT in the environment and for discovering biomarkers that can be used to develop specific bio-reporters at the molecular and genomic levels.

  13. Microcalorimetric Investigation of Influence of Fungicide SYP-L190 on Growth Metabolism of Tetrahymena thermophila and Bacillus thuringiensis

    Institute of Scientific and Technical Information of China (English)

    LI Hui-Rong; KU Zong-Jun; QIN Cai-Qin; ZHANG Zhong-Hai; LIU Yi

    2007-01-01

    Flumorph (SYP-L190) is a new systemic fungicide with good protective,curative and antisporulant activities but no phytotoxicity to certain plants.Its performance on the environmental ecosystem is unknown.Tetrahymena thermophila and Bacillus thuringiensis are two of biological indicators for the aquatic and soil environmental ecosystem respectively.Microcalorimetric technique based on the heat output was applied to evaluate the influence of fungicide flumorph (SYP-L190) on the two microorganisms.The thermogenic curves and corresponding thermodynamic and thermokinetic parameters were obtained.SYP-L 190 at a concentration of 50-100 μg·mL-1 had 5%-10% inhibitory ratios aganist Tetrahymena thermophila and was used as a protection reagent,while at a concentration of 100-200 μg·mL-1 SYP-L190 had 10%-20% inhibitory ratios and was used as a therapy reagent.The metabolic thermogenic curves of Bacillus thuringiensis contained bacterial growth phase and sporulation phase.The SYP-L190 at a concentration of 0-200 μg·mL-1 had no influence on bacterial growth phase,but led to a little lag of the sporulation phase with a constant heat output.Hormesis was obviously observed in present study.

  14. An intron in a ribosomal protein gene from Tetrahymena

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Andreasen, Per Hove; Dreisig, Hanne

    1986-01-01

    We have cloned and sequenced a single copy gene encoding a ribosomal protein from the ciliate Tetrahymena thermophila. The gene product was identified as ribosomal protein S25 by comparison of the migration in two-dimensional polyacrylamide gels of the protein synthesized by translation in vitro...

  15. Effect of melamine toxicity on Tetrahymena thermophila proliferation and metallothionein expression.

    Science.gov (United States)

    Li, Wei; Li, Hua; Zhang, Jie; Tian, Xuewen

    2015-06-01

    Melamine is a raw material in the chemical industry. Because of its high nitrogen content, melamine has been utilized by unscrupulous businessmen as a food additive to enhance the indices of protein content in food and feed testing. Tetrahymena has long been used as an excellent model organism in toxicological studies. The purpose of the present study was to determine the effect of melamine on Tetrahymena. In the present study, the effects of melamine on the proliferation and mating rate of Tetrahymena were examined by microscopic counting of the cell numbers. The comet assay and DAPI nuclear staining were performed to analyze the changes in the Tetrahymena genome. Flow cytometric analysis was conducted to detect apoptosis. Furthermore, RT-PCR was performed to determine the changes in the expression of the metallothionein gene in Tetrahymena that underwent stress treatment with varying concentrations of melamine. The results indicated that melamine affected the proliferation and sexual reproduction of Tetrahymena. High melamine concentrations damaged the Tetrahymena genome to a certain extent and induced apoptosis in the organism. Expression of the metallothionein gene was upregulated in Tetrahymena exposed to melamine stress to ameliorate melamine-induced damage. These results indicated that melamine displayed significant toxicity to Tetrahymena cells.

  16. : a database of ciliate genome rearrangements.

    Science.gov (United States)

    Burns, Jonathan; Kukushkin, Denys; Lindblad, Kelsi; Chen, Xiao; Jonoska, Nataša; Landweber, Laura F

    2016-01-01

    Ciliated protists exhibit nuclear dimorphism through the presence of somatic macronuclei (MAC) and germline micronuclei (MIC). In some ciliates, DNA from precursor segments in the MIC genome rearranges to form transcriptionally active genes in the mature MAC genome, making these ciliates model organisms to study the process of somatic genome rearrangement. Similar broad scale, somatic rearrangement events occur in many eukaryotic cells and tumors. The (http://oxytricha.princeton.edu/mds_ies_db) is a database of genome recombination and rearrangement annotations, and it provides tools for visualization and comparative analysis of precursor and product genomes. The database currently contains annotations for two completely sequenced ciliate genomes: Oxytricha trifallax and Tetrahymena thermophila.

  17. Phosphorylation of the SQ H2A.X motif is required for proper meiosis and mitosis in Tetrahymena thermophila.

    Science.gov (United States)

    Song, Xiaoyuan; Gjoneska, Elizabeta; Ren, Qinghu; Taverna, Sean D; Allis, C David; Gorovsky, Martin A

    2007-04-01

    Phosphorylation of the C terminus SQ motif that defines H2A.X variants is required for efficient DNA double-strand break (DSB) repair in diverse organisms but has not been studied in ciliated protozoa. Tetrahymena H2A.X is one of two similarly expressed major H2As, thereby differing both from mammals, where H2A.X is a quantitatively minor component, and from Saccharomyces cerevisiae where it is the only type of major H2A. Tetrahymena H2A.X is phosphorylated in the SQ motif in both the mitotic micronucleus and the amitotic macronucleus in response to DSBs induced by chemical agents and in the micronucleus during prophase of meiosis, which occurs in the absence of a synaptonemal complex. H2A.X is phosphorylated when programmed DNA rearrangements occur in developing macronuclei, as for immunoglobulin gene rearrangements in mammals, but not during the DNA fragmentation that accompanies breakdown of the parental macronucleus during conjugation, correcting the previous interpretation that this process is apoptosis-like. Using strains containing a mutated (S134A) SQ motif, we demonstrate that phosphorylation of this motif is important for Tetrahymena cells to recover from exogenous DNA damage and is required for normal micronuclear meiosis and mitosis and, to a lesser extent, for normal amitotic macronuclear division; its absence, while not lethal, leads to the accumulation of DSBs in both micro- and macronuclei. These results demonstrate multiple roles of H2A.X phosphorylation in maintaining genomic integrity in different phases of the Tetrahymena life cycle.

  18. Toxicogenomic investigation of Tetrahymena thermophila exposed to dichlorodiphenyltrichloroethane (DDT), tributyltin (TBT), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

    Science.gov (United States)

    Chang, Yue; Feng, LiFang; Miao, Wei

    2011-07-01

    Dichlorodiphenyltrichloroethane (DDT), tributyltin (TBT), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are persistent in the environment and cause continuous toxic effects in humans and aquatic life. Tetrahymena thermophila has the potential for use as a model for research regarding toxicants. In this study, this organism was used to analyze a genome-wide microarray generated from cells exposed to DDT, TBT and TCDD. To accomplish this, genes differentially expressed when treated with each toxicant were identified, after which their functions were categorized using GO enrichment analysis. The results suggested that the responses of T. thermophila were similar to those of multicellular organisms. Additionally, the context likelihood of relatedness method (CLR) was applied to construct a TCDD-relevant network. The T-shaped network obtained could be functionally divided into two subnetworks. The general functions of both subnetworks were related to the epigenetic mechanism of TCDD. Based on analysis of the networks, a model of the TCDD effect on T. thermophila was inferred. Thus, Tetrahymena has the potential to be a good unicellular eukaryotic model for toxic mechanism research at the genome level.

  19. Phenotypic assortment in Tetrahymena thermophila: assortment kinetics of antibiotic-resistance markers, tsA, death, and the highly amplified rDNA locus.

    Science.gov (United States)

    Merriam, E V; Bruns, P J

    1988-10-01

    Phenotypic assortment in Tetrahymena thermophila results from random distribution of alleles during amitotic division of the macronucleus. The rate of assortment is dependent on input ratio and the number of assorting units. The assortment of the antibiotic resistance markers Chx, Mpr and gal was determined and is consistent for each with the model of 45 assorting chromosomes. The gene tsA (previously ts-1) shows normal assortment, in contrast to previous reports. A mutation in the highly amplified ribosomal locus (rdnA2) assorts as if present at only 45 copies. Death of clones occurred at a rate consistent with assortment for a single gene.

  20. The zinc finger protein Zfr1p is localized specifically to conjugation junction and required for sexual development in Tetrahymena thermophila.

    Directory of Open Access Journals (Sweden)

    Jing Xu

    Full Text Available Conjugation in Tetrahymena thermophila involves a developmental program consisting of three prezygotic nuclear divisions, pronuclear exchange and fusion, and postzygotic and exconjugant stages. The conjugation junction structure appears during the initiation of conjugation development, and disappears during the exconjugant stage. Many structural and functional proteins are involved in the establishment and maintenance of the junction structure in T. thermophila. In the present study, a zinc finger protein-encoding gene ZFR1 was found to be expressed specifically during conjugation and to localize specifically to the conjugation junction region. Truncated Zfr1p localized at the plasma membrane in ordered arrays and decorated Golgi apparatus located adjacent to basal body. The N-terminal zinc finger and C-terminal hydrophobic domains of Zfr1p were found to be required for its specific conjugation junction localization. Conjugation development of ZFR1 somatic knockout cells was aborted at the pronuclear exchange and fusion conjugation stages. Furthermore, Zfr1p was found to be important for conjugation junction stability during the prezygotic nuclear division stage. Taken together, our data reveal that Zfr1p is required for the stability and integrity of the conjugation junction structure and essential for the sexual life cycle of the Tetrahymena cell.

  1. Differentially expressed genes of Tetrahymena thermophila in response to tributyltin (TBT) identified by suppression subtractive hybridization and real time quantitative PCR.

    Science.gov (United States)

    Feng, Lifang; Miao, Wei; Wu, Yuxuan

    2007-02-15

    Tributyltin (TBT) is widely used as antifouling paints, agriculture biocides, and plastic stabilizers around the world, resulting in great pollution problem in aquatic environments. However, it has been short of the biomonitor to detect TBT in freshwater. We constructed the suppression subtractive hybridization library of Tetrahymena thermophila exposed to TBT, and screened out 101 Expressed Sequence Tags whose expressions were significantly up- or down-regulated with TBT treatment. From this, a series of genes related to the TBT toxicity were discovered, such as glutathione-S-transferase gene (down-regulated), plasma membrane Ca2+ ATPase isoforms 3 gene (up-regulated) and NgoA (up-regulated). Furthermore, their expressions under different concentrations of TBT treatment (0.5-40 ppb) were detected by real time fluorescent quantitative PCR. The differentially expressed genes of T. thermophila in response to TBT were identified, which provide the basic to make Tetrahymena as a sensitive, rapid and convenient TBT biomonitor in freshwater based on rDNA inducible expression system.

  2. Functional intron+ and intron- rDNA in the same macronucleus of the ciliate Tetrahymena pigmentosa

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Engberg, J

    1985-01-01

    alleles was followed in the total culture and in single cells during their vegetative segregation and it was observed that replication was non-preferential with respect to the two alleles. The diallelic clones were also used to demonstrate that intron-containing rDNA was transcribed and the transcript......Diallelic clones of Tetrahymena pigmentosa containing equal amounts of intron+ and intron- rDNA in the macronucleus were constructed. The macronucleus of the resulting strains divides amitotically during vegetative growth and the diallelic genotype is therefore unstable. The coexistence of the two...

  3. Tetrahymena metallothioneins fall into two discrete subfamilies.

    Directory of Open Access Journals (Sweden)

    Silvia Díaz

    Full Text Available BACKGROUND: Metallothioneins are ubiquitous small, cysteine-rich, multifunctional proteins which can bind heavy metals. METHODOLOGY/PRINCIPAL FINDINGS: We report the results of phylogenetic and gene expression analyses that include two new Tetrahymena thermophila metallothionein genes (MTT3 and MTT5. Sequence alignments of all known Tetrahymena metallothioneins have allowed us to rationalize the structure of these proteins. We now formally subdivide the known metallothioneins from the ciliate genus Tetrahymena into two well defined subfamilies, 7a and 7b, based on phylogenetic analysis, on the pattern of clustering of Cys residues, and on the pattern of inducibility by the heavy metals Cd and Cu. Sequence alignment also reveals a remarkably regular, conserved and hierarchical modular structure of all five subfamily 7a MTs, which include MTT3 and MTT5. The former has three modules, while the latter has only two. Induction levels of the three T. thermophila genes were determined using quantitative real time RT-PCR. Various stressors (including heavy metals brought about dramatically different fold-inductions for each gene; MTT5 showed the highest fold-induction. Conserved DNA motifs with potential regulatory significance were identified, in an unbiased way, upstream of the start codons of subfamily 7a MTs. EST evidence for alternative splicing in the 3' UTR of the MTT5 mRNA with potential regulatory activity is reported. CONCLUSION/SIGNIFICANCE: The small number and remarkably regular structure of Tetrahymena MTs, coupled with the experimental tractability of this model organism for studies of in vivo function, make it an attractive system for the experimental dissection of the roles, structure/function relationships, regulation of gene expression, and adaptive evolution of these proteins, as well as for the development of biotechnological applications for the environmental monitoring of toxic substances.

  4. Evaluate the potential environmental toxicity of quantum dots on ciliated protozoa by microcalorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Qi [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Huang, Shan, E-mail: huangs@whu.edu.cn [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Su, Wei [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Li, Peiyuan [College of Pharmacy, Guangxi Traditional Chinese Medical University, Nanning 530001 (China); Liang, Zuocui; Ou, Jianzhen; Ma, Jianqiang [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Liu, Yi, E-mail: prof.liuyi@263.net [State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer The toxic effects of QDs to T. thermophila BF{sub 5} using a TAM air microcalorimeter. Black-Right-Pointing-Pointer QDs were acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner. Black-Right-Pointing-Pointer The toxicity of different ligands-capped QDs on T. thermophila BF{sub 5} was investigated. Black-Right-Pointing-Pointer QDs could be ingested by cells and affect the morphology of T. thermophila BF{sub 5}. - Abstract: In the present study, we evaluated the toxic effects of mercaptoacetic acid (MAA)-capped CdSe QDs and CdSe/ZnS QDs to particle-ingesting model ciliated protozoa Tetrahymena thermophila BF{sub 5} (T. thermophila BF{sub 5}) by using a TAM air isothermal microcalorimeter. These results suggested that both MAA-CdSe QDs and MAA-CdSe/ZnS QDs were indeed acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner, and the toxicities of both MAA-CdSe QDs and MAA-CdSe/ZnS QDs increased dramatically after UV irradiation due to the liberation of more toxic Cd{sup 2+}, which indicated that the toxicity of MAA-CdSe/ZnS QDs was less than that of MAA-CdSe QDs. Furthermore, the toxicity of different ligands-capped CdSe/ZnS QDs on T. thermophila BF{sub 5} was also investigated. The uptake of MAA-CdSe/ZnS QDs and adenosine 5 Prime -monophosphate (AMP)-CdSe/ZnS QDs by cells and the morphological change during the process of T. thermophila BF{sub 5} growth incubated with these QDs were further studied by fluorescence inverted microscopy.

  5. Genome-wide analysis of the phosphoinositide kinome from two ciliates reveals novel evolutionary links for phosphoinositide kinases in eukaryotic cells.

    Directory of Open Access Journals (Sweden)

    George Leondaritis

    Full Text Available BACKGROUND: The complexity of phosphoinositide signaling in higher eukaryotes is partly due to expansion of specific families and types of phosphoinositide kinases (PIKs that can generate all phosphoinositides via multiple routes. This is particularly evident in the PI3Ks and PIPKs, and it is considered an evolutionary trait associated with metazoan diversification. Yet, there are limited comprehensive studies on the PIK repertoire of free living unicellular organisms. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a genome-wide analysis of putative PIK genes in two free living ciliated cells, Tetrahymena and Paramecium. The Tetrahymena thermophila and Paramecium tetraurelia genomes were probed with representative kinases from all families and types. Putative homologs were verified by EST, microarray and deep RNA sequencing database searches and further characterized for domain structure, catalytic efficiency, expression patterns and phylogenetic relationships. In total, we identified and characterized 22 genes in the Tetrahymena thermophila genome and 62 highly homologues genes in Paramecium tetraurelia suggesting a tight evolutionary conservation in the ciliate lineage. Comparison to the kinome of fungi reveals a significant expansion of PIK genes in ciliates. CONCLUSIONS/SIGNIFICANCE: Our study highlights four important aspects concerning ciliate and other unicellular PIKs. First, ciliate-specific expansion of PI4KIII-like genes. Second, presence of class I PI3Ks which, at least in Tetrahymena, are associated with a metazoan-type machinery for PIP3 signaling. Third, expansion of divergent PIPK enzymes such as the recently described type IV transmembrane PIPKs. Fourth, presence of possible type II PIPKs and presumably inactive PIKs (hence, pseudo-PIKs not previously described. Taken together, our results provide a solid framework for future investigation of the roles of PIKs in ciliates and indicate that novel functions and novel regulatory

  6. Purification of Tetrahymena cytoskeletal proteins.

    Science.gov (United States)

    Honts, Jerry E

    2012-01-01

    Like all eukaryotic cells, Tetrahymena thermophila contains a rich array of cytoskeletal proteins, some familiar and some novel. A detailed analysis of the structure, function, and interactions of these proteins requires procedures for purifying the individual protein components. Procedures for the purification of actin and tubulin from Tetrahymena are reviewed, followed by a description of a procedure that yields proteins from the epiplasmic layer and associated structures, including the tetrins. Finally, the challenges and opportunities for future advances are assessed.

  7. Elucidation of clathrin-mediated endocytosis in tetrahymena reveals an evolutionarily convergent recruitment of dynamin.

    Directory of Open Access Journals (Sweden)

    Nels C Elde

    2005-11-01

    Full Text Available Ciliates, although single-celled organisms, contain numerous subcellular structures and pathways usually associated with metazoans. How this cell biological complexity relates to the evolution of molecular elements is unclear, because features in these cells have been defined mainly at the morphological level. Among these ciliate features are structures resembling clathrin-coated, endocytic pits associated with plasma membrane invaginations called parasomal sacs. The combination of genome-wide sequencing in Tetrahymena thermophila with tools for gene expression and replacement has allowed us to examine this pathway in detail. Here we demonstrate that parasomal sacs are sites of clathrin-dependent endocytosis and that AP-2 localizes to these sites. Unexpectedly, endocytosis in Tetrahymena also involves a protein in the dynamin family, Drp1p (Dynamin-related protein 1. While phylogenetic analysis of AP subunits indicates a primitive origin for clathrin-mediated endocytosis, similar analysis of dynamin-related proteins suggests, strikingly, that the recruitment of dynamin-family proteins to the endocytic pathway occurred independently during the course of the ciliate and metazoan radiations. Consistent with this, our functional analysis suggests that the precise roles of dynamins in endocytosis, as well as the mechanisms of targeting, differ in metazoans and ciliates.

  8. Listeria monocytogenes virulence factor Listeriolysin O favors bacterial growth in co-culture with the ciliate Tetrahymena pyriformis, causes protozoan encystment and promotes bacterial survival inside cysts

    Directory of Open Access Journals (Sweden)

    Ermolaeva Svetlana A

    2010-01-01

    Full Text Available Abstract Background The gram-positive pathogenic bacterium Listeria monocytogenes is widely spread in the nature. L. monocytogenes was reported to be isolated from soil, water, sewage and sludge. Listeriolysin O (LLO is a L. monocytogenes major virulence factor. In the course of infection in mammals, LLO is required for intracellular survival and apoptosis induction in lymphocytes. In this study, we explored the potential of LLO to promote interactions between L. monocytogenes and the ubiquitous inhabitant of natural ecosystems bacteriovorous free-living ciliate Tetrahymena pyriformis. Results Wild type L. monocytogenes reduced T. pyriformis trophozoite counts and stimulated encystment. The effects were observed starting from 48 h of co-incubation. On the day 14, trophozoites were eliminated from the co-culture while about 5 × 104 cells/ml remained in the axenic T. pyriformis culture. The deficient in the LLO-encoding hly gene L. monocytogenes strain failed to cause mortality among protozoa and to trigger protozoan encystment. Replenishment of the hly gene in the mutant strain restored toxicity towards protozoa and induction of protozoan encystment. The saprophytic non-haemolytic species L. innocua transformed with the LLO-expressing plasmid caused extensive mortality and encystment in ciliates. During the first week of co-incubation, LLO-producing L. monocytogenes demonstrated higher growth rates in association with T. pyriformis than the LLO-deficient isogenic strain. At latter stages of co-incubation bacterial counts were similar for both strains. T. pyriformis cysts infected with wild type L. monocytogenes caused listerial infection in guinea pigs upon ocular and oral inoculation. The infection was proved by bacterial plating from the internal organs. Conclusions The L. monocytogenes virulence factor LLO promotes bacterial survival and growth in the presence of bacteriovorous ciliate T. pyriformis. LLO is responsible for L. monocytogenes

  9. Transposon domestication versus mutualism in ciliate genome rearrangements.

    Directory of Open Access Journals (Sweden)

    Alexander Vogt

    Full Text Available Ciliated protists rearrange their genomes dramatically during nuclear development via chromosome fragmentation and DNA deletion to produce a trimmer and highly reorganized somatic genome. The deleted portion of the genome includes potentially active transposons or transposon-like sequences that reside in the germline. Three independent studies recently showed that transposase proteins of the DDE/DDD superfamily are indispensible for DNA processing in three distantly related ciliates. In the spirotrich Oxytricha trifallax, high copy-number germline-limited transposons mediate their own excision from the somatic genome but also contribute to programmed genome rearrangement through a remarkable transposon mutualism with the host. By contrast, the genomes of two oligohymenophorean ciliates, Tetrahymena thermophila and Paramecium tetraurelia, encode homologous PiggyBac-like transposases as single-copy genes in both their germline and somatic genomes. These domesticated transposases are essential for deletion of thousands of different internal sequences in these species. This review contrasts the events underlying somatic genome reduction in three different ciliates and considers their evolutionary origins and the relationships among their distinct mechanisms for genome remodeling.

  10. RAN1基因过表达抑制嗜热四膜虫大核无丝分裂%Overexpression of RAN1 Inhibits Macronuclear Amitosis in Tetrahymena thermophila

    Institute of Scientific and Technical Information of China (English)

    梁海霞; 许静; 王伟

    2013-01-01

    Ran is an evolutionary conserved GTPase and involved in the regulation of cell proliferation during mitosis and meiosis through RanGTP/RanGDP cycle. Knockdown of RAN1 may cause abnormal organization of intramacronuclear microtubule and inhibit macronuclear amitosis in Tetrahymena thermophila. To analyze the roles of Ranl in amitosis, we overexpressed Rani mutants and investigated the GTP-bound Ranl-mimetic ( Ran1Q70L ) and GDP-bound Ranl-mimetic ( Ran1T25N ) on macronuclear amitosis in T. thermophila. The results showed that Rani mutant overexpression decreased the cell proliferation rate and lead to abnormal macronuclear amitosis. The percentage of abnormal amitotic cells positively correlated with the Ranl overexpression levels. Immuno-fluorescence analysis showed that the overexpressed HA-Ranl was distributed throughout the cell during amitosis which disrupted the Ran gradient with high concentrations in the nucleus. The overexpressed HA-RanlQ70L was localized in both the macronuclear envelope and the cytoplasm; whereas the overexpressed HA-RanlT25N predominantly in the macronucleus and micronucleus. The localization of the Ranl mutants was the same with where the regulatory proteins of Ranl GTP/Ran1 GDP cycle localized. Our results suggested that the overexpression of Rani and its mutants inhibited the macronuclear amitotic progress by disrupting the Rani GTP/Ranl GDP cycle in T. thermophila.%Ran GTPase通过RanGTP/RanGDP循环的形式,参与调控多种细胞增殖方式:包括有丝分裂和减数分裂.敲减RAN1基因可导致嗜热四膜虫大核内微管组装紊乱,从而抑制大核无丝分裂.为进一步分析Ran1在无丝分裂中的功能,本研究将野生型Ran1以及模拟GTP( Ran1Q70L)和GDP( Ran1T25N)锁定形式的Ran1突变体在嗜热四膜虫中过量表达,均导致四膜虫细胞增殖速率下降,并引起大核无丝分裂异常,且这种核异常细胞比率与Ran1过表达量呈正相关.免疫荧光定位

  11. Toxicity of low concentration exposures of triclosan and triclocarban on Tetrahymena thermophila%低剂量三氯生和三氯卡班对嗜热四膜虫的毒性研究

    Institute of Scientific and Technical Information of China (English)

    白琦锋; 高礼; 袁涛

    2012-01-01

    Triclosan(TCS) and triclocarban(TCC),as two typical antibacterial agents,have been widely used in many kinds of cleaning products.Their ecotoxicity has become increasing concern,as their occurrences in environmental matrix have been frequently reported.In this paper,we studied the growth inhibition effects of environmentally relevant concentration exposure of TCS and TCC on Tetrahymena thermophila.The changes of the cell viability of Tetrahymena were further investigated.The results showed that the growth of Tetrahymena was inhibited significantly with μg·L-1 level TCS and TCC.The 24 h-EC50 of TCS and TCC was 141 μg·L-1and 728 μg·L-1,with NOEC of 2 μg·L-1 and 30 μg·L-1,LOEC of 4 μg·L-1 and 61 μg·L-1,respectively.Particularly,TCC seemly presented hormesis effect as it had growth stimulation at 1 to10 μg·L-1.In addition,when the concentrations of TCS and TCC reached 1000 μg·L-1,obvious damages of cell membrane were observed.Also,the activity of lysosomes was reduced to 88.62% and 95.75% of the control fluorescence values,respectively,when the cells were exposed to 1 μg·L-1of TCS and TCC for 2 h.This study provides important references for the ecological risk assessments of these two emerging pollutants.%研究了环境相关浓度水平(μg.L-1)的三氯生(TCS)和三氯卡班(TCC)暴露对嗜热四膜虫的生长抑制效应,并尝试探索这两种新生污染物对四膜虫细胞活性的影响.结果表明,μg.L-1水平的TCS和TCC对四膜虫的生长存在明显抑制作用,24 h-EC50分别为141μg.L-1、728μg.L-1;最低无效应浓度(NOEC)分别为2μg.L-1、30μg.L-1;最低效应浓度(LOEC)分别为4μg.L-1、61μg.L-1.其中,TCC在1—10μg.L-1水平表现出促进作用,可能是hormesis效应的体现.另外,在TCS和TCC浓度达到1000μg.L-1时均对四膜虫细胞膜产生明显损伤;TCS和TCC也影响其溶酶体活性,1μg.L-1暴露2 h时,荧光值(RFU)百分比分别降低至对照样品的88

  12. Horizontal gene transfer from Bacteria to rumen Ciliates indicates adaptation to their anaerobic, carbohydrates-rich environment

    Directory of Open Access Journals (Sweden)

    Takenaka Akio

    2006-02-01

    Full Text Available Abstract Background The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants was studied using ciliate Expressed Sequence Tags (ESTs. More than 4000 ESTs were sequenced from representatives of the two major groups of rumen Cilates: the order Entodiniomorphida (Entodinium simplex, Entodinium caudatum, Eudiplodinium maggii, Metadinium medium, Diploplastron affine, Polyplastron multivesiculatum and Epidinium ecaudatum and the order Vestibuliferida, previously called Holotricha (Isotricha prostoma, Isotricha intestinalis and Dasytricha ruminantium. Results A comparison of the sequences with the completely sequenced genomes of Eukaryotes and Prokaryotes, followed by large-scale construction and analysis of phylogenies, identified 148 ciliate genes that specifically cluster with genes from the Bacteria and Archaea. The phylogenetic clustering with bacterial genes, coupled with the absence of close relatives of these genes in the Ciliate Tetrahymena thermophila, indicates that they have been acquired via Horizontal Gene Transfer (HGT after the colonization of the gut by the rumen Ciliates. Conclusion Among the HGT candidates, we found an over-representation (>75% of genes involved in metabolism, specifically in the catabolism of complex carbohydrates, a rich food source in the rumen. We propose that the acquisition of these genes has greatly facilitated the Ciliates' colonization of the rumen providing evidence for the role of HGT in the adaptation to new niches.

  13. Horizontal gene transfer from Bacteria to rumen Ciliates indicates adaptation to their anaerobic, carbohydrates-rich environment

    Science.gov (United States)

    Ricard, Guénola; McEwan, Neil R; Dutilh, Bas E; Jouany, Jean-Pierre; Macheboeuf, Didier; Mitsumori, Makoto; McIntosh, Freda M; Michalowski, Tadeusz; Nagamine, Takafumi; Nelson, Nancy; Newbold, Charles J; Nsabimana, Eli; Takenaka, Akio; Thomas, Nadine A; Ushida, Kazunari; Hackstein, Johannes HP; Huynen, Martijn A

    2006-01-01

    Background The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants) was studied using ciliate Expressed Sequence Tags (ESTs). More than 4000 ESTs were sequenced from representatives of the two major groups of rumen Cilates: the order Entodiniomorphida (Entodinium simplex, Entodinium caudatum, Eudiplodinium maggii, Metadinium medium, Diploplastron affine, Polyplastron multivesiculatum and Epidinium ecaudatum) and the order Vestibuliferida, previously called Holotricha (Isotricha prostoma, Isotricha intestinalis and Dasytricha ruminantium). Results A comparison of the sequences with the completely sequenced genomes of Eukaryotes and Prokaryotes, followed by large-scale construction and analysis of phylogenies, identified 148 ciliate genes that specifically cluster with genes from the Bacteria and Archaea. The phylogenetic clustering with bacterial genes, coupled with the absence of close relatives of these genes in the Ciliate Tetrahymena thermophila, indicates that they have been acquired via Horizontal Gene Transfer (HGT) after the colonization of the gut by the rumen Ciliates. Conclusion Among the HGT candidates, we found an over-representation (>75%) of genes involved in metabolism, specifically in the catabolism of complex carbohydrates, a rich food source in the rumen. We propose that the acquisition of these genes has greatly facilitated the Ciliates' colonization of the rumen providing evidence for the role of HGT in the adaptation to new niches. PMID:16472398

  14. Identification of Aeromonas hydrophila Genes Preferentially Expressed after Phagocytosis by Tetrahymena and Involvement of Methionine Sulfoxide Reductases

    Science.gov (United States)

    Pang, Maoda; Lin, Xiaoqin; Liu, Jin; Guo, Changming; Gao, Shanshan; Du, Hechao; Lu, Chengping; Liu, Yongjie

    2016-01-01

    Free-living protozoa affect the survival and virulence evolution of pathogens in the environment. In this study, we explored the fate of Aeromonas hydrophila when co-cultured with the bacteriovorous ciliate Tetrahymena thermophila and investigated bacterial gene expression associated with the co-culture. Virulent A. hydrophila strains were found to have ability to evade digestion in the vacuoles of this protozoan. In A. hydrophila, a total of 116 genes were identified as up-regulated following co-culture with T. thermophila by selective capture of transcribed sequences (SCOTS) and comparative dot-blot analysis. A large proportion of these genes (42/116) play a role in metabolism, and some of the genes have previously been characterized as required for bacterial survival and replication within macrophages. Then, we inactivated the genes encoding methionine sulfoxide reductases, msrA, and msrB, in A. hydrophila. Compared to the wild-type, the mutants ΔmsrA and ΔmsrAB displayed significantly reduced resistance to predation by T. thermophila, and 50% lethal dose (LD50) determinations in zebrafish demonstrated that both mutants were highly attenuated. This study forms a solid foundation for the study of mechanisms and implications of bacterial defenses. PMID:28083518

  15. Acquisition of cell polarity during cell cycle and oral replacement in Tetrahymena.

    Science.gov (United States)

    Kaczanowska, Janina; Kaczanowski, Szymon; Kiersnowska, Mauryla; Fabczak, Hanna; Tulodziecka, Karolina; Kaczanowski, Andrzej

    2008-01-01

    The aim of this study was to search for a mechanism responsible for the acquisition of cell polarity in a ciliate Tetrahymena. Homologs of the mammalian genes coding for CDC42-GSK3beta- MARK/PAR1-MAPs proteins were found in the Tetrahymena genome (Eisen et al., 2006, and this study). These proteins belong to a pathway which controls assembly and disassembly of microtubule bundles and cell polarity in neural cells. In Tetrahymena, there are two types of morphogenesis: divisional and oral replacement (OR). In divisional morphogenesis, an elongation of longitudinal microtubule bundles (LMs) takes place during cell division. In contrast, in OR type morphogenesis, which occurs in starved non-dividing cells, a polar retraction of LMs occurs. In T. pyriformis, the frequency of developmental switch to OR morphogenesis increases in the presence of wortmannin, an inhibitor of the CDC42-GSK3beta-MARK pathway. In contrast, wortmannin when applied to dividing cells does not affect divisional morphogenesis. Using immunostaining with the antibody against mammalian mitotic phosphoproteins (MPM-2) we show that these proteins co-localize with the LMs and are distributed along the anterior-posterior gradient. In addition, we show that during OR type morphogenesis, the fate of LMs correlates with the anterior-posterior gradient of instability of the cortical structures. We used the conditional mouth-less mutant of T. thermophila (Tiedtke et al., 1988) to test if the presence of the oral apparatus is required for the maintenance of cell polarity. We discuss our results in relation to the hypothesis of GSK3-beta-MARK pathway involvement in the acquisition of cell polarity in Tetrahymena.

  16. Meiosis gene inventory of four ciliates reveals the prevalence of a synaptonemal complex-independent crossover pathway.

    Science.gov (United States)

    Chi, Jingyun; Mahé, Frédéric; Loidl, Josef; Logsdon, John; Dunthorn, Micah

    2014-03-01

    To establish which meiosis genes are present in ciliates, and to look for clues as to which recombination pathways may be treaded by them, four genomes were inventoried for 11 meiosis-specific and 40 meiosis-related genes. We found that the set of meiosis genes shared by Tetrahymena thermophila, Paramecium tetraurelia, Ichthyophthirius multifiliis, and Oxytricha trifallax is consistent with the prevalence of a Mus81-dependent class II crossover pathway that is considered secondary in most model eukaryotes. There is little evidence for a canonical class I crossover pathway that requires the formation of a synaptonemal complex (SC). This gene inventory suggests that meiotic processes in ciliates largely depend on mitotic repair proteins for executing meiotic recombination. We propose that class I crossovers and SCs were reduced sometime during the evolution of ciliates. Consistent with this reduction, we provide microscopic evidence for the presence only of degenerate SCs in Stylonychia mytilus. In addition, lower nonsynonymous to synonymous mutation rates of some of the meiosis genes suggest that, in contrast to most other nuclear genes analyzed so far, meiosis genes in ciliates are largely evolving at a slower rate than those genes in fungi and animals.

  17. 三聚氰胺对纤毛类原生动物梨形四膜虫的细胞毒性%Cytotoxicity Assessment of Melamine Using the Ciliated Protozoan Tetrahymena pyriforrnis

    Institute of Scientific and Technical Information of China (English)

    王正方; 齐小花; 邹明强; 张卓勇; 徐芳

    2009-01-01

    三聚氰胺曾被用为牛类的非蛋白类氮源,并被非法掺入食品中从而提高其表观蛋白含量.实验利用一种单细胞真核生物模型--纤毛类原生动物梨形四膜虫(Tetrahymena pyriformis)研究了三聚氰胺的细胞毒性.结果显示,三聚氰胺对梨形四膜虫的生长速率具有抑制作用,并且这种抑制作用与三聚氰胺浓度成正相关性,其IC50值为0.78g·L-1.细胞同时发生形变.实验证明梨形四膜虫生物测定法相对于动物实验具有耗时短、成本低、操作简便的优势,在潜在毒性物质的风险性评估实验中可成为一种优良的替代模型.%Melamine was once used as a non-protein nitrogen(NPN)source for cattle,and unethically added to food productions in order to increase the apparent protein content.In this study,the cytotoxicological impact of melamine was determined using a unicellular eukaryote bioassay model,the ciliated protozoan Tetrahymena pyriformis(T.pyriformis).The results showed a concentration-dependent inhibitory effect of melamine on the cell proliferation rate of T.pyriformis populations,and the IC50 value was estimated to be 0.78g·L-1.Deformed cells were also observed.Our experiment demonstrated that T. pyriformis bioassay,with advantages such as less time-consuming,lower cost and simpler operations,provides a good alternative in vitro method to animal experiments for the risk assessment of potentially toxic substances.

  18. Lectins and Tetrahymena - A review.

    Science.gov (United States)

    Csaba, György

    2016-09-01

    The unicellular ciliate Tetrahymena is a complete organism, one of the most highly developed protozoans, which has specialized organelles performing each of the functions characteristic to the cells of higher ranked animals. It is also able to produce, store, and secrete hormones of higher ranked animals and also react to them. It produces lectins that can bind them and has functions, which are influenced by exogenous lectins. The review lists the observations on the relationship between lectins and Tetrahymena and try to construe them on the basis of the data, which are at our disposal. Considering the data, lectins can be used by Tetrahymena as materials for influencing conjugation, for stimulating hormone receptors, and by this, mimic the hormonal functions. Lectins can influence phagocytosis and movement of the cells as well as the cell division. As Tetrahymena can recognize both related and hostile cells by the help of lectins and surface sugars, it could be surmised a complex predator-prey system. This could determine the survival of the population as well as the nourishment conditions. When Tetrahymena is pathogenic, it can use lectins as virulence factors.

  19. Evolutionary dynamics of a conserved sequence motif in the ribosomal genes of the ciliate Paramecium

    Directory of Open Access Journals (Sweden)

    Lynch Michael

    2010-05-01

    Full Text Available Abstract Background In protozoa, the identification of preserved motifs by comparative genomics is often impeded by difficulties to generate reliable alignments for non-coding sequences. Moreover, the evolutionary dynamics of regulatory elements in 3' untranslated regions (both in protozoa and metazoa remains a virtually unexplored issue. Results By screening Paramecium tetraurelia's 3' untranslated regions for 8-mers that were previously found to be preserved in mammalian 3' UTRs, we detect and characterize a motif that is distinctly conserved in the ribosomal genes of this ciliate. The motif appears to be conserved across Paramecium aurelia species but is absent from the ribosomal genes of four additional non-Paramecium species surveyed, including another ciliate, Tetrahymena thermophila. Motif-free ribosomal genes retain fewer paralogs in the genome and appear to be lost more rapidly relative to motif-containing genes. Features associated with the discovered preserved motif are consistent with this 8-mer playing a role in post-transcriptional regulation. Conclusions Our observations 1 shed light on the evolution of a putative regulatory motif across large phylogenetic distances; 2 are expected to facilitate the understanding of the modulation of ribosomal genes expression in Paramecium; and 3 reveal a largely unexplored--and presumably not restricted to Paramecium--association between the presence/absence of a DNA motif and the evolutionary fate of its host genes.

  20. Cross-study analysis of genomic data defines the ciliate multigenic epiplasmin family: strategies for functional analysis in Paramecium tetraurelia

    Directory of Open Access Journals (Sweden)

    Ravet Viviane

    2009-06-01

    Full Text Available Abstract Background The sub-membranous skeleton of the ciliate Paramecium, the epiplasm, is composed of hundreds of epiplasmic scales centered on basal bodies, and presents a complex set of proteins, epiplasmins, which belong to a multigenic family. The repeated duplications observed in the P. tetraurelia genome present an interesting model of the organization and evolution of a multigenic family within a single cell. Results To study this multigenic family, we used phylogenetic, structural, and analytical transcriptional approaches. The phylogenetic method defines 5 groups of epiplasmins in the multigenic family. A refined analysis by Hydrophobic Cluster Analysis (HCA identifies structural characteristics of 51 epiplasmins, defining five separate groups, and three classes. Depending on the sequential arrangement of their structural domains, the epiplasmins are defined as symmetric, asymmetric or atypical. The EST data aid in this classification, in the identification of putative regulating sequences such as TATA or CAAT boxes. When specific RNAi experiments were conducted using sequences from either symmetric or asymmetric classes, phenotypes were drastic. Local effects show either disrupted or ill-shaped epiplasmic scales. In either case, this results in aborted cell division. Using structural features, we show that 4 epiplasmins are also present in another ciliate, Tetrahymena thermophila. Their affiliation with the distinctive structural groups of Paramecium epiplasmins demonstrates an interspecific multigenic family. Conclusion The epiplasmin multigenic family illustrates the history of genomic duplication in Paramecium. This study provides a framework which can guide functional analysis of epiplasmins, the major components of the membrane skeleton in ciliates. We show that this set of proteins handles an important developmental information in Paramecium since maintenance of epiplasm organization is crucial for cell morphogenesis.

  1. The mitochondrial genomes of the ciliates Euplotes minuta and Euplotes crassus.

    NARCIS (Netherlands)

    Graaf, R.M. de; Alen, T.A. van; Dutilh, B.E.; Kuiper, J.W.P.; Zoggel, H.J. van; Huynh, M.B.; Gortz, H.D.; Huynen, M.A.; Hackstein, J.H.P.

    2009-01-01

    BACKGROUND: There are thousands of very diverse ciliate species from which only a handful mitochondrial genomes have been studied so far. These genomes are rather similar because the ciliates analysed (Tetrahymena spp. and Paramecium aurelia) are closely related. Here we study the mitochondrial geno

  2. Highly Divergent Mitochondrial ATP Synthase Complexes in Tetrahymena thermophila

    NARCIS (Netherlands)

    Nina, Praveen Balabaskaran; Dudkina, Natalya V.; Kane, Lesley A.; van Eyk, Jennifer E.; Boekema, Egbert J.; Mather, Michael W.; Vaidya, Akhil B.; Eisen, Jonathan A.

    2010-01-01

    The F-type ATP synthase complex is a rotary nano-motor driven by proton motive force to synthesize ATP. Its F(1) sector catalyzes ATP synthesis, whereas the F(o) sector conducts the protons and provides a stator for the rotary action of the complex. Components of both F(1) and F(o) sectors are highl

  3. Generation and analysis of expressed sequence tags from the ciliate protozoan parasite Ichthyophthirius multifiliis

    Directory of Open Access Journals (Sweden)

    Arias Covadonga

    2007-06-01

    Full Text Available Abstract Background The ciliate protozoan Ichthyophthirius multifiliis (Ich is an important parasite of freshwater fish that causes 'white spot disease' leading to significant losses. A genomic resource for large-scale studies of this parasite has been lacking. To study gene expression involved in Ich pathogenesis and virulence, our goal was to generate expressed sequence tags (ESTs for the development of a powerful microarray platform for the analysis of global gene expression in this species. Here, we initiated a project to sequence and analyze over 10,000 ESTs. Results We sequenced 10,368 EST clones using a normalized cDNA library made from pooled samples of the trophont, tomont, and theront life-cycle stages, and generated 9,769 sequences (94.2% success rate. Post-sequencing processing led to 8,432 high quality sequences. Clustering analysis of these ESTs allowed identification of 4,706 unique sequences containing 976 contigs and 3,730 singletons. These unique sequences represent over two million base pairs (~10% of Plasmodium falciparum genome, a phylogenetically related protozoan. BLASTX searches produced 2,518 significant (E-value -5 hits and further Gene Ontology (GO analysis annotated 1,008 of these genes. The ESTs were analyzed comparatively against the genomes of the related protozoa Tetrahymena thermophila and P. falciparum, allowing putative identification of additional genes. All the EST sequences were deposited by dbEST in GenBank (GenBank: EG957858–EG966289. Gene discovery and annotations are presented and discussed. Conclusion This set of ESTs represents a significant proportion of the Ich transcriptome, and provides a material basis for the development of microarrays useful for gene expression studies concerning Ich development, pathogenesis, and virulence.

  4. Comparative study of infection with Tetrahymena of different ornamental fish species

    DEFF Research Database (Denmark)

    Sharon, G.; Leibowitz, M. Pimenta; Chettri, Jiwan Kumar;

    2014-01-01

    Tetrahymena is a ciliated protozoan that can infect a wide range of fish species, although it is most commonly reported in guppies (Poecilia reticulata). The aim of this study was to compare the susceptibility to infection with Tetrahymena of five different ornamental fish species from two...... different super orders. The species examined were platy (Xiphophorus), molly (Poecilia sphenops) and angelfish (Pterophyllum scalare) of the Acanthopterygii super order (which also includes guppies) and goldfish (Carassius auratus auratus) and koi carp (Cyprinus carpio) of the Ostariophysi super order...

  5. The mitochondrial genomes of the ciliates Euplotes minuta and Euplotes crassus

    Directory of Open Access Journals (Sweden)

    Huynh Minh

    2009-11-01

    Full Text Available Abstract Background There are thousands of very diverse ciliate species from which only a handful mitochondrial genomes have been studied so far. These genomes are rather similar because the ciliates analysed (Tetrahymena spp. and Paramecium aurelia are closely related. Here we study the mitochondrial genomes of the hypotrichous ciliates Euplotes minuta and Euplotes crassus. These ciliates are only distantly related to Tetrahymena spp. and Paramecium aurelia, but more closely related to Nyctotherus ovalis, which possesses a hydrogenosomal (mitochondrial genome. Results The linear mitochondrial genomes of the hypotrichous ciliates Euplotes minuta and Euplotes crassus were sequenced and compared with the mitochondrial genomes of several Tetrahymena species, Paramecium aurelia and the partially sequenced mitochondrial genome of the anaerobic ciliate Nyctotherus ovalis. This study reports new features such as long 5'gene extensions of several mitochondrial genes, extremely long cox1 and cox2 open reading frames and a large repeat in the middle of the linear mitochondrial genome. The repeat separates the open reading frames into two blocks, each having a single direction of transcription, from the repeat towards the ends of the chromosome. Although the Euplotes mitochondrial gene content is almost identical to that of Paramecium and Tetrahymena, the order of the genes is completely different. In contrast, the 33273 bp (excluding the repeat region piece of the mitochondrial genome that has been sequenced in both Euplotes species exhibits no difference in gene order. Unexpectedly, many of the mitochondrial genes of E. minuta encoding ribosomal proteins possess N-terminal extensions that are similar to mitochondrial targeting signals. Conclusion The mitochondrial genomes of the hypotrichous ciliates Euplotes minuta and Euplotes crassus are rather different from the previously studied genomes. Many genes are extended in size compared to mitochondrial

  6. Inheritance of the group I rDNA intron in Tetrahymena pigmentosa.

    Science.gov (United States)

    Nielsen, H; Simon, E M; Engberg, J

    1992-01-01

    We have previously argued from phylogenetic sequence data that the group I intron in the rRNA genes of Tetrahymena was acquired by different Tetrahymena species at different times during evolution. We have now approached the question of intron mobility experimentally by crossing intron+ and intron- strains looking for a strong polarity in the inheritance of the intron (intron homing). Based on the genetic analysis we find that the intron in T. pigmentosa is inherited as a neutral character and that intron+ and intron- alleles segregate in a Mendelian fashion with no sign of intron homing. In an analysis of vegetatively growing cells containing intron+ and intron- rDNA, initially in the same macronucleus, we similarly find no evidence of intron homing. During the course of this work, we observed to our surprise that progeny clones from some crosses contained three types of rDNA. One possible explanation is that T. pigmentosa has two rdn loci in contrast to the single locus found in T. thermophila. Some of the progeny clones from the genetic analysis were expanded for several hundred generations, and allelic assortment of the rDNA was demonstrated by subcloning analysis.

  7. A novel DNA deletion-ligation reaction catalyzed in vitro by a developmentally controlled activity from Tetrahymena cells.

    Science.gov (United States)

    Robinson, E K; Cohen, P D; Blackburn, E H

    1989-09-08

    Developmentally controlled genomic deletion-ligations occur during ciliate macronuclear differentiation. We have identified a novel activity in Tetrahymena cell-free extracts that efficiently catalyzes a specific set of intramolecular DNA deletion-ligation reactions. When synthetic DNA oligonucleotide substrates were used, all the deletion-ligation products resembled those formed in vivo in that they resulted from deletions between pairs of short direct repeats. The reaction is ATP-dependent, salt-sensitive, and strongly influenced by the oligonucleotide substrate sequence. The deletion-ligation activity has an apparent size of 200-500 kd, no nuclease-sensitive component, and is highly enriched in cells developing new macronuclei. The temperature inactivation profile of the activity parallels the temperature lethality profile specific for Tetrahymena cells developing new macronuclei. We suggest that this deletion-ligation activity carries out the genomic deletions in developing macronuclei in vivo.

  8. Exo1 and Mre11 execute meiotic DSB end resection in the protist Tetrahymena.

    Science.gov (United States)

    Lukaszewicz, Agnieszka; Shodhan, Anura; Loidl, Josef

    2015-11-01

    The resection of 5'-DNA ends at a double-strand break (DSB) is an essential step in recombinational repair, as it exposes 3' single-stranded DNA (ssDNA) tails for interaction with a repair template. In mitosis, Exo1 and Sgs1 have a conserved function in the formation of long ssDNA tails, whereas this step in the processing of programmed meiotic DSBs is less well-characterized across model organisms. In budding yeast, which has been most intensely studied in this respect, Exo1 is a major meiotic nuclease. In addition, it exerts a nuclease-independent function later in meiosis in the conversion of DNA joint molecules into ZMM-dependent crossovers. In order to gain insight into the diverse meiotic roles of Exo1, we investigated the effect of Exo1 deletion in the ciliated protist Tetrahymena. We found that Exo1 together with Mre11, but without the help of Sgs1, promotes meiotic DSB end resection. Resection is completely eliminated only if both Mre11 and Exo1 are missing. This is consistent with the yeast model where Mre11 promotes resection in the 3'-5' direction and Exo1 in the opposite 5'-3' direction. However, while the endonuclease activity of Mre11 is essential to create an entry site for exonucleases and hence to start resection in budding yeast, Tetrahymena Exo1 is able to create single-stranded DNA in the absence of Mre11. Excluding a possible contribution of the Mre11 cofactor Sae2 (Com1) as an autonomous endonuclease, we conclude that there exists another unknown nuclease that initiates DSB processing in Tetrahymena. Consistent with the absence of the ZMM crossover pathway in Tetrahymena, crossover formation is independent of Exo1.

  9. Macronuclear Cytology of Synchronized Tetrahymena pyriformis

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, I. L.; Padilla, G. M.; Miller, Jr., O. L.

    1966-05-01

    Elliott, Kennedy and Bak ('62) and Elliott ('63) followed fine structural changes in macronuclei of Tetrahymena pyriformis which were synchronized by the heat shock method of Scherbaum and Zeuthen ('54). Using Elliott's morphological descriptions as a basis, we designed our investigations with two main objectives: First, to again study the. morphological changes which occur in the macronucleus of Tetrahymena synchronized by the heat shock method. The second objective was to compare these observations with Tetrahymena synchronized by an alternate method recently reported by Padilla and Cameron ('64). Therefore, we were able to compare the results from two different synchronization methods and to contrast these findings with the macronuclear cytology of Tetrahymena taken from a logarithmically growing culture. Comparison of cells treated in these three different ways enables us to evaluate the two different synchronization methods and to gain more information on the structural changes taking place in the macronucleus of Tetrahymena as a function of the cell cycle. Our observations were confined primarily to nucleolar morphology. The results indicate that cells synchronized by the Padilla and Cameron method more closely resemble logarithmically growing Tetrahymena in the macronuclear structure than do cells obtained by the Scherbaum and·Zeuthen synchronization method. .

  10. Effect of diphenyl, o-phenylphenol and 2-(4-thiazoyl) benzimidazole on growth of tetrahymena pyriformis

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, K.; Yoshikawa, H.; Sugitani, A.; Kawai, M.

    1988-08-01

    Diphenyl (DP), o-phenylphenol (OPP), 2-(4-thiazoyl) benzimidazole (TBZ), are used as fungicides for citrus fruits. The acute toxicity of these compounds has been established for whole animals. However, additional information as to the cytotoxic effect of these fungicides is required. The ciliated protozoan, Tetrahymena pyriformis, is a single cell organism easily grown in an axenic medium, and has nutritional requirements similal to those of higher animals. Therefore, T. pyriformis has been used as a tool for the determination of the toxicity of food colors and heavy metals. The authors report the toxicity of DP, OPP and TBZ using T. pyriformis as a model test system.

  11. Cycloheptaamylose-dansyl chloride complex as a fluorescent label of surface membranes in living ciliates.

    Science.gov (United States)

    Wyroba, E; Bottiroli, G; Giordano, P

    1981-12-01

    Labelling of surface membrane of living ciliates: Paramecium aurelia and Tetrahymena pyriformis with fluorescent compound--cycloheptaamylose-dansyl chloride complex (CDC) has been achieved. Fluorescence micrographs of the dried samples showed specific localization of CDC on the cell membrane without any intracellular penetration. On the contrary the ciliates which have been dead during labelling revealed a non-specific fluorescence of their whole bodies. Microspectrofluorimetric analysis of labelled Paramecium cells was performed with Leitz microspectrograph. Spectrum of fluorescence emission measured over the cell membrane level had maximum at 450 nm. Strikingly, the emission maximum of the cells dead at the moment of labelling was shifted 10 nm to a longer wavelength. The rate of photofading measured in this case was almost 3-fold higher than for the ciliates labelled as living ones. Fluorescence excitation spectra did not show any difference in the peak position. Thus CDC staining appears to be an useful method of supravital labelling of cell surface enabling also to distinguish--on the basis of spectral characteristics--the ciliates being alive from those dead at the moment of fluorochrome binding.

  12. A simplified experimental model for clearance of some pathogenic bacteria using common bacterivorous ciliated spp. in Tigris river

    Science.gov (United States)

    Ali, Talib Hassan; Saleh, Dhuha Saad

    2014-03-01

    Bacteria-specific uptake rates of three different protozoan taxa on a pure and mixed bacterial community was studied by means of a simplified and functionally reproducible experimental model. The bacterial species Shigella flexneri, Escherichia coli and Salmonella typhi were isolated and classified from stool samples of patients suffering from diarrhea. Paramecium caudatum, Tetrahymena pyriformis and Halteria grandinella, free living ciliate Protozoans, were isolated and identified from Tigris river water. Pure and mixed ( E. coli + S. typhi), ( E. coli + Sh. flexneri) bacterial cultures were used with each ciliate genera to evaluate the following: predator duplication rate, prey reduction rate, clearance rate and net grazing rate. We used selective lactose fermentation phenomena of enteric bacteria on MacConkey medium for the quantification of bacteria cultural characteristics. The final bacteria concentration was reduced by growing protozoa of 98-99.9 % compared to protozoa-free controls. It showed that Tetrahymena pyriformis had the highest duplication rate (4.13 time/day) in both types of cultures (pure and mixed), followed by Paramecium caudatum and Halteria grandinella, respectively. Paramecium caudatum had the highest rate of ingestion in both types of cultures (26 × 103 bacteria/organism/hr) and yielded the longest time required for 90 % bacterial reduction in a pure suspension of S. typhi (166 h). Clearance rates of pathogenic bacteria by ciliates ranged between 106 nanoliter/organism/h by P. caudatum to S. typhi and 1.92 nanoliter/organism/h seen in T. pyriformis in ( E. coli + S. typhi) mixed culture. We used aquatic experimental microcosms under controlled conditions to explore bacteria-dependent ciliate growth and examined whether these ciliates could discriminate between equally sized bacterial preys in a mixture.

  13. A knockout mutation of a constitutive GPCR in Tetrahymena decreases both G-protein activity and chemoattraction.

    Directory of Open Access Journals (Sweden)

    Thomas J Lampert

    Full Text Available Although G-protein coupled receptors (GPCRs are a common element in many chemosensory transduction pathways in eukaryotic cells, no GPCR or regulated G-protein activity has yet been shown in any ciliate. To study the possible role for a GPCR in the chemoresponses of the ciliate Tetrahymena, we have generated a number of macronuclear gene knockouts of putative GPCRs found in the Tetrahymena Genome database. One of these knockout mutants, called G6, is a complete knockout of a gene that we call GPCR6 (TTHERM_00925490. Based on sequence comparisons, the Gpcr6p protein belongs to the Rhodopsin Family of GPCRs. Notably, Gpcr6p shares highest amino acid sequence homologies to GPCRs from Paramecium and several plants. One of the phenotypes of the G6 mutant is a decreased responsiveness to the depolarizing ions Ba²⁺ and K⁺, suggesting a decrease in basal excitability (decrease in Ca²⁺ channel activity. The other major phenotype of G6 is a loss of chemoattraction to lysophosphatidic acid (LPA and proteose peptone (PP, two known chemoattractants in Tetrahymena. Using microsomal [³⁵S]GTPγS binding assays, we found that wild-type (CU427 have a prominent basal G-protein activity. This activity is decreased to the same level by pertussis toxin (a G-protein inhibitor, addition of chemoattractants, or the G6 mutant. Since the basal G-protein activity is decreased by the GPCR6 knockout, it is likely that this gene codes for a constitutively active GPCR in Tetrahymena. We propose that chemoattractants like LPA and PP cause attraction in Tetrahymena by decreasing the basal G-protein stimulating activity of Gpcr6p. This leads to decreased excitability in wild-type and longer runs of smooth forward swimming (less interrupted by direction changes towards the attractant. Therefore, these attractants may work as inverse agonists through the constitutively active Gpcr6p coupled to a pertussis-sensitive G-protein.

  14. Toxic Effect of a Pesticide, Diflubenzuron on Freshwater Microinvertebrate (Tetrahymena pyriformis)

    Institute of Scientific and Technical Information of China (English)

    ROUABHI Rachid; DJEBAR-BERREBBAH H; DJEBAR MR

    2006-01-01

    The impact of diflubenzuron (DFB) on Tetrahymena pyriformis, a ciliated protiste was studied. The treatment with DFB at concentrations of 10 and 20 μg/mL could appreciably reduce the growth of the protiste. The surveillance of protozoa′s respiratory metabolism with polarography technique showed a sensitive inhibition of its oxygen consumption, and at 20 μg/mL concentration the oxygen consumption was increased. For any malformation of morphology and perturbation in swimming trajectory, the neutral red coloration was done. This technique (neutral red) showed that there was a toxic effect of DFB on T. pyriformis, especially at the highest concentration;this toxicity was translated by rotatory swimming in same place and the increasing of coloration quantity in digestive vacuoles. Fig 5, Ref 15

  15. Vanadate affects nuclear division and induces aberrantly-shaped cells during subsequent cytokinesis in Tetrahymena

    DEFF Research Database (Denmark)

    Nilsson, Jytte R.

    1999-01-01

    cellebiology,endocytosis,monsters,nuclear elongation,sodium orthovanadate,Tetrahymena pyriformis,proliferation......cellebiology,endocytosis,monsters,nuclear elongation,sodium orthovanadate,Tetrahymena pyriformis,proliferation...

  16. The secondary structure of large-subunit rRNA divergent domains, a marker for protist evolution

    DEFF Research Database (Denmark)

    Lenaers, G; Nielsen, Henrik; Engberg, J;

    1988-01-01

    ), Tetrahymena thermophila (ciliate), Physarum polycephalum and Dictyostelium discoideum (slime moulds), Crithidia fasciculata and Giardia lamblia (parasitic flagellates). The folding for the D3, D7a and D10 divergent domains has been refined and a consensus model for the protist 24-26S rRNA structure...

  17. Modules for C-terminal epitope tagging of Tetrahymena genes

    Science.gov (United States)

    Kataoka, Kensuke; Schoeberl, Ursula E.; Mochizuki, Kazufumi

    2010-01-01

    Although epitope tagging has been widely used for analyzing protein function in many organisms, there are few genetic tools for epitope tagging in Tetrahymena. In this study, we describe several C-terminal epitope tagging modules that can be used to express tagged proteins in Tetrahymena cells by both plasmid- and PCR-based strategies. PMID:20624430

  18. Biological treatment of whey by Tetrahymena pyriformis and impact study on laboratory-scale wastewater lagoon process.

    Science.gov (United States)

    Bonnet, J L; Bogaerts, P; Bohatier, J

    1999-06-01

    A procedure based on a biological treatment of whey was tested as part of research on waste treatment at the scale of small cheesemaking units. We studied the potential biodegradation of whey by a protozoan ciliate, Tetrahymena pyriformis, and evaluated the functional, microbiological and physiological disturbances caused by crude whey and the biodegraded whey in laboratory-scale pilots mimicking a natural lagoon treatment. The results show that T. pyriformis can strongly reduce the pollutant load of whey. In the lagoon pilots serving as example of receptor media, crude whey gradually but completely arrested operation, whereas with the biodegraded whey adverse effects were only temporary, and normal operation versus a control was gradually recovered in a few days.

  19. Transgenerational function of Tetrahymena Piwi protein Twi8p at distinctive noncoding RNA loci.

    Science.gov (United States)

    Farley, Brian M; Collins, Kathleen

    2017-04-01

    Transgenerational transmission of genome-regulatory epigenetic information can determine phenotypes in the progeny of sexual reproduction. Sequence specificity of transgenerational regulation derives from small RNAs assembled into Piwi-protein complexes. Known targets of transgenerational regulation are primarily transposons and transposon-derived sequences. Here, we extend the scope of Piwi-mediated transgenerational regulation to include unique noncoding RNA loci. Ciliates such as Tetrahymena have a phenotypically silent germline micronucleus and an expressed somatic macronucleus, which is differentiated anew from a germline genome copy in sexual reproduction. We show that the nuclear-localized Tetrahymena Piwi protein Twi8p shuttles from parental to zygotic macronuclei. Genetic elimination of Twi8p has no phenotype for cells in asexual growth. On the other hand, cells lacking Twi8p arrest in sexual reproduction with zygotic nuclei that retain the germline genome structure, without the DNA elimination and fragmentation required to generate a functional macronucleus. Twi8p-bound small RNAs originate from long-noncoding RNAs with a terminal hairpin, which become detectable in the absence of Twi8p. Curiously, the loci that generate Twi8p-bound small RNAs are essential for asexual cell growth, even though Twi8 RNPs are essential only in sexual reproduction. Our findings suggest the model that Twi8 RNPs act on silent germline chromosomes to permit their conversion to expressed macronuclear chromosomes. Overall this work reveals that a Piwi protein carrying small RNAs from long-noncoding RNA loci has transgenerational function in establishing zygotic nucleus competence for gene expression.

  20. Complete mitochondrial genome sequence of three Tetrahymena species reveals mutation hot spots and accelerated nonsynonymous substitutions in Ymf genes.

    Directory of Open Access Journals (Sweden)

    Mike M Moradian

    Full Text Available The ciliate Tetrahymena, a model organism, contains divergent mitochondrial (Mt genome with unusual properties, where half of its 44 genes still remain without a definitive function. These genes could be categorized into two major groups of KPC (known protein coding and Ymf (genes without an identified function. To gain insights into the mechanisms underlying gene divergence and molecular evolution of Tetrahymena (T. Mt genomes, we sequenced three Mt genomes of T.paravorax, T.pigmentosa, and T.malaccensis. These genomes were aligned and the analyses were carried out using several programs that calculate distance, nucleotide substitution (dn/ds, and their rate ratios (omega on individual codon sites and via a sliding window approach. Comparative genomic analysis indicated a conserved putative transcription control sequence, a GC box, in a region where presumably transcription and replication initiate. We also found distinct features in Mt genome of T.paravorax despite similar genome organization among these approximately 47 kb long linear genomes. Another significant finding was the presence of at least one or more highly variable regions in Ymf genes where majority of substitutions were concentrated. These regions were mutation hotspots where elevated distances and the dn/ds ratios were primarily due to an increase in the number of nonsynonymous substitutions, suggesting relaxed selective constraint. However, in a few Ymf genes, accelerated rates of nonsynonymous substitutions may be due to positive selection. Similarly, on protein level the majority of amino acid replacements occurred in these regions. Ymf genes comprise half of the genes in Tetrahymena Mt genomes, so understanding why they have not been assigned definitive functions is an important aspect of molecular evolution. Importantly, nucleotide substitution types and rates suggest possible reasons for not being able to find homologues for Ymf genes. Additionally, comparative genomic

  1. ATP-binding cassette transporter enhances tolerance to DDT in Tetrahymena.

    Science.gov (United States)

    Ning, YingZhi; Dang, Huai; Liu, GuangLong; Xiong, Jie; Yuan, DongXia; Feng, LiFang; Miao, Wei

    2015-03-01

    The reuse of dichlorodiphenyltrichloroethane (DDT) as an indoor residual spray was permitted by the World Health Organization in 2007, and approximately 14 countries still use DDT to control disease vectors. The extensive exposure of insects to DDT has resulted in the emergence of DDT resistance, especially in mosquitoes, and the mechanism for this resistance in mosquitoes has been widely reported. Spraying can also introduce DDT directly into surface water, and DDT can subsequently accumulate in microorganisms, but the mechanism for the resistance to DDT degradation in microorganisms is unclear. Using whole-genome microarray analysis, we detected an abcb15 gene that was up-regulated in a specific manner by DDT treatment in T. thermophile. The deduced ABCB15 peptide sequence had two transmembrane domains (TMDs) and two nucleotide-binding domains (NBDs) to form the structure TMD-NBD-TMD-NBD, and each NBD contained three conserved motifs: Walker-A, C-loop, and Walker-B, which indicated the T. thermophila abcb15 was a typical ABC transporter gene. The expression of ABCB15 fused with a C-terminal green fluorescent protein was found to be on the periphery of the cell, suggesting that ABCB15 was a membrane pump protein. In addition, cells with abcb15 partially knocked down (abcb15-KD) grew slower than wild-type cells in the presence of 256 mg L(-1) DDT, indicating the tolerance of abcb15-KD strain to DDT exposure was decreased. Thus, we suggest that in Tetrahymena, the membrane pump protein encoded by ABCT gene abcb15 can enhance the tolerance to DDT and protect cells from this exogenous toxin by efficiently pumping it to the extracellular space.

  2. Complete sequence of the mitochondrial genome of Tetrahymena pyriformis and comparison with Paramecium aurelia mitochondrial DNA.

    Science.gov (United States)

    Burger, G; Zhu, Y; Littlejohn, T G; Greenwood, S J; Schnare, M N; Lang, B F; Gray, M W

    2000-03-24

    We report the complete nucleotide sequence of the Tetrahymena pyriformis mitochondrial genome and a comparison of its gene content and organization with that of Paramecium aurelia mtDNA. T. pyriformis mtDNA is a linear molecule of 47,172 bp (78.7 % A+T) excluding telomeric sequences (identical tandem repeats of 31 bp at each end of the genome). In addition to genes encoding the previously described bipartite small and large subunit rRNAs, the T. pyriformis mitochondrial genome contains 21 protein-coding genes that are clearly homologous to genes of defined function in other mtDNAs, including one (yejR) that specifies a component of a cytochrome c biogenesis pathway. As well, T. pyriformis mtDNA contains 22 open reading frames of unknown function larger than 60 codons, potentially specifying proteins ranging in size from 74 to 1386 amino acid residues. A total of 13 of these open reading frames ("ciliate-specific") are found in P. aurelia mtDNA, whereas the remaining nine appear to be unique to T. pyriformis; however, of the latter, five are positionally equivalent and of similar size in the two ciliate mitochondrial genomes, suggesting they may also be homologous, even though this is not evident from sequence comparisons. Only eight tRNA genes encoding seven distinct tRNAs are found in T. pyriformis mtDNA, formally confirming a long-standing proposal that most T. pyriformis mitochondrial tRNAs are nucleus-encoded species imported from the cytosol. Atypical features of mitochondrial gene organization and expression in T. pyriformis mtDNA include split and rearranged large subunit rRNA genes, as well as a split nad1 gene (encoding subunit 1 of NADH dehydrogenase of respiratory complex I) whose two segments are located on and transcribed from opposite strands, as is also the case in P. aurelia. Gene content and arrangement are very similar in T. pyriformis and P. aurelia mtDNAs, the two differing by a limited number of duplication, inversion and rearrangement events

  3. Genomic insights into the fungal lignocellulolytic system of Myceliophthora thermophila

    Directory of Open Access Journals (Sweden)

    Anthi eKarnaouri

    2014-06-01

    Full Text Available The microbial conversion of solid cellulosic biomass to liquid biofuels may provide a renewable energy source for transportation fuels. Cellulolytic fungi represent a promising group of organisms, as they have evolved complex systems for adaptation to their natural habitat. The filamentous fungus Myceliophthora thermophila constitutes an exceptionally powerful cellulolytic microorganism that synthesizes a complete set of enzymes necessary for the breakdown of plant cell wall. The genome of this fungus has been recently sequenced and annotated, allowing systematic examination and identification of enzymes required for the degradation of lignocellulosic biomass. The genomic analysis revealed the existence of an expanded enzymatic repertoire including numerous cellulases, hemicellulases and enzymes with auxiliary activities, covering the most of the recognized CAZy families. Most of them were predicted to possess a secretion signal and undergo through post translational glycosylation modifications. These data offer a better understanding of activities embedded in fungal lignocellulose decomposition mechanisms and suggest that M. thermophila could be made usable as an industrial production host for cellulolytic and hemicellulolytic enzymes.

  4. Gravity-dependent changes in bioconvection of Tetrahymena and Chlamydomonas during parabolic flight: increases in wave number induced by pre- and post-parabola hypergravity.

    Science.gov (United States)

    Kage, Azusa; Asato, Eriko; Chiba, Yoko; Wada, Yuuko; Katsu-Kimura, Yumiko; Kubota, Ayami; Sawai, Satoe; Niihori, Maki; Baba, Shoji A; Mogami, Yoshihiro

    2011-03-01

    Bioconvection emerges in a dense suspension of swimming protists as a consequence of their negative-gravitactic upward migration and later settling as a blob of density greater than that of water. Thus, gravity is an important parameter governing bioconvective pattern formation. However, inconsistencies are found in previous studies dealing with the response of bioconvection patterns to increased gravity acceleration (hypergravity); the wave number of the patterns has been reported to decrease during the hypergravity phases of parabolic aircraft flight, while it increases in centrifugal hypergravity. In this paper, we reassess the responses of bioconvection to altered gravity during parabolic flight on the basis of vertical and horizontal observations of the patterns formed by Tetrahymena thermophila and Chlamydomonas reinhardtii. Spatiotemporal analyses of the horizontal patterns revealed an increase in the pattern wave number in both pre- and post-parabola hypergravity. Vertical pattern analysis was generally in line with the horizontal pattern analysis, and further revealed that hypergravity-induced changes preceded at the top layer of the suspensions while microgravity-induced changes appeared to occur from the bottom part of the settling blobs. The responses to altered gravity were rather different between the two sample species: T. thermophila tended to drastically modify its bioconvection patterns in response to changes in gravity level, while the patterns of C. reinhardtii responded to a much lesser extent. This difference can be attributed to the distinct physical and physiological properties of the individual organisms, suggesting a significant contribution of the gyrotactic property to the swimming behavior of some protists.

  5. Ciliate communities consistently associated with coral diseases

    Science.gov (United States)

    Sweet, M. J.; Séré, M. G.

    2016-07-01

    Incidences of coral disease are increasing. Most studies which focus on diseases in these organisms routinely assess variations in bacterial associates. However, other microorganism groups such as viruses, fungi and protozoa are only recently starting to receive attention. This study aimed at assessing the diversity of ciliates associated with coral diseases over a wide geographical range. Here we show that a wide variety of ciliates are associated with all nine coral diseases assessed. Many of these ciliates such as Trochilia petrani and Glauconema trihymene feed on the bacteria which are likely colonizing the bare skeleton exposed by the advancing disease lesion or the necrotic tissue itself. Others such as Pseudokeronopsis and Licnophora macfarlandi are common predators of other protozoans and will be attracted by the increase in other ciliate species to the lesion interface. However, a few ciliate species (namely Varistrombidium kielum, Philaster lucinda, Philaster guamense, a Euplotes sp., a Trachelotractus sp. and a Condylostoma sp.) appear to harbor symbiotic algae, potentially from the coral themselves, a result which may indicate that they play some role in the disease pathology at the very least. Although, from this study alone we are not able to discern what roles any of these ciliates play in disease causation, the consistent presence of such communities with disease lesion interfaces warrants further investigation.

  6. The Cutaneous Ciliated Cyst in Young Male: The Possibility of Ciliated Cutaneous Eccrine Cyst

    Science.gov (United States)

    Kim, Youngjoon; Kim, Hyunjung

    2015-01-01

    Cutaneous ciliated cyst was described as a painless cyst occurring on the lower limbs of women between the ages of 15 and 30 years. The cysts are typically lined by ciliated cuboidal to columnar epithelium with pseudostratified areas and focal squamous metaplasia is occasionally present. Immunohistochemical studies have demonstrated that the cysts are PR and ER positive, similar to the epithelia of the fallopian tubes. However, outliers of cutaneous ciliated cysts, including those in male patients and in unexpected locations such as the scalp, finger, and scapular area, have been reported. Thus, some hypotheses have been proposed including the Mullerian heterotopias, ciliated metaplasia of eccrine sweat glands, and embryonic remnants of the cloacal membrane. We report a rare case of cutaneous ciliated cyst on the left shoulder of a 7-year-old boy and this is the eighth case of cutaneous ciliated cyst in male patients. Moreover, through reviewing the articles, we try to propose the classification of the cutaneous ciliated cysts into the cutaneous Mullerian cysts and the ciliated cutaneous eccrine cysts. PMID:26491452

  7. The Cutaneous Ciliated Cyst in Young Male: The Possibility of Ciliated Cutaneous Eccrine Cyst

    Directory of Open Access Journals (Sweden)

    Youngjoon Kim

    2015-01-01

    Full Text Available Cutaneous ciliated cyst was described as a painless cyst occurring on the lower limbs of women between the ages of 15 and 30 years. The cysts are typically lined by ciliated cuboidal to columnar epithelium with pseudostratified areas and focal squamous metaplasia is occasionally present. Immunohistochemical studies have demonstrated that the cysts are PR and ER positive, similar to the epithelia of the fallopian tubes. However, outliers of cutaneous ciliated cysts, including those in male patients and in unexpected locations such as the scalp, finger, and scapular area, have been reported. Thus, some hypotheses have been proposed including the Mullerian heterotopias, ciliated metaplasia of eccrine sweat glands, and embryonic remnants of the cloacal membrane. We report a rare case of cutaneous ciliated cyst on the left shoulder of a 7-year-old boy and this is the eighth case of cutaneous ciliated cyst in male patients. Moreover, through reviewing the articles, we try to propose the classification of the cutaneous ciliated cysts into the cutaneous Mullerian cysts and the ciliated cutaneous eccrine cysts.

  8. Mating of the stichotrichous ciliate Oxytricha trifallax induces production of a class of 27 nt small RNAs derived from the parental macronucleus.

    Directory of Open Access Journals (Sweden)

    Alan M Zahler

    Full Text Available Ciliated protozoans possess two types of nuclei; a transcriptionally silent micronucleus, which serves as the germ line nucleus, and a transcriptionally active macronucleus, which serves as the somatic nucleus. The macronucleus is derived from a new diploid micronucleus after mating, with epigenetic information contributed by the parental macronucleus serving to guide the formation of the new macronucleus. In the stichotrichous ciliate Oxytricha trifallax, the macronuclear DNA is highly processed to yield gene-sized nanochromosomes with telomeres at each end. Here we report that soon after mating of Oxytricha trifallax, abundant 27 nt small RNAs are produced that are not present prior to mating. We performed next generation sequencing of Oxytricha small RNAs from vegetative and mating cells. Using sequence comparisons between macronuclear and micronuclear versions of genes, we found that the 27 nt RNA class derives from the parental macronucleus, not the developing macronucleus. These small RNAs are produced equally from both strands of macronuclear nanochromosomes, but in a highly non-uniform distribution along the length of the nanochromosome, and with a particular depletion in the 30 nt telomere-proximal positions. This production of small RNAs from the parental macronucleus during macronuclear development stands in contrast to the mechanism of epigenetic control in the distantly related ciliate Tetrahymena. In that species, 28-29 nt scanRNAs are produced from the micronucleus and these micronuclear-derived RNAs serve as epigenetic controllers of macronuclear development. Unlike the Tetrahymena scanRNAs, the Oxytricha macronuclear-derived 27 mers are not modified by 2'O-methylation at their 3' ends. We propose models for the role of these "27macRNAs" in macronuclear development.

  9. Imaging features of ciliated hepatic foregut cyst

    Institute of Scientific and Technical Information of China (English)

    Song-Hua Fang; Dan-Jun Dong; Shi-Zheng Zhang

    2005-01-01

    Ciliated hepatic foregut cyst (CHFC) is a very rare cystic lesion of the liver that is histologically similar to bronchogenic cyst. We report one case of CHFC that was hard to distinguish from solid-cystic neoplasm in imaging features. Magnetic resonance imaging was helpful in differentiating these cysts from other lesions.

  10. GENETIC RELATIONSHIPS OF FIVE CILIATE STRAINS INFERRED FROM ISSR ANALYSIS%五株纤毛虫遗传关系的ISSR分析

    Institute of Scientific and Technical Information of China (English)

    张文静; 余育和; 沈韫芬

    2005-01-01

    采用ISSR分子标记技术,尝试对四种五株纤毛虫(褶累枝虫(Epistylis plicatilis)、绿草履虫(Paramecium bursaria)、多态喇叭虫(Stentor polymorphus)、嗜热四膜虫BF1株(Tetrahymena thermophila BF1)和嗜热四膜虫BF5株(T.thermophila BF5))进行遗传关系研究.用13个ISSR引物对五株纤毛虫进行扩增,六个ISSR引物获得多态片段.根据Nei's遗传距离矩阵构建了五株纤毛虫的遗传关系树状图.UPGMA,NJ聚类图表明:两株嗜热四膜虫最先聚在一起;其次是褶累枝虫和多态喇叭虫聚在一起,然后再与嗜热四膜虫聚在一起;咽膜亚纲的绿草履虫形成独立的一枝.结果显示:①缘毛亚纲纤毛虫可能是寡膜纲中较独特的一个类群,建议提升缘毛亚纲纤毛虫的分类地位;②缘毛亚纲褶累枝虫与膜口亚纲嗜热四膜虫的亲缘关系近于咽膜亚纲绿草履虫,在寡膜纲中绿草履虫处于原始地位;③五株纤毛虫基因组中均含有微卫星DNA序列:(GTG)4、(GACA)4、(AG)8、(CAA)6和(GAA)6.

  11. QSTR with extended topochemical atom (ETA) indices. 14. QSAR modeling of toxicity of aromatic aldehydes to Tetrahymena pyriformis

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Kunal, E-mail: kunalroy_in@yahoo.com [Drug Theoretics and Cheminformatics Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700 032 (India); Das, Rudra Narayan [Drug Theoretics and Cheminformatics Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700 032 (India)

    2010-11-15

    Aldehydes are a toxic class of chemicals causing severe health hazards. In this background, quantitative structure-toxicity relationship (QSTR) models have been developed in the present study using Extended Topochemical Atom (ETA) indices for a large group of 77 aromatic aldehydes for their acute toxicity against the protozoan ciliate Tetrahymena pyriformis. The ETA models have been compared with those developed using various non-ETA topological indices. Attempt was also made to include the n-octanol/water partition coefficient (log K{sub o/w}) as an additional descriptor considering the importance of hydrophobicity in toxicity prediction. Thirty different models were developed using different chemometric tools. All the models have been validated using internal validation and external validation techniques. The statistical quality of the ETA models was found to be comparable to that of the non-ETA models. The ETA models have shown the important effects of steric bulk, lipophilicity, presence of electronegative atom containing substituents and functionality of the aldehydic oxygen to the toxicity of the aldehydes. The best ETA model (without using log K{sub o/w}) shows encouraging statistical quality (Q{sub int}{sup 2}=0.709,Q{sub ext}{sup 2}=0.744). It is interesting to note that some of the topological models reported here are better in statistical quality than previously reported models using quantum chemical descriptors.

  12. Gene : CBRC-PABE-17-0002 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available aining protein [Tetrahymena thermophila SB210] 1e-10 32% MYVRPPVAICPILCVLSLWGSNRMYVRPPGAICPILCVFSLWGSNHMYVRPPGAICPI...LCVLSLWGANRMYVRPPVAICPILCVLSLWGSNRMYVRPPGAICPILCVFSLWGSNHMYVRPPGAICPILCVLSLWGSNHRYLRPPGAICPI...LCVFSLWGSNHMYVRPPGAICPILCVLSLWGSNHRYVRPPGAIPHVIEALLISIFFLFVL ...

  13. Ultrastructure of the rumen ciliate Dasytricha ruminantium.

    Science.gov (United States)

    Gordon Paul, R; Butler, R D; Williams, A G

    1989-04-14

    The ciliate Dasytricha ruminantium possesses cilia over the entire surface. Both the oral and somatic kineties are composed of monokinetids comprising a kinetosome, a tangential ribbon of 5 transverse microtubules, a weakly convergent bundle of 5 postciliary microtubules, a short kinetodesmal fibre, and a single microtubule homologous to T(2) of other litostomate ciliates [15]. The reversed orientation of the kineties within and around the vestibulum may be a consequence of the evolutionary migration of the vestibulum from the anterior to the posterior of the cell. The vestibulum leads to the cytostome and a cytopharynx of the rhabdos type [3]. Microtubules lining the exit canals of the posterior contractile vacuole and cytoproct are believed to originate from somatic kinetids. The ecto-endoplasmic boundary layer (eeb) is composed of two microfibrillar layers. A large extension of the eeb connects the vestibulum to the cell cortex but does not form a karyophore as seen in the closely related genus Isotricha [12].

  14. Ciliates and the rare biosphere: a review.

    Science.gov (United States)

    Dunthorn, Micah; Stoeck, Thorsten; Clamp, John; Warren, Alan; Mahé, Frédéric

    2014-01-01

    Here we provide a brief review of the rare biosphere from the perspective of ciliates and other microbial eukaryotes. We trace research on rarity from its lack of much in-depth focus in morphological and Sanger sequencing projects, to its central importance in analyses using high throughput sequencing strategies. The problem that the rare biosphere is potentially comprised of mostly errors is then discussed in the light of asking community-comparative, novel-diversity, and ecosystem-functioning questions.

  15. Draft Genome Sequence of the Moderately Thermophilic Bacterium Schleiferia thermophila Strain Yellowstone (Bacteroidetes).

    Science.gov (United States)

    Thiel, Vera; Hamilton, Trinity L; Tomsho, Lynn P; Burhans, Richard; Gay, Scott E; Ramaley, Robert F; Schuster, Stephan C; Steinke, Laurey; Bryant, Donald A

    2014-08-28

    The draft genome sequence of the moderately thermophilic bacterium Schleiferia thermophila strain Yellowstone (Bacteroidetes), isolated from Octopus Spring (Yellowstone National Park, WY, USA) was sequenced and comprises 2,617,694 bp in 35 contigs. The draft genome is predicted to encode 2,457 protein coding genes and 37 tRNA encoding genes and two rRNA operons.

  16. First report of folliculinid ciliates affecting Caribbean scleractinian corals

    Science.gov (United States)

    Cróquer, A.; Bastidas, C.; Lipscomp, D.; Rodríguez-Martínez, R. E.; Jordan-Dahlgren, E.; Guzman, H. M.

    2006-05-01

    This is the first report of a ciliate of the genus Halofolliculina infecting hard coral species of six families (Acroporidae, Agaricidae, Astrocoeniidae, Faviidae, Meandrinidae and Poritidae) and milleporids in the Caribbean. Surveys conducted during 2004 2005 in Venezuela, Panama and México confirmed that this ciliate affects up to 25 scleractinian species. The prevalence of this ciliate at the coral community level was variable across sites, being most commonly found at Los Roques, Venezuela, and at Bocas del Toro, Panama (prevalence 0.2 2.5%), but rarely observed in the Mexican Caribbean. Ciliates were more prevalent within populations of acroporids ( Acropora palmata, Acropora cervicornis and Acropora prolifera) in Los Roques. Recent observations also corroborate the presence of these ciliates in Curacao and Puerto Rico. Our observations indicate that ciliates affecting corals have a wider distribution than previously thought, and are no longer exclusively found in the Indo-Pacific and Red Sea.

  17. Effects of various environmental conditions on the transformation of chlorinated solvents by Methanosarcina thermophila cell exudates.

    Science.gov (United States)

    Baeseman, J L; Novak, P J

    2001-12-20

    Several microbiologically produced biomolecules have been shown to degrade chlorinated contaminants found in groundwater systems. It was discovered that the cell-free exudates of the methanogen Methanosarcina thermophila were capable of carbon tetrachloride (CT) and chloroform (CF) degradation. Characterization of the exudates suggested that the active agents were porphorinogen-type molecules, possibly containing zinc. This research was performed to determine if the exudates from M. thermophila could be used for remediation purposes. The cell exudates were found to be capable of degrading CT, CF, tetrachloroethene, trichloroethene, and 1,1,1-trichloroethane. CT degradation was used to gauge exudate activity under a variety of conditions that would be encountered in the environment. The cell exudates were active when incubated in two types of soil matrices and at temperatures ranging from 4 to 23 degrees C. Over a 35-day period approximately 10.2 micromoles of CT were degraded by M. thermophila exudates. To test the hypothesis that the exudates contained either a zinc porphorinogen or a quinone, experiments were performed with zinc 5,10,15,20-tetra (4-pyridyl)-21 H, 23 H-porphine tetrakis, protoporphyrin IX zinc, and juglone. The two zinc porphyrins were capable of mediating CT degradation at rates comparable to those observed with the M. thermophila exudates; however, juglone was only capable of very slow CT transformation. The electron-transfer activity of the M. thermophila cell exudates was therefore more consistent with the activity of porphorinogens rather than quinones. Finally, in two enrichment cultures established from aquifer material and marine sediment, the possibility of excreted agents capable of degrading CT was evident.

  18. Biodiversity patterns of soil ciliates along salinity gradients.

    Science.gov (United States)

    Zhao, Feng; Xu, Kuidong

    2016-04-01

    We evaluated ciliate diversity in saline soils with a salinity range from 6.5 to 65 psu by the morphological method of the Ludox-quantitative protargol stain (QPS) and the molecular techniques of ciliate-specific clone library and denaturing gradient gel electrophoresis. No active ciliates could be detected with the Ludox-QPS method, while high molecular diversity of ciliates was found. The highest ciliate molecular diversity was obtained from the soil at salinity of 8.9 psu, moderate diversity was found at salinity of 6.5 psu, and the diversity sharply decreased at salinity of 50.5 psu. By contrast, the number of ciliate classes clearly decreased with increasing soil salinity: six, five, four and two classes from sites with salinity of 6.5 psu, 8.9 psu, 29.5 psu and 50.5 psu, respectively. Ciliate diversity pattern is different from that of bacteria, whose diversity is also high in extremely saline environments. Meanwhile, the composition of ciliate community was significantly different along salinity gradient. Colpodea and Oligohymenophorea were diverse in soils at salinity less than 29.5 psu, while absent in soils with salinity above 50.5 psu. BIOENV analysis indicated soil salinity and water content were the main factors regulating the distribution of ciliates in saline soils.

  19. 8-Methoxypsoralen DNA interstrand cross-linking of the ribosomal RNA genes in Tetrahymena thermophila. Distribution, repair and effect on rRNA synthesis

    DEFF Research Database (Denmark)

    Fengquin, X; Nielsen, Henrik; Zhen, W;

    1993-01-01

    between three domains (terminal spacer, transcribed region and central spacer) as defined by restriction enzyme analysis (BamHI and ClaI). It is furthermore shown that a dosage resulting in approximately one cross-link per rDNA molecule (21 kbp, two genes) is sufficient to block RNA synthesis. Finally...

  20. Reality-and-Desire in Ciliates

    Science.gov (United States)

    Brijder, Robert; Hoogeboom, Hendrik Jan

    The theory of gene assembly in ciliates has a number of similarities with the theory of sorting by reversal. Both theories model processes that are based on splicing, and have a fixed begin and end product. The main difference is the type of splicing operations used to obtain the end product from the begin product. In this overview paper, we show how the concept of breakpoint graph, known from the theory of sorting by reversal, can be used in the theory of gene assembly. Our aim is to present the material in an intuitive and informal manner to allow for an efficient introduction into the subject.

  1. Structure and folding of the Tetrahymena telomerase RNA pseudoknot

    Science.gov (United States)

    Cash, Darian D.; Feigon, Juli

    2017-01-01

    Telomerase maintains telomere length at the ends of linear chromosomes using an integral telomerase RNA (TER) and telomerase reverse transcriptase (TERT). An essential part of TER is the template/pseudoknot domain (t/PK) which includes the template, for adding telomeric repeats, template boundary element (TBE), and pseudoknot, enclosed in a circle by stem 1. The Tetrahymena telomerase holoenzyme catalytic core (p65-TER-TERT) was recently modeled in our 9 Å resolution cryo-electron microscopy map by fitting protein and TER domains, including a solution NMR structure of the Tetrahymena pseudoknot. Here, we describe in detail the structure and folding of the isolated pseudoknot, which forms a compact structure with major groove U•A-U and novel C•G-A+ base triples. Base substitutions that disrupt the base triples reduce telomerase activity in vitro. NMR studies also reveal that the pseudoknot does not form in the context of full-length TER in the absence of TERT, due to formation of a competing structure that sequesters pseudoknot residues. The residues around the TBE remain unpaired, potentially providing access by TERT to this high affinity binding site during an early step in TERT-TER assembly. A model for the assembly pathway of the catalytic core is proposed. PMID:27899638

  2. Dynamics of Tetrahymena macronuclear lamina during cell division

    Institute of Scientific and Technical Information of China (English)

    CHENBIN; ZHONGHEZHAI

    1994-01-01

    During mitosis,the nuclear lamina in higher eukaryotic cells undergoes a distinctly morphological change.It breaks down into lamin polymers or monomers at prophase.At telophase,the lamins reassemble around the condensed chromatin to form the layer of lamina.Using antiserum to mammalian lamins,we studied the dynamics of lamina during cell division in the macronuleus of Tetrahymena shanghaiensis,which divided in the way of amitosis.In contrast to those in higher animal cells,the typical perinuclear lamin distribution in the macronucleus persisted throughout the whole cell cycle.It was further found that in some synchronized cells,the lamin distribution bisplayed an unusual pattern consisting of a series of spots within the macronucleus.Using South-western hybridization,we found that the purified 66 KD lamin in Tetrahymena showed specific affinity with the telomere DNA sequence in the same species.Therefore,we propose that pattern of immunofluorescence may be due to the interaction of lamin protein with the nucleoli and the condensed chromatins in the macronucleus.

  3. Molecular mechanisms of thermal resistance of the insect trypanosomatid Crithidia thermophila

    Science.gov (United States)

    Ishemgulova, Aygul; Butenko, Anzhelika; Kortišová, Lucie; Boucinha, Carolina; Grybchuk-Ieremenko, Anastasiia; Morelli, Karina A.; Tesařová, Martina; Kraeva, Natalya; Grybchuk, Danyil; Pánek, Tomáš; Flegontov, Pavel; Lukeš, Julius; Votýpka, Jan; Pavan, Márcio Galvão; Opperdoes, Fred R.; Spodareva, Viktoria; d'Avila-Levy, Claudia M.; Kostygov, Alexei Yu.

    2017-01-01

    In the present work, we investigated molecular mechanisms governing thermal resistance of a monoxenous trypanosomatid Crithidia luciliae thermophila, which we reclassified as a separate species C. thermophila. We analyzed morphology, growth kinetics, and transcriptomic profiles of flagellates cultivated at low (23°C) and elevated (34°C) temperature. When maintained at high temperature, they grew significantly faster, became shorter, with genes involved in sugar metabolism and mitochondrial stress protection significantly upregulated. Comparison with another thermoresistant monoxenous trypanosomatid, Leptomonas seymouri, revealed dramatic differences in transcription profiles of the two species with only few genes showing the same expression pattern. This disparity illustrates differences in the biology of these two parasites and distinct mechanisms of their thermotolerance, a prerequisite for living in warm-blooded vertebrates. PMID:28328988

  4. Population dynamics of active and total ciliate populations in arable soil amended with wheat

    DEFF Research Database (Denmark)

    Ekelund, F.; Frederiksen, Helle B.; Ronn, R.

    2002-01-01

    of ciliate growth, the population of cystic ciliates increased 100-fold. We suggest that internal population regulation is the major factor governing ciliate encystment and that the rate of encystment depends on ciliate density. This model provides a quantitative explanation of ciliatostasis and can explain...

  5. SPECIES COMPOSITION OF PSAMMOPHILIC CILIATES OF SUMGAIT CASPIAN COAST

    Directory of Open Access Journals (Sweden)

    I. Kh. Alekperov

    2014-01-01

    Full Text Available Abstract. Comparative data on the species composition and species saprobic indicators of the psammon ciliates from Sumgait coast of the Caspian Sea are given.Methods. “Alive” samples were collected using a small clean plastic wide mouth bottles. Further processing was carried out under laboratory conditions. Small quantities of soil were examined under a binocular microscope MBS-9 . Ciliates detected microvessel caught and fixed castors for further impregnation kinetoma silver nitrate (Chatton et Lwoff, 1930 or silver proteinate. To determine the keys for ciliates used Foyssner’s major publications (Foissner et al., 1991, 1992, 1999 and “Free-living ciliates Atlas” (Alekperov, 2005.Results. We observed 75 species of ciliates during the studies, which species composition and distribution of the collection points are shown in table 1. Diagrams with average data were made relations groups psammophilous ciliates indicators saprobity different zones for each of the sites investigated Sumgait coast.Main conclusions. Environmental analysis using benthic ciliates indicators saprobity different zones showed that as expected, the industrial zone of Sumgayit coast coast, despite the decline in recent years, the total amount of pollution that is still highly contaminated portion of the coastal zone of the Caspian Sea.

  6. Vacuum ultraviolet photolysis of diclofenac and the effects of its treated aqueous solutions on the proliferation and migratory responses of Tetrahymena pyriformis

    Energy Technology Data Exchange (ETDEWEB)

    Arany, Eszter [Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Rerrich Béla tér 1 (Hungary); Láng, Júlia [Department of Genetics, Cell- and Immunobiology, Semmelweis University, H-1089 Budapest, Nagyvárad tér 4 (Hungary); Somogyvári, Dávid [Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Rerrich Béla tér 1 (Hungary); Láng, Orsolya [Department of Genetics, Cell- and Immunobiology, Semmelweis University, H-1089 Budapest, Nagyvárad tér 4 (Hungary); Alapi, Tünde [Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Rerrich Béla tér 1 (Hungary); Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7 (Hungary); Ilisz, István [Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7 (Hungary); and others

    2014-01-01

    The effects of dissolved O{sub 2}, phosphate buffer and the initial concentration of diclofenac on the vacuum ultraviolet photolysis of this contaminant molecule were studied. Besides kinetic measurements, the irradiated, multicomponent samples were characterized via the proliferation and migratory responses (in sublethal concentrations) of the bioindicator eukaryotic ciliate Tetrahymena pyriformis. The results suggest that hydroxyl radicals, hydrogen atoms and hydroperoxyl radicals may all contribute to the degradation of diclofenac. The aromatic by-products of diclofenac were presumed to include a hydroxylated derivative, 1-(8-chlorocarbazolyl)acetic acid and 1-(8-hydroxycarbazolyl)acetic acid. The biological activity of photoexposed samples reflected the chemical transformation of diclofenac and was also dependent on the level of dissolved O{sub 2}. The increase in toxicity of samples taken after different irradiation times did not exceed a factor of two. Our results suggest that the combination of vacuum ultraviolet photolysis with toxicity and chemotactic measurements can be a valuable method for the investigation of the elimination of micropollutants. - Highlights: • The radical-scavenging effect of phosphates seems to be negligible. • Only higher concentrations of HO{sub 2}{sup ·} contribute to the degradation of diclofenac. • Toxicity of VUV-treated samples decreases with increasing rate of mineralization. • Dissolved O{sub 2} enhances the mineralization of diclofenac by affecting the radical set. • Treated samples retain the chemorepellent character of the parent compound.

  7. Tetrahymena pyriformis cells are deficient in all mannose-P-dolichol-dependent mannosyltransferases but not in mannose-P-dolichol synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Yagodnik, C.; de la Canal, L.; Parodi, A.J.

    1987-09-08

    Cells of the ciliated protozoan Tetrahymena pyriformis incubated with (/sup 14/C)glucose were found to synthesize Man-P-dolichol and Glc-P-dolichol, as well as Glc/sub 3/Man/sub 5/GlcNAc/sub 2/-P-P-dolichol, the latter being the main and largest lipid derivative formed. The missing mannose residues were those known to be transferred from Man-P-dolichol in other systems. Formation of Man-P-dolichol and of dolichol-P-P-oligosaccharides containing up to five mannose units was detected in cell-free assays containing protozoan membranes, rat liver dolichol-P, unlabeled Man/sub 4-9/GlcNAc/sub 2/-P-P-dolichol from pig liver, and GDP-(/sup 14/C)Man. Under exactly the same conditions but with UDP-(/sup 14/C)Glc instead of GDP-(/sup 14/C)Man, Glc-P-dolichol and dolichol-P-P-oligosaccharides containing five mannose and one to three glucose residues were formed in the absence of the pig liver compounds. In the presence of the latter, dolichol-P-P derivatives containing nine mannose and one to three glucose units were also synthesized. It is concluded that T. pyriformis cells are deficient in all Man-P-dolichol-dependent mannosyltransferases but not in Man-P-dolichol synthesis. The role of the latter compound in this microorganism is unknown.

  8. Studies on experimental culture of a marine ciliate Fabrea salina

    Digital Repository Service at National Institute of Oceanography (India)

    Rattan, R.; Ansari, Z.A.; Chatterji, A.

    Studies were conducted on the culture of a marine ciliate, Fabrea salina in the laboratory condition. Three types of inert feed; commercial yeast, fermented wheat bran and fermented rise bran were tested to study their suitability as artificial feed...

  9. Impact of Soil Texture on Soil Ciliate Communities

    Science.gov (United States)

    Chau, J. F.; Brown, S.; Habtom, E.; Brinson, F.; Epps, M.; Scott, R.

    2014-12-01

    Soil water content and connectivity strongly influence microbial activities in soil, controlling access to nutrients and electron acceptors, and mediating interactions between microbes within and between trophic levels. These interactions occur at or below the pore scale, and are influenced by soil texture and structure, which determine the microscale architecture of soil pores. Soil protozoa are relatively understudied, especially given the strong control they exert on bacterial communities through predation. Here, ciliate communities in soils of contrasting textures were investigated. Two ciliate-specific primer sets targeting the 18S rRNA gene were used to amplify DNA extracted from eight soil samples collected from Sumter National Forest in western South Carolina. Primer sets 121F-384F-1147R (semi-nested) and 315F-959R were used to amplify soil ciliate DNA via polymerase chain reaction (PCR), and the resulting PCR products were analyzed by gel electrophoresis to obtain quantity and band size. Approximately two hundred ciliate 18S rRNA sequences were obtained were obtained from each of two contrasting soils. Sequences were aligned against the NCBI GenBank database for identification, and the taxonomic classification of best-matched sequences was determined. The ultimate goal of the work is to quantify changes in the ciliate community under short-timescale changes in hydrologic conditions for varying soil textures, elucidating dynamic responses to desiccation stress in major soil ciliate taxa.

  10. Effect of Pivotal Environmental Factors on Intracellular Proliferation of Legionella pneumophila within Tetrahymena thermophila BF1%关键环境因子对嗜肺军团菌(Legionella pneumophila)在嗜热四膜虫(Tetrahymena thermophila)细胞内增殖的影响

    Institute of Scientific and Technical Information of China (English)

    黄绍松; 徐润林; 马林; 冯文如; 何晖; 陆勇军

    2007-01-01

    嗜肺军团菌是一种生活在人工水环境中的条件性致病菌,环境条件对该菌的存活和胞内增殖具有重要的影响.本文用作者建立的军团菌-四膜虫模型,研究了空调水池水、Fe3+和感染温度3种关键性环境因子对嗜肺军团菌在嗜热四膜虫宿主细胞内增殖的影响.结果发现,尽管空调水中Fe3+浓度大大低于培养基中的Fe3+浓度,但适合嗜肺军团菌在嗜热四膜虫宿主胞内的存活和增殖;感染缓冲液中的Fe3+能够被嗜热四膜虫富集,并被胞内的军团菌加以利用,缓冲液中浓度0.05×10-6的Fe3+即可显著促进胞内军团菌的增殖,但0.1×10-6和0.5×10-6的Fe3+促进军团菌胞内增殖的效果差异不显著;较高的温度对军团菌的胞内增殖也有明显促进作用,35℃时,即使感染复数等于10,军团菌也可进行胞内复制扩增,并最终裂解宿主细胞.图7表1参17

  11. Synthesis of acetyl coenzyme A by carbon monoxide dehydrogenase complex from acetate-grown Methanosarcina thermophila.

    OpenAIRE

    Abbanat, D R; Ferry, J G

    1990-01-01

    The carbon monoxide dehydrogenase (CODH) complex from Methanosarcina thermophila catalyzed the synthesis of acetyl coenzyme A (acetyl-CoA) from CH3I, CO, and coenzyme A (CoA) at a rate of 65 nmol/min/mg at 55 degrees C. The reaction ended after 5 min with the synthesis of 52 nmol of acetyl-CoA per nmol of CODH complex. The optimum temperature for acetyl-CoA synthesis in the assay was between 55 and 60 degrees C; the rate of synthesis at 55 degrees C was not significantly different between pHs...

  12. The mitochondrial genome sequence of the ciliate Paramecium caudatum reveals a shift in nucleotide composition and codon usage within the genus Paramecium

    Directory of Open Access Journals (Sweden)

    Berendonk Thomas U

    2011-05-01

    Full Text Available Abstract Background Despite the fact that the organization of the ciliate mitochondrial genome is exceptional, only few ciliate mitochondrial genomes have been sequenced until today. All ciliate mitochondrial genomes are linear. They are 40 kb to 47 kb long and contain some 50 tightly packed genes without introns. Earlier studies documented that the mitochondrial guanine + cytosine contents are very different between Paramecium tetraurelia and all studied Tetrahymena species. This raises the question of whether the high mitochondrial G+C content observed in P. tetraurelia is a characteristic property of Paramecium mtDNA, or whether it is an exception of the ciliate mitochondrial genomes known so far. To test this question, we determined the mitochondrial genome sequence of Paramecium caudatum and compared the gene content and sequence properties to the closely related P. tetraurelia. Results The guanine + cytosine content of the P. caudatum mitochondrial genome was significantly lower than that of P. tetraurelia (22.4% vs. 41.2%. This difference in the mitochondrial nucleotide composition was accompanied by significantly different codon usage patterns in both species, i.e. within P. caudatum clearly A/T ending codons dominated, whereas for P. tetraurelia the synonymous codons were more balanced with a higher number of G/C ending codons. Further analyses indicated that the nucleotide composition of most members of the genus Paramecium resembles that of P. caudatum and that the shift observed in P. tetraurelia is restricted to the P. aurelia species complex. Conclusions Surprisingly, the codon usage bias in the P. caudatum mitochondrial genome, exemplified by the effective number of codons, is more similar to the distantly related T. pyriformis and other single-celled eukaryotes such as Chlamydomonas, than to the closely related P. tetraurelia. These differences in base composition and codon usage bias were, however, not reflected in the amino

  13. Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection.

    Science.gov (United States)

    Sharon, G; Pimenta-Leibowitz, M; Vilchis, M C L; Isakov, N; Zilberg, D

    2015-01-01

    Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non-stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI-, NI- and I-treated groups (94.5, 64 and 62.3 μg mg(-1), respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re-infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3-75%, higher than in the non-exposed control (40.6% mortality).

  14. Autophagy prevents autophagic cell death in Tetrahymena in response to oxidative stress.

    Science.gov (United States)

    Zhang, Si-Wei; Feng, Jiang-Nan; Cao, Yi; Meng, Li-Ping; Wang, Shu-Lin

    2015-05-18

    Autophagy is a major cellular pathway used to degrade long-lived proteins or organelles that may be damaged due to increased reactive oxygen species (ROS) generated by cellular stress. Autophagy typically enhances cell survival, but it may also act to promote cell death under certain conditions. The mechanism underlying this paradox, however, remains unclear. We showed that Tetrahymena cells exerted increased membrane-bound vacuoles characteristic of autophagy followed by autophagic cell death (referred to as cell death with autophagy) after exposure to hydrogen peroxide. Inhibition of autophagy by chloroquine or 3-methyladenine significantly augmented autophagic cell death induced by hydrogen peroxide. Blockage of the mitochondrial electron transport chain or starvation triggered activation of autophagy followed by cell death by inducing the production of ROS due to the loss of mitochondrial membrane potential. This indicated a regulatory role of mitochondrial ROS in programming autophagy and autophagic cell death in Tetrahymena. Importantly, suppression of autophagy enhanced autophagic cell death in Tetrahymena in response to elevated ROS production from starvation, and this was reversed by antioxidants. Therefore, our results suggest that autophagy was activated upon oxidative stress to prevent the initiation of autophagic cell death in Tetrahymena until the accumulation of ROS passed the point of no return, leading to delayed cell death in Tetrahymena.

  15. The role of ciliate protozoa in the rumen

    Directory of Open Access Journals (Sweden)

    Charles James Newbold

    2015-11-01

    Full Text Available First described in 1843, Rumen protozoa with their striking appearance were assumed to be important for the welfare of their host. However, despite contributing up to 50% of the bio-mass in the rumen, the role of protozoa in rumen microbial ecosystem remains unclear.Phylogenetic analysis of 18S rDNA libraries generated from the rumen of cattle, sheep, and goats has revealed an unexpected diversity of ciliated protozoa although variation in gene copy number between species makes it difficult to obtain absolute quantification. Despite repeated attempts it has proven impossible to maintain rumen protozoa in axenic culture. Thus it has been difficult to establish conclusively a role of ciliate protozoa in rumen fibre degradation. The development of techniques to clone and express ciliate genes in  phage, together with bioinformatic indices to confirm the ciliate origin of the genes has allowed the isolation and characterisation of fibrolytic genes from rumen protozoa. Elimination of the ciliate protozoa increases microbial protein supply by up to 30% and reduces methane production by up to 11%. Our recent findings suggest that holotrich protozoa play a disproportionate role in supporting methanogenesis whilst the small entodiniium are responsible for much of the bacterial protein turnover. As yet no method to control protozoa in the rumen that is safe and practically applicable has been developed, however a range of plant extract capable of controlling if not completely eliminating rumen protozoa have been described.

  16. The Role of Ciliate Protozoa in the Rumen.

    Science.gov (United States)

    Newbold, Charles J; de la Fuente, Gabriel; Belanche, Alejandro; Ramos-Morales, Eva; McEwan, Neil R

    2015-01-01

    First described in 1843, Rumen protozoa with their striking appearance were assumed to be important for the welfare of their host. However, despite contributing up to 50% of the bio-mass in the rumen, the role of protozoa in rumen microbial ecosystem remains unclear. Phylogenetic analysis of 18S rDNA libraries generated from the rumen of cattle, sheep, and goats has revealed an unexpected diversity of ciliated protozoa although variation in gene copy number between species makes it difficult to obtain absolute quantification. Despite repeated attempts it has proven impossible to maintain rumen protozoa in axenic culture. Thus it has been difficult to establish conclusively a role of ciliate protozoa in rumen fiber degradation. The development of techniques to clone and express ciliate genes in λ phage, together with bioinformatic indices to confirm the ciliate origin of the genes has allowed the isolation and characterization of fibrolytic genes from rumen protozoa. Elimination of the ciliate protozoa increases microbial protein supply by up to 30% and reduces methane production by up to 11%. Our recent findings suggest that holotrich protozoa play a disproportionate role in supporting methanogenesis whilst the small Entodinium are responsible for much of the bacterial protein turnover. As yet no method to control protozoa in the rumen that is safe and practically applicable has been developed, however a range of plant extract capable of controlling if not completely eliminating rumen protozoa have been described.

  17. Colonization dynamics of ciliate morphotypes modified by shifting sandy sediments.

    Science.gov (United States)

    Risse-Buhl, Ute; Felsmann, Katja; Mutz, Michael

    2014-08-01

    Sandy stream-bed sediments colonized by a diverse ciliate community are subject to various disturbance regimes. In microcosms, we investigated the effect of sediment shifting on the colonization dynamics of 3 ciliate morphotypes differing in morphology, behavior and feeding strategy. The dynamics of the ciliate morphotypes inhabiting sediment pore water and overlying water were observed at 3 sediment shifting frequencies: (1) stable sediments, (2) periodically shifting sediments such as migrating ripples, and (3) continuously shifting sediments as occurring during scour events of the uppermost sediment. Sediment shifting significantly affected the abundance and growth rate of the ciliate morphotypes. The free-swimming filter feeder Dexiostoma campylum was vulnerable to washout by sediment shifting since significantly higher numbers occurred in the overlying water than in pore water. Abundance of D. campylum only increased in pore water of stable sediments. On the contrary, the vagile grasper feeder Chilodonella uncinata and the sessile filter feeder Vorticella convallaria had positive growth rates and successfully colonized sediments that shifted periodically and continuously. Thus, the spatio-temporal pattern of sediment dynamics acts as an essential factor of impact on the structure, distribution and function of ciliate communities in sand-bed streams.

  18. Evaluation of guppy (Poecilia reticulata Peters) immunization against Tetrahymena sp. by enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    Sharon, Galit; Nath, Pulak R; Isakov, Noah; Zilberg, Dina

    2014-09-15

    Analysis of the effectiveness of guppy (Poecilia reticulata Peters) immunization based on measurements of antibody (Ab) titers suffers from a shortage of reagents that can detect guppy antibodies (Abs). To overcome this problem, we immunized mice with different preparations of guppy immunoglobulins (Igs) and used the mouse antisera to develop a quantitative enzyme-linked immunosorbent assay (ELISA). The most efficient immunogen for mouse immunization was guppy Igs adsorbed on protein A/G beads. Antisera from mice boosted with this immunoglobulin (Ig) preparation were highly specific and contained high Ab titers. They immunoreacted in a Western blot with Ig heavy and light chains from guppy serum, and Ig heavy chain from guppy whole-body homogenate. The mouse anti-guppy Ig was applied in an ELISA aimed at comparing the efficiency of different routes of guppy immunization against Tetrahymena: (i) anal intubation with sonicated Tetrahymena (40,000 Tetrahymena/fish in a total volume of 10 μL) mixed with domperidon, deoxycholic acid and free amino acids (valine, leucine, isoleucine, phenylalanine and tryptophan), or (ii) intraperitoneal (i.p.) injection of sonicated Tetrahymena in complete Freund's adjuvant (15,000 Tetrahymena/fish in total a volume of 20 μL). Negative control fish were anally intubated with the intubation mixture without Tetrahymena, or untreated. ELISA measurement of anti-Tetrahymena Ab titer revealed a significantly higher level of Abs in i.p.-immunized guppies, compared to the anally intubated and control fish. In addition, the efficiency of immunization was tested by monitoring guppy mortality following (i) i.p. challenge with Tetrahymena (900 Tetrahymena/fish) or (ii) cold stress followed by immersion in water containing 10,000 Tetrahymena/mL. Fish mortality on day 14 post-Tetrahymena infection by i.p. injection exceeded 50% in the control and anally intubated fish, compared to 31% in i.p.-immunized fish. Immunization did not protect from

  19. Use of 3-aminopropanol as an ethanolamine analogue in the study of phospholipid metabolism in Tetrahymena.

    Science.gov (United States)

    Smith, J D; Barrows, L J

    1988-01-01

    About 50% of the ethanolamine in phosphatidylethanolamine in Tetrahymena is replaced by 3-aminopropan-1-ol when the compound is added to the growth medium. The phosphatidylpropanolamine which is formed is not converted into the corresponding phosphatidylcholine analogue by methylation. There is an increase in phosphatidylcholine formed by the phosphotransferase pathway from free [3H]choline and a decrease in the phosphatidylcholine formed by the methylation pathway from [14C]methionine. The nature of the observed phospholipid alterations suggests that the regulation of phosphatidylcholine biosynthesis in Tetrahymena may be different from that found in higher eukaryotes. Images Fig. 1. PMID:3178752

  20. Evaluation of lugol solution used for counting rumen ciliates

    Directory of Open Access Journals (Sweden)

    Marta D'Agosto

    1999-01-01

    Full Text Available The present study proposes a modification of the technique described by PURSER & MOIR (1959 for the quantitative evaluation of rumen ciliate based on an adaptation described by DEHORITY (I984. The modifying process includes: the replacement of two drops of brilliant green dye, for at least four hours, by three drops of lugol solution, for at least 15 minutes. It was made a comparative evaluation of these stainings. It was concluded that lugol solution can replace the brilliant green dye showing the following advantages: staining time reduction and subsequent speeding of sample processing; evidence of skeletal plates of entodiniomorphs making its identification easier; improved observation of small ciliates and inconspicuous structures; improved total counting and generic identification of the ciliates.

  1. Dicty_cDB: VHE717 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available d21, 5' end. 70 3e-13 3 EV830481 |EV830481.1 TTSB084TH Tetrahymena thermophila SB210 cDNA library (Heavy metals...trahymena thermophila SB210 cDNA library (Heavy metals) Tetrahymena thermophila c

  2. Updating rDNA restriction enzyme maps of Tetrahymena reveals four new intron-containing species

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Simon, E M; Engberg, J

    1985-01-01

    The extrachromosomal rDNA molecules from a number of Tetrahymena strains were characterized by restriction enzyme mapping using three different restriction enzymes combined with gel blotting and hybridization analysis. Strains from four out of six recently described species were found to contain...

  3. An approach to measure ciliate grazing on living heterotrophic nanoflagellates

    DEFF Research Database (Denmark)

    Christoffersen, K.; González, J. M.

    2003-01-01

    . Here we present an approach for the assessment of ciliate grazing on living heterotrophic nanoflagellates. Stationary phase cultures of a heterotrophic nanoflagellate (Cafeteria sp.) were live-stained by allowing them to take up fluorescently labelled macromolecules. Controls revealed that this label...

  4. Comparative genomic analysis of the thermophilic biomass-degrading fungi Myceliophthora thermophila and Thielavia terrestris.

    Science.gov (United States)

    Berka, Randy M; Grigoriev, Igor V; Otillar, Robert; Salamov, Asaf; Grimwood, Jane; Reid, Ian; Ishmael, Nadeeza; John, Tricia; Darmond, Corinne; Moisan, Marie-Claude; Henrissat, Bernard; Coutinho, Pedro M; Lombard, Vincent; Natvig, Donald O; Lindquist, Erika; Schmutz, Jeremy; Lucas, Susan; Harris, Paul; Powlowski, Justin; Bellemare, Annie; Taylor, David; Butler, Gregory; de Vries, Ronald P; Allijn, Iris E; van den Brink, Joost; Ushinsky, Sophia; Storms, Reginald; Powell, Amy J; Paulsen, Ian T; Elbourne, Liam D H; Baker, Scott E; Magnuson, Jon; Laboissiere, Sylvie; Clutterbuck, A John; Martinez, Diego; Wogulis, Mark; de Leon, Alfredo Lopez; Rey, Michael W; Tsang, Adrian

    2011-10-02

    Thermostable enzymes and thermophilic cell factories may afford economic advantages in the production of many chemicals and biomass-based fuels. Here we describe and compare the genomes of two thermophilic fungi, Myceliophthora thermophila and Thielavia terrestris. To our knowledge, these genomes are the first described for thermophilic eukaryotes and the first complete telomere-to-telomere genomes for filamentous fungi. Genome analyses and experimental data suggest that both thermophiles are capable of hydrolyzing all major polysaccharides found in biomass. Examination of transcriptome data and secreted proteins suggests that the two fungi use shared approaches in the hydrolysis of cellulose and xylan but distinct mechanisms in pectin degradation. Characterization of the biomass-hydrolyzing activity of recombinant enzymes suggests that these organisms are highly efficient in biomass decomposition at both moderate and high temperatures. Furthermore, we present evidence suggesting that aside from representing a potential reservoir of thermostable enzymes, thermophilic fungi are amenable to manipulation using classical and molecular genetics.

  5. Comparative genomic analysis of the thermophilic biomass-degrading fungi Myceliophthora thermophila and Thielavia terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Berka, Randy M.; Grigoriev, Igor V.; Otillar, Robert; Salamov, Asaf; Grimwood, Jane; Reid, Ian; Ishmael, Nadeeza; John, Tricia; Darmond, Corinne; Moisan, Marie-Claude; Henrissat, Bernard; Coutinho, Pedro M.; Lombard, Vincent; Natvig, Donald O.; Lindquist, Erika; Schmutz, Jeremy; Lucas, Susan; Harris, Paul; Powlowski, Justin; Bellemare, Annie; Taylor, David; Butler, Gregory; de Vries, Ronald P.; Allijn, Iris E.; van den Brink, Joost; Ushinsky, Sophia; Storms, Reginald; Powell, Amy J.; Paulsen, Ian T.; Elbourne, Liam D. H.; Baker, Scott E.; Magnuson, Jon; LaBoissiere, Sylvie; Clutterbuck, A. John; Martinez, Diego; Wogulis, Mark; de Leon, Alfredo Lopez; Rey, Michael W.; Tsang, Adrian

    2011-10-02

    Thermostable enzymes and thermophilic cell factories may afford economic advantages in the production of many chemicals and biomass-based fuels. Here we describe and compare the genomes of two thermophilic fungi, Myceliophthora thermophila and Thielavia terrestris. To our knowledge, these genomes are the first described for thermophilic eukaryotes and the first complete telomere-to-telomere genomes for filamentous fungi. Genome analyses and experimental data suggest that both thermophiles are capable of hydrolyzing all major polysaccharides found in biomass. Examination of transcriptome data and secreted proteins suggests that the two fungi use shared approaches in the hydrolysis of cellulose and xylan but distinct mechanisms in pectin degradation. Characterization of the biomass-hydrolyzing activity of recombinant enzymes suggests that these organisms are highly efficient in biomass decomposition at both moderate and high temperatures. Furthermore, we present evidence suggesting that aside from representing a potential reservoir of thermostable enzymes, thermophilic fungi are amenable to manipulation using classical and molecular genetics.

  6. Polymerization of Various Lignins via Immobilized Myceliophthora thermophila Laccase (MtL

    Directory of Open Access Journals (Sweden)

    Daniela Huber

    2016-08-01

    Full Text Available Enzymatic polymerization of lignin is an environmentally-friendly and sustainable method that is investigated for its potential in opening-up new applications of one of the most abundant biopolymers on our planet. In this work, the laccase from Myceliophthora thermophila was successfully immobilized onto Accurel MP1000 beads (67% of protein bound to the polymeric carrier and the biocatalyzed oxidation of Kraft lignin (KL and lignosulfonate (LS were carried out. Fluorescence intensity determination, phenol content analysis and size exclusion chromatography were performed in order to elucidate the extent of the polymerization reaction. The collected results show an 8.5-fold decrease of the LS samples’ fluorescence intensity after laccase-mediated oxidation and a 12-fold increase of the weight average molecular weight was obtained.

  7. Comparative genomic analysis of the thermophilic biomass-degrading fungi Myceliophthora thermophila and Thielavia terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Berka, Randy M.; Grigoriev, Igor V.; Otillar, Robert; Salamov, Asaf; Grimwood, Jane; Reid, Ian; Ishmael, Nadeeza; John, Tricia; Darmond, Corinne; Moisan, Marie-Claude; Henrissat, Bernard; Coutinho, Pedro M.; Lombard, Vincent; Natvig, Donald O.; Lindquist, Erika; Schmutz, Jeremy; Lucas, Susan; Harris, Paul; Powlowski, Justin; Bellemare, Annie; Taylor, David; Butler, Gregory; de Vries, Ronald P.; Allijn, Iris E.; van den Brink, Joost; Ushinsky, Sophia; Storms, Reginald; Powell, Amy J.; Paulsen, Ian T.; Elbourne, Liam D. H.; Baker, Scott. E.; Magnuson, Jon; LaBoissiere, Sylvie; Clutterbuck, A. John; Martinez, Diego; Wogulis, Mark; Lopez de Leon, Alfredo; Rey, Michael W.; Tsang, Adrian

    2011-05-16

    Thermostable enzymes and thermophilic cell factories may afford economic advantages in the production of many chemicals and biomass-based fuels. Here we describe and compare the genomes of two thermophilic fungi, Myceliophthora thermophila and Thielavia terrestris. To our knowledge, these genomes are the first described for thermophilic eukaryotes and the first complete telomere-to-telomere genomes for filamentous fungi. Genome analyses and experimental data suggest that both thermophiles are capable of hydrolyzing all major polysaccharides found in biomass. Examination of transcriptome data and secreted proteins suggests that the two fungi use shared approaches in the hydrolysis of cellulose and xylan but distinct mechanisms in pectin degradation. Characterization of the biomass-hydrolyzing activity of recombinant enzymes suggests that these organisms are highly efficient in biomass decomposition at both moderate and high temperatures. Furthermore, we present evidence suggesting that aside from representing a potential reservoir of thermostable enzymes, thermophilic fungi are amenable to manipulation using classical and molecular genetics.

  8. Combinatorial QSAR modeling of chemical toxicants tested against Tetrahymena pyriformis.

    Science.gov (United States)

    Zhu, Hao; Tropsha, Alexander; Fourches, Denis; Varnek, Alexandre; Papa, Ester; Gramatica, Paola; Oberg, Tomas; Dao, Phuong; Cherkasov, Artem; Tetko, Igor V

    2008-04-01

    Selecting most rigorous quantitative structure-activity relationship (QSAR) approaches is of great importance in the development of robust and predictive models of chemical toxicity. To address this issue in a systematic way, we have formed an international virtual collaboratory consisting of six independent groups with shared interests in computational chemical toxicology. We have compiled an aqueous toxicity data set containing 983 unique compounds tested in the same laboratory over a decade against Tetrahymena pyriformis. A modeling set including 644 compounds was selected randomly from the original set and distributed to all groups that used their own QSAR tools for model development. The remaining 339 compounds in the original set (external set I) as well as 110 additional compounds (external set II) published recently by the same laboratory (after this computational study was already in progress) were used as two independent validation sets to assess the external predictive power of individual models. In total, our virtual collaboratory has developed 15 different types of QSAR models of aquatic toxicity for the training set. The internal prediction accuracy for the modeling set ranged from 0.76 to 0.93 as measured by the leave-one-out cross-validation correlation coefficient ( Q abs2). The prediction accuracy for the external validation sets I and II ranged from 0.71 to 0.85 (linear regression coefficient R absI2) and from 0.38 to 0.83 (linear regression coefficient R absII2), respectively. The use of an applicability domain threshold implemented in most models generally improved the external prediction accuracy but at the same time led to a decrease in chemical space coverage. Finally, several consensus models were developed by averaging the predicted aquatic toxicity for every compound using all 15 models, with or without taking into account their respective applicability domains. We find that consensus models afford higher prediction accuracy for the

  9. On computational properties of gene assembly in ciliates

    Directory of Open Access Journals (Sweden)

    Vladimir Rogojin

    2010-11-01

    Full Text Available Gene assembly in stichotrichous ciliates happening during sexual reproduction is one of the most involved DNA manipulation processes occurring in biology. This biological process is of high interest from the computational and mathematical points of view due to its close analogy with such concepts and notions in theoretical computer science as permutation and linked list sorting and string rewriting. Studies on computational properties of gene assembly in ciliates represent a good example of interdisciplinary research contributing to both computer science and biology. We review here a number of general results related both to the development of different computational methods enhancing our understanding on the nature of gene assembly, as well as to the development of new biologically motivated computational and mathematical models and paradigms. Those paradigms contribute in particular to combinatorics, formal languages and computability theories.

  10. Ultrastructure of extrusomes in hypotrichous ciliate Pseudourostyla nova

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yao; WANG Zhengjun; ZHANG Jun; GU Fukang

    2011-01-01

    The ultrastructure of extrusomes of the hypotrichous ciliate Pseudourostyla nova was observed in scanning and transmission electron microscopy and enzyme-cytochemistry. The results show that the distribution, morphological characteristics, morphogenesis process, and extrusive process of the extrusomes in P. nova are different from the trichocysts in Paramecium, suggesting that the extrusomes of P. nova can respond to environmental stimuli, play an important role in the defense of this species, and cannot be regarded as "trichocysts". The results also suggest that the extrusomes might be originated from the Golgi apparatus and mature in the cytoplasm; after the extrusion of mature extrusomes, the residual substance might be reabsorbed and reused by the ciliate cell via food vacuoles, and take part in material recycling of the cell.

  11. Phylogeny of intestinal ciliates, including Charonina ventriculi, and comparison of microscopy and 18S rRNA gene pyrosequencing for rumen ciliate community structure analysis.

    Science.gov (United States)

    Kittelmann, Sandra; Devente, Savannah R; Kirk, Michelle R; Seedorf, Henning; Dehority, Burk A; Janssen, Peter H

    2015-04-01

    The development of high-throughput methods, such as the construction of 18S rRNA gene clone or pyrosequencing libraries, has allowed evaluation of ciliate community composition in hundreds of samples from the rumen and other intestinal habitats. However, several genera of mammalian intestinal ciliates have been described based only on morphological features and, to date, have not been identified using molecular methods. Here, we isolated single cells of one of the smallest but widely distributed intestinal ciliates, Charonina ventriculi, and sequenced its 18S rRNA gene. We verified the sequence in a full-cycle rRNA approach using fluorescence in situ hybridization and thereby assigned an 18S rRNA gene sequence to this species previously known only by its morphology. Based on its full-length 18S rRNA gene sequence, Charonina ventriculi was positioned within the phylogeny of intestinal ciliates in the subclass Trichostomatia. The taxonomic framework derived from this phylogeny was used for taxonomic assignment of trichostome ciliate 18S rRNA gene sequence data stemming from high-throughput amplicon pyrosequencing of rumen-derived DNA samples. The 18S rRNA gene-based ciliate community structure was compared to that obtained from microscopic counts using the same samples. Both methods allowed identification of dominant members of the ciliate communities and classification of the rumen ciliate community into one of the types first described by Eadie in 1962. Notably, each method is associated with advantages and disadvantages. Microscopy is a highly accurate method for evaluation of total numbers or relative abundances of different ciliate genera in a sample, while 18S rRNA gene pyrosequencing represents a valuable alternative for comparison of ciliate community structure in a large number of samples from different animals or treatment groups.

  12. Biogenic amines at a low level of evolution: Production, functions and regulation in the unicellular Tetrahymena.

    Science.gov (United States)

    Csaba, György

    2015-06-01

    The unicellular eukaryote Tetrahymena synthesize, store and secrete biogenic amines (histamine, serotonin, epinephrine, dopamine, melatonin) and also can take up amines from the milieu. It also has (G-protein-coupled) receptors (binding sites) for these amines as well, as second messengers. The factors infuencing the mentioned processes are shown. For certain amines the genes and the coded enzymes are demonstrated. The amines influence phagocytosis, cell division, ciliary regeneration, glucose metabolism and chemotaxis. There are interhormone actions between the amines, and between the amines and other hormones produced by Tetrahymena. The critical review discusses the role of amines in the early stages of evolution and compares this to their functions in mammals. It tries to give answer how and why biogenic amines were selected to hormones, and why new functions formed for them in higher ranked animals, preserving also the ancient ones.

  13. Assessment of the efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and Tetrahymena spp.

    Science.gov (United States)

    Vaerewijck, M J M; Sabbe, K; Baré, J; Spengler, H-P; Favoreel, H W; Houf, K

    2012-03-01

    The efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and two Tetrahymena spp. was determined based on the European Standard EN 1276:2009 suspension test. Trophozoite viability was assessed by determination of the membrane integrity using flow cytometry as a fast screening technique. Bovine serum albumin was added to simulate clean (0.3 g/liter) and dirty (3 g/liter) conditions. Benzalkonium chloride caused cell lysis at concentrations above 50 mg/liter under clean and dirty conditions. A concentration of 50 mg of free chlorine per liter had a strong biocidal effect on acanthamoebae and tetrahymenae after 15 min under clean and dirty conditions. Our results suggest that benzalkonium chloride and sodium hypochlorite were effective against the three microorganisms at concentrations commonly applied in the food industry.

  14. QSAR studies for the acute toxicity of nitrobenzenes to the Tetrahymena pyriformis

    Directory of Open Access Journals (Sweden)

    Wang Dan-Dan

    2014-01-01

    Full Text Available Quantitative structure-activity relationship (QSAR models play a key role in finding the relationship between molecular structures and the toxicity of nitrobenzenes to Tetrahymena pyriformis. In this work, genetic algorithm, along with partial least square (GA-PLS was employed to select optimal subset of descriptors that have significant contribution to the toxicity of nitrobenzenes to Tetrahymena pyriformis. A set of five descriptors, namely G2, HOMT, G(Cl…Cl, Mor03v and MAXDP, was used for the prediction of the toxicity of 45 nitrobenzene derivatives and then were used to build the model by multiple linear regression (MLR method. It turned out that the built model, whose stability was confirmed using the leave-one-out validation and external validation test, showed high statistical significance (R2=0.963, Q2LOO=0.944. Moreover, Y-scrambling test indicated there was no chance correlation in this model.

  15. Toxicity caused by para-substituted phenols on Tetrahymena pyriformis: The structure-activity relationships

    OpenAIRE

    Jäntschi, Lorentz; Violeta POPESCU; Bolboaca, Sorana D.

    2008-01-01

    The toxicity of thirty para-substituted phenols on Tetrahymena pyriformis was modelled using an original methodology that uses the complex structural information of the compounds. Two models were built. The methodology allows atomic properties to be assigned to toxicity based on the selection of pairs of descriptors from the entire family, which is called Molecular Descriptors Family (MDF). One model has two independent structural descriptors and the other has four. The model with four descri...

  16. Harmful Ciliates and Dominant Genus in Culture Ponds of Young Abalone

    Institute of Scientific and Technical Information of China (English)

    黄建荣; 徐润林; 廖家遗

    2004-01-01

    By using the methods of qualitative and quantitative analysis, the species composition and dominant genus of harmful, ciliates in young abalone culture ponds are studied. Totally 68 species of ciliates, belonging to 3 classes, 16 orders and 46 genus, are found. The dominant ciliate species are Aspidisca leptaspis, Vorticella sp. and Euplotes rariseta. During the young abalone cultivation, the numbers of young abalones increase first,and then show a trend of decreasing. The relationship between the density and composition of ciliates and the density of algae in the young abalone culture ponds is also discussed.

  17. Marinamoeba thermophila, a new marine heterolobosean amoeba growing at 50 degrees C.

    Science.gov (United States)

    De Jonckheere, Johan F; Baumgartner, Manuela; Opperdoes, Fred R; Stetter, Karl O

    2009-08-01

    Two amoeba strains were isolated from marine sediment taken at the same place with 18 months interval from a region of the sea floor heated by extended submarine hot springs and fumaroles. These thermophilic amoebae grow at temperatures up to 50 degrees C. Sequences of the internal transcribed spacer demonstrated that the two strains belong to the same species and are different from any genus for which sequences are known. Phylogeny using small subunit ribosomal RNA places the amoeba in the Heterolobosea. Their closest relatives are the hypersaline flagellate Pleurostomum flabellatum and the hypersaline amoeba Tulamoeba peronaphora. The freshwater amoeboflagellate genera Naegleria and Willaertia belong to the same phylogenetic clade in the Vahlkampfiidae. The new marine species does not transform into flagellates. It forms cysts, which are round to ellipsoidal with few pores. Because of their unique place in the molecular phylogenetic tree, and because there is no morphologically identical species found in the literature, these isolates are considered to be a new species and a new genus, Marinamoeba thermophila.

  18. Bioconversion of Biomass-Derived Phenols Catalyzed by Myceliophthora thermophila Laccase

    Directory of Open Access Journals (Sweden)

    Anastasia Zerva

    2016-04-01

    Full Text Available Biomass-derived phenols have recently arisen as an attractive alternative for building blocks to be used in synthetic applications, due to their widespread availability as an abundant renewable resource. In the present paper, commercial laccase from the thermophilic fungus Myceliophthora thermophila was used to bioconvert phenol monomers, namely catechol, pyrogallol and gallic acid in water. The resulting products from catechol and gallic acid were polymers that were partially characterized in respect to their optical and thermal properties, and their average molecular weight was estimated via solution viscosity measurements and GPC. FT-IR and 1H-NMR data suggest that phenol monomers are connected with ether or C–C bonds depending on the starting monomer, while the achieved molecular weight of polycatechol is found higher than the corresponding poly(gallic acid. On the other hand, under the same condition, pyrogallol was dimerized in a pure red crystalline compound and its structure was confirmed by 1H-NMR as purpurogallin. The herein studied green synthesis of enzymatically synthesized phenol polymers or biological active compounds could be exploited as an alternative synthetic route targeting a variety of applications.

  19. Prevalent ciliate symbiosis on copepods: high genetic diversity and wide distribution detected using small subunit ribosomal RNA gene.

    Science.gov (United States)

    Guo, Zhiling; Liu, Sheng; Hu, Simin; Li, Tao; Huang, Yousong; Liu, Guangxing; Zhang, Huan; Lin, Senjie

    2012-01-01

    Toward understanding the genetic diversity and distribution of copepod-associated symbiotic ciliates and the evolutionary relationships with their hosts in the marine environment, we developed a small subunit ribosomal RNA gene (18S rDNA)-based molecular method and investigated the genetic diversity and genotype distribution of the symbiotic ciliates on copepods. Of the 10 copepod species representing six families collected from six locations of Pacific and Atlantic Oceans, 9 were found to harbor ciliate symbionts. Phylogenetic analysis of the 391 ciliate 18S rDNA sequences obtained revealed seven groups (ribogroups), six (containing 99% of all the sequences) belonging to subclass Apostomatida, the other clustered with peritrich ciliate Vorticella gracilis. Among the Apostomatida groups, Group III were essentially identical to Vampyrophrya pelagica, and the other five groups represented the undocumented ciliates that were close to Vampyrophrya/Gymnodinioides/Hyalophysa. Group VI ciliates were found in all copepod species but one (Calanus sinicus), and were most abundant among all ciliate sequences obtained, indicating that they are the dominant symbiotic ciliates universally associated with copepods. In contrast, some ciliate sequences were found only in some of the copepods examined, suggesting the host selectivity and geographic differentiation of ciliates, which requires further verification by more extensive sampling. Our results reveal the wide occurrence and high genetic diversity of symbiotic ciliates on marine copepods and highlight the need to systematically investigate the host- and geography-based genetic differentiation and ecological roles of these ciliates globally.

  20. Prevalent ciliate symbiosis on copepods: high genetic diversity and wide distribution detected using small subunit ribosomal RNA gene.

    Directory of Open Access Journals (Sweden)

    Zhiling Guo

    Full Text Available Toward understanding the genetic diversity and distribution of copepod-associated symbiotic ciliates and the evolutionary relationships with their hosts in the marine environment, we developed a small subunit ribosomal RNA gene (18S rDNA-based molecular method and investigated the genetic diversity and genotype distribution of the symbiotic ciliates on copepods. Of the 10 copepod species representing six families collected from six locations of Pacific and Atlantic Oceans, 9 were found to harbor ciliate symbionts. Phylogenetic analysis of the 391 ciliate 18S rDNA sequences obtained revealed seven groups (ribogroups, six (containing 99% of all the sequences belonging to subclass Apostomatida, the other clustered with peritrich ciliate Vorticella gracilis. Among the Apostomatida groups, Group III were essentially identical to Vampyrophrya pelagica, and the other five groups represented the undocumented ciliates that were close to Vampyrophrya/Gymnodinioides/Hyalophysa. Group VI ciliates were found in all copepod species but one (Calanus sinicus, and were most abundant among all ciliate sequences obtained, indicating that they are the dominant symbiotic ciliates universally associated with copepods. In contrast, some ciliate sequences were found only in some of the copepods examined, suggesting the host selectivity and geographic differentiation of ciliates, which requires further verification by more extensive sampling. Our results reveal the wide occurrence and high genetic diversity of symbiotic ciliates on marine copepods and highlight the need to systematically investigate the host- and geography-based genetic differentiation and ecological roles of these ciliates globally.

  1. Inheritance of the group I rDNA intron in Tetrahymena pigmentosa

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Simon, E M; Engberg, J

    1992-01-01

    . In an analysis of vegetatively growing cells containing intron+ and intron- rDNA, initially in the same macronucleus, we similarly find no evidence of intron homing. During the course of this work, we observed to our surprise that progeny clones from some crosses contained three types of rDNA. One possible...... explanation is that T. pigmentosa has two rdn loci in contrast to the single locus found in T. thermophila. Some of the progeny clones from the genetic analysis were expanded for several hundred generations, and allelic assortment of the rDNA was demonstrated by subcloning analysis....

  2. Act together – implications of symbioses in aquatic ciliates

    Directory of Open Access Journals (Sweden)

    Claudia eDziallas

    2012-08-01

    Full Text Available Mutual interactions in form of symbioses can increase the fitness of organisms and provide them with the capacity to occupy new ecological niches. The formation of obligate symbioses allows for rapid evolution of new life forms including multitrophic consortia. Microbes are important components of many known endosymbioses and their short generation times and strong potential for genetic exchange may be important drivers of speciation. Hosts provide endo- and ectosymbionts with stable, nutrient-rich environments and protection from environmental stresses. This is of particular importance in aquatic ecosystems, which are often highly variable, harsh and nutrient-deficient habitats. Thus it is not surprising that symbioses are widespread in both marine and freshwater environments. Symbioses in aquatic ciliates are good model systems for exploring symbiont-host interactions. Many ciliate species are globally distributed and have been intensively studied in the context of plastid evolution. Their relatively large cell size offers an ideal habitat for numerous microorganisms with different functional traits including commensalism and parasitism. Phagocytosis facilitates the formation of symbiotic relationships, particularly since some ingested microorganisms can escape the digestion. For example, photoautotrophic algae and methanogens represent endosymbionts that greatly extend the biogeochemical functions of their hosts. Consequently, symbiotic relationships between protists and prokaryotes are widespread and often result in new ecological functions of symbiotic communities. This enables ciliates to thrive under a wide range of environmental conditions including ultraoligotrophic or anoxic habitats. We summarize the current understanding of this exciting research topic to identify the many areas in which knowledge is lacking and to stimulate future research by providing an overview on new methodologies and by formulating a number of emerging

  3. Bioassay of environmental nickel dusts in a particle feeding ciliate

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Sonneborn, J.; Leibovitz, B.; Donathan, R.; Fisher, G.L.

    1986-01-01

    The ciliated protozoan Paramecium was used to quantitate cytotoxic and genotoxic effects of nickel particles. The biological response of these eukaryotic cells to pure nickel powder and iron-nickel powder was assayed and compared to the effect of the inorganic carcinogen nickel subsulfide. Cytotoxicity was determined by the percent survival of treated cells. Genotoxicity was indicated by significant increases in the fraction of nonviable offspring (presumed index of lethal mutations) found after self-fertilization (autogamy) in parents from the nickel-treated versus neutral control groups. The cells were exposed to the dusts and the biological effects determined. Only the nickel subsulfide consistently showed a significant increase in offspring lethality.

  4. Actin evolution in ciliates (Protist, Alveolata) is characterized by high diversity and three duplication events.

    Science.gov (United States)

    Yi, Zhenzhen; Huang, Lijuan; Yang, Ran; Lin, Xiaofeng; Song, Weibo

    2016-03-01

    Ciliates possess two distinct nuclear genomes and unique genomic features, including highly fragmented chromosomes and extensive chromosomal rearrangements. Recent transcriptomic surveys have revealed that ciliates have several multi-copy genes providing an ideal template to study gene family evolution. Nonetheless, this process remains little studied in ciliated protozoa and consequently, the evolutionary patterns that govern it are not well understood. In this study, we focused on obtaining fine-scale information relative to ciliate species divergence for the first time. A total of 230 actin gene sequences were derived from this study, among which 217 were from four closely related Pseudokeronopsis species and 13 from other hypotrichous ciliates. Our investigation shows that: (1) At least three duplication events occurred in ciliates: diversification of three actin genes (Actin I, II, III) happened after the divergence of ciliate classes but before that of subclasses. And several recent and genus-specific duplications were followed within Actin I (Sterkiella, Oxytricha, Uroleptus, etc.), Actin II (Sterkiella), respectively. (2) Within the genus Pseudokeronopsis, Actin I gene duplication events happened after P. carnea and P. erythrina diverged. In contrast, in the morphologically similar species P. flava and P. rubra, the duplication event preceded diversification of the two species. The Actin II gene duplication events preceded divergence of the genus Pseudokeronopsis. (3) Phylogenetic analyses revealed that actin is suitable for resolving ciliate classes, but may not be used to infer lower taxon relationships.

  5. A BRIEF HISTORY OF CILIATE STUDIES (LATE XVII THE FIRST THIRD OF THE XX CENTURY)

    OpenAIRE

    2004-01-01

    The most prominent protistologists who worked with ciliates from the Leeuwenhoek time up to the beginning of the XX century are mentioned. Their achievements in ciliatology and especially in taxonomy of ciliates are briefly discussed on the basis of the original literature and reviews, published during the last 150 years.

  6. Grazing on autotrophic and heterotrophic picoplankton by ciliates isolated from Lake Kinneret, Israel

    NARCIS (Netherlands)

    Hadas, O.; Malinsky-Rushansky, N.; Pinkas, R.; Cappenberg, T.E.

    1998-01-01

    The rates of ingestion of three ciliates (Colpoda steinii, Cyclidium sp. and Stylonichia sp.) on fluorescently labeled heterotrophic bacteria, picocyanobacteria (Synechococcus P, CN) and a picoeukaryote isolated from Lake Kinneret were measured. Uptake values were 930, 35 and 1210 bacteria ciliate (

  7. New Primers Targeting Full-Length Ciliate 18S rRNA Genes and Evaluation of Dietary Effect on Rumen Ciliate Diversity in Dairy Cows.

    Science.gov (United States)

    Zhang, Jun; Zhao, Shengguo; Zhang, Yangdong; Sun, Peng; Bu, Dengpan; Wang, Jiaqi

    2015-12-01

    Analysis of the full-length 18S rRNA gene sequences of rumen ciliates is more reliable for taxonomical classification and diversity assessment than the analysis of partial hypervariable regions only. The objective of this study was to develop new oligonucleotide primers targeting the full-length 18S rRNA genes of rumen ciliates, and to evaluate the effect of different sources of dietary fiber (corn stover or a mixture of alfalfa hay and corn silage) and protein (mixed rapeseed, cottonseed, and/or soybean meals) on rumen ciliate diversity in dairy cows. Primers were designed based on a total of 137 previously reported ciliate 18S rRNA gene sequences. The 3'-terminal sequences of the newly designed primers, P.1747r_2, P.324f, and P.1651r, demonstrated >99% base coverage. Primer pair D (P.324f and P.1747r_2) was selected for the cloning and sequencing of ciliate 18S rRNA genes because it produced a 1423-bp amplicon, and did not amply the sequences of other eukaryotic species, such as yeast. The optimal species-level cutoff value for distinguishing between the operational taxonomic units of different ciliate species was 0.015. The phylogenetic analysis of full-length ciliate 18S rRNA gene sequences showed that distinct ciliate profiles were induced by the different sources of dietary fiber and protein. Dasytricha and Entodinium were the predominant genera in the ruminal fluid of dairy cattle, and Dasytricha was significantly more abundant in cows fed with corn stover than in cows fed with alfalfa hay and corn silage.

  8. SHORT TIME DYNAMICS OF CILIATE ABUNDANCE IN THE BOHAI SEA (CHINA)

    Institute of Scientific and Technical Information of China (English)

    张武昌; 王荣

    2002-01-01

    The ciliate community in the Bohai Sea (China) was studied from23 September to 7 October 1998. A hurricane struck the study area between the two grid station investigations, which were six days apart. Six tintinnid species(Favella panamensis, Leptotintinnus nordqvisti, Tintinnopsis butschlii, T. karajacensis, T. Radix and Wangiella dicollaria) were identified. Total cililate abundance in the surface layer ranged from 20 to 770 ind/l. In the first grid investigation, Tintinnopsis karajacensis dominated in the warm, low salinity waters at the Huanghe River mouth. Aloricate ciliate sp.1 dominated in the cold, high salinity waters in the northwest of the study area and the Bohai Strait. In the second grid investigation, T. Karajacensis almost disappeared. The abundance of aloricate ciliate sp.1 decreased drastically. The aloricate ciliate sp.2 dominatedat the Bohai Strait. The change of ciliate abundance may be due to the disturbance of hurricane.``

  9. Ecological functions of ciliated protozoa in marine ecosystem:effects on accumulation of ambient ammonia

    Institute of Scientific and Technical Information of China (English)

    Xu Henglong; Song Weibo; Zhu Mingzhuang; Wang Mei; Ma Honggang; Hu Xiaozhong

    2005-01-01

    Effects of ciliated protozoa, Euplotes vannus and Uronema marinum, on accumulation of ammonia in marine waters are detected using experimental ecological method, in order to reveal the contributions and functions of ciliates to the marine ecosystem. During experiments, the concentrations of ammonia-N, and the densities of ciliates and bacteria are measured. The results reveal that ciliates can change the procedure of ammonia accumulation by their grazing activity, and maintain ambient ammonium at low levels through interrupting the stationary phase of bacteria population growth and enhancing their growth and metabolism. The present work confirms that ciliates, as bacteria-predators, play positive roles in maintaining and improving water quality in marine ecosystems, especially in intensive mariculture biotopes.

  10. Ciliated protozoa of two antarctic lakes: analysis by quantitative protargol staining and examination of artificial substrates

    Science.gov (United States)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Coats, D. W.; Wharton RA, J. r. (Principal Investigator)

    1999-01-01

    Planktonic and artificial substrate-associated ciliates have been identified in two perennially ice-covered antarctic lakes of the McMurdo Dry Valleys. Abundances estimated by quantitative protargol staining ranged from Vorticella. The taxonomic findings compare favorably with those of previous investigators; however four previously unreported genera were observed in both Lakes Fryxell and Hoare. The variability in the depth distributions of ciliates in Lake Fryxell is explained in terms of lake physicochemical properties and ciliate prey distributions, while factors related to temporal succession in the Lake Hoare assemblage remain unexplained. Local marine or temperate zone freshwater habitats are a more likely source than the surrounding dry valleys soils for present ciliate colonists in these lakes. Although the taxonomic uncertainties require further examination, our results suggest that ciliate populations in these antarctic lakes undergo significant fluctuations and are more diverse than was previously recognized.

  11. Revisiting fifty years of research on pheromone signaling in ciliates.

    Science.gov (United States)

    Luporini, Pierangelo; Pedrini, Bill; Alimenti, Claudio; Vallesi, Adriana

    2016-08-01

    Among protists, pheromones have been identified in a great variety of algal species for their activity in driving gamete-gamete interactions for fertilization. Analogously in ciliates, pheromones have been identified for their activity in inducing the sexual phenomenon of conjugation. Although this identification was pioneered by Kimball more than fifty years ago, an effective isolation and chemical characterization of ciliate pheromones has remained confined to species of Blepharisma, Dileptus and Euplotes. In Euplotes species, in which the molecular structures have been determined, pheromones form species-specific families of structurally homologous helical, cysteine-rich, highly-stable proteins. Being structurally homologous, they can bind cells in competition with one another, raising interesting functional analogies with the families of growth factors and cytokines that regulate cell differentiation and development in higher organisms. In addition to inducing conjugation by binding cells in heterologous fashion, Euplotes pheromones act also as autocrine growth factors by binding to, and promoting the vegetative reproduction of the same cells from which they originate. This autocrine activity is most likely primary, providing a concrete example of how the original function of a molecule can be obscured during evolution by the acquisition of a new one.

  12. Metabolismo del glutatión y enzimas antioxidantes frente al estrés por metal(oid)es y otros agentes, en el ciliado-modelo "Tetrahymena thermophila"

    OpenAIRE

    Ortega Herrero, Ruth

    2015-01-01

    El estrés oxidativo se define como el estado celular de desequilibrio entre moléculas oxidantes y antioxidantes. Esta definición se basa en la hipótesis Redox que se desarrolla en cuatro postulados: 1)Todo sistema vivo presenta elementos redox que son moléculas ricas en residuos de cisteína y que toman parte en los procesos de señalización celular, tráfico de macromoléculas y regulación fisiológica. 2)Estos elementos se coordinan mediante circuitos redox, que tienen nodos comunes como el gl...

  13. Diverse modes of reproduction in the marine free-living ciliate Glauconema trihymene

    Directory of Open Access Journals (Sweden)

    Zufall Rebecca A

    2010-04-01

    Full Text Available Abstract Background Most free-living ciliates reproduce by equal fission or budding during vegetative growth. In certain ciliates, reproduction occurs inside the cyst wall, viz. reproductive cysts, but more complex reproductive strategies have generally been thought to be confined to parasitic or symbiotic species, e.g. Radiophrya spp. Results In addition to equal fission, asymmetric binary division and reproductive cysts were discovered in the free-living bacterivorous scuticociliate Glauconema trihymene Thompson, 1966. Asymmetric division is an innate physiological state that can be induced by sufficient food, and the higher the food concentration, the longer the asymmetric division persists. During asymmetric division, nuclear and somatic structures divide with transiently arrested cytokinesis and variable positioning of macronuclei. Phylogenetic analysis, based on the small subunit of ribosomal DNA (SSU rDNA sequences, showed that the G. trihymene isolate studied here nests with typical scuticociliates and is paraphyletic to both the symbiotic apostome and astome ciliates, some of which also produce progeny by asymmetric division. Conclusions The asymmetric division in G. trihymene has no precedent among undisturbed free-living ciliates. The coexistence of multiple modes of reproduction may represent a previously undescribed reproductive strategy for ciliates living on food patches in coastal waters. This may also be indicative of similar reproductive strategies among other polyphenic ciliates, which have not been intensively studied. Asymmetric division provides a special opportunity for studying ciliates' phenotypic plasticity and may also illuminate the origins of multicellularity.

  14. Climate scaling behaviour in the dynamics of the marine interstitial ciliate community

    Science.gov (United States)

    Varotsos, Costas A.; Mazei, Yuri A.; Burkovsky, Igor; Efstathiou, Maria N.; Tzanis, Chris G.

    2016-08-01

    The present paper uses characteristics of the marine interstitial ciliate community in the White Sea intertidal sandflat during the period of 1991-2011, in order to study its long-term dynamics, investigating in particular whether it exhibits scaling behaviour into its fluctuations, which is a characteristic feature of the climate system. To this aim, a recently proposed version of the detrended fluctuation analysis is herewith employed which has been successfully applied to a wide range of simulated and physiologic time series in recent years. In case that the fluctuations of the ciliate community present self-similarity processes, an ideal field test for the currently proposed biological models will be established, allowing to evaluate their reliability. Indeed, we show for the first time that different ciliate species exhibit long-range power-law persistent correlations. This means that ciliate fluctuations in different intervals are positively correlated, obeying a power-law behaviour. Although the origin of power-law temporal evolution of ciliates should be further investigated, this finding is probably associated with the self-organized criticality of ciliates. It should be noted that the long-range correlations obtained do not imply the presence of specific cycles but rather the existence of dynamic links between long-term and short-term temporal evolution. The scaling behaviour found in marine interstitial ciliate community should be taken into account in the investigation of their response to the present or future climate change.

  15. First report of ciliate (Protozoa) epibionts on deep-sea harpacticoid copepods

    Science.gov (United States)

    Sedlacek, Linda; Thistle, David; Fernandez-Leborans, Gregorio; Carman, Kevin R.; Barry, James P.

    2013-08-01

    We report the first observations of ciliate epibionts on deep-sea, benthic harpacticoid copepods. One ciliate epibiont species belonged to class Karyorelictea, one to subclass Suctoria, and one to subclass Peritrichia. Our samples came from the continental rise off central California (36.709°N, 123.523°W, 3607 m depth). We found that adult harpacticoids carried ciliate epibionts significantly more frequently than did subadult copepodids. The reason for the pattern is unknown, but it may involve differences between adults and subadult copepodids in size or in time spent swimming. We also found that the ciliate epibiont species occurred unusually frequently on the adults of two species of harpacticoid copepod; a third harpacticoid species just failed the significance test. When we ranked the 57 harpacticoid species in our samples in order of abundance, three species identified were, as a group, significantly more abundant than expected by chance if one assumes that the abundance of the group and the presence of ciliate epibionts on them were uncorrelated. High abundance may be among the reasons a harpacticoid species carries a ciliate epibiont species disproportionately frequently. For the combinations of harpacticoid species and ciliate epibiont species identified, we found one in which males and females differed significantly in the proportion that carried epibionts. Such a sex bias has also been reported for shallow-water, calanoid copepods.

  16. Cloning, expression and characterization of an ethanol tolerant GH3 β-glucosidase from Myceliophthora thermophila

    Directory of Open Access Journals (Sweden)

    Anthi Karnaouri

    2013-02-01

    Full Text Available The β-glucosidase gene bgl3a from Myceliophthora thermophila, member of the fungal glycosyl hydrolase (GH family 3, was cloned and expressed in Pichia pastoris. The mature β-glucosidase gene, which results after the excision of one intron and the secreting signal peptide, was placed under the control of the strong alcohol oxidase promoter (AOX1 in the plasmid pPICZαC. The recombinant enzyme (90 kDa was purified and characterized in order to evaluate its biotechnological potential. Recombinant P. pastoris efficiently secreted β-glucosidase into the medium and produced high level of enzymatic activity (41 U/ml after 192 h of growth, under methanol induction. MtBgl3a was able to hydrolyze low molecular weight substrates and polysaccharides containing β-glucosidic residues. The Km was found to be 0.39 mM on p-β-NPG and 2.64 mM on cellobiose. Optimal pH and temperature for the p-β-NPG hydrolysis were 5.0 and 70 °C. The β-glucosidase exhibits a half life of 143 min at 60 °C. Kinetic parameters of inhibition were determined for D-glucose, D-xylose and D-gluconic acid, indicating tolerance of the enzyme for these sugars and oxidized products. The recombinant enzyme was stimulated by short chain alcohols and has been shown to efficiently synthesize methyl-D-glucoside in the presence of methanol due to its transglycosylation activity. The stability of MtBgl3a in ethanol was prominent, and it retained most of its original activity after we exposed it to 50% ethanol for 6 h. The high catalytic performance, good thermal stability and tolerance to elevated concentrations of ethanol, D-xylose and D-glucose qualify this enzyme for use in the hydrolysis of lignocellulosic biomass for biofuel production, as part of an efficient complete multi-enzyme cocktail.

  17. Ultraviolet light photobiology of the protozoan Tetrahymena pyriformis and chemical reactivation of DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, J.S.

    1988-01-01

    The tunable dye laser was developed in order to perform UV-B and UV-C (254-320 nm) action spectra studies on several different organisms. Using the laser, action spectra studies have been performed for Escherichia coli, Saccharomyces, Chlamydomonas, Caenorhabditis elegans, Paramecium, and Tetrahymena pyriformis. Studies generally indicate increasing LD{sub 50} values with increasing wavelength. Two notable findings were made: (1) The action spectra does not follow the DNA absorption spectra at 280, 290 and 295 nm; (2) The repair competent/repair defective sensitization factor does not remain constant throughout the wavelength region. In addition it was found that the repair defective strain of E. coli, Bs-1, showed an increase in survival with increasing UV irradiation, at certain dose levels. Further experiments were designed to better characterize the reactivation. Tetrahymena were exposed to UV-C and reactivated with methyl methanesulfonate (MMS) and 4-nitro quinoline oxide (4-NQO). In both cases survival was seen to increase after chemical exposure. Likewise, UV-C was found to reactivate chemical damage (MMS).

  18. Effects of indomethacin on the divisional morphogenesis and cytoskeleton-dependent processes of Tetrahymena.

    Science.gov (United States)

    Kovács, Péter; Pállinger, Eva

    2003-06-01

    Indomethacin (0.1 mM) causes significantly altered phospholipid synthesis in Tetrahymena and is able to influence the inositol phospholipid signalling system (9). In the present study the effects of indomethacin on the course of cell division, cyclin expression, the cortical microtubular system and on cytoskeleton-dependent processes (motility, phagocytosis) were investigated. As expected from its interference with the synthesis of phospholipids, indomethacin affected Tetrahymena in a number of ways: the structure of the cortical microtubular system became irregular; in many cells the stomatogenesis (development of new oral apparatus) and the development of the fission furrow was not accompanied by elongation of the macronucleus, which is a typical phenomenon of the normal course of mitosis: apparently indomethacin uncouples these phenomena. After indomethacin treatment, the expression of both cyclin A and cyclin B(1) were reduced significantly. The cell growth rate, motility and phagocytotic activity were all considerably reduced. There are probably additional mechanisms responsible for the effect of indomethacin on the systems that control divisional morphogenesis, for microtubule-dependent processes and for the connection between nuclear and cortical alterations during the cell cycle. Effects on protein phosphorylation/dephosphorylation, on cyclin expression and on microtubular functions are probably involved. These possibilities are discussed.

  19. NCBI nr-aa BLAST: CBRC-OLAT-12-0010 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-12-0010 ref|XP_001032622.2| Dentin sialophosphoprotein precursor, putativ...e [Tetrahymena thermophila SB210] gb|EAR84959.2| Dentin sialophosphoprotein precursor, putative [Tetrahymena thermophila SB210] XP_001032622.2 4e-17 58% ...

  20. NCBI nr-aa BLAST: CBRC-CINT-01-0190 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CINT-01-0190 ref|XP_001023368.1| Leucine Rich Repeat family protein [Tetrahyme...na thermophila SB210] gb|EAS03123.1| Leucine Rich Repeat family protein [Tetrahymena thermophila SB210] XP_001023368.1 0.69 30% ...

  1. NCBI nr-aa BLAST: CBRC-PABE-17-0002 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PABE-17-0002 ref|XP_001007370.1| Leucine Rich Repeat family protein [Tetrahyme...na thermophila SB210] gb|EAR87125.1| Leucine Rich Repeat family protein [Tetrahymena thermophila SB210] XP_001007370.1 0.76 34% ...

  2. NCBI nr-aa BLAST: CBRC-OGAR-01-0552 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OGAR-01-0552 ref|XP_001032073.2| Leucine Rich Repeat family protein [Tetrahyme...na thermophila SB210] gb|EAR84410.2| Leucine Rich Repeat family protein [Tetrahymena thermophila SB210] XP_001032073.2 6e-06 13% ...

  3. Ciliated hepatic foregut cyst: report of first case in China and review of literature

    Institute of Scientific and Technical Information of China (English)

    蔡秀军; 黄迪宇; 梁霄; 虞洪; 李伟; 王先法; 彭淑牖

    2004-01-01

    Objective: To report the first case of ciliated hepatic foregut cyst in China, and review of literature to introduce the characteristics of this disease for doctors to recognize this disease.Method: Report the clinical procedure of diagnosis and treatment for the first case of ciliated hepatic foregut cyst in China, and to review the embryologic genesis, incidence,clinical manifestation, radiologic features and therapeutic principle of this disease. Results: We performed the resection for ciliated hepatic foregut cyst under laparoscopy; the patient recovered well after the procedure. Conclusion: Ciliated hepatic foregut cyst is quite rare clinically, belongs to non-parasitic,solitary and unilocular cystic lesion, is always less than 4cm in diameter, mostly seen in the left lobe, and has the tendency of malignant change. It should be removed as soon as diagnosed.

  4. New records of epibiont Ciliates (Ciliophora) from Indian coast with descriptions of six new species

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterjee, T.; Fernandez-Leborans, G.; Ramteke, D.; Ingole, B

    Six epibiont ciliates Cothurnia palkensis, C. nova, C. disper, C. dovgali, C. mannaerensis and C. clampi are described as new for science from the Indian coast. Acineta truncata Collin, 1909 and A. tuberosa Ehrenberg, 1834 are reported here...

  5. Benthic ciliate and meiofaunal communities in two contrasting habitats of an intertidal estuarine wetland

    Science.gov (United States)

    Du, Yongfen; Xu, Kuidong; Warren, Alan; Lei, Yanli; Dai, Renhai

    2012-05-01

    Annual variations in benthic meiofaunal and ciliated protozoan communities were investigated using monthly samplings from June 2006 to May 2007 in two habitats characterized by different vegetal coverage in an estuarine intertidal wetland of Qingdao Jiaozhou Bay, China. The sediment composition was stable at each site: sediments densely covered with seagrass (Suaeda glauca) in the lower estuarine site (Station S) were finer, with higher content of organic matter, phaeopigments and water than sediments at the upper estuarine site (Station S-P) which was unvegetated other than for patches of S. glauca and common reed (Phragmites australis). Chlorophyll a exhibited a similar distribution in the two habitats. A total of 14 meiofaunal groups, and 249 species of ciliates belonging to 37 genera, 28 families and 16 orders, were isolated from the two sites. Univariate and multivariate measures of the communities were significantly different between the two habitats. There were higher abundances of ciliates and meiofauna, and a greater diversity of ciliates, at Station S than Station S-P (223 vs. 61 species). Herbivorous ciliates were numerically predominant in ciliate communities at both sites. The representative ciliates at Station S-P belonged to the Cyrtophorida and appeared to be a reduced subset of the assemblage at Station S, which was characterized by members of the Prostomatida, Cyrtophorida, Hypotrichida and Scuticociliatida. More than 96% of the total meiofauna were nematodes, accounting for 93% of the differences in the abundance compositions of the meiofaunal communities between habitats. The average individual weights of nematodes were nearly 3 times greater at Station S than Station S-P, indicating a distinctive species composition at each site. Temperature, salinity and food availability were key factors that regulated the ciliate and meiofaunal community structure. Nematodes were the dominant group in terms of the combined abundance, biomass and benthic

  6. Ciliated protozoa of two antarctic lakes: analysis by quantitative protargol staining and examination of artificial substrates

    Science.gov (United States)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Coats, D. W.; Wharton RA, J. r. (Principal Investigator)

    1999-01-01

    Planktonic and artificial substrate-associated ciliates have been identified in two perennially ice-covered antarctic lakes of the McMurdo Dry Valleys. Abundances estimated by quantitative protargol staining ranged from < 5 to 31690 cells l-1, levels that are comparable to those previously obtained using other methods. Nineteen ciliate taxa were identified from these lakes, with the most frequently encountered genera being Plagiocampa, Askenasia, Monodinium, Sphaerophrya and Vorticella. The taxonomic findings compare favorably with those of previous investigators; however four previously unreported genera were observed in both Lakes Fryxell and Hoare. The variability in the depth distributions of ciliates in Lake Fryxell is explained in terms of lake physicochemical properties and ciliate prey distributions, while factors related to temporal succession in the Lake Hoare assemblage remain unexplained. Local marine or temperate zone freshwater habitats are a more likely source than the surrounding dry valleys soils for present ciliate colonists in these lakes. Although the taxonomic uncertainties require further examination, our results suggest that ciliate populations in these antarctic lakes undergo significant fluctuations and are more diverse than was previously recognized.

  7. Modeling the toxicity of aromatic compounds to tetrahymena pyriformis: the response surface methodology with nonlinear methods.

    Science.gov (United States)

    Ren, Shijin

    2003-01-01

    Response surface models based on multiple linear regression had previously been developed for the toxicity of aromatic chemicals to Tetrahymena pyriformis. However, a nonlinear relationship between toxicity and one of the molecular descriptors in the response surface model was observed. In this study, response surface models were established using six nonlinear modeling methods to handle the nonlinearity exhibited in the aromatic chemicals data set. All models were validated using the method of cross-validation, and prediction accuracy was tested on an external data set. Results showed that response surface models based on locally weighted regression scatter plot smoothing (LOESS), multivariate adaptive regression splines (MARS), neural networks (NN), and projection pursuit regression (PPR) provided satisfactory power of model fitting and prediction and had similar applicabilities. The response surface models based on nonlinear methods were difficult to interpret and conservative in discriminating toxicity mechanisms.

  8. Genotoxic effects of linear alkyl benzene sulfonate, sodium pentachlorophenate and dichromate on Tetrahymena pyriformis.

    Science.gov (United States)

    Wu, Y; Shen, Y

    1992-01-01

    DNA in macro- and micronuclei of Tetrahymena pyriformis treated with linear alkyl benzene sulfonate (LAS) and sodium pentachlorophenate (PCP-Na) were determined by microspectrophotometry. The effects on rate of formation of macronuclear DNA extrusion bodies were also studied. We found DNA content of micronuclei in 0.14 ppm LAS and 0.9 ppb PCP-Na was lower than in that of the control, and LAS was able to increase the formation rate of macronuclear DNA extrusion bodies (the formation rate was 54% in 11.3 ppm LAS and 25.6% in 16.7 ppm dichromate). We concluded that 0.14 ppm LAS (below the maximum acceptable toxicant concentration) was genotoxic, whereas 0.014 ppm LAS was not. Dichromate 0.05 ppm and 0.9 ppb PCP-Na, equal to and below the maximum acceptable toxicant concentration, respectively, were potentially genotoxic.

  9. Mixotrophic growth of two thermophilic Methanosarcina strains, Methanosarcina thermophila TM-1 and Methanosarcina sp. SO-2P, on methanol and hydrogen/carbon dioxide

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Ahring, Birgitte Kiær

    1997-01-01

    Two thermophilic strains, Methanosarcina thermophila TM-1 and Methanosarcina sp. SO-2P, were capable of mixotrophic growth on methanol and H-2/CO2. Activated carbon was, however, found to be necessary to support good growth. Both strains used hydrogen and methanol simultaneously. When methanol wa...... was depleted, hydrogen utilization continued and methane was further produced with concurrent cell growth. UV epifluorescence microscopy revealed that aggregates of both strains exhibited a bright red fluorescence besides the usual blue-green fluorescence....

  10. Ciliate Paramecium is a natural reservoir of Legionella pneumophila

    Science.gov (United States)

    Watanabe, Kenta; Nakao, Ryo; Fujishima, Masahiro; Tachibana, Masato; Shimizu, Takashi; Watarai, Masahisa

    2016-04-01

    Legionella pneumophila, the causative agent of Legionnaires’ disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L. pneumophila in the environment remains largely unknown. Here we established a novel natural host model of L. pneumophila endosymbiosis using the ciliate Paramecium caudatum. We also identified Legionella endosymbiosis-modulating factor A (LefA), which contributes to the change in life stage from endosymbiosis to host lysis, enabling escape to the environment. We isolated L. pneumophila strains from the environment, and they exhibited cytotoxicity toward P. caudatum and induced host lysis. Acidification of the Legionella-containing vacuole (LCV) was inhibited, and enlarged LCVs including numerous bacteria were observed in P. caudatum infected with L. pneumophila. An isogenic L. pneumophila lefA mutant exhibited decreased cytotoxicity toward P. caudatum and impaired the modification of LCVs, resulting in the establishment of endosymbiosis between them. Our results suggest that L. pneumophila may have a mechanism to switch their endosymbiosis in protistan hosts in the environment.

  11. Hydrodynamical entrapment of ciliates at the air-liquid interface

    Science.gov (United States)

    Ferracci, Jonathan; Ueno, Hironori; Numayama-Tsuruta, Keiko; Imai, Yohsuke; Yamaguchi, Takami; Ishikawa, Takuji

    2012-11-01

    We found the new phenomenon of the entrapment of ciliates at the air-water interface, though they are not trapped by a solid interface. We first characterize the behaviours of cells at the interface by comparing it to those away from interfaces. The results showed that the cell's swimming velocity is considerably reduced at the air-water interface. In order to experimentally verify the possible physiological causes of the entrapment, we observed their behaviours in absence of positive chemotaxis for oxygen and the negative geotaxis. The results illustrated that the entrapment phenomenon was not dependent on these physiological conditions. The experiments using surfactant revealed that the entrapment phenomenon was strongly affected by the velocity-stress conditions at the interface. This fact was confirmed numerically by a boundary element method, i.e. the stress-free condition at the air-liquid interface is one of the main mechanisms of the entrapment phenomenon found in the experiments. Since the entrapment phenomenon found in this study affects the cell-cell interactions and the mass transport at the interface, the knowledge obtained in this study is useful for better understanding the complex behaviours of swimming microorganisms in nature. PhD student in the Physiological Flow Studies Laboratory.

  12. Ciliate Paramecium is a natural reservoir of Legionella pneumophila

    Science.gov (United States)

    Watanabe, Kenta; Nakao, Ryo; Fujishima, Masahiro; Tachibana, Masato; Shimizu, Takashi; Watarai, Masahisa

    2016-01-01

    Legionella pneumophila, the causative agent of Legionnaires’ disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L. pneumophila in the environment remains largely unknown. Here we established a novel natural host model of L. pneumophila endosymbiosis using the ciliate Paramecium caudatum. We also identified Legionella endosymbiosis-modulating factor A (LefA), which contributes to the change in life stage from endosymbiosis to host lysis, enabling escape to the environment. We isolated L. pneumophila strains from the environment, and they exhibited cytotoxicity toward P. caudatum and induced host lysis. Acidification of the Legionella-containing vacuole (LCV) was inhibited, and enlarged LCVs including numerous bacteria were observed in P. caudatum infected with L. pneumophila. An isogenic L. pneumophila lefA mutant exhibited decreased cytotoxicity toward P. caudatum and impaired the modification of LCVs, resulting in the establishment of endosymbiosis between them. Our results suggest that L. pneumophila may have a mechanism to switch their endosymbiosis in protistan hosts in the environment. PMID:27079173

  13. Application of nested PCR-DGGE (denaturing gradient gel electrophoresis) for the analysis of ciliate communities in soils.

    Science.gov (United States)

    Shimano, Satoshi; Sambe, Mitsuo; Kasahara, Yasuhiro

    2012-01-01

    Ciliates play important roles as prey and predators in ecosystems. Changes in the ciliate community can affect the composition and population of microfauna and microflora in ecosystems. To investigate the structure of ciliate communities, we developed a nested PCR-DGGE method, which combines a universal eukaryotic-specific primer set in the first PCR step with a ciliate-specific primer set in the second PCR step, to amplify 18S rRNA genes from ciliates. The 300 bp DGGE fragments generated more bands on the gel than the 600 bp DGGE fragments. Prior to bead beating, DNA extraction of ciliates from soil samples was optimized with a combination of freeze-thaw cycles and ultrasonication. We applied this nested PCR-DGGE method to agricultural soils amended with 0, 120, 300, and 600 t ha⁻¹ year⁻¹ of livestock slurry. The results from the DGGE profiles and principal component analysis (PCA) revealed that the supplement of slurry to soils influenced the ciliate communities. From phylogenetic analysis, 108 DGGE bands were assigned to six classes, which included Spirotrichea and Colpodea, of the subphylum Intramacronucleata, and one class of the subphylum Postciliodesmatophora. These results indicated that a wide variety of taxonomic groups were detected by DGGE profiling. Thus, the nested PCR-DGGE method described here could clearly differentiate between ciliate communities within soil samples and allowed for the phylogenetic identification of these ciliates at the class level.

  14. First report of predation of Giardia sp. cysts by ciliated protozoa and confirmation of predation of Cryptosporidium spp. oocysts by ciliate species.

    Science.gov (United States)

    Siqueira-Castro, Isabel Cristina Vidal; Greinert-Goulart, Juliane Araújo; Bonatti, Tais Rondello; Yamashiro, Sandra; Franco, Regina Maura Bueno

    2016-06-01

    Ciliated protozoa are important components of the microbial food web in various habitats, especially aquatic environments. These organisms are useful bioindicators for both environmental quality assessment and the wastewater purification process. The pathogenic parasitic protozoan species Giardia and Cryptosporidium represent a significant concern for human health, being responsible for numerous disease outbreaks worldwide. The predation of cysts and oocysts in 15 ciliate species from water and sewage samples collected in Campinas, São Paulo, Brazil were verified under laboratory conditions. The ciliated protozoan species were selected based on their mode of nutrition, and only bacterivorous and suspension-feeders were considered for the experiments. The species Blepharisma sinuosum, Euplotes aediculatus, Sterkiella cavicola, Oxytricha granulifera, Vorticella infusionum, Spirostomum minus, and Stentor coeruleus ingested cysts and oocysts, the resistance forms of Giardia spp. and Cryptosporidium spp., respectively. This is the first time that the ingestion of Giardia cysts by ciliated protozoa has been reported. These findings may contribute to a better understanding of the biological removal of these pathogens from aquatic environments.

  15. On classical and quantum error-correction in ciliate mate selection.

    Science.gov (United States)

    Clark, Kevin B

    2010-07-01

    Ciliated protozoa sensing pheromones secreted from nonself mating types engage in preconjugal "courtship" dances and contacts. Using simulated "social" trials, I recently showed the heterotrich ciliate, Spirostomum ambiguum, can learn to advertise degrees of mating fitness to "suitors" and "rivals" when serially contracting or (ciliary) reversing at variable rates. Conspicuous consumers signal higher quality reproductive status by playing "harder-to-get" via metabolically wasteful avoidance displays that hinder the exchange of preconjugal touches between "courting" couples. Conversely, prudent savers conserve energy pending situations more favorable for conjugating a partner. These ciliates reply with lower avoidance frequencies, guaranteeing nearby conspecifics of being "easier-to-get". By deciding to switch from behavioral strategies signaling conspicuous consumption to those signaling prudent savings, fitter ciliates learn to altruistically sacrifice net payoffs and persuade suitors to participate in paired reproduction. Less fit ciliates, unable to sustain long periods of high response rates, switch their behavioral strategies of prudent savings to briefly emit conspicuous consumption and thus learn to opportunistically cheat superior rivals. Mating competency depends, in part, on the efficiency of heuristics formed from recursive strategy searches and use. Heuristics represent stored patterns of action which evolve into ordered computational networks supporting entire courting repertoires. As ciliates expand signaling skills over many trials, the connectivity between strategies strengthens from Hebbian-like learning, leading to faster decisions about the appropriateness of courting messages and replies. The best experts master signaling decisions at efficiencies comparable to finding target solutions from superposed states with Grover's quantum search algorithm. I here append these findings with a critique on the feasibility of serial behavioral strategies to

  16. Philasterides dicentrarchi, a histophagous ciliate causing scuticociliatosis in olive flounder, Philasterides dicentrarchi--histopathology investigations.

    Science.gov (United States)

    Harikrishnan, Ramasamy; Jin, Chang-Nam; Kim, Ju-Sang; Balasundaram, Chellam; Heo, Moon-Soo

    2012-03-01

    Philasterides dicentrarchi is a histophagous scuticociliate infecting Korean olive flounder farms in Jeju Island, South Korea, where it causes significant economic losses. However, the route of entry of these parasites in olive flounder is currently unknown. In the present study, we attempted experimental infection with different doses (concentrations) of P. dicentrarchi by intraperitoneal (IP) injection; maximum cumulative mortality of 95% was recorded on the administration of 2.1×10(8) ciliates/ml. In small size group (3 cm length, 24±2 gwt) the ciliates were found in connective tissues of muscle, fins, and nervous tissue while in large size group (5 cm length, 47±3 gwt), the ciliates were predominantly occurred with associated symptoms of liquefaction in the central nervous system. The major clinico-pathological manifestations were loss of scales, appearance of bleached spots that coalesced to form brownish patches, hemorrhagic, and severe dermal necrotic lesion. In addition there was degeneration of muscle fibers, necrosis of the hepatic parenchyma, and severe edema of the intestinal walls, extensive fouling, necrotic degeneration and hyperplasia in the gill bronchial epithelium. In this study, many ciliates were found in the blood vessel, brain, dorsal fins, muscle, kidney, and vertebra of infected flounder. The histopathological investigations are of significant importance in view of possible routes of entry into the host and doses of ciliates that trigger fast infection for potential utility of drugs as a strategy for the control of P. dicentrarchi in farmed olive flounder.

  17. Are freshwater mixotrophic ciliates less sensitive to solar ultraviolet radiation than heterotrophic ones?

    Science.gov (United States)

    Sonntag, Bettina; Summerer, Monika; Sommaruga, Ruben

    2011-01-01

    We tested whether mixotrophic ciliates are more resistant to solar ultraviolet radiation (UVR) than heterotrophic ones because symbiotic algae can provide self-shading by cell matter absorption and eventually by direct UV screening from mycosporine-like amino acids (MAAs). Sensitivity of a natural assemblage to solar radiation was tested in experiments in the original lake and in a more UV transparent alpine lake after transplantation of the ciliates. In both lakes, the assemblage was exposed either to full sunlight, to photosynthetically active radiation only, or kept in the dark. In each lake, exposure was for 5 h at the surface and at the depth corresponding to the 10% attenuation depth at 320 nm. Overall, when the assemblage was exposed to surface UVR, only one out of four dominant mixotrophic ciliates, Vorticella chlorellata, was more resistant than heterotrophic species. The higher UV resistance in V. chlorellata was related to the presence of MAAs and the high percentage of ciliate volume occupied by algal symbionts. Our results indicate that effects of UVR were species-specific and depended on efficient screening of these wavelengths, but also on the depth preference of the ciliates and thus, on their previous exposure history to UVR.

  18. Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1

    Science.gov (United States)

    SONNTAG, BETTINA; SUMMERER, MONIKA; SOMMARUGA, RUBEN

    2011-01-01

    We tested whether mixotrophic ciliates are more resistant to solar ultraviolet radiation (UVR) than heterotrophic ones because symbiotic algae can provide self-shading by cell matter absorption and eventually by direct UV screening from mycosporine-like amino acids (MAAs). Sensitivity of a natural assemblage to solar radiation was tested in experiments in the original lake and in a more UV transparent alpine lake after transplantation of the ciliates. In both lakes, the assemblage was exposed either to full sunlight, to photosynthetically active radiation only, or kept in the dark. In each lake, exposure was for 5 h at the surface and at the depth corresponding to the 10% attenuation depth at 320 nm. Overall, when the assemblage was exposed to surface UVR, only one out of four dominant mixotrophic ciliates, Vorticella chlorellata, was more resistant than heterotrophic species. The higher UV resistance in V. chlorellata was related to the presence of MAAs and the high percentage of ciliate volume occupied by algal symbionts. Our results indicate that effects of UVR were species-specific and depended on efficient screening of these wavelengths, but also on the depth preference of the ciliates and thus, on their previous exposure history to UVR. PMID:21414057

  19. Epithelial Cell Culture from Human Adenoids: A Functional Study Model for Ciliated and Secretory Cells

    Directory of Open Access Journals (Sweden)

    Claudia González

    2013-01-01

    Full Text Available Background. Mucociliary transport (MCT is a defense mechanism of the airway. To study the underlying mechanisms of MCT, we have both developed an experimental model of cultures, from human adenoid tissue of ciliated and secretory cells, and characterized the response to local chemical signals that control ciliary activity and the secretion of respiratory mucins in vitro. Materials and Methods. In ciliated cell cultures, ciliary beat frequency (CBF and intracellular Ca2+ levels were measured in response to ATP, UTP, and adenosine. In secretory cultures, mucin synthesis and secretion were identified by using immunodetection. Mucin content was taken from conditioned medium and analyzed in the presence or absence of UTP. Results. Enriched ciliated cell monolayers and secretory cells were obtained. Ciliated cells showed a basal CBF of 10.7 Hz that increased significantly after exposure to ATP, UTP, or adenosine. Mature secretory cells showed active secretion of granules containing different glycoproteins, including MUC5AC. Conclusion. Culture of ciliated and secretory cells grown from adenoid epithelium is a reproducible and feasible experimental model, in which it is possible to observe ciliary and secretory activities, with a potential use as a model to understand mucociliary transport control mechanisms.

  20. Involvement of Crawling and Attached Ciliates in the Aggregation of Particles in Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    Lucía Arregui

    2008-01-01

    Full Text Available The biological community in activated sludge wastewater plants is organized within this ecosystem as bioaggregates or flocs, in which the biotic component is embedded in a complex matrix comprised of extracellular polymeric substances mainly of microbial origin. The aim of this work is to study the role of different floc-associated ciliates commonly reported in wastewater treatment plants-crawling Euplotes and sessile Vorticella- in the formation of aggregates. Flocs, in experiments with ciliates and latex beads, showed more compactation and cohesion among particles than those in the absence of ciliates. Ciliates have been shown to contribute to floc formation through different mechanisms such as the active secretion of polymeric substances (extrusomes, their biological activities (movement and feeding strategies, or the cysts formation capacity of some species. Staining with lectins coupled to fluorescein showed that carbohydrate of the matrix contained glucose, manose, N-acetyl-glucosamine and galactose. Protein fraction revealed over the latex beads surfaces could probably be of bacterial origin, but nucleic acids represented an important fraction of the extracellular polymeric substances of ciliate origin.

  1. [Comparison of ciliate diversity in biodisc reactors which purify industrial wastewater].

    Science.gov (United States)

    Luna-Pabello, V M; Durán De Bazúa, C; Aladro-Lubel, M A

    1995-01-01

    The comparative study of the ciliate populations present in rotating biological reactors (biodiscs reactors) of 20 l working volume, treating three different wastewaters is the aim of this project. Wastewaters chosen were those of a maize mill, of a sugarcane/ethyl alcohol plant, and of a recycled paper mill. Its dissolved organic contents, measured as soluble chemical oxygen demand (COD) and five-day biochemical oxygen demand (BOD5), were 2040 mg COD/l and 585 mg BOD5/l for maize mill effluents (nejayote), 2000 mg COD/l and 640 mg BOD5/l for sugarcane/ethanol effluents (vinasses), and 960 mg COD/l and 120 mg BOD5/l for whitewaters of the paper industry. Results obtained indicate that ciliate proliferate in all chambers of reactors treating these wastewaters. The ciliates were more abundant in vinasses, followed by nejayote, and then whitewaters. Among protozoa, ciliates were present as follows: 19 species in total. Three of them were common for the three systems. Free swimming ciliates were in higher proportion than pedunculated ones. Its diversity was higher for the whitewaters system, next for nejayote, and the lesser, for vinasses, corroborating the fact that less polluted waters have higher organisms' diversity.

  2. Rumen ciliate protozoa of domestic sheep (Ovis aries) and goat (Capra aegagrus hircus) in Kyrgyzstan.

    Science.gov (United States)

    Gürelli, Gözde; Canbulat, Savaş; Aldayarov, Nurbek; Dehority, Burk A

    2016-03-01

    Species composition and concentration of rumen ciliate protozoa were investigated in the rumen contents of 14 domestic sheep and 1 goat living in Bishkek, Kyrgyzstan. This is the first report on rumen ciliates from ruminants living in Kyrgyzstan. In sheep 12 genera, 28 species and 12 morphotypes were detected, whereas in goat 8 genera, 12 species and 4 morphotypes were detected. The density of ciliates in sheep was (28.1 ± 20.0) × 10(4) cells mL(-1) and in goat was 37.0 × 10(4) cells mL(-1). Dasytricha ruminantium, Isotricha prostoma, Entodinium simulans and Ophryoscolex caudatus were major species (100%) in sheep, and for the first time, Diplodinium rangiferi was detected in a domestic goat.

  3. Relationship between spatial pattern of basal bodies and membrane skeleton (epiplasm) during the cell cycle of Tetrahymena: cdaA mutant and anti-membrane skeleton immunostaining.

    Science.gov (United States)

    Kaczanowska, J; Buzanska, L; Ostrowski, M

    1993-01-01

    Microtubular basal bodies and epiplasm (membrane skeleton) are the main components of the cortical skeleton of Tetrahymena. The aim of this report was to study functional interactions of basal bodies and epiplasm during the cell cycle. The cortex of Tetrahymena cells was stained with anti-epiplasm antibody. This staining produced a bright epiplasmic layer with a dark pattern of unstained microtubular structures. The fluorescence of the anti-epiplasm antibody disappeared at sites of newly formed microtubular structures, so the new basal body domains and epiplasmic layer could be followed throughout the cell cycle. Different patterns of deployment of new basal bodies were observed in early and advanced dividers. In advanced dividers the fluorescence of the epiplasmic layer diminished locally within the forming fission line where the polymerization of new basal bodies largely extincted. In wild type Tetrahymena, the completion of the micronuclear metaphase/anaphase transition was associated with a transition from the pattern of new basal body deployment and epiplasm staining of the early divider to the pattern of the advanced dividers. The signal for the fission line formation in Tetrahymena (absent in cdaA1 Tetrahymena mutationally arrested in cytokinesis) brings about 1) transition of patterns of deployment of basal bodies and epiplasmic layer on both sides of the fission line; and 2) coordination of cortical divisional morphogenesis with the micronuclear mitotic cycle.

  4. Dealing with the presence of the ciliate Euplotes sp. in cultures of the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Dutz, Jörg

    2014-01-01

    Ciliates in live feed cultures can be a pest that lower production yields. This could dramatically affect the management and success of copepod cultures. In this study, we investigated the effect of the ciliate Euplotes sp. on egg production, specific egg production and egg hatching success...... of Acartia tonsa fed with Rhodomonas salina. We found that at a concentration of 2 cells ml-1, Euplotes sp. had no effect on the production and hatching success of eggs but increased/decreased the mortality/quality of non-subitaneous eggs. Euplotes sp. had a good fatty acid profile containing high proportion...

  5. Characterization and application of a novel class II thermophilic peroxidase from Myceliophthora thermophila in biosynthesis of polycatechol.

    Science.gov (United States)

    Zerva, Anastasia; Christakopoulos, Paul; Topakas, Evangelos

    2015-01-01

    A peroxidase from the thermophilic fungus Myceliophthora thermophila that belongs to ascomycete Class II based on PeroxiBase classification was functionally expressed in methylotrophic yeast Pichia pastoris. The putative peroxidase from the genomic DNA was successfully cloned in P. pastoris X-33 under the transcriptional control of the alcohol oxidase (AOX1) promoter. The heterologous production was greatly enhanced by the addition of hemin with a titer of 0.41 U mL(-1) peroxidase activity at the second day of incubation. The recombinant enzyme was purified to homogeneity (50 kDa) and characterized using a series of phenolic substrates that indicated similar characteristics with those of generic peroxidases. In addition, the enzyme was found thermostable, retaining its activity for temperatures up to 60 °C after eight hours incubation. Moreover, the enzyme displayed remarkable H2O2 stability, retaining more than 80% of its initial activity after 24h incubation in 5000-fold molar excess of H2O2. The ability of the peroxidase to polymerize catechol at high superoxide concentrations, together with its high thermostability and substrate specificity, indicate a potential commercial significance of the enzyme.

  6. Characterization of Deciliation-Regeneration Process of Tetrahymena Pyriformis for Cellular Robot Fabrication

    Institute of Scientific and Technical Information of China (English)

    Dal Hyung Kim; Sean E. Brigandi; Paul Kim; Doyoung Byun; Min Jun Kim

    2011-01-01

    Artificial magnetotactic Tetrahymena pyriformis GL (T. pyriformis) cells were created by the internalization of iron oxide nano particles and became controllable with a time-varying external magnetic field. Thus, T. pyriformis can be utilized as a cellular robot to conduct micro-scale tasks such as transportation and manipulation. To complete these tasks, loading inorganic or organic materials onto the cell body is essential, but functionalization of the cell membrane is obstructed by their motile organelles, cilia. Dibucaine HCl, a local anesthetic, removes the cilia from the cell body, and the functional group would be absorbed more efficiently during cilia regeneration. In this paper, we characterize the recovery of artificial magnetotactic T.pyriformis after the deciliation process to optimize a cellular robot fabrication process. After sufficient time to recover, the motility rate and the average velocity of the deciliated cells were six and ten percent lower than that of non-deciliated cells, respectively. We showed that the motile cells after recovery can still be controlled using magnetotaxis, making T. pyriformis a good candidate to be used as a cellular robot.

  7. The accidental protozoologist--my journey through the world of ciliates.

    Science.gov (United States)

    Bleyman, Lea K

    2003-01-01

    The Past-President's Address has been the opportunity for the speaker to reminisce about the road traveled to get to this time in life. In this paper, I continue in that tradition. During my journey to the present day, I visited different laboratories, studying the genetics of mating and mating types in Paramecium, Tetrahymena, Blepharisma and Euplotes. I have met and worked with many distinguished scientists, including other Past-Presidents of the Society. I also became an active participant in the Society of Protozoologists. I hope the recounting of my trip will be both entertaining and enlightening.

  8. Ciliate ingestion and digestion: flow cytometric measurements and regrowth of a digestion-resistant campylobacter jejuni

    Science.gov (United States)

    We developed a method to measure ingestion and digestion rates of bacterivorous protists feeding on pathogenic bacteria. We tested this method using the enteric bacteria Campylobacter jejuni and a freshwater colpodid ciliate. Campylobacter and a non-pathogenic bacteria isolated from the environment ...

  9. Modeling the distribution of ciliate protozoa in the reticulo-rumen using linear programming

    NARCIS (Netherlands)

    Hook, S.E.; Dijkstra, J.; Wright, A.G.; McBride, B.W.; France, J.

    2012-01-01

    The flow of ciliate protozoa from the reticulo-rumen is significantly less than expected given the total density of rumen protozoa present. To maintain their numbers in the reticulo-rumen, protozoa can be selectively retained through association with feed particles and the rumen wall. Few mathematic

  10. Ciliated protozoa community of a combined UASB-activated sludge system in southeastern Brazil.

    Science.gov (United States)

    Siqueira-Castro, Isabel Cristina Vidal; Greinert-Goulart, Juliane Araújo; Rossetto, Renato; Guimarães, José Roberto; Franco, Regina Maura Bueno

    2016-12-01

    The aims of the present study were (1) to evaluate the abundance and taxonomic composition of ciliated protozoa in the activated sludge of a full-scale combined anaerobic-aerobic system operating in a tropical country and (2) to study the relationship between the effluent quality, the physicochemical variables, and the ciliates present in the operating system. The total ciliate fauna of the activated sludge of the Piçarrão Wastewater Treatment Plant (Piçarrão WWTP) was composed of 36 morphospecies belonging to 33 genera. These included 21 species observed in the activated sludge samples on the day of collection and 15 species found in cultures. The activated sludge of the Piçarrão WWTP contained a diversified ciliate community composed mainly of indicator organisms. The most frequently occurring morphospecies were Aspidisca cicada, Vorticella spp., Gastronauta aloisi, Acineria uncinata, and Epistylis plicatilis complex. These results showed that satisfactory operating conditions prevailed at the Piçarrão WWTP. In the combined UASB-activated sludge system, the presence of Aspidisca cicada suggests the occurrence of denitrification in the process while the presence of Acineria uncinata and G. alosi indicates the removal of carbonaceous organic matter.

  11. Effects of histamine on ciliary beat frequency of ciliated cells from guinea pigs nasal mucosa.

    Science.gov (United States)

    An, Fengwei; Xing, Lijun; Zhang, Zhiqiang; Chen, Lei

    2015-10-01

    We aimed to investigate the effect of histamine on ciliary beat frequency (CBF) through combining high-speed digital microscopy and patch-clamp technology. Ciliated cells were obtained from septum and turbinate of 90-120-day-old healthy male guinea pigs. Tight seal was formed by applying negative pressure on the glass electrode after the drawing and pushing progress. Then, we enrolled high-speed digital microscopy to measure CBF before and after treatment with histamine of different concentrations ranging from 10(-6) to 10(-1) mol/L in Hank's solution and D-Hank's solution as well as after administrating adenosine triphosphate. One-way ANOVA, Student's t test or Kruskal-Wallis test was used for statistical comparisons. Glass electrode fix up ciliated cell is available at tip diameter of 2-5 μm and negative pressure of 10-20 cmH2O column. The baseline CBF in Hank's solution was higher than in D-Hank's solution. Treatment with 10(-6)-l0(-3) mol/L histamine of concentrations can stimulate a rise of CBF. Nevertheless, CBF in all groups decreased to baseline CBF within 20 min. Generally, 10(-2) mol/L histamine can stimulate a rise of CBF; meanwhile, the high concentration of histamine killed 50% ciliated cell. Histamine at 10(-1) mol/L killed all ciliated cells. Ciliary beating activity decreased in Ca(2+)-free solution. Moreover, adenosine triphosphate could increase CBF effectively after the stimulation effect of histamine. We construct an effective technology integrating patch-clamp technique with CBF measurements on ciliated cells. Extracellular histamine stimulation could increase CBF effectively.

  12. Bose-Einstein condensates form in heuristics learned by ciliates deciding to signal 'social' commitments.

    Science.gov (United States)

    Clark, Kevin B

    2010-03-01

    Fringe quantum biology theories often adopt the concept of Bose-Einstein condensation when explaining how consciousness, emotion, perception, learning, and reasoning emerge from operations of intact animal nervous systems and other computational media. However, controversial empirical evidence and mathematical formalism concerning decoherence rates of bioprocesses keep these frameworks from satisfactorily accounting for the physical nature of cognitive-like events. This study, inspired by the discovery that preferential attachment rules computed by complex technological networks obey Bose-Einstein statistics, is the first rigorous attempt to examine whether analogues of Bose-Einstein condensation precipitate learned decision making in live biological systems as bioenergetics optimization predicts. By exploiting the ciliate Spirostomum ambiguum's capacity to learn and store behavioral strategies advertising mating availability into heuristics of topologically invariant computational networks, three distinct phases of strategy use were found to map onto statistical distributions described by Bose-Einstein, Fermi-Dirac, and classical Maxwell-Boltzmann behavior. Ciliates that sensitized or habituated signaling patterns to emit brief periods of either deceptive 'harder-to-get' or altruistic 'easier-to-get' serial escape reactions began testing condensed on initially perceived fittest 'courting' solutions. When these ciliates switched from their first strategy choices, Bose-Einstein condensation of strategy use abruptly dissipated into a Maxwell-Boltzmann computational phase no longer dominated by a single fittest strategy. Recursive trial-and-error strategy searches annealed strategy use back into a condensed phase consistent with performance optimization. 'Social' decisions performed by ciliates showing no nonassociative learning were largely governed by Fermi-Dirac statistics, resulting in degenerate distributions of strategy choices. These findings corroborate

  13. De novo transcriptomes of a mixotrophic and a heterotrophic ciliate from marine plankton.

    Directory of Open Access Journals (Sweden)

    Luciana F Santoferrara

    Full Text Available Studying non-model organisms is crucial in the context of the current development of genomics and transcriptomics for both physiological experimentation and environmental characterization. We investigated the transcriptomes of two marine planktonic ciliates, the mixotrophic oligotrich Strombidium rassoulzadegani and the heterotrophic choreotrich Strombidinopsis sp., and their respective algal food using Illumina RNAseq. Our aim was to characterize the transcriptomes of these contrasting ciliates and to identify genes potentially involved in mixotrophy. We detected approximately 10,000 and 7,600 amino acid sequences for S. rassoulzadegani and Strombidinopsis sp., respectively. About half of these transcripts had significant BLASTP hits (E-value <10-6 against previously-characterized sequences, mostly from the model ciliate Oxytricha trifallax. Transcriptomes from both the mixotroph and the heterotroph species provided similar annotations for GO terms and KEGG pathways. Most of the identified genes were related to housekeeping activity and pathways such as the metabolism of carbohydrates, lipids, amino acids, nucleotides, and vitamins. Although S. rassoulzadegani can keep and use chloroplasts from its prey, we did not find genes clearly linked to chloroplast maintenance and functioning in the transcriptome of this ciliate. While chloroplasts are known sources of reactive oxygen species (ROS, we found the same complement of antioxidant pathways in both ciliates, except for one enzyme possibly linked to ascorbic acid recycling found exclusively in the mixotroph. Contrary to our expectations, we did not find qualitative differences in genes potentially related to mixotrophy. However, these transcriptomes will help to establish a basis for the evaluation of differential gene expression in oligotrichs and choreotrichs and experimental investigation of the costs and benefits of mixotrophy.

  14. An important base triple anchors the substrate helix recognition surface within the Tetrahymena ribozyme active site.

    Science.gov (United States)

    Szewczak, A A; Ortoleva-Donnelly, L; Zivarts, M V; Oyelere, A K; Kazantsev, A V; Strobel, S A

    1999-09-28

    Key to understanding the structural biology of catalytic RNA is determining the underlying networks of interactions that stabilize RNA folding, substrate binding, and catalysis. Here we demonstrate the existence and functional importance of a Hoogsteen base triple (U300.A97-U277), which anchors the substrate helix recognition surface within the Tetrahymena group I ribozyme active site. Nucleotide analog interference suppression analysis of the interacting functional groups shows that the U300.A97-U277 triple forms part of a network of hydrogen bonds that connect the P3 helix, the J8/7 strand, and the P1 substrate helix. Product binding and substrate cleavage kinetics experiments performed on mutant ribozymes that lack this base triple (C A-U, U G-C) or replace it with the isomorphous C(+).G-C triple show that the A97 Hoogsteen triple contributes to the stabilization of both substrate helix docking and the conformation of the ribozyme's active site. The U300. A97-U277 base triple is not formed in the recently reported crystallographic model of a portion of the group I intron, despite the presence of J8/7 and P3 in the RNA construct [Golden, B. L., Gooding, A. R., Podell, E. R. & Cech, T. R. (1998) Science 282, 259-264]. This, along with other biochemical evidence, suggests that the active site in the crystallized form of the ribozyme is not fully preorganized and that substantial rearrangement may be required for substrate helix docking and catalysis.

  15. Effect of concanavalin A (Con-A) on the hormone production of the unicellular Tetrahymena and the immune cells of the rat. A comparative study.

    Science.gov (United States)

    Csaba, György; Pállinger, Eva

    2008-01-01

    Tetrahymena populations were treated with 10(-15) g ml(-1) or 10(-6) g ml(-1) concanavalin-A (Con-A) in tryptone-yeast medium for 1 h. Rat peritoneal immune cells (mast cells, lymphocytes, monocyte-granulocyte group) were also treated with 10(-6) g ml(-1) Con-A, for 1 h. The cells' hormone (ACTH, histamine, serotonin, endorphin, triiodothyronine (T(3))) content was measured by using immunocytochemistry and flow cytometry. The extremely low dose of Con-A universally and significantly elevated the hormone contents, while the result of higher dose was uncertain. In the immune cells, Con-A significantly decreased the ACTH level in each cell type and histamine level in mast cells. The results demonstrate the very high sensitivity of Tetrahymena receptors for a non-hormone (lectin) molecule, which can bind to the insulin receptors and mimics the effect of insulin. The results also show that Tetrahymena receptors are more sensitive to lower concentrations of molecules than to higher ones. The universal hormone-production stimulating effect of Con-A-which is observed in Tetrahymena-is specified in rat.

  16. Comparison of primary and secondary 26S rRNA structures in two Tetrahymena species: evidence for a strong evolutionary and structural constraint in expansion segments

    DEFF Research Database (Denmark)

    Engberg, J; Nielsen, Henrik; Lenaers, G

    1990-01-01

    criteria. The majority of the nucleotide changes between the two Tetrahymena LSU rRNAs and the positions of a relatively large deletion and of the processing cleavage sites resulting in the generation of the hidden break are all located within the so-called divergent domains or expansion segments...

  17. Colonization of periphytic ciliated protozoa on an artificial substrate in mariculture waters with notes on responses to environmental factors

    Institute of Scientific and Technical Information of China (English)

    Jiqiu Li; Henglong Xu; Xiaofeng Lin; Weibo Song

    2009-01-01

    Colonization of periphytic ciliates and their usefulness for monitoring water quality were evaluated using the glass slide method in two enclosed mariculture ponds used to culture crab larva and in a natural seawater reservoir. The results revealed that (1) the ciliate species composition and colonizing process differed between the culturing ponds and the natural reservoir and (2) the dominant ciliate species showed a greater distribution in terms of both the abundance and the occurrence frequency. This study also demonstrated that structural parameters were strongly related to water conditions. For example, the abundance was positively associated with NO-3-N and soluble reactive phosphate (P < 0.05), whereas the species number, species diversity and evenness were negatively correlated with nutrients (e.g. NO-3N and NH3-N) and temperature (P < 0.05). These findings support the evidence that periphytic ciliates are useful bioindicators of water quality in enclosed mariculture ecosystems.

  18. DNA-guided establishment of nucleosome patterns within coding regions of a eukaryotic genome.

    Science.gov (United States)

    Beh, Leslie Y; Müller, Manuel M; Muir, Tom W; Kaplan, Noam; Landweber, Laura F

    2015-11-01

    A conserved hallmark of eukaryotic chromatin architecture is the distinctive array of well-positioned nucleosomes downstream from transcription start sites (TSS). Recent studies indicate that trans-acting factors establish this stereotypical array. Here, we present the first genome-wide in vitro and in vivo nucleosome maps for the ciliate Tetrahymena thermophila. In contrast with previous studies in yeast, we find that the stereotypical nucleosome array is preserved in the in vitro reconstituted map, which is governed only by the DNA sequence preferences of nucleosomes. Remarkably, this average in vitro pattern arises from the presence of subsets of nucleosomes, rather than the whole array, in individual Tetrahymena genes. Variation in GC content contributes to the positioning of these sequence-directed nucleosomes and affects codon usage and amino acid composition in genes. Given that the AT-rich Tetrahymena genome is intrinsically unfavorable for nucleosome formation, we propose that these "seed" nucleosomes--together with trans-acting factors--may facilitate the establishment of nucleosome arrays within genes in vivo, while minimizing changes to the underlying coding sequences.

  19. Automated image analysis reveals the dynamic 3-dimensional organization of multi-ciliary arrays.

    Science.gov (United States)

    Galati, Domenico F; Abuin, David S; Tauber, Gabriel A; Pham, Andrew T; Pearson, Chad G

    2015-12-23

    Multi-ciliated cells (MCCs) use polarized fields of undulating cilia (ciliary array) to produce fluid flow that is essential for many biological processes. Cilia are positioned by microtubule scaffolds called basal bodies (BBs) that are arranged within a spatially complex 3-dimensional geometry (3D). Here, we develop a robust and automated computational image analysis routine to quantify 3D BB organization in the ciliate, Tetrahymena thermophila. Using this routine, we generate the first morphologically constrained 3D reconstructions of Tetrahymena cells and elucidate rules that govern the kinetics of MCC organization. We demonstrate the interplay between BB duplication and cell size expansion through the cell cycle. In mutant cells, we identify a potential BB surveillance mechanism that balances large gaps in BB spacing by increasing the frequency of closely spaced BBs in other regions of the cell. Finally, by taking advantage of a mutant predisposed to BB disorganization, we locate the spatial domains that are most prone to disorganization by environmental stimuli. Collectively, our analyses reveal the importance of quantitative image analysis to understand the principles that guide the 3D organization of MCCs.

  20. Molecular evidence that phylogenetically diverged ciliates are active in microbial mats of deep-sea cold-seep sediment.

    Science.gov (United States)

    Takishita, Kiyotaka; Kakizoe, Natsuki; Yoshida, Takao; Maruyama, Tadashi

    2010-01-01

    Cold seeps are areas of the seafloor where hydrogen sulfide- and methane-rich fluid seepage occurs, often sustaining chemosynthetic ecosystems. It is well known that both archaea and bacteria oxidize sulfides and methane to produce chemical energy and that several endemic animals use this energy to thrive in cold seeps. On the other hand, there is little knowledge regarding diversity and ecology of microbial eukaryotes in this ecosystem. In this study we isolated environmental RNA and DNA from microbial mats of cold-seep sediment in Sagami Bay, Japan, and retrieved eukaryotic small-subunit ribosomal RNA sequences with polymerase chain reaction methods followed by clone library construction. Most RNA-derived clones obtained were from ciliates, although DNA-derived clones were mainly from the fungus Cryptococcus curvatus, suggesting that ciliates are active in the environment. The ciliate sequences were phylogenetically diverse, and represented eight known class lineages as well as undesignated lineages. Because most ciliates are bacterivorous, it is highly likely that the ciliates for which sequences were recovered play a role in the food web of this ecosystem as grazers of microbial mats. In addition, given that the environment studied is under highly reduced (anoxic) conditions, based on the prokaryotic community structure deduced from T-RFLP profiles, the ciliates detected may be obligatory or facultative anaerobes.

  1. The bacterivory of interstitial ciliates in association with bacterial biomass and production in the hyporheic zone of a lowland stream.

    Science.gov (United States)

    Königs, Sascha; Cleven, Ernst-Josef

    2007-07-01

    Rates of bacteria ingestion by interstitial ciliates were estimated and compared to bacterial biomass and production. Investigation was carried out in the hyporheic zone of a lowland stream. FISH was applied to quantitatively determine bacteria within the ciliate's food vacuoles. To estimate bacteria ingestion rates using FISH, we had to strike a new path. When numbers of bacteria in the food vacuoles remains constant with time (bacterial digestion and ingestion are at equilibrium), ingestion rate can be estimated based on the digestion time and the average number of bacteria per cell. Ciliate community was predominantly composed of bacterivorous ciliates. FISH-signals deriving from ingested bacteria were detected in Cinetochilum margaritaceum, 'other small scuticociliates', Pleuronema spp., and Vorticella spp. Ingestion rates for these taxa were 78, 150, 86, and 38 bacteria ind(-1) h(-1), respectively. The grazing impacts on bacterial biomass and carbon production were calculated based on these ingestion rates. Ciliate grazing caused a decrease in bacterial biomass of 0.024% day(-1) and in bacterial carbon production of 1.60%. These findings suggest that interstitial ciliate grazing impact on bacteria biomass and production was too low to represent an important link in the carbon flow of the hyporheic zone under study.

  2. Ciliates and their picophytoplankton-feeding activity in a high-altitude warm-monomictic saline lake.

    Science.gov (United States)

    Pestová, Dana; Macek, Miroslav; Elena Martínez Pérez, María

    2008-02-01

    The impact of feeding on autotrophic picoplankton (APP) on the ciliate composition of the assemblage was surveyed monthly along a depth gradient in the maar crater, athalassohaline, warm monomictic Lake Alchichica (Puebla, Mexico) from June 2003 to December 2005. Numbers of APP were evaluated from their autofluorescence. DAPI staining and the Fluorescently Labeled Bacteria technique were employed to count ciliates and estimate their feeding rates. A total of 38 taxa of ciliates have been identified using Quantitative Protargol Staining. Peritrichs followed by minute spirotrichs (particularly Halteria grandinella) often numerically dominated the ciliate assemblage and emerged as the most efficient APP feeders. A maximum of 54 ciliate cells ml(-1) was observed in the surface layer at the end of the mixing period, during the development of diatoms (Cyclotella alchichicana), the cyanobacterial bloom (Nodularia sp.) and its decay. Vorticellids (Pelagovorticella natans, Vorticella sp.) had the highest APP uptake (median 130 APP cil(-1) h(-1)). Mixotrophic Euplotes cf. daidaleos were important APP grazers near the oxycline. Scuticociliates (Cyclidium glaucoma, Uronema nigricans and an anaerobic cf. Isocyclidium globossum), were numerically dominant within the hypolimnetic assemblages and did not ingest APP. Generally, APP were not an important food source for the majority of the ciliate assemblage, being positively selected by a few species during the APP decay in aerobic and microaerobic conditions.

  3. Developing and Integrating Advanced Movement Features Improves Automated Classification of Ciliate Species.

    Directory of Open Access Journals (Sweden)

    Ali Soleymani

    Full Text Available Recent advances in tracking technologies such as GPS or video tracking systems describe the movement paths of individuals in unprecedented details and are increasingly used in different fields, including ecology. However, extracting information from raw movement data requires advanced analysis techniques, for instance to infer behaviors expressed during a certain period of the recorded trajectory, or gender or species identity in case data is obtained from remote tracking. In this paper, we address how different movement features affect the ability to automatically classify the species identity, using a dataset of unicellular microbes (i.e., ciliates. Previously, morphological attributes and simple movement metrics, such as speed, were used for classifying ciliate species. Here, we demonstrate that adding advanced movement features, in particular such based on discrete wavelet transform, to morphological features can improve classification. These results may have practical applications in automated monitoring of waste water facilities as well as environmental monitoring of aquatic systems.

  4. Necessity Is the Mother of Invention: Ciliates, Transposons, and Transgenerational Inheritance.

    Science.gov (United States)

    Allen, Sarah E; Nowacki, Mariusz

    2017-03-01

    Ciliates are a fascinating model system for the study of the interaction between eukaryotic germlines and somatic lines, especially with regard to the invasion and defence against transposable elements. They separate their germline and somatic line into two nuclei within the same cell, and they silence transposons and repetitive elements by way of deleting them from their somatic genome. This large-scale deletion event uses a series of intricate sequence targeting pathways involving small RNAs and transposases, part of which consists of a transnuclear comparison between maternal soma and daughter germline. We present recent progress in this dynamic field, and argue that these DNA targeting pathways provide an optimal system for the transgenerational inheritance of acquired traits. Ciliates thus also demonstrate the evolutionary value of transposable elements, both as sources of sequence diversity and also as drivers of adaptive evolution by necessitating defensive systems.

  5. Dependence of reproductive rate on cell size and temperature in freshwater ciliated protozoa

    Energy Technology Data Exchange (ETDEWEB)

    Finlay, B.J.

    1977-01-01

    Reproductive rates have been calculated for ten species of ciliated protozoa in defined conditions. Interspecific double log regressions of generation time vs. cell volume have been computed at each of three temperatures (8.5/sup 0/C, 15/sup 0/C, and 20/sup 0/C) indicating a significant dependence of reproductive rate on cell size. Recorded generation times varied from 6.38 h in Vorticella microstoma at 20/sup 0/C to 1004 h in Spirostomum teres at 8.5/sup 0/C. These values correspond to a range in r/sub m/ (day)/sup -1/ of 2.607 to 0.017 and lambda (day)/sup -1/ of 13.554 to 1.017. The relationship between these data and similar published data for marine ciliates is examined and the value of such regressions in ecological studies of the protozoa is discussed.

  6. Ciliates learn to diagnose and correct classical error syndromes in mating strategies

    Directory of Open Access Journals (Sweden)

    Kevin Bradley Clark

    2013-08-01

    Full Text Available Preconjugal ciliates learn classical repetition error-correction codes to safeguard mating messages and replies from corruption by rivals and local ambient noise. Because individual cells behave as memory channels with Szilárd engine attributes, these coding schemes also might be used to limit, diagnose, and correct mating-signal errors due to noisy intracellular information processing. The present study, therefore, assessed whether heterotrich ciliates effect fault-tolerant signal planning and execution by modifying engine performance, and consequently entropy content of codes, during mock cell-cell communication. Socially meaningful serial vibrations emitted from an ambiguous artificial source initiated ciliate behavioral signaling performances known to advertise mating fitness with varying courtship strategies. Microbes, employing calcium-dependent Hebbian-like decision making, learned to diagnose then correct error syndromes by recursively matching Boltzmann entropies between signal planning and execution stages via power or refrigeration cycles. All eight serial contraction and reversal strategies incurred errors in entropy magnitude by the execution stage of processing. Absolute errors, however, subtended expected threshold values for single bit-flip errors in three-bit replies, indicating coding schemes protected information content throughout signal production. Ciliate preparedness for vibrations selectively and significantly affected the magnitude and valence of Szilárd engine performance during modal and nonmodal strategy corrective cycles. But entropy fidelity for all replies mainly improved across learning trials as refinements in engine efficiency. Fidelity neared maximum levels for only modal signals coded in resilient three-bit repetition error-correction sequences. Together, these findings demonstrate microbes can elevate survival/reproductive success by learning to implement classical fault-tolerant information processing in

  7. Assessing mariculture water quality with the structural and functional characteristics of a ciliate community

    Institute of Scientific and Technical Information of China (English)

    LI Jiqiu; XU Henglong; LIN Xiaofeng; AL-RASHEID Khaled A.S.

    2011-01-01

    Ciliated protozoa play important roles in micro-ecosystems, especially in marine biotopes. However, few studies have been carried out on the periphytic, or aufwuch, forms in mariculture waters so far. In this study, we sampled periphytic ciliate communities in two closed mariculture ponds (ponds CP1 and CP2) and a natural seawater reservoir (pond RP) using a glass slide method to evaluate their colonizing processes and general ecological features, as well as their application as water quality indicators. We analyzed species compositions, structural parameters (species number, richness, diversity, evenness, abundance and dBP) and functional parameters (G, Seq, and T90%). Pond RP was characterized by higher levels of structural parameters (except for abundance and dBp) and more equal proportion of the major taxonomic groups. The values of 5eq were significantly higher in pond RP and similar in both pond CP1 and CP2. It was also demonstrated that environmental factors, including NO2-H, NO3-H, NH3-H, soluble reactive phosphate, temperature and pH, were the first principal factors affecting the communities. Among them, temperature and chemical factors were all significantly and negatively correlated with species number (P<0.01), richness (P<0.01), diversity (P<0.01), and positive correlated with abundance (P<0.01). Opposite correlations between pH and structural parameters were observed. This study showed that there were significant differences in species composition, structural parameters and functional parameters of the periphytic ciliate communities among the ponds, which were in agreement with the water quality. Results of this study confirmed the periphytic ciliate communities to be useful bioindicators of water quality in intensive mariculture waters.

  8. Morphological Studies on the Infraciliature of a Planktonic Ciliate, Tintinnopsis brasiliensis (Ciliophora: Tintinina)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A poorly-described marine planktonic ciliate, Tintinnopsis brasiliensis Kofoid & Campbell, 1929, collected from the Taiping Cape of Qingdao, China, was morphologically investigated based on permanent preparation after protargol impregnation and was compared with other related congeners. According to the infraciliature, three ciliary groups can be recognized, which reveals a very stable structure among specimens and denotes that the pattern of infraciliature is, apart from the features of the lorica, a highly reliable criterion for species identification.

  9. Lethal giant larvae 2 regulates development of the ciliated organ Kupffer's vesicle.

    Science.gov (United States)

    Tay, Hwee Goon; Schulze, Sabrina K; Compagnon, Julien; Foley, Fiona C; Heisenberg, Carl-Philipp; Yost, H Joseph; Abdelilah-Seyfried, Salim; Amack, Jeffrey D

    2013-04-01

    Motile cilia perform crucial functions during embryonic development and throughout adult life. Development of organs containing motile cilia involves regulation of cilia formation (ciliogenesis) and formation of a luminal space (lumenogenesis) in which cilia generate fluid flows. Control of ciliogenesis and lumenogenesis is not yet fully understood, and it remains unclear whether these processes are coupled. In the zebrafish embryo, lethal giant larvae 2 (lgl2) is expressed prominently in ciliated organs. Lgl proteins are involved in establishing cell polarity and have been implicated in vesicle trafficking. Here, we identified a role for Lgl2 in development of ciliated epithelia in Kupffer's vesicle, which directs left-right asymmetry of the embryo; the otic vesicles, which give rise to the inner ear; and the pronephric ducts of the kidney. Using Kupffer's vesicle as a model ciliated organ, we found that depletion of Lgl2 disrupted lumen formation and reduced cilia number and length. Immunofluorescence and time-lapse imaging of Kupffer's vesicle morphogenesis in Lgl2-deficient embryos suggested cell adhesion defects and revealed loss of the adherens junction component E-cadherin at lateral membranes. Genetic interaction experiments indicate that Lgl2 interacts with Rab11a to regulate E-cadherin and mediate lumen formation that is uncoupled from cilia formation. These results uncover new roles and interactions for Lgl2 that are crucial for both lumenogenesis and ciliogenesis and indicate that these processes are genetically separable in zebrafish.

  10. Lethal giant larvae 2 regulates development of the ciliated organ Kupffer’s vesicle

    Science.gov (United States)

    Tay, Hwee Goon; Schulze, Sabrina K.; Compagnon, Julien; Foley, Fiona C.; Heisenberg, Carl-Philipp; Yost, H. Joseph; Abdelilah-Seyfried, Salim; Amack, Jeffrey D.

    2013-01-01

    Motile cilia perform crucial functions during embryonic development and throughout adult life. Development of organs containing motile cilia involves regulation of cilia formation (ciliogenesis) and formation of a luminal space (lumenogenesis) in which cilia generate fluid flows. Control of ciliogenesis and lumenogenesis is not yet fully understood, and it remains unclear whether these processes are coupled. In the zebrafish embryo, lethal giant larvae 2 (lgl2) is expressed prominently in ciliated organs. Lgl proteins are involved in establishing cell polarity and have been implicated in vesicle trafficking. Here, we identified a role for Lgl2 in development of ciliated epithelia in Kupffer’s vesicle, which directs left-right asymmetry of the embryo; the otic vesicles, which give rise to the inner ear; and the pronephric ducts of the kidney. Using Kupffer’s vesicle as a model ciliated organ, we found that depletion of Lgl2 disrupted lumen formation and reduced cilia number and length. Immunofluorescence and time-lapse imaging of Kupffer’s vesicle morphogenesis in Lgl2-deficient embryos suggested cell adhesion defects and revealed loss of the adherens junction component E-cadherin at lateral membranes. Genetic interaction experiments indicate that Lgl2 interacts with Rab11a to regulate E-cadherin and mediate lumen formation that is uncoupled from cilia formation. These results uncover new roles and interactions for Lgl2 that are crucial for both lumenogenesis and ciliogenesis and indicate that these processes are genetically separable in zebrafish. PMID:23482490

  11. Unfolding Thermodynamics of Cysteine-Rich Proteins and Molecular Thermal-Adaptation of Marine Ciliates

    Directory of Open Access Journals (Sweden)

    Giorgia Cazzolli

    2013-11-01

    Full Text Available Euplotes nobilii and Euplotes raikovi are phylogenetically closely allied species of marine ciliates, living in polar and temperate waters, respectively. Their evolutional relation and the sharply different temperatures of their natural environments make them ideal organisms to investigate thermal-adaptation. We perform a comparative study of the thermal unfolding of disulfide-rich protein pheromones produced by these ciliates. Recent circular dichroism (CD measurements have shown that the two psychrophilic (E. nobilii and mesophilic (E. raikovi protein families are characterized by very different melting temperatures, despite their close structural homology. The enhanced thermal stability of the E. raikovi pheromones is realized notwithstanding the fact that these proteins form, as a rule, a smaller number of disulfide bonds. We perform Monte Carlo (MC simulations in a structure-based coarse-grained (CG model to show that the higher stability of the E. raikovi pheromones is due to the lower locality of the disulfide bonds, which yields a lower entropy increase in the unfolding process. Our study suggests that the higher stability of the mesophilic E. raikovi phermones is not mainly due to the presence of a strongly hydrophobic core, as it was proposed in the literature. In addition, we argue that the molecular adaptation of these ciliates may have occurred from cold to warm, and not from warm to cold. To provide a testable prediction, we identify a point-mutation of an E. nobilii pheromone that should lead to an unfolding temperature typical of that of E. raikovi pheromones.

  12. Chromosome copy number variation and control in the ciliate Chilodonella uncinata.

    Directory of Open Access Journals (Sweden)

    Kevin J Spring

    Full Text Available Copy number variations are widespread in eukaryotes. The unusual genome architecture of ciliates, in particular, with its process of amitosis in macronuclear division, provides a valuable model in which to study copy number variation. The current model of amitosis envisions stochastic distribution of macronuclear chromosomes during asexual reproduction. This suggests that amitosis is likely to result in high levels of copy number variation in ciliates, as dividing daughter cells can have variable copy numbers of chromosomes if chromosomal distribution during amitosis is a stochastic process. We examined chromosomal distribution during amitosis in Chilodonella uncinata, a ciliate with gene-size macronuclear chromosomes. We quantified 4 chromosomes in evolving populations of C. uncinata and modeled the amitotic distribution process. We found that macronuclear chromosomes differ in copy number from one another but that copy number does not change as expected under a stochastic process. The chromosome carrying SSU increased in copy number, which is consistent with selection to increase abundance; however, two other studied chromosomes displayed much lower than expected among-line variance. Our models suggest that balancing selection is sufficient to explain the observed maintenance of chromosome copy during asexual reproduction.

  13. Integrative taxonomy of ciliates: Assessment of molecular phylogenetic content and morphological homology testing.

    Science.gov (United States)

    Vďačný, Peter

    2017-02-24

    The very diverse and comparatively complex morphology of ciliates has given rise to numerous taxonomic concepts. However, the information content of the utilized molecular markers has seldom been explored prior to phylogenetic analyses and taxonomic decisions. Likewise, robust testing of morphological homology statements and the apomorphic nature of diagnostic characters of ciliate taxa is rarely carried out. Four phylogenetic techniques that may help address these issues are reviewed. (1) Split spectrum analysis serves to determine the exact number and quality of nucleotide positions supporting individual nodes in phylogenetic trees and to discern long-branch artifacts that cause spurious phylogenies. (2) Network analysis can depict all possible evolutionary trajectories inferable from the dataset and locate and measure the conflict between them. (3) A priori likelihood mapping tests the suitability of data for reconstruction of a well resolved tree, visualizes the tree-likeness of quartets, and assesses the support of an internal branch of a given tree topology. (4) Reconstruction of ancestral morphologies can be applied for analyzing homology and apomorphy statements without circular reasoning. Since these phylogenetic tools are rarely used, their principles and interpretation are introduced and exemplified using various groups of ciliates. Finally, environmental sequencing data are discussed in this light.

  14. Methods for the cultivation of ciliated protozoa from the large intestine of horses.

    Science.gov (United States)

    Bełżecki, Grzegorz; Miltko, Renata; Michałowski, Tadeusz; McEwan, Neil R

    2016-01-01

    This paper describes cultivation methods for ciliates from the digestive tract of horses. Members of three different genera were successfully grown in vitro for short periods of time. However, only cells belonging to the genus Blepharocorys, which resides in the horse's large intestine, were maintained for longer periods. This Blepharocorys culture was successfully grown in vitro after inoculation of freshly excreted horse faeces in culture medium containing a population of bacteria. The ciliates survived for over six months, and the density of their population varied between 1.7 × 10(3) and 2.4 × 10(3) cells mL(-1). Favourable conditions for the prolonged cultivation of this ciliate were observed when the medium was prepared by mixing horse faeces and 'caudatum' salt solution in a 1:1 V/V ratio together with food (60% powdered meadow hay, 16% wheat gluten, 12% barley flour and 12% microcrystalline cellulose) supplied as 0.20 mg mL(-1) culture per day.

  15. The ability of the rumen ciliate protozoan Diploplastron affine to digest and ferment starch.

    Science.gov (United States)

    Wereszka, K; Michałowski, T

    2012-07-01

    The ciliate Diploplastron affine is known as a common species of the rumen fauna in cattle and sheep. This protozoon is able to digest cellulose, whereas its amylolytic activity is not well known. The objective of the reported studies was to examine the ability of D. affine to digest starch and to use this polysaccharide to cover the requirement for energy. The enzymatic studies showed that the protozoal cell extract degraded starch to reducing products with the rate being equivalent to 2.4 ± 0.47 μmol/L glucose per mg protein per min. Maltose, maltotriose and a small quantity of glucose were the end products of starch degradation. The degradation rate of maltose was only 0.05 μmol/L glucose per mg protein per min. Two peaks in α-amylase and a single peak in maltase activity were found following molecular filtration of ciliate cell extract, whereas three starch-degrading enzymes were identified by a zymographic technique. Incubation of the bacteria-free ciliates with starch in the presence of antibiotics resulted in a release of volatile fatty acids with the net rate of 25 pmol per protozoan per h. Acetic acid followed by butyric acid was the main product of starch fermentation. The results confirmed the ability of D. affine to utilize starch in energy-yielding processes.

  16. Ciliate biogeography in Antarctic and Arctic freshwater ecosystems: endemism or global distribution of species?

    Science.gov (United States)

    Petz, Wolfgang; Valbonesi, Alessandro; Schiftner, Uwe; Quesada, Antonio; Cynan Ellis-Evans, J

    2007-02-01

    Ciliate diversity was investigated in situ in freshwater ecosystems of the maritime (South Shetland Islands, mainly Livingston Island, 63 degrees S) and continental Antarctic (Victoria Land, 75 degrees S), and the High Arctic (Svalbard, 79 degrees N). In total, 334 species from 117 genera were identified in both polar regions, i.e. 210 spp. (98 genera) in the Arctic, 120 spp. (73 genera) in the maritime and 59 spp. (41 genera) in the continental Antarctic. Forty-four species (13% of all species) were common to both Arctic and Antarctic freshwater bodies and 19 spp. to both Antarctic areas (12% of all species). Many taxa are cosmopolitans but some, e.g. Stentor and Metopus spp., are not, and over 20% of the taxa found in any one of the three areas are new to science. Cluster analysis revealed that species similarity between different biotopes (soil, moss) within a study area was higher than between similar biotopes in different regions. Distinct differences in the species composition of freshwater and terrestrial communities indicate that most limnetic ciliates are not ubiquitously distributed. These observations and the low congruence in species composition between both polar areas, within Antarctica and between high- and temperate-latitude water bodies, respectively, suggest that long-distance dispersal of limnetic ciliates is restricted and that some species have a limited geographical distribution.

  17. Ciliates and the rare biosphere-community ecology and population dynamics.

    Science.gov (United States)

    Weisse, Thomas

    2014-01-01

    Application of deep sequencing technologies to environmental samples and some detailed morphological studies suggest that there is a vast, yet unexplored rare ciliate biosphere, tentatively defined in terms of operational taxonomic units. However, very few studies complemented molecular and phylogenetic data with morphological and ecological descriptions of the species inventory. This is mainly because the sampling effort increases strongly with decreasing species abundance. In spite of this limited knowledge, it is clear that species that are rare under certain environmental conditions (temporal rare biosphere) may become abundant when the physical, chemical, and biological variables of their habitat change. Furthermore, some species may always be present in low numbers if their dispersal rates are exceedingly high (accidental rare biosphere). An intriguing question is whether there are some species that are always rare, i.e., in every suitable environment. This permanent rare biosphere is conceptually different from the temporal rare biosphere. This review characterizes typical aquatic habitats of the rare ciliate biosphere, portrays different scenarios under which some or even many species may be permanently rare (background fauna), and identifies some fundamental questions that need to be addressed to achieve a better understanding of the population dynamics of the rare ciliate biosphere.

  18. Chloroplast symbiosis in a marine ciliate: ecophysiology and the risks and rewards of hosting foreign organelles.

    Science.gov (United States)

    McManus, George B; Schoener, Donald M; Haberlandt, Katharine

    2012-01-01

    Simultaneous use of both heterotrophic and autotrophic metabolism ("mixotrophy") is common among protists. Strombidium rassoulzadegani is a planktonic mixotrophic marine ciliate that saves chloroplasts from its algal food and obtains a nutritional subsidy via photosynthesis. Cultures from the northeast, northwest, and southwest Atlantic Ocean show similar numerical response parameters (maximum growth rate, food concentration at which growth is half its maximum, and threshold food concentration for growth), and some isolates have been maintained in vitro for over 3 years. This ciliate grows equally well when fed on the green alga Tetraselmis chui (strain PLY429) or the cryptophyte Rhodomonas lens (strain RHODO). It appears to be an obligate mixotroph, requiring both food and light to achieve positive growth, when feeding on either of these algae. However, it has also been grown for several weeks (>10 generations) heterotrophically on the dinoflagellate Prorocentrum minimum (strain EXUV) during which it grows better in dark than in light. In this paper, we review the ecology of S. rassoulzadegani, discuss some aspects of its photo- and feeding physiology, and speculate on benefits and costs to the ciliate of chloroplast symbiosis.

  19. Myosin Id is required for planar cell polarity in ciliated tracheal and ependymal epithelial cells.

    Science.gov (United States)

    Hegan, Peter S; Ostertag, Eric; Geurts, Aron M; Mooseker, Mark S

    2015-10-01

    In wild type (WT) tracheal epithelial cells, ciliary basal bodies are oriented such that all cilia on the cell surface beat in the same upward direction. This precise alignment of basal bodies and, as a result, the ciliary axoneme, is termed rotational planar cell polarity (PCP). Rotational PCP in the multi-ciliated epithelial cells of the trachea is perturbed in rats lacking myosin Id (Myo1d). Myo1d is localized in the F-actin and basal body rich subapical cortex of the ciliated tracheal epithelial cell. Scanning and transmission electron microscopy of Myo1d knock out (KO) trachea revealed that the unidirectional bending pattern is disrupted. Instead, cilia splay out in a disordered, often radial pattern. Measurement of the alignment axis of the central pair axonemal microtubules was much more variable in the KO, another indicator that rotational PCP is perturbed. The asymmetric localization of the PCP core protein Vangl1 is lost. Both the velocity and linearity of cilia-driven movement of beads above the tracheal mucosal surface was impaired in the Myo1d KO. Multi-ciliated brain ependymal epithelial cells exhibit a second form of PCP termed translational PCP in which basal bodies and attached cilia are clustered at the anterior side of the cell. The precise asymmetric clustering of cilia is disrupted in the ependymal cells of the Myo1d KO rat. While basal body clustering is maintained, left-right positioning of the clusters is lost.

  20. Building up a QSAR model for toxicity toward Tetrahymena pyriformis by the Monte Carlo method: A case of benzene derivatives.

    Science.gov (United States)

    Toropova, Alla P; Schultz, Terry W; Toropov, Andrey A

    2016-03-01

    Data on toxicity toward Tetrahymena pyriformis is indicator of applicability of a substance in ecologic and pharmaceutical aspects. Quantitative structure-activity relationships (QSARs) between the molecular structure of benzene derivatives and toxicity toward T. pyriformis (expressed as the negative logarithms of the population growth inhibition dose, mmol/L) are established. The available data were randomly distributed three times into the visible training and calibration sets, and invisible validation sets. The statistical characteristics for the validation set are the following: r(2)=0.8179 and s=0.338 (first distribution); r(2)=0.8682 and s=0.341 (second distribution); r(2)=0.8435 and s=0.323 (third distribution). These models are built up using only information on the molecular structure: no data on physicochemical parameters, 3D features of the molecular structure and quantum mechanics descriptors are involved in the modeling process.

  1. Phylogenetic position of Licnophora, Lechriopyla, and Schizocaryum, three unusual ciliates (phylum Ciliophora) endosymbiotic in echinoderms (phylum Echinodermata).

    Science.gov (United States)

    Lynn, Denis H; Strüder-Kypke, Michaela

    2002-01-01

    Various echinoderms are colonized by species from several classes of the Phylum Ciliophora, indicating that the echinoderm "habitat" has been invaded independently on numerous occasions throughout evolutionary history. Two "echinoderm" ciliates whose phylogenetic positions have been problematic are Licnophora macfarlandi Stevens, 1901 and Schizocaryum dogieli Poljansky and Golikova, 1957. Licnophora macfarlandi is an endosymbiont of the respiratory trees of holothuroids, and S. dogieli is found in the esophagus of echinoids. A third species, Lechriopyla mystax Lynch, 1930, is a plagiopylid ciliate found in the intestine of echinoids. Host echinoderms were collected near the Friday Harbor Laboratories, San Juan Island, WA. Specimens of S. dogieli and L. mystax were obtained from the esophagus and intestine, respectively, of the sea urchin Strongylocentrotus pallidus. Specimens of L. macfarlandi were collected from the fluid obtained from the respiratory trees of Parastichopus californicus. Using small subunit ribosomal RNA (SSrRNA) sequences of these three ciliates and a global alignment of SSrRNA sequences of other ciliates, we established the following. 1) Licnophora is a spirotrich ciliate, clearly related to the hypotrichs and stichotrichs; this is corroborated by its possession of macronuclear replication bands. 2) Lechriopyla is the sister genus to Plagiopyla and is a member of the Class Plagiopylea, which was predicted based on its cytology. 3) Schizocaryum clusters in the Class Oligohymenophorea and is most closely related to the scuticociliates; there are currently no morphological features known to relate Schizocaryum to the scuticociliates.

  2. Macronuclear genome structure of the ciliate Nyctotherus ovalis: Single-gene chromosomes and tiny introns

    Directory of Open Access Journals (Sweden)

    Landweber Laura F

    2008-12-01

    Full Text Available Abstract Background Nyctotherus ovalis is a single-celled eukaryote that has hydrogen-producing mitochondria and lives in the hindgut of cockroaches. Like all members of the ciliate taxon, it has two types of nuclei, a micronucleus and a macronucleus. N. ovalis generates its macronuclear chromosomes by forming polytene chromosomes that subsequently develop into macronuclear chromosomes by DNA elimination and rearrangement. Results We examined the structure of these gene-sized macronuclear chromosomes in N. ovalis. We determined the telomeres, subtelomeric regions, UTRs, coding regions and introns by sequencing a large set of macronuclear DNA sequences (4,242 and cDNAs (5,484 and comparing them with each other. The telomeres consist of repeats CCC(AAAACCCCn, similar to those in spirotrichous ciliates such as Euplotes, Sterkiella (Oxytricha and Stylonychia. Per sequenced chromosome we found evidence for either a single protein-coding gene, a single tRNA, or the complete ribosomal RNAs cluster. Hence the chromosomes appear to encode single transcripts. In the short subtelomeric regions we identified a few overrepresented motifs that could be involved in gene regulation, but there is no consensus polyadenylation site. The introns are short (21–29 nucleotides, and a significant fraction (1/3 of the tiny introns is conserved in the distantly related ciliate Paramecium tetraurelia. As has been observed in P. tetraurelia, the N. ovalis introns tend to contain in-frame stop codons or have a length that is not dividable by three. This pattern causes premature termination of mRNA translation in the event of intron retention, and potentially degradation of unspliced mRNAs by the nonsense-mediated mRNA decay pathway. Conclusion The combination of short leaders, tiny introns and single genes leads to very minimal macronuclear chromosomes. The smallest we identified contained only 150 nucleotides.

  3. Using Sorting by Reversal: Breakpoint Graph for Gene Assembly in Ciliates

    Science.gov (United States)

    Brijder, Robert; Jan Hoogeboom, Hendrik

    2007-09-01

    The theory of gene assembly in ciliates has much in common with the theory of sorting by reversal. Both model processes that are based on splicing, and have a fixed begin and end product. The main difference is the type of splicing operations used to obtain the end product from the begin product. In this overview paper we show that the concept of breakpoint graph, known from the theory of sorting by reversal, has many uses in the theory of gene assembly. Our aim is to present the material in an intuitive and informal manner to allow for an efficient introduction into the subject.

  4. On the marine ciliate, Pseudocohnilembus hargisi (Protozoa, ciliophora, scuticociliatida) with comparison of its related species

    Science.gov (United States)

    Gong, Jun; Ma, Hong-Wei; Song, Wei-Bo

    2002-09-01

    The living morphology, nuclear apparatus, infraciliature and silverline system of the poorly-known ciliate Pseudocohnilembus hargisi Evans & Thompson, 1964, collected from a shrimp culture pond in Qingdao, China, were examined by observation of the live specimen; and by the pyridinated carbonate method and Chatton-Lwoff technique. The main characteristics: 13 14 (usually 13) longitudinal or slightly spirally arranged somatic kineties; single contractile vacuole with usually 2 (1 2) pores at posterior ends of the fourth and fifth somatic kineties to the right of the buccal cavity. Several related congeners were compared and morphometrically tabulated.

  5. ON THE MARINE CILIATE, Pseudocohnilembus hargisi (PROTOZOA,CILIOPHORA, SCUTICOCILIATIDA) WITH COMPARISON OF ITS RELATED SPECIES

    Institute of Scientific and Technical Information of China (English)

    龚骏; 马宏伟; 宋微波

    2002-01-01

    The living morphology, nuclear apparatus, infraciliature and silverline system o f the poorly-known ciliate Pseudocohnilembus hargisi Evans & Thompson, 1964 , collected from a shrimp culture pond in Qingdao, China, were examined by obser vation of the live specimen; and by the pyridinated carbonate method and Chatton -Lwoff technique. The main characteristics: 13-14 (usually 13) longitudinal or slightly spirally arranged somatic kineties; single contractile vacuole with usually 2 ( 1-2) pores at posterior ends of the fourth and fifth somatic kineties to the rig ht of the buccal cavity. Several related congeners were compared and morphometri cally tabulated.

  6. Mechanical strain determines the axis of planar polarity in ciliated epithelia

    OpenAIRE

    2015-01-01

    Epithelia containing multiciliated cells align beating cilia along a common planar axis specified by the conserved planar cell polarity (PCP) pathway. Specification of the planar axis is also thought to require a long-range cue to align the axis globally, but the nature of this cue in ciliated and other epithelia remains poorly understood. We examined this issue using the Xenopus larval skin where ciliary flow aligns to the anterior-posterior (A-P) axis. We first show that a planar axis initi...

  7. Ciliate protozoa in the rumen of Kafue lechwe, Kobus leche kafuensis, in Zambia, with the description of four new species.

    Science.gov (United States)

    Imai, S; Tsutsumi, Y; Yumura, S; Mulenga, A

    1992-01-01

    The composition of the rumen ciliate fauna in 76 Kafue lechwe inhabiting a limited area in Zambia was surveyed and five genera containing 24 species with 16 formae belonging to the family Ophryoscolecidae were identified. Four new species belonging to Diplodiniinae were recognized and described as Diplodinium lochinvarense n. sp., Diplodinium leche n. sp., Diplodinium zambiense n. sp., and Metadinium ossiculi n. sp. In addition, Ostracodinium gracile form fissilaminatum Dogiel, 1932 was found for the second time and described as Metadinium fissilaminatum n. comb. The species composition was fairly unusual. Seven of the species have been found only in African wild antelopes and these species were found more frequently than cosmopolitan species. There was no evidence of isotrichid species. The average density of ciliates per 1 ml of the rumen fluid was 25.7 x 10(4), and the number of ciliate species per head of host was 10.8.

  8. Preparation of Ag/AgBr/TiO2 as Catalyst Carriers and Its Damage to Plasmid DNA andTetrahymena

    Institute of Scientific and Technical Information of China (English)

    LIU Liwei; ZHANG Yinlong

    2015-01-01

    The composites based on the TiO2 are potentially used in wetland pollution control. In this work, the biological effect of the Ag/AgBr/TiO2/Active carbon (AC) composites was studied on the plasmid DNA andTetrahymena membrane. The atomic force micrograph (AFM) images showed that, in the presence of the composites under illumination, most pUC18 DNA molecules showed quite different topography and were opened and relaxed circle shapes. After DNA was catalyzed for 40 min, all supercoiled and circular DNA were changed into the linear DNA molecules. The gel electrophoresis experiment confirmed the results and demonstrated the dynamic process of DNA degradation. ATR-FTIR spectra revealed that amide groups and PO2− of the phospho-lipid phospho-diester onTetrahymena surface were oxidized in the presence of the composites under illumination. An increase in the lfuorescence polarization of DPH was observed, relfecting a signiifcant decrease in membrane lfuidity ofTetrahymena.

  9. Expression of Tetrahymena snRNA gene variants including a U1 gene with mutations in the 5' splice site recognition sequence

    DEFF Research Database (Denmark)

    Eugen-Olsen, J; Hagemeister, J J; Hellung-Larsen, P

    1997-01-01

    The expression of U1, U2 and U5 snRNA gene variants has been studied under different physiological states of Tetrahymena. Variants of all three snRNA genes are expressed. Among the snRNAs detected is U1-3, a variant with 66 mutations compared to the normal U1 snRNA. Three of these mutations affec...... the 5' splice site recognition sequence. The U1-3 snRNA is present in a few hundred copies per cell. The expression of Tetrahymena snRNA genes is independent of the physiological state of the cell.......The expression of U1, U2 and U5 snRNA gene variants has been studied under different physiological states of Tetrahymena. Variants of all three snRNA genes are expressed. Among the snRNAs detected is U1-3, a variant with 66 mutations compared to the normal U1 snRNA. Three of these mutations affect...

  10. Stress and Protists: No life without stress

    Science.gov (United States)

    Slaveykova, Vera; Sonntag, Bettina; Gutiérrez, Juan Carlos

    2017-01-01

    We report a summary of the symposium “Stress and Protists: No life without stress”, which was held in September 2015 on the VII European Congress of Protistology in partnership with the International Society of Protistologists (Seville, Spain). We present an overview on general comments and concepts on cellular stress which can be also applied to any protist. Generally, various environmental stressors may induce similar cell responses in very different protists. Two main topics are reported in this manuscript: (i) metallic nanoparticles as environmental pollutants and stressors for aquatic protists, and (ii) ultraviolet radiation – induced stress and photoprotective strategies in ciliates. Model protists such as Chlamydomonas reinhardtii and Tetrahymena thermophila were used to assess stress caused by nanoparticles while stress caused by ultraviolet radiation was tested with free living planktonic ciliates as well as with the symbiont-bearing model ciliate Paramecium bursaria. For future studies, we suggest more intensive analyses on protist stress responses to specific environmental abiotic and/or biotic stressors at molecular and genetic levels up to ecological consequences and food web dynamics. PMID:27365178

  11. Phosphorus, nitrogen and chlorophyll-a are significant factors controlling ciliate communities in summer in the northern Beibu Gulf, South China Sea.

    Science.gov (United States)

    Wang, Yibo; Zhang, Wenjing; Lin, Yuanshao; Cao, Wenqing; Zheng, Lianming; Yang, Jun

    2014-01-01

    Ciliates (protozoa) are ubiquitous components of plankton community and play important roles in aquatic ecosystems in regards of their abundance, biomass, diversity and energy turnover. Based on the stratified samples collected from the northern Beibu Gulf in August 2011, species composition, abundance, biomass, diversity and spatial pattern of planktonic ciliates were studied. Furthermore the main environmental factors controlling ciliate communities were determined. A total of 101 species belonging to 44 genera and 7 orders (i.e., Oligotrichida, Haptorida, Euplotida, Sessilida, Pleurostomatida, Scuticociliatida and Tintinnida) were identified. The variation of ciliate communities was significant at horizontal level, but that was not at vertical level. Based on cluster analysis, ciliate communities were divided into three main groups. Redundancy analysis (RDA) revealed that Group A, existing in the waters with higher concentration of phosphorus and nitrogen, was dominated by Tintinnidium primitivum. Group B in the waters with lower temperature and chlorophyll-a concentration, was dominated by Leegaardiella ovalis. Group C, existing in the waters with higher temperature and chlorophyll-a concentration, was dominated by large Strombidium spp. and Mesodinium rubrum. Combining multiple analytic methods, our results strongly supported that phosphorus, nitrogen and chlorophyll-a were the most significant factors affecting the ciliate communities in the northern Beibu Gulf in summer. Concentration of phosphorus and nitrogen primarily influenced ciliate biomass, implying a potential impact of eutrophication on ciliate growth. The correlation with chlorophyll-a concentration, on one hand indicate the response of ciliates to the food availability, and on the other hand, the ciliates containing chloroplasts or endosymbionts may contribute greatly to the chlorophyll-a.

  12. Phosphorus, nitrogen and chlorophyll-a are significant factors controlling ciliate communities in summer in the northern Beibu Gulf, South China Sea.

    Directory of Open Access Journals (Sweden)

    Yibo Wang

    Full Text Available Ciliates (protozoa are ubiquitous components of plankton community and play important roles in aquatic ecosystems in regards of their abundance, biomass, diversity and energy turnover. Based on the stratified samples collected from the northern Beibu Gulf in August 2011, species composition, abundance, biomass, diversity and spatial pattern of planktonic ciliates were studied. Furthermore the main environmental factors controlling ciliate communities were determined. A total of 101 species belonging to 44 genera and 7 orders (i.e., Oligotrichida, Haptorida, Euplotida, Sessilida, Pleurostomatida, Scuticociliatida and Tintinnida were identified. The variation of ciliate communities was significant at horizontal level, but that was not at vertical level. Based on cluster analysis, ciliate communities were divided into three main groups. Redundancy analysis (RDA revealed that Group A, existing in the waters with higher concentration of phosphorus and nitrogen, was dominated by Tintinnidium primitivum. Group B in the waters with lower temperature and chlorophyll-a concentration, was dominated by Leegaardiella ovalis. Group C, existing in the waters with higher temperature and chlorophyll-a concentration, was dominated by large Strombidium spp. and Mesodinium rubrum. Combining multiple analytic methods, our results strongly supported that phosphorus, nitrogen and chlorophyll-a were the most significant factors affecting the ciliate communities in the northern Beibu Gulf in summer. Concentration of phosphorus and nitrogen primarily influenced ciliate biomass, implying a potential impact of eutrophication on ciliate growth. The correlation with chlorophyll-a concentration, on one hand indicate the response of ciliates to the food availability, and on the other hand, the ciliates containing chloroplasts or endosymbionts may contribute greatly to the chlorophyll-a.

  13. Novel insights into the genetic diversity of Balantidium and Balantidium-like cyst-forming ciliates.

    Directory of Open Access Journals (Sweden)

    Kateřina Pomajbíková

    Full Text Available Balantidiasis is considered a neglected zoonotic disease with pigs serving as reservoir hosts. However, Balantidium coli has been recorded in many other mammalian species, including primates. Here, we evaluated the genetic diversity of B. coli in non-human primates using two gene markers (SSrDNA and ITS1-5.8SDNA-ITS2. We analyzed 49 isolates of ciliates from fecal samples originating from 11 species of captive and wild primates, domestic pigs and wild boar. The phylogenetic trees were computed using Bayesian inference and Maximum likelihood. Balantidium entozoon from edible frog and Buxtonella sulcata from cattle were included in the analyses as the closest relatives of B. coli, as well as reference sequences of vestibuliferids. The SSrDNA tree showed the same phylogenetic diversification of B. coli at genus level as the tree constructed based on the ITS region. Based on the polymorphism of SSrDNA sequences, the type species of the genus, namely B. entozoon, appeared to be phylogenetically distinct from B. coli. Thus, we propose a new genus Neobalantidium for the homeothermic clade. Moreover, several isolates from both captive and wild primates (excluding great apes clustered with B. sulcata with high support, suggesting the existence of a new species within this genus. The cysts of Buxtonella and Neobalantidium are morphologically indistinguishable and the presence of Buxtonella-like ciliates in primates opens the question about possible occurrence of these pathogens in humans.

  14. Evaluation of Enrichment Protocols for Bacterial Endosymbionts of Ciliates by Real-Time PCR.

    Science.gov (United States)

    Castelli, Michele; Lanzoni, Olivia; Rossi, Leonardo; Potekhin, Alexey; Schrallhammer, Martina; Petroni, Giulio

    2016-06-01

    Large-scale studies on obligate bacterial endosymbionts may frequently require preliminary purification and enrichment protocols, which are often elaborate to set up and to evaluate, especially if the host organism is a protist. The purpose of this study was to develop a real-time PCR-based strategy and employ it for assessing two of such enrichment protocols for Holospora caryophila, hosted by the ciliate Paramecium. Four SSU rRNA gene-targeted real-time PCR assays were designed, which allowed to compare the amount of H. caryophila to other organisms, namely the host, its food bacterium (Raoultella planticola), and free-living bacteria present in the culture medium. By the use of the real-time PCR assays in combination, it was possible to conclude that the "cell fractionation" protocol was quite successful in the enrichment of the symbiont, while the "Percoll gradient" protocol will need further refinements to be fully repeatable. The proposed approach has the potential to facilitate and encourage future studies on the yet underexplored field of bacterial endosymbionts of ciliates and other protists. It can also find valuable applications for experimental questions other than those tested, such as fast and precise assessment of symbiont abundance in natural populations and comparison among multiple coexisting symbionts.

  15. Differential localization and functional specialization of centrin analogs in the parasitic ciliate Trichodina pediculus.

    Science.gov (United States)

    Viguès, Bernard; Colombet, Jonathan; Damaj, Raghida

    2016-09-01

    Trichodinids are ciliated protozoans that reversibly attach to the tegument of marine and freshwater host-organisms via an adhesive disc. In this study, we have used permeabilized cell models of Trichodina pediculus to examine the distribution of centrins, a Ca(2+)-binding protein associated with centrioles and/or contractile filamentous structures in a large number of protists. The previous finding that filamentous material of the adhesive disc comprised a 23-kDa centrin analog suggested that this protein might be a disc-specific isoform. This possibility was explored through immunolabeling methods using two distinct antibodies, anti-ecto-endoplasmic boundary (EEB) and anti-Hscen2 previously shown to react respectively with centrin-based filament networks and with centrioles. Immunofluorescence microscopy showed that anti-EEB reacts with filamentous material of the disc but not with basal bodies. Conversely, anti-Hscen2 cross-reacted with basal bodies but failed to label any type of structure occurring in the disc area. More detailed data on localization of this protein was obtained by immunoelectron microscopy showing gold particles deposits in the lumen of basal bodies. The different patterns revealed by this immunochemical approach suggest that the two protein antigens concerned by this study are distinct centrin isoforms that presumably perform organelle-specific function in the ciliate T. pediculus.

  16. Evolutionary relationship and species separation of four morphologically similar stichotrichous ciliates (Protozoa,Ciliophora)

    Institute of Scientific and Technical Information of China (English)

    Zhenzhen Yi; John Clamp; Khaled A.S.A1-Rasheid; Abdulaziz A.Al-Khedhairy; Zigui Chen; Weibo Song

    2009-01-01

    Phylogenetic and taxonomic studies on ciliate protists using molecular approaches have been demonstrated to be very reliable to form strong conclusions and results.In the present work,species separation of some morphologically similar stichotrichous ciliates,two species of Pseudokeronopsis and two species of Apokeronopsis,was reexamined using amplified ribosomal DNA restriction analysis (PCRRFLP).Five of 10 restriction enzymes revealed species-specific polymorphic patterns,of which four similar stichotrichs could be significantly separated and identified.Among them,EcoR I offered almost no significantly different restriction fragment patterns,but the four species could be separated from one another and identified with Hae III.Distinctly different restriction digestion haplotypes and similarity indices separated the species,and were used to construct a phylogeny.Phylogenies based on ITS2 nucleotide sequences and ITS2 secondary structures supported the separation of Pseudokeronopsis and Apokeronopsis using RFLP analysis,although three Pseudokeronopsis carnea populations did not cluster together.In addition,phylogenetic analyses using multiple algorithms confirmed that these two genera formed two distinct groups within the urostylids.(C) 2008 National Natural Science Foundation of China and Chinese Academy of Sciences.Published by Elsevier Limited and Science in China Press.All rights reserved.

  17. Structures, biological activities and phylogenetic relationships of terpenoids from marine ciliates of the genus Euplotes.

    Science.gov (United States)

    Guella, Graziano; Skropeta, Danielle; Di Giuseppe, Graziano; Dini, Fernando

    2010-07-08

    In the last two decades, large scale axenic cell cultures of the marine species comprising the family Euplotidae have resulted in the isolation of several new classes of terpenoids with unprecedented carbon skeletons including the (i) euplotins, highly strained acetylated sesquiterpene hemiacetals; (ii) raikovenals, built on the bicyclo[3.2.0]heptane ring system; (iii) rarisetenolides and focardins containing an octahydroazulene moiety; and (iv) vannusals, with a unique C30 backbone. Their complex structures have been elucidated through a combination of nuclear magnetic resonance spectroscopy, mass spectrometry, molecular mechanics and quantum chemical calculations. Despite the limited number of biosynthetic experiments having been performed, the large diversity of ciliate terpenoids has facilitated the proposal of biosynthetic pathways whereby they are produced from classical linear precursors. Herein, the similarities and differences emerging from the comparison of the classical chemotaxonomy approach based on secondary metabolites, with species phylogenesis based on genetic descriptors (SSU-rDNA), will be discussed. Results on the interesting ecological and biological properties of ciliate terpenoids are also reported.

  18. Structures, Biological Activities and Phylogenetic Relationships of Terpenoids from Marine Ciliates of the Genus Euplotes

    Directory of Open Access Journals (Sweden)

    Fernando Dini

    2010-07-01

    Full Text Available In the last two decades, large scale axenic cell cultures of the marine species comprising the family Euplotidae have resulted in the isolation of several new classes of terpenoids with unprecedented carbon skeletons including the (i euplotins, highly strained acetylated sesquiterpene hemiacetals; (ii raikovenals, built on the bicyclo[3.2.0]heptane ring system; (iii rarisetenolides and focardins containing an octahydroazulene moiety; and (iv vannusals, with a unique C30 backbone. Their complex structures have been elucidated through a combination of nuclear magnetic resonance spectroscopy, mass spectrometry, molecular mechanics and quantum chemical calculations. Despite the limited number of biosynthetic experiments having been performed, the large diversity of ciliate terpenoids has facilitated the proposal of biosynthetic pathways whereby they are produced from classical linear precursors. Herein, the similarities and differences emerging from the comparison of the classical chemotaxonomy approach based on secondary metabolites, with species phylogenesis based on genetic descriptors (SSU-rDNA, will be discussed. Results on the interesting ecological and biological properties of ciliate terpenoids are also reported.

  19. A cover of glass: first report of biomineralized silicon in a ciliate, Maryna umbrellata (Ciliophora: Colpodea).

    Science.gov (United States)

    Foissner, Wilhelm; Weissenbacher, Birgit; Krautgartner, Wolf-Dietrich; Lütz-Meindl, Ursula

    2009-01-01

    Using hydrofluoric acid, scanning electron microscope-assisted X-ray microanalysis, and energy-filtered transmission electron microscopy, we present the first definite proof of biomineralized silicon [(SiO(2))](n) in a ciliophoran protist, Maryna umbrellata, a common inhabitant of ephemeral pools. In the trophic specimen, the amorphic silicon (glass) granules are accumulated in the anterior half of the body. When entering the dormant stage, most glass granules are excreted to form the surface cover of the globular resting cyst. Most likely, the silicon granules are synthesized in vesicles of the Golgi apparatus. First, nanospheres with a size of 20-40 nm are formed in a fibrous matrix; they grow to be spongious complexes, eventually becoming amorphous glass granules with an average size of 819 nm x 630 nm. In the transmission electron microscope, the silicon granules show the characteristic fracture pattern of glass known from many other silicon-bearing organisms. A literature survey suggests that silicon is very rare in ciliates. The fine structure and genesis of silicon granules in M. umbrellata are very similar to those of other organisms, including vascular plants and animals, indicating a common mechanism. Light perception and protection against mechanical stress and predators might be functions of the silicon granules in M. umbrellata. The palaeontological significance of glass cysts in ciliates is also discussed.

  20. Diversity of apostome ciliates, Chromidina spp. (Oligohymenophorea, Opalinopsidae), parasites of cephalopods of the Mediterranean Sea

    Science.gov (United States)

    2016-01-01

    Chromidina spp. are enigmatic apostome ciliates (Oligohymenophorea, Opalinopsidae) that parasitise the renal and pancreatic appendages of cephalopods. Only four species have been described, among which only three have been formally named. No DNA sequence has been reported so far. To investigate Chromidina spp. diversity, we sampled cephalopods in the Mediterranean Sea off Tunis, Tunisia, and identified two distinct Chromidina spp. in two different host species: Loligo vulgaris and Sepia officinalis. From haematoxylin-stained slides, we described morphological traits for these parasitic species and compared them to previous descriptions. We also re-described the morphology of Chromidina elegans (Foettinger, 1881) from Chatton and Lwoff’s original materials and designated a neohapantotype and paraneohapantotypes for this species. We describe a new species, Chromidina chattoni Souidenne, Florent and Grellier n. sp., found in L. vulgaris off Tunisia, and evidence for a probable novel species, found in S. officinalis off Tunisia, although this latter species presents similarities to some morphological stages previously described for Chromidina cortezi Hochberg, 1971. We amplified, for the first time, an 18S rDNA marker for these two Chromidina species. Phylogenetic analysis supports the association of Chromidina within apostome ciliates. Genetic distance analysis between 18S rDNA sequences of representative apostomes indicates Pseudocollinia as the most closely related genus to Chromidina. PMID:27530149

  1. Diversity of apostome ciliates, Chromidina spp. (Oligohymenophorea, Opalinopsidae, parasites of cephalopods of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Souidenne Dhikra

    2016-01-01

    Full Text Available Chromidina spp. are enigmatic apostome ciliates (Oligohymenophorea, Opalinopsidae that parasitise the renal and pancreatic appendages of cephalopods. Only four species have been described, among which only three have been formally named. No DNA sequence has been reported so far. To investigate Chromidina spp. diversity, we sampled cephalopods in the Mediterranean Sea off Tunis, Tunisia, and identified two distinct Chromidina spp. in two different host species: Loligo vulgaris and Sepia officinalis. From haematoxylin-stained slides, we described morphological traits for these parasitic species and compared them to previous descriptions. We also re-described the morphology of Chromidina elegans (Foettinger, 1881 from Chatton and Lwoff’s original materials and designated a neohapantotype and paraneohapantotypes for this species. We describe a new species, Chromidina chattoni Souidenne, Florent and Grellier n. sp., found in L. vulgaris off Tunisia, and evidence for a probable novel species, found in S. officinalis off Tunisia, although this latter species presents similarities to some morphological stages previously described for Chromidina cortezi Hochberg, 1971. We amplified, for the first time, an 18S rDNA marker for these two Chromidina species. Phylogenetic analysis supports the association of Chromidina within apostome ciliates. Genetic distance analysis between 18S rDNA sequences of representative apostomes indicates Pseudocollinia as the most closely related genus to Chromidina.

  2. ATP4 and ciliation in the neuroectoderm and endoderm of Xenopus embryos and tadpoles

    Directory of Open Access Journals (Sweden)

    Peter Walentek

    2015-09-01

    Full Text Available During gastrulation and neurulation, foxj1 expression requires ATP4a-dependent Wnt/β-catenin signaling for ciliation of the gastrocoel roof plate (Walentek et al. Cell Rep. 1 (2012 516–527. and the mucociliary epidermis (Walentek et al. Dev. Biol. (2015 of Xenopus laevis embryos. These data suggested that ATP4a and Wnt/β-catenin signaling regulate foxj1 throughout Xenopus development. Here we analyzed whether foxj1 expression was also ATP4a-dependent in other ciliated tissues of the developing Xenopus embryo and tadpole. We found that in the floor plate of the neural tube ATP4a-dependent canonical Wnt signaling was required for foxj1 expression, downstream of or in parallel to Hedgehog signaling. In the developing tadpole brain, ATP4-function was a prerequisite for the establishment of cerebrospinal fluid flow. Furthermore, we describe foxj1 expression and the presence of multiciliated cells in the developing tadpole gastrointestinal tract. Our work argues for a general requirement of ATP4-dependent Wnt/β-catenin signaling for foxj1 expression and motile ciliogenesis throughout Xenopus development.

  3. Composition and distribution of planktonic ciliates in the southern South China Sea during late summer: Comparison between surface and 75 m deep layer

    Science.gov (United States)

    Liu, Huaxue; Shen, Pingping; Li, Chunhou; Chen, Zuozhi; Qi, Zhanhui; Huang, Honghui

    2016-02-01

    Ciliates are very important components in most marine ecosystem. They are trophic link between the microbial food web and grazing food chain. In this study, ciliates were collected from 11 sites in the southern South China Sea (SCS) during August 25 to September 28, 2011. Their composition and distribution at the surface and 75 m deep depth of the ocean were studied. A total of 30 species belonging to 22 genera were identified, and 22 species of 15 genera were Tintinnids. Eutintinnus fraknoii and E. stramentus were the most common species. The other dominants were strombidiids ciliates including Strombidium conicum and S. globosaneum, which were followed by the tide form, Mesodinium pulex. Ciliates abundance ranged from 46 ind L-1 to 368 ind L-1 in the open sites, 46-368 ind L-1 at surface and 73-198 ind L-1 at 75 m deep layer. In the Yongshu reef, ciliates abundance ranged from 167 ind L-1 to 365 ind L-1 in the water column, similar to that in Sanya coral reef waters. Ciliates composition showed obvious difference between surface and 75 m deep layer at station S2 ( P deep layer, salinity was negatively related to mixed layer depth ( P < 0.05), but positively to chlorophyll a concentration ( P < 0.05), indicating that the change of vertical mixing in water column influenced vertical distribution of ciliates in the southern SCS.

  4. Tolerance of ciliated protozoan Paramecium bursaria (Protozoa,Ciliophora) to ammonia and nitrites

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32x-9.51 (R2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h-LC50 value for ammonia was fotnd to be 95.50 mg/L. A linear correlation between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equation y=2.86x+0.89 (R2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2862.85e-0.0ax (R2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y = 127.15e-0.13x (R2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.

  5. Spatiotemporal variation in community structure of marine benthic ciliates in the Yellow Sea during and after macroalgal and giant jellyfish blooms

    Science.gov (United States)

    Zhou, Bailing; Xu, Kuidong

    2016-07-01

    The annual bloom of the green macroalgal Ulva prolifera from May through July since 2008 and another of giant jellyfish Nemopilema nomurai from June through September have been frequent events in the Yellow Sea. However, the patterns of benthic ciliate communities during and after the blooms are still not known. In combination with analyses of benthic environmental factors, we investigated the distribution and community composition of benthic ciliates in the Yellow Sea in July and November 2011. In July, ciliates had high standing crops and diversity in the northern Yellow Sea, and in the inshore area off the southern Shandong Peninsula, where large numbers of green macroalgae accumulated. In November, the abundance, biomass and diversity of ciliates were high in the sea areas off the Shandong Peninsula and Changjiang estuary, where a large quantity of jellyfish occurred in August. Neither the abundance nor the biomass had significant difference between seasons, or between different compartments of the Yellow Sea. The species number, and both Margalef and Shannon-Wiener indices of ciliates were all significantly higher in November than in July. In both seasons, prostomateans and karyorelicteans consistently constituted the first and second most important ciliate groups in biomass; and carnivorous ciliates constituted the primary feeding type in terms of biomass as well as species richness, followed by bacterivores, algivores and omnivores. Compared with that in June 2007 when no macroalgae occurred, the percentage of small-sized bacterivores (e.g. Metacystis spp., Euplotes spp. and scuticociliates) increased in July 2011. The proportion of carnivorous ciliates increased in November, and this increased dominance of carnivorous ciliates may be a response to the increase in predominance of heterotrophic nanoflagellates, which might in turn be ascribed to an effect of green macroalgal and giant jellyfish blooms in the Yellow Sea.

  6. Evaluation of double formalin--Lugol's fixation in assessing number and biomass of ciliates: an example of estimations at mesoscale in NE Atlantic.

    Science.gov (United States)

    Karayanni, Hera; Christaki, Urania; Van Wambeke, France; Dalby, Andrew P

    2004-03-01

    Ciliated protozoa are potential grazers of primary and bacterial production and act as intermediaries between picoplankton and copepods and other large suspension feeders. Accurate determination of ciliate abundance and feeding mode is crucial in oceanic carbon budget estimations. However, the impact of different fixatives on the abundance and cell volume of ciliates has been investigated in only a few studies using either laboratory cultures or natural populations. Lugol's solution and formalin are the most commonly used fixatives for the preservation of ciliates samples. In the present study, the aim was to compare 0.4% Lugol's solution and 2% borated-formalin fixation and evaluate the need of counting duplicate samples each using a different fixative. For this, a large number of samples (n = 110) from the NE Atlantic was analyzed in the frame of POMME program (Multidisciplinary Mesoscale Ocean Program). We established a statistically significant relationship (p Lugol's and formalin fixed samples for both abundance (r2 = 0.50) and biomass (r2 = 0.76) of aloricate ciliates which showed that counts were higher in Lugol's solution by a factor of 2 and a non-taxon specific cell-loss in formalin. However, loricate ciliate abundance in our samples which were represented primarily by Tintinnus spp. did not show any difference between the two treatments. Abundance and biomass of mixotrophic ciliates (chloroplast-bearing cells) were for various reasons underestimated in both treatments. Our results show that unique fixation by formalin may severely underestimate ciliates abundance and biomass although their population may not alter. For this reason, Lugol's solution is best for the estimation of their abundance and biomass. However, for counts of mixotrophs and the evaluation of the ecological role of ciliates in carbon flux, double fixation is essential. Compromises regarding the fixatives have lead to severe underestimations of mixotrophs in studies conducted by now.

  7. Influence of ciliated protozoa and heterotrophic nanoflagellates on the fate of primary production in the northeast Atlantic Ocean

    Science.gov (United States)

    Karayanni, Hera; Christaki, Urania; van Wambeke, France; Denis, Michel; Moutin, Thierry

    2005-07-01

    Heterotrophic nanoflagellates and ciliates and their herbivorous activity were studied within the framework of the Programme Océan Multidisciplinaire Méso Echelle (POMME) in the northeastern Atlantic between 16°-22°W and 38°-45°N during winter, spring, and late summer/autumn 2001. Ciliate ingestion rates of Synechococcus and eukaryotic algae were measured using fluorescently labeled prey. Heterotrophic nanoflagellate ingestion rates of Synechococcus and Prochlorococcus were also estimated. Heterotrophic nanoflagellate and ciliate standing stock within the surface layer (0-100 m) showed seasonal variation, with maximal values in spring (866 mg C m-2 and 637 mg C m-2, respectively). Oligotrichs dominated the ciliate assemblages, except at one site visited during spring, where a tintinnid bloom was observed. Ingestion of photosynthetic cells less than 10 μm in size was positively correlated (r = 0.7, p consumption reflected differences in the evolution of the phytoplankton bloom and in the structure of the microbial food web, both associated with the strong mesoscale hydrodynamic variability of the study area. In that context it is worthy to note that when tintinnids reached high abundances locally (1260 cells L-1), their impact as phytoplankton grazers was important and reached 69% of primary production. Generally, heterotrophic nanoflagellates and ciliates were relatively more important in determining the fate of phytogenic carbon during spring. Another interesting feature of primary production consumption was that during the autumn, when Prochlorococcus dominated the phytoplankton community, the protozoan grazing activity was ineffective in regulating the fate of primary producers.

  8. A Comparative Study of Two Quantum Chemical Descriptors in Predicting Toxicity of Aliphatic Compounds towards Tetrahymena pyriformis

    Directory of Open Access Journals (Sweden)

    Altaf Hussain Pandith

    2010-01-01

    Full Text Available Quantum chemical parameters such as LUMO energy, HOMO energy, ionization energy (I, electron affinity (A, chemical potential (μ, hardness (η electronegativity (χ, philicity (ωα, and electrophilicity (ω of a series of aliphatic compounds are calculated at the B3LYP/6-31G(d level of theory. Quantitative structure-activity relationship (QSAR models are developed for predicting the toxicity (pIGC50 of 13 classes of aliphatic compounds, including 171 electron acceptors and 81 electron donors, towards Tetrahymena pyriformis. The multiple linear regression modeling of toxicity of these compounds is performed by using the molecular descriptor log P (1-octanol/water partition coefficient in conjunction with two other quantum chemical descriptors, electrophilicity (ω and energy of the lowest unoccupied molecular orbital (ELUMO. A comparison is made towards the toxicity predicting the ability of electrophilicity (ω versus ELUMO as a global chemical reactivity descriptor in addition to log P. The former works marginally better in most cases. There is a slight improvement in the quality of regression by changing the unit of IGC50 from mg/L to molarity and by removing the racemates and the diastereoisomers from the data set.

  9. DNA content alterations in Tetrahymena pyriformis macronucleus after exposure to food preservatives sodium nitrate and sodium benzoate.

    Science.gov (United States)

    Loutsidou, Ariadni C; Hatzi, Vasiliki I; Chasapis, C T; Terzoudi, Georgia I; Spiliopoulou, Chara A; Stefanidou, Maria E

    2012-12-01

    The toxicity, in terms of changes in the DNA content, of two food preservatives, sodium nitrate and sodium benzoate was studied on the protozoan Tetrahymena pyriformis using DNA image analysis technology. For this purpose, selected doses of both food additives were administered for 2 h to protozoa cultures and DNA image analysis of T. pyriformis nuclei was performed. The analysis was based on the measurement of the Mean Optical Density which represents the cellular DNA content. The results have shown that after exposure of the protozoan cultures to doses equivalent to ADI, a statistically significant increase in the macronuclear DNA content compared to the unexposed control samples was observed. The observed increase in the macronuclear DNA content is indicative of the stimulation of the mitotic process and the observed increase in MOD, accompanied by a stimulation of the protozoan proliferation activity is in consistence with this assumption. Since alterations at the DNA level such as DNA content and uncontrolled mitogenic stimulation have been linked with chemical carcinogenesis, the results of the present study add information on the toxicogenomic profile of the selected chemicals and may potentially lead to reconsideration of the excessive use of nitrates aiming to protect public health.

  10. Importance and nutritional value of large ciliates for the reproduction of Acartia clausi during the post spring-bloom period in the North Sea

    DEFF Research Database (Denmark)

    Dutz, Jörg; Peters, J.

    2008-01-01

    enriched with large prey (> 20 mu m). The mineral (C, N) and lipid contents of the food suspensions were determined for size-fractionated samples to characterize the nutritional composition of prey. Large oligotrich ciliates and Strobiliidae dominated the seston biomass. Ciliates, particularly...... of the mineral and lipid content confirmed a high seston nutritional quality. The 20 to 48 mu m fraction reflected the composition of female diets and indicated an enrichment of N and polyunsaturated fatty acids (PUFA) in the diet compared to total seston. The fraction > 48 mu m consisted mostly of ciliates...

  11. Ciliated Median Raphe Cyst of Perineum Presenting as Perianal Polyp: A Case Report with Immunohistochemical Study, Review of Literature, and Pathogenesis

    Directory of Open Access Journals (Sweden)

    Jayesh Sagar

    2006-01-01

    Full Text Available Median raphe cyst is a very rare, benign congenital lesion occurring mainly on the ventral aspect of the penis, but can develop anywhere in the midline between the external urethral meatus and anus. We report a case of median raphe cyst in the perineum presenting as a perianal polyp in a 65-year-old, English white male with exceptionally rare ciliated epithelium. According to our knowledge, this is the third such case of ciliated median raphe cyst in the English literature. This case, also the first case of ciliated median raphe cyst in the perineum location, focuses on pathogenesis of median raphe cyst.

  12. New Record of Two Marine Ciliates (Ciliophora: Spirotrichea in South Korea

    Directory of Open Access Journals (Sweden)

    Kang-San Kim

    2013-04-01

    Full Text Available Two marine hypotrichous ciliates, Anteholosticha petzi and Ponturostyla enigmatica, were collected from the Yellow Sea and the Korea Strait, respectively, and described using live observation and protargol-impregnated specimens. Furthermore, the nuclear small subunit ribosomal RNA gene of each was sequenced and compared to previously annotated sequences retrieved from the GenBank. Anteholosticha petzi is characterized by 3 frontal cirri (FC, 2 frontoterminal cirri (FTC, 8-12 transverse cirri (TC, 1 buccal cirrus (BC, 9-12 midventral pairs (MP, 3 bipolar dorsal kineties (DK, and 3 types of colorless cortical granules. Ponturostyla enigmatica is characterized by 8 FC, 5 ventral cirri (VC, 5-7 TC, 6-7 marginal rows (MR on each side, 4 complete and 2-3 partial DK, and greenish cortical granules. This is the first identification and description of these 2 species, A. petzi and P. enigmatica, in South Korea.

  13. Physical hydrodynamic propulsion model study on creeping viscous flow through a ciliated porous tube

    Indian Academy of Sciences (India)

    NOREEN SHER AKBAR; ADIL WAHID BUTT; DHARMENDRA TRIPATHI; O ANWAR BÉG

    2017-03-01

    The present investigation focusses on a mathematical study of creeping viscous flow induced by metachronal wave propagation in a horizontal ciliated tube containing porous media. Creeping flow limitations are imposed, i.e. inertial forces are small compared to viscous forces and therefore a very low Reynolds number (Re $\\ll$ 1) is taken into account. The wavelength of metachronal wave is also considered to be very large for cilia movement. The physical problem is linearized and exact solutions are developed for the differential equation problem. Mathematica software is used to compute and illustrate numerical results. The influence of slip parameter and Darcy number on velocity profile, pressure gradient and trapping of bolus are discussed with the aid of graphs. It is found that with increasing magnitude of the slip parameter, the trapped bolus inside the streamlines increases in size. The study is relevant to biological propulsion of medical micromachines in drug delivery.

  14. Current status of parasitic ciliates Chilodonella spp. (Phyllopharyngea: Chilodonellidae) in freshwater fish aquaculture.

    Science.gov (United States)

    Bastos Gomes, G; Jerry, D R; Miller, T L; Hutson, K S

    2016-07-30

    Freshwater fish farming contributes to more than two-thirds of global aquaculture production. Parasitic ciliates are one of the largest causes of production loss in freshwater farmed fishes, with species from the genus Chilodonella being particularly problematic. While Chilodonella spp. include 'free-living' fauna, some species are involved in mortality events of fish, particularly in high-density aquaculture. Indeed, chilodonellosis causes major productivity losses in over 16 species of farmed freshwater fishes in more than 14 countries. Traditionally, Chilodonella species are identified based on morphological features; however, the genus comprises yet uncharacterized cryptic species, which indicates the necessity for molecular diagnostic methods. This review synthesizes current knowledge on the biology, ecology and geographic distribution of harmful Chilodonella spp. and examines pathological signs, diagnostic methods and treatments. Recent advances in molecular diagnostics and the ability to culture Chilodonella spp. in vitro will enable the development of preventative management practices and sustained freshwater fish aquaculture production.

  15. Thermodynamic Stability of Psychrophilic and Mesophilic Pheromones of the Protozoan Ciliate Euplotes

    Directory of Open Access Journals (Sweden)

    Kurt Wüthrich

    2013-01-01

    Full Text Available Three psychrophilic protein pheromones (En-1, En-2 and En-6 from the polar ciliate, Euplotes nobilii, and six mesophilic pheromones (Er-1, Er-2, Er-10, Er-11, Er-22 and Er-23 from the temperate-water sister species, Euplotes raikovi, were studied in aqueous solution for their thermal unfolding and refolding based on the temperature dependence of their circular dichroism (CD spectra. The three psychrophilic proteins showed thermal unfolding with mid points in the temperature range 55–70 °C. In contrast, no unfolding was observed for any of the six mesophilic proteins and their regular secondary structures were maintained up to 95 °C. Possible causes of these differences are discussed based on comparisons of the NMR structures of the nine proteins.

  16. Epibiotic ciliates Scyphidia sp. and diatoms on Tigriopus fulvus (Copepoda: Harpacticoida exoskeleton

    Directory of Open Access Journals (Sweden)

    Luigi Pane

    2014-12-01

    Full Text Available Several microorganisms – epibionts – can adhere to living supports taking advantage for their survival, feeding and movement. Epibiosis occurs particularly in aquatic environments, on both benthic and planktonic organisms, among which copepods and cladocerans represent an important living support. The harpacticoid copepod Tigriopus fulvus, living in the splashpools of rocky coasts, was studied to recognize the occurrence of epibionts on the exoskeleton surface using scanning electon microscopy techniques. The first evidence of ciliate Scyphidia sp. on Tigriopus fulvus has been described and the occurrence of algae Cocconeis sp. has been observed as well. Epibionts were found to adhere to antennae, a site linked to the exploitation of water currents carrying food particles to mouthparts and to swimming legs. The reason of the occurrence on swimming legs is less clear and needs further observations. Pertinent results are described and discussed and the influence of epibionts on life cycle and behavior of Tigriopus fulvus is considered.

  17. Divisional morphogenesis in the marine ciliate Anteholosticha manca(Kahl,1932) Berger,2003(Ciliophora: Urostylida)

    Institute of Scientific and Technical Information of China (English)

    LI Liqiong; HU Xiaozhong; WARREN Alan; AL-RASHEID Khaled A S; AL - FARRAJ Saleh A; SHAO Chen; SONG Weibo

    2008-01-01

    The cortical development and macronuclear evolution of the marine hypotrichous ciliate Anteholosticha manca,collected from the coastal waters near Qingdao,China,were investigated using the protargol impregnation method.The morphogenesis of A.manca is generally typical for the genus,and can be characterized as the following features:(1) in the proter,a new oral primordium is formed on the bottom (beneath the pellicle) of the buccal cavity,disorganization of the parental undulating membranes do not contribute to the formation of this primordium; (2) FVT-cirral anlagen in both dividers develop independently,and very likely on-ly a few midventral cirri join in the formation of these primordia; (3) both marginal row and dorsal kinety anlagen develop intraki-netally within the parental structure; (4) at the middle stage,macronuclear segments fuse together to form a single mass as ob-served in most of its related forms.

  18. Physical hydrodynamic propulsion model study on creeping viscous flow through a ciliated porous tube

    Science.gov (United States)

    Akbar, Noreen Sher; Butt, Adil Wahid; Tripathi, Dharmendra; Bég, O. Anwar

    2017-03-01

    The present investigation focusses on a mathematical study of creeping viscous flow induced by metachronal wave propagation in a horizontal ciliated tube containing porous media. Creeping flow limitations are imposed, i.e. inertial forces are small compared to viscous forces and therefore a very low Reynolds number (Re ≪ 1) is taken into account. The wavelength of metachronal wave is also considered to be very large for cilia movement. The physical problem is linearized and exact solutions are developed for the differential equation problem. Mathematica software is used to compute and illustrate numerical results. The influence of slip parameter and Darcy number on velocity profile, pressure gradient and trapping of bolus are discussed with the aid of graphs. It is found that with increasing magnitude of the slip parameter, the trapped bolus inside the streamlines increases in size. The study is relevant to biological propulsion of medical micromachines in drug delivery.

  19. Stability and kinetic behavior of immobilized laccase from Myceliophthora thermophila in the presence of the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate.

    Science.gov (United States)

    Fernández-Fernández, María; Moldes, Diego; Domínguez, Alberto; Sanromán, M Ángeles; Tavares, Ana Paula M; Rodríguez, Oscar; Macedo, Eugénia A

    2014-01-01

    The use of ionic liquids (ILs) as reaction media for enzymatic reactions has increased their potential because they can improve enzyme activity and stability. Kinetic and stability properties of immobilized commercial laccase from Myceliophthora thermophila in the water-soluble IL 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4 ]) have been studied and compared with free laccase. Laccase immobilization was carried out by covalent binding on glyoxyl-agarose beads. The immobilization yield was 100%, and the activity was totally recovered. The Michaelis-Menten model fitted well to the kinetic data of enzymatic oxidation of a model substrate in the presence of the IL [emim][EtSO4 ]. When concentration of the IL was augmented, the values of Vmax for free and immobilized laccases showed an increase and slight decrease, respectively. The laccase-glyoxyl-agarose derivative improved the laccase stability in comparison with the free laccase regarding the enzymatic inactivation in [emim][EtSO4 ]. The stability of both free and immobilized laccase was slightly affected by small amounts of IL (<50%). A high concentration of the IL (75%) produced a large inactivation of free laccase. However, immobilization prevented deactivation beyond 50%. Free and immobilized laccase showed a first-order thermal inactivation profile between 55 and 70°C in the presence of the IL [emim][EtSO4 ]. Finally, thermal stability was scarcely affected by the presence of the IL.

  20. Population dynamics of marine ciliate Euplotes vannus (Protozoa, Ciliophora) in different artificial seawaters

    Science.gov (United States)

    Xu, Henglong; Zhu, Mingzhuang; Jiang, Yong; Gao, Shan; Min, Gi-Sik; Al-Rasheid, Khaled A. S.

    2011-01-01

    To study population dynamics of marine ciliates in different artificial seawaters (ASW), the population growth dynamics of a common marine ciliate Euplotes vannus were investigated using beef extract media and rice media for five types of ASW and natural seawater (NSW). The results show that: (1) the population growth rate was in the order of NSW>Flack ASW>Nakamula ASW>Schmadz ASW>Oshima ASW>Subow ASW and was considerably higher in rice media than in beef extract media (apart from Subow ASW); (2) the maximum density of E. vannus in stationary phase in each treatment was ranked as Flack ASW>Nakamula ASW>Schmadz ASW>NSW>Oshima ASW>Subow ASW, and was again higher in rice media than in beef extract media (except for Subow ASW); (3) the exponential and stationary phases were longer in rice media than in beef extract media; (4) strains of E. vannus that had been domesticated for >1 year in ASW grew significantly slower, with lower maximum density and longer stationary phase than those isolated and maintained in NSW. It was demonstrated that: (1) E. vannus may grow well in Flack, Nakamula and Schmads ASW compared with NSW (mainly in terms of growth rate); and (2) Oshima ASW is the preferred choice for stock cultures of E. vannus, but the ASWs Flack, Nakamula and Schmadz are preferred for mass culture. These findings suggest that these three ASWs are effective for the cultivation of marine protozoa for experimental studies on ecology, toxicology and molecular biology.

  1. Modeling the distribution of ciliate protozoa in the reticulo-rumen using linear programming.

    Science.gov (United States)

    Hook, S E; Dijkstra, J; Wright, A-D G; McBride, B W; France, J

    2012-01-01

    The flow of ciliate protozoa from the reticulo-rumen is significantly less than expected given the total density of rumen protozoa present. To maintain their numbers in the reticulo-rumen, protozoa can be selectively retained through association with feed particles and the rumen wall. Few mathematical models have been designed to model rumen protozoa in both the free-living and attached phases, and the data used in the models were acquired using classical techniques. It has therefore become necessary to provide an updated model that more accurately represents these microorganisms and incorporates the recent literature on distribution, sequestration, and generation times. This paper represents a novel approach to synthesizing experimental data on rumen microorganisms in a quantitative and structured manner. The development of a linear programming model of rumen protozoa in an approximate steady state will be described and applied to data from healthy ruminants consuming commonly fed diets. In the model, protozoa associated with the liquid phase and protozoa attached to particulate matter or sequestered against the rumen wall are distinguished. Growth, passage, death, and transfer of protozoa between both pools are represented. The results from the model application using the contrasting diets of increased forage content versus increased starch content indicate that the majority of rumen protozoa, 63 to 90%, are found in the attached phase, either attached to feed particles or sequestered on the rumen wall. A slightly greater proportion of protozoa are found in the attached phase in animals fed a hay diet compared with a starch diet. This suggests that experimental protocols that only sample protozoa from the rumen fluid could be significantly underestimating the size of the protozoal population of the rumen. Further data are required on the distribution of ciliate protozoa in the rumen of healthy animals to improve model development, but the model described herein

  2. First record of protozoan parasites, Tetrahymena rostrata and Callimastix equi from the edible oyster in Sundarbans region of West Bengal, India.

    Science.gov (United States)

    Biswas, Tanima; Bandyopadhyay, Probir Kumar

    2016-09-01

    Several protozoan parasites have been found infecting the edible oysters, hence deteriorating the meat quality. Protozoan parasites such as, Tetrahymena rostrata and Callimastix equi infested the edible oyster in Sundarbans region, West Bengal, India, are first record from this region. Due to filter feeding habit of the organisms, oysters provides excellent ecological services in regard to efficient cleaning of infectious agents from surrounding water as a potential measure to improve water quality. However, these environmental benefits are associated with public heath risks from contaminated oysters intended for human consumption.

  3. Ciliate community structure and interactions within the planktonic food web in two alpine lakes of contrasting transparency.

    Science.gov (United States)

    Kammerlander, Barbara; Koinig, Karin A; Rott, Eugen; Sommaruga, Ruben; Tartarotti, Barbara; Trattner, Florian; Sonntag, Bettina

    2016-11-01

    Climate warming is accelerating the retreat of glaciers and recently, many 'new' glacial turbid lakes have been created. In the course of time, the loss of the hydrological connectivity to a glacier causes, however, changes in their water turbidity and turns these ecosystems into clear ones.To understand potential differences in the food-web structure between glacier-fed turbid and clear alpine lakes, we sampled ciliates, phyto-, bacterio- and zooplankton in one clear and one glacial turbid alpine lake, and measured key physicochemical parameters. In particular, we focused on the ciliate community and the potential drivers for their abundance distribution.In both lakes, the zooplankton community was similar and dominated by the copepod Cyclops abyssorum tatricus and rotifers including Polyarthra dolichoptera, Keratella hiemalis, Keratella cochlearis and Notholca squamula. The phytoplankton community structure differed and it was dominated by the planktonic diatom Fragilaria tenera and the cryptophyte alga Plagioselmis nannoplanctica in the glacial turbid lake, while chrysophytes and dinoflagellates were predominant in the clear one.Ciliate abundance and richness were higher in the glacial turbid lake (∼4000-27 800 Ind L(-1), up to 29 species) than in the clear lake (∼570-7150 Ind L(-1), up to eight species). The dominant species were Balanion planctonicum, Askenasia cf. chlorelligera, Urotricha cf. furcata and Mesodinium cf. acarus. The same species dominated in both lakes, except for Mesodinium cf. acarus and some particle-associated ciliates, which occurred exclusively in the glacial turbid lake. The relative underwater solar irradiance (i.e. percentage of PAR and UVR at depth) significantly explained their abundance distribution pattern, especially in the clear water lake. In the glacial turbid lake, the abundance of the dominating ciliate taxa was mainly explained by the presence of predatory zooplankton.Our results revealed an unexpected high

  4. Primers to block the amplification of symbiotic apostome ciliate 18S rRNA gene in a PCR-based copepod diet study

    Science.gov (United States)

    Yi, Xiaoyan; Zhang, Huan; Liu, Guangxing

    2014-05-01

    Pelagic copepods play an important role in the marine food web. However, a full understanding of the ecological status of this zooplankton group depends on the careful study of their natural diets. In previous PCR-based copepod diet studies, we found many apostome ciliates that live symbiotically under the exoskeleton of the copepods, and their sequences were often over-represented in the 18S rRNA gene (18S rDNA) libraries. As a first step to address this issue, we designed three apostome ciliate 18S rDNA blocking primers, and tested their blocking efficiency against apostome ciliate 18s rDNA under various PCR conditions. Using a semi-quantitative PCR method, we optimized the conditions to efficiently amplify the 18S rDNA of the prey while simultaneously excluding the symbiotic apostome ciliates. This technique will facilitate PCR-based diet studies of copepods and other zooplankton in their natural environments.

  5. Structure and seasonal dynamics of the protozoan community (heterotrophic flagellates, ciliates, amoeboid protozoa) in the plankton of a large river (River Danube, Hungary).

    Science.gov (United States)

    Kiss, Aron Keve; Acs, Eva; Kiss, Keve Tihamér; Török, Júlia Katalin

    2009-05-01

    Seasonal dynamics of all major protozoan groups were investigated in the plankton of the River Danube, upstream of Budapest (Hungary), by bi-weekly sampling over a 1-year long period. Sixty-one heterotrophic flagellate, 14 naked amoeba, 50 testate amoeba, 4 heliozoan and 83 ciliate morphospecies were identified. The estimated abundance ranges of major groups throughout the year were as follows: heterotrophic flagellates, 0.27-7.8 x 10(6)ind.l(-1); naked amoebae, max. 3300ind.l(-1); testaceans, max. 1600ind.l(-1); heliozoans, max. 8500ind.l(-1); ciliates, 132-34,000ind.l(-1). In terms of biovolume, heterotrophic flagellates dominated throughout the year (max. 0.58mm(3)l(-1)), and ciliates only exceeded their biovolume in summer (max. 0.76mm(3)l(-1)). Naked amoeba and heliozoan biovolume was about one, and testacean biovolume 1-3, orders of magnitude lower than that of ciliates. In winter, flagellates, mainly chrysomonads, had the highest biomass, whilst ciliates were dominated by peritrichs. In 2005 from April to July a long spring/summer peak occurred for all protozoan groups. Beside chrysomonads typical flagellates were choanoflagellates, bicosoecids and abundant microflagellates (large chrysomonads and Collodictyon). Most abundant ciliates were oligotrichs, while Phascolodon, Urotricha, Vorticella, haptorids, Suctoria, Climacostomum and Stokesia also contributed significantly to biovolume during rapid succession processes. In October and November a second high protozoan peak occurred, with flagellate dominance, and slightly different taxonomic composition.

  6. [Relationship of bacteria of Bacillus genus with ciliate Colpoda steinii and their impact on germination of plant seeds].

    Science.gov (United States)

    Pogorelova, V V; Bega, Z T; Kurdish, I K

    2012-01-01

    Features of symbiotic coexistence of bacteria of the genus Bacillus with ciliates Colpoda steinii have been studied. In their mutual cultivation during 10 days the number of bacteria B. subtilis IMV V-7023 was reduced 4.4 times, B. pumilus 3 - 3.4 times, B. megaterium 12 - 2.5 times. In the mixed culture with B. pumilus 3 the number of the ciliates increased gradualluy while under availability of the other two bacilli strains the number of protozoan increased in the first two days, after that their amount decreased. Treatment of some plants seeds by suspension of B. subtilis IMV V-7023 with the protozoan increased their germination and stimulated the growth of plants at the early stages of development.

  7. Ectopic Ciliated Cyst in the Mandible Secondary to Genioplasty and Lefort after Two Years: A Case Report and Literature Review

    Science.gov (United States)

    Seifi, Safoura; Sohanian, Shabnam; Khakbaz, Oveis; Abesi, Farida; Aliakbarpour, Fatemeh; Rayani, Arezoo

    2016-01-01

    Introduction: The ectopic ciliated cyst is a rare non-odontogenic cyst which occurs as a delayed complication after maxillary sinus radical surgery; this lesion emerges due to the destruction of the sinus mucosa during the surgery and entrapment of the respiratory epithelium in the region. This lesion has been observed in very rare cases following genioplasty and bimaxillary orthognathic surgery. Case Report: We reported a case of the ectopic ciliated cyst in in the mandible of a 37-year-old Iranian woman following genioplasty and Lefort 1 surgery after 2 years. Its treatment was enucleation. Conclusion: Long-term follow-up after cosmetic surgery of both jaws is recommended due to the probability of this cyst. PMID:27738612

  8. Blooms of a benthic ciliate, Maristentor dinoferus (Heterotrichea: Maristentoridae, on coral reefs of Guam, Mariana Islands. (Note

    Directory of Open Access Journals (Sweden)

    Schefter, M.

    2012-05-01

    Full Text Available Maristentor dinoferus is visible in situ with the naked eye; it forms aggregations at several scales: individuals form dynamic clusters within colonies that are normally widely scattered, but in recurrent blooms during the dry seasons of 2005 through 2007, colonies often formed close together in patches (metapopulations. Patches were extremely abundant in Guam, both in Apra Harbor and on the outer coast. This is the first time that long-term changes in a benthic ciliate population have been documented in situ and that multi-scale patchiness has been reported for a benthic ciliate. Colonies were mapped and monitored; some patches over 1 m diameter were recorded. Since 2008, the distribution has again consisted of scattered colonies, as it did from 1999–2004.

  9. The influence of environmental characteristics on the distribution of ciliates (Protozoa, Ciliophora in an urban stream of southeast Brazil

    Directory of Open Access Journals (Sweden)

    RJP. Dias

    Full Text Available The aim of this research was to study the ciliated protozoa community at three sampling stations that receive different levels of domestic sewage along the São Pedro Stream in the municipality of Juiz de Fora, Minas Gerais, Brazil, in order to determine the influence of organic pollution on this community and to assess the feasibility of using ciliates as water quality indicators. Four physical-chemical parameters of the water samples were evaluated: dissolved oxygen concentration, electrical conductivity, pH and temperature. The sediment was obtained manually, using dredges with capacity of 300 mL, at each collection point. Point 1 was located in a rural region that receives a low sewage load, while Points 2 and 3 were located in populated regions receiving high sewage loads. We found 22 ciliate species, of which 18 are included in the saprobic system and are considered bioindicators. These showed beta-mesosaprobic environments at Point 1 and alfa-mesosaprobic to polisaprobic environments at Points 2 and 3. The low levels of dissolved oxygen and the high electrical conductivity values at Points 2 and 3, together with the strong similarity between the ciliate taxocenoses of these points and the weak similarity between Point 1 and the other two, confirm the high sewage loads received at the latter two points. The combination of the biological indicators and physical-chemical analyses therefore proved itself to be an efficient method of evaluating water quality, and has excellent potential to support decisions on the conservation of headwaters and recuperation of degraded environments in lotic systems.

  10. Blooms of a benthic ciliate, Maristentor dinoferus (Heterotrichea: Maristentoridae), on coral reefs of Guam, Mariana Islands. (Note)

    OpenAIRE

    Schefter, M.; Lobban, C.S.

    2012-01-01

    Maristentor dinoferus is visible in situ with the naked eye; it forms aggregations at several scales: individuals form dynamic clusters within colonies that are normally widely scattered, but in recurrent blooms during the dry seasons of 2005 through 2007, colonies often formed close together in patches (metapopulations). Patches were extremely abundant in Guam, both in Apra Harbor and on the outer coast. This is the first time that long-term changes in a benthic ciliate population have been ...

  11. Can the halophilic ciliate Fabrea salina be used as a bio-control of microalgae blooms in solar salterns?

    Science.gov (United States)

    Hong, Hyun Pyo; Choi, Joong Ki

    2015-09-01

    The microlage Dunaliella salina, a major producer in salterns, is a serious problem for salt production. In this study we tried to assess if Fabrea salina can control D. salina. By parameterising numerical and functional response (growth and grazing vs prey abundance, respectively) at 90 psu and 30°C, where the ciliate is abundant and grows well, we developed a predator-prey model. The model is used to explore how change in microalga growth rate affect the dynamics, and the functional response is used in combination with field data to assess the potential impact of F. salina on D. salina. Over the 20 d simulation the ciliate controlled the prey population under all prey growth rates; although once D. salina were exhausted below the threshold level, F. salina died due to starvation, allowing the alga to increase in abundance, resulting in one or two predatorprey cycle, depending on prey growth rate. In general, the model predicted trends observed by others in the field, suggesting that it provided a good prediction of what may occur under the conditions we examined. Likewise we show that the ciliate can have a high impact on microalgal populations in the field. Finally, a literature review indicated that F. salina could be a good competitor with other protozoa and metazoan in salterns, depending on salinity and temperature, which requires further study and attention. In summary, we encourage continued studies on this unique ciliate on solar salterns and suggest that it may be useful in the bio-control of micoalgae.

  12. Determination of trace elements in freshwater rotifers and ciliates by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Woelfl, S.; Óvári, M.; Nimptsch, J.; Neu, T. R.; Mages, M.

    2016-02-01

    Element determination in plankton is important for the assessment of metal contamination of aquatic environments. Until recently, it has been difficult to determine elemental content in rotifers or ciliates derived from natural plankton samples because of the difficulty in handling and separation of these fragile organisms. The aim of this study was to evaluate methods for separation of rotifers and large ciliates from natural plankton samples (μg range dry weight) and subsequent analysis of their elemental content using total-reflection X-ray fluorescence spectrometry (TXRF). Plankton samples were collected from different aquatic environments (three lakes, one river) in Chile, Argentina and Hungary. From one to eighty specimens of five rotifer species (Brachionus calyciflorus, Brachionus falcatus, Asplanchna sieboldii, Asplanchna sp., Philodina sp.) and four to twelve specimens of one large ciliate (Stentor amethystinus) were prepared according to the dry method originally developed for microcrustaceans, and analysed by TRXF following in situ microdigestion. Our results demonstrated that it possible to process these small and fragile organisms (individual dry mass: 0.17-9.39 μg ind- 1) via careful washing and preparation procedures. We found species-dependent differences of the element mass fractions for some of the elements studied (Cr, Mn, Fe, Ni, Cu, Zn, As, Pb), especially for Cu, Fe and Mn. One large rotifer species (A. sieboldii) also showed a negative correlation between individual dry weight and the element content for Pb, Ni and Cr. We conclude that our application of the in situ microdigestion-TRXF method is suitable even for rotifers and ciliates, greatly expanding the possibilities for use of plankton in biomonitoring of metal contamination in aquatic environments.

  13. Connecting alveolate cell biology with trophic ecology in the marine plankton using the ciliate Favella as a model.

    Science.gov (United States)

    Echevarria, Michael L; Wolfe, Gordon V; Strom, Suzanne L; Taylor, Alison R

    2014-10-01

    Planktonic alveolates (ciliates and dinoflagellates), key trophic links in marine planktonic communities, exhibit complex behaviors that are underappreciated by microbiologists and ecologists. Furthermore, the physiological mechanisms underlying these behaviors are still poorly understood except in a few freshwater model ciliates, which are significantly different in cell structure and behavior than marine planktonic species. Here, we argue for an interdisciplinary research approach to connect physiological mechanisms with population-level outcomes of behaviors. Presenting the tintinnid ciliate Favella as a model alveolate, we review its population ecology, behavior, and cellular/molecular biology in the context of sensory biology and synthesize past research and current findings to construct a conceptual model describing the sensory biology of Favella. We discuss how emerging genomic information and new technical methods for integrating research across different levels of biological organization are paving the way for rapid advance. These research approaches will yield a deeper understanding of the role that planktonic alveolates may play in biogeochemical cycles, and how they may respond to future ocean conditions.

  14. Ecological functions of ciliated protozoa in marine ecosystem: effects of ammonium on the population growth of Euplotes vannus

    Institute of Scientific and Technical Information of China (English)

    Xu Henglong; Song Weibo; Zhu Mingzhuang; Wang Mei; Ma Honggang; Xu Xiaozhong

    2005-01-01

    The effects of ammonium on the population growth of the marine ciliate, Euplotes vannus, were examined using ecotoxicological method. It is showed that ammonium exerts inhibitory effects on the growth of the ciliate populations in a concentration-dependent way. Statistical analysis reveals that the population growth dynamics exposed to ammonium-N concentration over 100mg/L are significantly different from that in the control at P<0.05 level. Linear regression determined that the 24h, 36h, 48h, 60h, 72h and 84h IC50 values of ammonium-N are 19.68, 201.51, 167.49, 47.86, 50.43 and 43.11 concentration over 100mg/L, respectively (P<0.05; pH 8.2; salinity 28 ppt; temperature, 25℃). The results indicate that the tolerance to ammonium in E. vannus is considerably higher than that of the larvae or juveniles of some metozoa, such as cultured prawns and oysters. Therefore, it is believed that the high tolerance to ammonium is necessary for ciliated protozoa to play positive roles in maintaining and improving water quality in marine ecosystems, especially in the intensive aquaculture waters with high-level ammonium. In addition, the correlation between IC50 values and exposure time was discussed.

  15. Acute toxicities of potassium permanganate, formalin, and Lugol's iodine solution to a marine ciliate, Pleuronema coronatum (ciliophora, scuticociliatida)

    Science.gov (United States)

    Yantao, Qiu; Weibo, Song

    2002-10-01

    Acute toxicities of potassium permanganate, formalin, and Lugol’s iodine solution to a commonly occurred marine ciliate Pleuronema coronatum (Ciliophora, Scuticociliatida) were measured. Linear regression analysis of the results highlighted the close relationships between doses of the medicines and mortalities of the organisms, thus providing a capability to predict toxicity effects from the dose. Toxic effects of the medicines on the ciliates were described in the present paper, and the median lethal concentrations (LC50 values) were given. Results of measurements indicated that 2 h-LC50 and 12 h-LC50 values of formalin on P. coronatum were 59.00×10-6 and 43.57×10-6, while those of Lugol’s solutions were 90.13 and 67.84×10-6 respectively. The tolerance of P. coronatum to formalin is apparently lower than that to Lugol’s iodine solution and potassium permanganate is a suitable medicine to kill ciliates in short time.

  16. Acute Toxicities of Potassium Permanganate, Formalin, and Lugol's Iodine Solution to a Marine Ciliate,Pleuronema coronatum ( Ciliophora, Scuticociliatida)

    Institute of Scientific and Technical Information of China (English)

    QIU Yantao; SONG Weibo

    2002-01-01

    Acute toxicities of potassium permanganate, formalin, and Lugol's iodine solution to a commonly occurred ma-rine ciliate Pleuronema coronatum (Ciliophora, Scuticociliatida) were measured. Linear regression analysis of the resultshighlighted the close relationships between doses of the medicines and mortalities of the organisms, thus providing a capabili-ty to predict toxicity effects from the dose. Toxic effects of the medicines on the ciliates were described in the present paper,and the median lethal concentrations (LC50 values) were given. Results of measurements indicated that 2 h-LC50 and 12 h-LC50 values of formalin on P. coronatum were 59.00 × 10-6 and 43.57 × 10 6, while those of Lugol's solutions were 90.13 and67.84 × 10 6 respectively. The tolerance of P. coronatum to formalin is apparently lower than that to Lugol' s iodine solutionand potassium permanganate is a suitable medicine to kill ciliates in short time.

  17. Direct measurement of tubulin and bulk message distributions on polysomes of growing, starved and deciliated Tetrahymena using RNA gel blots of sucrose gradients containing acrylamide.

    Science.gov (United States)

    Calzone, F J; Callahan, R; Gorovsky, M A

    1988-10-25

    A method was developed using sucrose gradients containing acrylamide which greatly simplifies the measurement of the polysomal distribution of messages. After centrifugation, the acrylamide was polymerized, forming a "polysome gel". RNA gel blots of polysome gels were used to determine the polysomal distributions of alpha-tubulin and total polyadenylated mRNA in growing, starved (nongrowing) and starved-deciliated Tetrahymena and the number of messages loaded onto polysomes was calculated. These measurements indicated that the translational efficiencies of alpha-tubulin mRNA and total polyadenylated mRNA are largely unaffected when the rates of tubulin and total protein synthesis vary dramatically. Thus, differential regulation of alpha-tubulin mRNA translation initiation does not contribute to the greater than 100-fold induction of tubulin synthesis observed during cilia regeneration and in growing cells. The major translation-level process regulating tubulin synthesis in Tetrahymena appears to be a change in message loading mediated by a non-specific message recruitment or unmasking factor.

  18. The trophic role and impact of plankton ciliates in the microbial web structure of a tropical polymictic lake dominated by filamentous cyanobacteria

    Directory of Open Access Journals (Sweden)

    Alfonso Esquivel

    2016-03-01

    Full Text Available The recent interest in the plankton structures and dynamics in tropical and subtropical lakes has revealed important trends that set these lakes apart from temperate lakes, and one of the main differences is the enhanced importance of the microbial food web with respect to net plankton. Ciliates are a key component of subtropical and tropical microbial webs because of their role as dominant picoplankton grazers and their ability to channel picoplankton production to the uppermost trophic levels. Plankton ciliates have been found to play a crucial role in the survival of fish larvae in lakes that share several features with Lake Catemaco, a eutrophic tropical Mexican lake. Therefore, the plankton ciliate composition, abundance, and biomass of Lake Catemaco were studied to assess their role in the microbial food web. The data were obtained from surface and bottom water samples collected at eleven points during three surveys in 2011 and an additional survey in 2013, with the surveys covering the local climatic seasons. The most abundant components of the plankton ciliate assemblages were small prostomatids (Urotricha spp., choreotrichs (Rimostrombidium spp., cyclotrichs (Mesodinium and Askenasia, and scuticociliates (Cyclidium, Cinetochilum, Pleuronema, and Uronema. Other important ciliates in terms of abundance and/or biomass were haptorids (Actinobolina, Belonophrya, Monodinium, Paradileptus, and Laginophrya, Halteria, oligotrichs (Limnostrombidium and Pelagostrombidium, Linostomella, Bursaridium, Cyrtolophosis, and Litonotus. The ciliate abundance averaged 57 cells mL-1 and ranged from 14 to 113 cells mL-1. The mean ciliate biomass was 71 µg C L-1 and ranged from 10 to 202 µg C L-1. Differences were not detected in ciliate abundance or biomass between the sampling points or sampling depths (surface to bottom; however, significant differences were observed between seasons for both variables. Nano-sized filamentous cyanobacteria were the most

  19. Geometric control of ciliated band regulatory states in the sea urchin embryo.

    Science.gov (United States)

    Barsi, Julius C; Li, Enhu; Davidson, Eric H

    2015-03-01

    The trapezoidal ciliated band (CB) of the postgastrular sea urchin embryo surrounds the oral ectoderm, separating it from adjacent embryonic territories. Once differentiated, the CB is composed of densely arranged cells bearing long cilia that endow the larva with locomotion and feeding capability. The spatial pattern from which the CB will arise is first evidenced during pregastrular stages by expression of the pioneer gene onecut. Immediately after gastrulation, the CB consists of four separate regulatory state domains, each of which expresses a unique set of transcription factors: (1) the oral apical CB, located within the apical neurogenic field; (2) the animal lateral CB, which bilaterally separates the oral from aboral ectoderm; (3) the vegetal lateral CB, which bilaterally serves as signaling centers; and (4) the vegetal oral CB, which delineates the boundary with the underlying endoderm. Remarkably, almost all of the regulatory genes specifically expressed within these domains are downregulated by interference with SoxB1 expression, implying their common activation by this factor. Here, we show how the boundaries of the CB subdomains are established, and thus ascertain the design principle by which the geometry of this unique and complex regulatory state pattern is genomically controlled. Each of these boundaries, on either side of the CB, is defined by spatially confined transcriptional repressors, the products of regulatory genes operating across the border of each subdomain. In total this requires deployment of about ten different repressors, which we identify in this work, thus exemplifying the complexity of information required for spatial regulatory organization during embryogenesis.

  20. Genesis of amorphous calcium carbonate containing alveolar plates in the ciliate Coleps hirtus (Ciliophora, Prostomatea).

    Science.gov (United States)

    Lemloh, Marie-Louise; Marin, Frédéric; Herbst, Frédéric; Plasseraud, Laurent; Schweikert, Michael; Baier, Johannes; Bill, Joachim; Brümmer, Franz

    2013-02-01

    In the protist world, the ciliate Coleps hirtus (phylum Ciliophora, class Prostomatea) synthesizes a peculiar biomineralized test made of alveolar plates, structures located within alveolar vesicles at the cell cortex. Alveolar plates are arranged by overlapping like an armor and they are thought to protect and/or stiffen the cell. Although their morphology is species-specific and of complex architecture, so far almost nothing is known about their genesis, their structure and their elemental and mineral composition. We investigated the genesis of new alveolar plates after cell division and examined cells and isolated alveolar plates by electron microscopy, energy-dispersive X-ray spectroscopy, FTIR and X-ray diffraction. Our investigations revealed an organic mesh-like structure that guides the formation of new alveolar plates like a template and the role of vesicles transporting inorganic material. We further demonstrated that the inorganic part of the alveolar plates is composed out of amorphous calcium carbonate. For stabilization of the amorphous phase, the alveolar vesicles, the organic fraction and the element phosphorus may play a role.

  1. Electrochemical study of the interaction between Eu{sup 3+} and ciliate Euplotes octocarinatus centrin

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Baojuan; Wang Ziwei [Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006 (China); Tian Yanni, E-mail: tianyann@sxu.edu.c [Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006 (China); Wang Zhijun [Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006 (China); Yang Binsheng, E-mail: yangbs@sxu.edu.c [Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006 (China)

    2010-05-01

    A new species was formed when protein P{sub 23} (one segment of ciliate Euplotes octocarinatus centrin) was added to a solution of Eu{sup 3+}. The interaction between P{sub 23} and Eu{sup 3+} was investigated by cyclic voltammetry, pulse voltammetry and electrochemical impedance spectroscopy in 10 mM N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid (HEPES) buffer (pH 7.4) using a pyrolytic graphite electrode. The formal potential (E{sup o}') of Eu{sup 3+} shifted from -0.61 to -0.84 V (versus saturated calomel electrode) after P{sub 23} was added to the Eu{sup 3+} solution. The diffusion coefficient (D), the charge-transfer coefficient (alpha) and the electron transfer standard rate constant (k{sub s}) were obtained in the absence and the presence of P{sub 23}. The affinity constant of Eu{sup 3+} and P{sub 23} was determined to be (1.89 +- 0.51) x 10{sup 4} M{sup -1}. The electrochemical investigation of europium bound to the protein provided useful data for the studies of calcium-binding proteins.

  2. Calcium in ciliated protozoa: sources, regulation, and calcium-regulated cell functions.

    Science.gov (United States)

    Plattner, H; Klauke, N

    2001-01-01

    In ciliates, a variety of processes are regulated by Ca2+, e.g., exocytosis, endocytosis, ciliary beat, cell contraction, and nuclear migration. Differential microdomain regulation may occur by activation of specific channels in different cell regions (e.g., voltage-dependent Ca2+ channels in cilia), by local, nonpropagated activation of subplasmalemmal Ca stores (alveolar sacs), by different sensitivity thresholds, and eventually by interplay with additional second messengers (cilia). During stimulus-secretion coupling, Ca2+ as the only known second messenger operates at approximately 5 microM, whereby mobilization from alveolar sacs is superimposed by "store-operated Ca2+ influx" (SOC), to drive exocytotic and endocytotic membrane fusion. (Content discharge requires binding of extracellular Ca2+ to some secretory proteins.) Ca2+ homeostasis is reestablished by binding to cytosolic Ca2+-binding proteins (e.g., calmodulin), by sequestration into mitochondria (perhaps by Ca2+ uniporter) and into endoplasmic reticulum and alveolar sacs (with a SERCA-type pump), and by extrusion via a plasmalemmal Ca2+ pump and a Na+/Ca2+ exchanger. Comparison of free vs total concentration, [Ca2+] vs [Ca], during activation, using time-resolved fluorochrome analysis and X-ray microanalysis, respectively, reveals that altogether activation requires a calcium flux that is orders of magnitude larger than that expected from the [Ca2+] actually required for local activation.

  3. Biochemical and immunological characterization of the microfibrillar ecto-endoplasmic boundary in the ciliate Isotricha prostoma.

    Science.gov (United States)

    Vigues, B; Metenier, G; Groliere, C A

    1984-01-01

    The cytoplasm of the ciliated protozoan Isotricha prostoma is compartmented by a continuous fibrillar system made up of a double layer of 4 nm-diameter filaments: the microfibrillar ecto-endoplasmic boundary (EEB). Isolation of this structure after treatment of the cells in a buffer of low ionic strength in the presence of the detergent Triton X-100 evidenced connections linking the two filamentous layers. One dimensional electrophoresis on SDS-polyacrylamide gel of EEB fractions revealed several major proteins with apparent molecular weights between 11 and 23 K. Of these, two neighboring bands of MW22 and 23 K were removed from gels and used as antigens to obtain rabbit antibodies. The antiserum obtained reacted specifically with injected proteins as shown by the technique of immunological detection on nitrocellulose sheets using the peroxidase reaction product. Electron microscopy localization of the antigens with anti-IgG coupled with colloidal gold showed significant labeling of the EEB within the cortex of Isotricha permeabilized with Triton X-100. We hope that the 22-23 K antiserum will prove to be a useful tool for the comparative study of other non-actin filament systems in Protozoa.

  4. Molecular Phylogeny of Mobilid and Sessilid Ciliates Symbiotic in Eastern Pacific Limpets (Mollusca: Patellogastropoda).

    Science.gov (United States)

    Irwin, Nicholas A T; Lynn, Denis H

    2015-01-01

    The phylogenetic relationships of the ciliate subclass Peritrichia, composed of the orders Mobilida and Sessilida, have recently come under debate as morphological and molecular analyses have struck contrasting conclusions as to the monophyly of the group. We provide additional molecular data to assess the monophyly of the Peritrichia by sequencing the small subunit ribosomal RNA genes of two symbiotic peritrichs, Urceolaria korschelti and Scyphidia ubiquita, found inhabiting the mantle cavity of limpets. Although phylogenetic analyses indicated a nonmonophyletic Peritrichia, approximately unbiased tests revealed that the monophyletic hypothesis could not be rejected. With regard to the Mobilida, our analysis showed divergence within the family Trichodinidae related to host taxa-a molluscan clade and a fish clade. For the Sessilida, the family Scyphidiidae was sister to the Astylozoidae. In our sampling of U. korschelti and S. ubiquita, both species showed significant genetic divergence among geographically isolated, yet morphologically indistinguishable populations. We hypothesize that cryptic speciation has produced these morphologically identical species and argue that more extensive genomic analyses are required to fully assess the monophyly, biogeography, and ultimately biodiversity of the peritrichs.

  5. Adaptation responses of individuals to environmental changes in the ciliate Euplotes crassus

    Science.gov (United States)

    Kim, Se-Joo; Kim, Jin-Hyoung; Ju, Se-Jong

    2017-03-01

    Although the response unit of living organisms to environmental changes is at the individual level, most experiments on the adaptation responses of ciliates have been conducted in batches, comprising multiple-individuals, due to their microscopic size. However, here, we confirmed that individuals undergo different division cycles in monocultures of Euplotes crassus. They also exhibited transcript variations of 4.63-fold in SSU and of 22.78- fold in Hsp70. Additionally, in salt-stressed E. crassus individuals, SSU transcripts of individuals varied by 6.92-fold at 27 psu, 8.69- fold at 32 psu, and 2.51-fold at 37 psu. However, the maximum difference in Hsp70 was only 4.23-fold under all conditions. These results suggest there may be different biological rhythms even in siblings derived from the same parent. It can also be inferred that various environmental factors have different effects on different E. crassus individuals. Therefore, to elucidate relationships between organism adaptations and environmental changes, studies at the individual level should be conducted with multi-individual approaches.

  6. Distribution of a centrosomal antigen during morphogenesis in the ciliated protozoan Euplotes.

    Science.gov (United States)

    Fleury, A; Lemullois, M; Coffe, G

    1998-07-01

    Ciliates assemble basal bodies in great number at many stages of the life-cycle. In order to understand their assembly mechanisms, we screened a library of monoclonal antibodies directed against pericentriolar material. One of these antibodies, CTR210, was used previously to follow steps of this assembly process: in Paraurostyla, new basal bodies appear along a scaffold of linear structures recognized by this antibody. The very unusual behavior of this antigen deserved confirmation in other species. In the present study, we show by immunofluorescence that, in another phylogenetically very distant species, Euplotes, basal bodies are assembled in the same pathway during division. In addition, this antibody recognizes a filamentous ring located at the division furrow and linking many basal body assemblages. By cell fractionation and cytoskeletal extraction, we obtained fractions enriched in basal bodies and associated material. Such fractions still display a high complexity in protein composition. These fractions were used to characterize the main target of the antibody as a doublet of 45 kDa. These results confirm previous results in terms of functionality of the protein recognized by the antibody, but raise new questions in terms of the assignment of the recognized protein to the HSP70 family as hypothesized previously.

  7. Studies on the in vitro cultivation of ciliate protozoa from the kangaroo forestomach.

    Science.gov (United States)

    Dehority, Burk A; Wright, André-Denis G

    2014-08-01

    The methods used for culturing rumen protozoa were found to be unsatisfactory for growth of ciliate protozoa from the kangaroo forestomach. Based on published measurements of physical parameters in the marsupial forestomach, several modifications were incorporated into the procedure, i.e., an increase in % hydrogen in the gas phase, adjustment of initial pH of the medium to 6.9-7.0 range, feed only forage as a substrate and incubate at a lower temperature (33-36 °C). Only incubation at the lower temperature increased survival time of the kangaroo protozoa. Two species of Bitricha were still viable after 28 d in culture. Cultures had to be terminated at that time. One of the species differed considerably in size and shape from previously described species and based on 18S rRNA data, may represent a new species of Bitricha. The second species, present in low numbers was identified as Bitricha oblata. In a separate trial, Macropodinium yalanbense survived for 11 d, at which time these cultures also had to be terminated.

  8. Trichodina modesta: an exotic ciliate in the Neotropical region parasitizing an unusual host

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    Gustavo Moraes Ramos Valladão

    Full Text Available In this study, an important ornamental fish, Betta splendens (Osphronemidae, from three different Brazilian states was examined for parasitic infestations. Smears with parasites were impregnated with silver nitrate or stained using Giemsa for taxonomic evaluation. A disc-shaped trichodinid with a body diameter of 39.7 ± 3.3 µm, adhesive disc diameter of 32.9 ± 3.1 µm and denticulate ring diameter of 19.5 ± 2.0 µm was found. The morphological characteristics resembled those of Trichodina modesta Lom, 1970, a species that shows clear host specificity for Cypriniformes. Until now, its occurrence was restricted to the Eurasian region. In the present study, a new host for T. modesta is reported and therefore the first occurrence of this species in the Americas. The parasite was possibly introduced into the Neotropical region through the exotic fish trade, especially of Cypriniformes used by aquarists. The distribution of this ciliate is discussed and a checklist of localities and hosts for the species is provided.

  9. Space station image captures a red tide ciliate bloom at high spectral and spatial resolution.

    Science.gov (United States)

    Dierssen, Heidi; McManus, George B; Chlus, Adam; Qiu, Dajun; Gao, Bo-Cai; Lin, Senjie

    2015-12-01

    Mesodinium rubrum is a globally distributed nontoxic ciliate that is known to produce intense red-colored blooms using enslaved chloroplasts from its algal prey. Although frequent enough to have been observed by Darwin, blooms of M. rubrum are notoriously difficult to quantify because M. rubrum can aggregate into massive clouds of rusty-red water in a very short time due to its high growth rates and rapid swimming behavior and can disaggregate just as quickly by vertical or horizontal dispersion. A September 2012 hyperspectral image from the Hyperspectral Imager for the Coastal Ocean sensor aboard the International Space Station captured a dense red tide of M. rubrum (10(6) cells per liter) in surface waters of western Long Island Sound. Genetic data confirmed the identity of the chloroplast as a cryptophyte that was actively photosynthesizing. Microscopy indicated extremely high abundance of its yellow fluorescing signature pigment phycoerythrin. Spectral absorption and fluorescence features were related to ancillary photosynthetic pigments unique to this organism that cannot be observed with traditional satellites. Cell abundance was estimated at a resolution of 100 m using an algorithm based on the distinctive yellow fluorescence of phycoerythrin. Future development of hyperspectral satellites will allow for better enumeration of bloom-forming coastal plankton, the associated physical mechanisms, and contributions to marine productivity.

  10. Inter-annual ciliate distribution variation within the late stratification oxycline in a monomictic lake, Lake Alchichica (Mexico

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    Ximena Sánchez Medina

    2016-03-01

    Full Text Available noxia, and ciliates might play a very important role in the plankton community budget there. We analysed changes in the composition and biomass of the ciliate assemblage and other microbial loop components throughout the oxycline just at the end of stratification in a warm-monomictic lake, Lake Alchichica, Mexico (four samplings: 2006-2008, 2010; the results were compared with those obtained from another lake from the region, La Preciosa, sampled in 2010. Bacteria, autotrophic picoplankton (APP and flagellates were analysed using epifluorescence microscopy. Ciliates were evaluated either in DAPI stained samples (looking for pigmented organelles and/or ingested phototrophs or in quantitative protargol stain (QPS permanent preparations, where they were identified at the genus or species level. The end of the stratification period in Lake Alchichica was characterized by almost uniform heterotrophic picoplankton (HPP numbers (106 cells mL-1 throughout the water column. Meanwhile, APP showed epilimnetic and/or metalimnetic maxima of 105 cells mL-1 followed by an order of magnitude drop in the hypolimnion. A very important peak (105 cells mL-1 of the autotrophic or mixotrophic flagellate Pyramimonas sp. was observed repeatedly above and within the oxycline of Lake Alchichica. Ciliate biomass maxima were found around the oxycline and in the above-bottom layer. The top of the oxycline was dominated by Euplotes spp. and Spirostomum teres fine- to coarse-filter feeders (feeding upon APP, nanodiatoms and algae. Raptorial haptorids (in particular, Phialina sp. were the second most important group, generally occupying the layer below euplotids, followed by Holophrya and Prorodon facultative anaerobic prostomes. Sometimes, strictly anaerobic Caenomorpha sp. was found to be important in the anoxic hypolimnion. Minute picoplankton feeding species (both APP and heterotrophic bacteria feeders were important throughout the water column: in the epilimnion

  11. Distribution and Abundance of Interstitial Ciliates in Southampton Water in Relation to Physicochemical Conditions, Metal Pollution and the Availability of Food Organisms

    Science.gov (United States)

    Al-Rasheid, K. A. S.; Sleigh, M. A.

    1995-07-01

    Sediment samples were collected at low tide from eight sandy and muddy shores around Southampton Water on one occasion in July and one occasion in September. The temperature and pH of the sediments were measured at the time of collection, the water content of the sediments was determined and samples subjected to granulometric analysis. The population densities of bacteria and microflagellates were determined and the ciliates in sub-samples were identified to genus level and enumerated. The concentrations of cadmium, copper, lead, mercury and nickel in the interstitial water and in the dried sediments were measured by the dithizone and atomic absorption methods, respectively. These metal concentrations were compared with literature values for other British estuaries. Ciliates belonging to 23 genera were found in the sediments, the diversity of ciliates varying widely between stations. Bacterial numbers (mean ˜5×10 8 cm -3) at the various stations correlate with the surface area of the sediment particles and also correlate weakly with flagellate numbers (mean ˜2×10 4 cm -3). Total ciliate numbers (mean ˜1×10 3 cm -3) correlated quite strongly with flagellate numbers, but not with bacterial numbers. Euplotes, Strombidiumand Uronemawere common at all stations and generally dominated; Didinium, Mesodinium pulexand Pleuronemawere also found at all stations, and the latter two were often numerous; Uronychiawas found at seven stations. The distributions of Acinetopsis, Blepharisma, Lacrymaria, M. pulex, Paramecium, Spirostomum, Strombidiumand Vorticellashowed similar correlations to one another, and tended to favour sites nearer to sources of freshwater; these ciliates also showed a correlation with pH, river waters locally being alkaline. None of the ciliates showed correlations with any physical characteristics of the sediments. There were no negative correlations of ciliate distributions with metal pollutants. The levels of metal pollutants found in water drained

  12. Ultrastructure of the ciliated cells of the free-swimming larva, and sessile stages, of the marine sponge Haliclona indistincta (Demospongiae: Haplosclerida).

    Science.gov (United States)

    Stephens, Kelly M; Ereskovsky, Alexander; Lalor, Pierce; McCormack, Grace P

    2013-11-01

    We provide a detailed, comparative study of the ciliated cells of the marine haplosclerid sponge Haliclona indistincta, in order to make data available for future phylogenetic comparisons at the ultrastructural level. Our study focuses on the description and analysis of the larval epithelial cells, and choanocytes of the metamorphosed juvenile sponge. The ultrastructure of the two cell types is sufficiently different to prevent our ability to conclusively determine the origin of the choanocytes from the larval ciliated cells. However, ciliated, epithelial cells were observed in a migratory position within the inner cell mass of the larval stages. Some cilia were observed within the cell's cytoplasm, which is indicative of the ciliated epithelial cell undergoing transdifferentiation into a choanocyte; while traces of other ciliated epithelial cells were contained within phagosomes, suggesting they are phagocytosed. We compared our data with other species described in the literature. However, any phylogenetic inference must wait until further detailed comparisons can be made with species whose phylogenetic position has been determined by other means, such as phylogenomics, in order to more closely link genomic, and morphological information.

  13. Characterization of rumen ciliate community composition in domestic sheep, deer, and cattle, feeding on varying diets, by means of PCR-DGGE and clone libraries.

    Science.gov (United States)

    Kittelmann, Sandra; Janssen, Peter H

    2011-03-01

    The structure and variability of ciliate protozoal communities in the rumens of domestic New Zealand ruminants feeding on different diets was investigated. The relative abundance of ciliates compared with bacteria was similar across all samples. However, molecular fingerprinting of communities showed ruminant-specific differences in species composition. Community compositions of cattle were significantly influenced by diet. In contrast, diet effects in deer and sheep were weaker than the animal-to-animal variation. Cloning and sequencing of almost-full-length 18S rRNA genes from representative samples revealed that New Zealand ruminants were colonized by at least nine genera of ciliates and allowed the assignment of samples to two distinct community types. Cattle contained A-type communities, with most sequences closely related to those of the genera Polyplastron and Ostracodinium. Deer and sheep (with one exception) harboured B-type communities, with the majority of sequences belonging to the genera Epidinium and Eudiplodinium. It has been suggested that species composition of ciliate communities may impact methane formation in ruminants, with the B-type producing more methane. Therefore, manipulation of ciliate communities may be a means of mitigating methane emissions from grazing sheep and deer in New Zealand.

  14. Ciliate Nassula sp. grazing on a microcystin-producing cyanobacterium (Planktothrix agardhii): impact on cell growth and in the microcystin fractions

    Energy Technology Data Exchange (ETDEWEB)

    Combes, Audrey; Dellinger, Marc [' Molecules de communication et adaptation des microorganismes' , UMR 7245 CNRS-MNHN, Museum national d' Histoire naturelle, CP 39, 57 rue Cuvier, F-75231 Paris Cedex 05 (France); Cadel-six, Sabrina [' Unite Caracterisation des Toxines' - Laboratoire de securite des aliments de Maisons-Alfort - ANSES, F-94701 Maisons Alfort Cedex (France); Amand, Severine [' Molecules de communication et adaptation des microorganismes' , UMR 7245 CNRS-MNHN, Museum national d' Histoire naturelle, CP 39, 57 rue Cuvier, F-75231 Paris Cedex 05 (France); Comte, Katia, E-mail: kcomte@mnhn.fr [' Molecules de communication et adaptation des microorganismes' , UMR 7245 CNRS-MNHN, Museum national d' Histoire naturelle, CP 39, 57 rue Cuvier, F-75231 Paris Cedex 05 (France)

    2013-01-15

    The proliferation of microcystins (MCs)-producing cyanobacteria (MCs) can have detrimental effects on the food chain in aquatic environments. Until recently, few studies had focused on the fate of MCs in exposed organisms, such as primary consumers of cyanobacteria. In this study, we investigate the impact of an MC-producing strain of the cyanobacterium Planktothrix agardhii on the growth and physiology of a Nassula sp. ciliate isolated from a non-toxic cyanobacterial bloom. We show that this Nassula sp. strain was able to consume and grow while feeding exclusively on an MC-producing cyanobacterium over a prolonged period of time (8 months). In short-term exposure experiments (8 days), ciliates consuming an MC-producing cyanobacterial strain displayed slower growth rate and higher levels of antioxidant enzymes than ciliates feeding on two non-MC-producing strains. Three high-performance methods (LC/MS, LC/MS-MS and ELISA) were used to quantify the free and bound MCs in the culture medium and in the cells. We show that ciliate grazing led to a marked decrease in free MCs (methanol extractable) in cells, the MCs were therefore no longer found in the surrounding culture medium. These findings suggest that MCs may have undergone redistribution (free vs bound MCs) or chemical degradation within the ciliates.

  15. Gene expression in a paleopolyploid: a transcriptome resource for the ciliate Paramecium tetraurelia

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    Kapusta Aurélie

    2010-10-01

    Full Text Available Abstract Background The genome of Paramecium tetraurelia, a unicellular model that belongs to the ciliate phylum, has been shaped by at least 3 successive whole genome duplications (WGD. These dramatic events, which have also been documented in plants, animals and fungi, are resolved over evolutionary time by the loss of one duplicate for the majority of genes. Thanks to a low rate of large scale genome rearrangement in Paramecium, an unprecedented large number of gene duplicates of different ages have been identified, making this organism an outstanding model to investigate the evolutionary consequences of polyploidization. The most recent WGD, with 51% of pre-duplication genes still in 2 copies, provides a snapshot of a phase of rapid gene loss that is not accessible in more ancient polyploids such as yeast. Results We designed a custom oligonucleotide microarray platform for P. tetraurelia genome-wide expression profiling and used the platform to measure gene expression during 1 the sexual cycle of autogamy, 2 growth of new cilia in response to deciliation and 3 biogenesis of secretory granules after massive exocytosis. Genes that are differentially expressed during these time course experiments have expression patterns consistent with a very low rate of subfunctionalization (partition of ancestral functions between duplicated genes in particular since the most recent polyploidization event. Conclusions A public transcriptome resource is now available for Paramecium tetraurelia. The resource has been integrated into the ParameciumDB model organism database, providing searchable access to the data. The microarray platform, freely available through NimbleGen Systems, provides a robust, cost-effective approach for genome-wide expression profiling in P. tetraurelia. The expression data support previous studies showing that at short evolutionary times after a whole genome duplication, gene dosage balance constraints and not functional change are

  16. Preliminary insights into the impact of dietary starch on the ciliate, Neobalantidium coli, in captive chimpanzees.

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    Kateřina Schovancová

    Full Text Available Infections caused by the intestinal ciliate Neobalantidium coli are asymptomatic in most hosts. In humans and captive African great apes clinical infections occasionally occur, manifested mainly by dysentery; however, factors responsible for development of clinical balantidiasis have not been fully clarified. We studied the effect of dietary starch on the intensities of infection by N. coli in two groups of captive chimpanzees. Adult chimpanzees infected by N. coli from the Hodonín Zoo and from the Brno Zoo, Czech Republic, were fed with a high starch diet (HSD (average 14.7% of starch for 14 days, followed by a five-day transition period and subsequently with a period of low starch diet (LoSD (average 0.1% of starch for another 14 days. We collected fecal samples during the last seven days of HSD and LoSD and fixed them in 10% formalin. We quantified trophozoites of N. coli using the FLOTAC method. The numbers of N. coli trophozoites were higher during the HSD (mean ± SD: 49.0 ± 134.7 than during the LoSD (3.5 ± 6.8. A generalized linear mixed-effects model revealed significantly lower numbers of the N. coli trophozoites in the feces during the LoSD period in comparison to the HSD period (treatment contrast LoSD vs. HSD: 2.7 ± 0.06 (SE, z = 47.7; p<<0.001. We conclude that our data provide a first indication that starch-rich diet might be responsible for high intensities of infection of N. coli in captive individuals and might predispose them for clinically manifested balantidiasis. We discuss the potential nutritional modifications to host diets that can be implemented in part to control N. coli infections.

  17. Feeding by heterotrophic dinoflagellates and ciliates on the free-living dinoflagellate Symbiodinium sp. (Clade E).

    Science.gov (United States)

    Jeong, Hae Jin; Lim, An Suk; Yoo, Yeong Du; Lee, Moo Joon; Lee, Kyung Ha; Jang, Tae Young; Lee, Kitack

    2014-01-01

    To investigate heterotrophic protists grazing on Symbiodinium sp., we tested whether the common heterotrophic dinoflagellates Gyrodinium dominans, Gyrodinium moestrupii, Gyrodinium spirale, Oblea rotundata, Oxyrrhis marina, and Polykrikos kofoidii and the ciliates Balanion sp. and Parastrombidinopsis sp. preyed on the free-living dinoflagellate Symbiodinium sp. (clade E). We measured the growth and ingestion rates of O. marina and G. dominans on Symbiodinium sp. as a function of prey concentration. Furthermore, we compared the results to those obtained for other algal prey species. In addition, we measured the growth and ingestion rates of other predators at single prey concentrations at which these rates of O. marina and G. dominans were saturated. All predators tested in the present study, except Balanion sp., preyed on Symbiodinium sp. The specific growth rates of O. marina and G. dominans on Symbiodinium sp. increased rapidly with increasing mean prey concentration < ca. 740-815 ng C/ml (7,400-8,150 cells/ml), but became saturated at higher concentrations. The maximum growth rates of O. marina and G. dominans on Symbiodinium sp. (0.87 and 0.61/d) were much higher than those of G. moestrupii and P. kofoidii (0.11 and 0.04/d). Symbiodinium sp. did not support positive growth of G. spirale, O. rotundata, and Parastrombidinopsis sp. However, the maximum ingestion rates of P. kofoidii and Parastrombidinopsis sp. (6.7-10.0 ng C/predator/d) were much higher than those of O. marina and G. dominans on Symbiodinium sp. (1.9-2.1 ng C/predator/d). The results of the present study suggest that Symbiodinium sp. may increase or maintain the populations of some predators.

  18. Proteomic approach to reveal the proteins associated with encystment of the ciliate Euplotes encysticus.

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    Jiwu Chen

    Full Text Available In order to identify and reveal the proteins related to encystment of the ciliate Euplotes encysticus, we analyzed variation in the abundance of the proteins isolated from the resting cyst comparing with proteins in the vegetative cell. 2-D electrophoresis, MALDI-TOF MS techniques and Bioinformatics were used for proteome separation, quantification and identification. The comparative proteomics studies revealed 26 proteins with changes on the expression in the resting cysts, including 12 specific proteins and 14 differential proteins. 12 specific proteins and 10 out of the 14 differential proteins were selected and identified by MALDI-TOF MS. The identified specific proteins with known functions included type II cytoskeletal 1, keratin, Nop16 domain containing protein, protein arginine n-methyltransferase, epsilon-trimethyllysine hydroxylase and calpain-like protein. The identified differential proteins with known functions included Lysozyme C, keratinocyte growth factor, lysozyme homolog AT-2, formate acetyltransferase, alpha S1 casein and cold-shock protein. We discussed the functions of these proteins as well as their contribution in the process of encystment. These identified proteins covered a wide range of molecular functions, including gene regulation, RNA regulation, proteins degradation and oxidation resistance, stress response, material transport and cytoskeleton organization. Therefore, differential expression of these proteins was essential for cell morphological and physiological changes during encystment. This suggested that the peculiar proteins and differential proteins might play important roles in the process of the vegetative cells transforming into the resting cysts. These observations may be novel findings that bring new insights into the detailed mechanisms of dormancy.

  19. Effect of the nature of energy and nitrogen sources on the population of ciliates in the rumen of sheep

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    Houcine Selmi,

    2011-01-01

    Full Text Available The effect of the nature of raw materials in concentrate on the population of ciliated protozoa was evaluated in the rumen of Sicilo-Sarde sheep. Four rams with permanent rumen canulas, 4.8 ± 0.5 years with an average live weight of 45.25 ± 3.5 kg were used. Rams were fed a common base ration of hay oats (1.5 kg DM/ head/day. Animals were supplemented with 500g/head/day of one of four iso-energetic and iso-proteic concentrates. The four concentrates were: A concentrate (10% barley, 43.3% corn, 25% wheat bran, 17.7% soybean meal and 4% CMV, B concentrate (71.5% barley, 17.5% horse bean, soybean meal, 7% and 4% CMV, C concentrate (66% white sorghum, 30% fava, 4% CMV and D concentrate (71% triticale, 18% horse bean, soybean meal, 7%, 4% CMV. The determination of ciliates was performed on unfiltered rumen fluid, collected two hours after the morning meal. The enumeration of protozoa and determination of various genuses were carried out with a HAWSKLEY counting room after several dilutions, using a microscope. The population of ciliates for, the concentrate B was significantly higher (P<0.05 than those for A, C and D concentrates while different genus of these protozoa were comparable among diets. It can be concluded from this study that the use of local resources in the diet of sheep increased micro organisms in the rumen.

  20. A mesocosm study of the changes in marine flagellate and ciliate communities in a crude oil bioremediation trial.

    Science.gov (United States)

    Gertler, Christoph; Näther, Daniela J; Gerdts, Gunnar; Malpass, Mark C; Golyshin, Peter N

    2010-07-01

    Protozoan grazers play an important role in controlling the density of crude-oil degrading marine communities as has been evidenced in a number of microcosm experiments. However, small bioreactors contain a low initial titre of protozoa and the growth of hydrocarbon-depleting bacteria is accompanied by the fast depletion of mineral nutrients and oxygen, which makes microcosms rather unsuitable for simulating the sequence of events after the oil spill in natural seawater environment. In the present study, the population dynamics of marine protozoan community have been analysed in a 500 l mesocosm experiment involving bioaugmented oil booms that contained oil sorbents and slow-release fertilisers. A significant increase in numbers of marine flagellates and ciliates on biofilms of oil-degrading microbes was microscopically observed as early as 8 days after the start of the experiment, when protozoa exhibited a population density peak making up to 3,000 cells ml(-1). Further, the protozoan density varied throughout the experiment, but never dropped below 80 cells ml(-1). An 18S rRNA gene-based fingerprinting analysis revealed several changes within the eukaryotic community over the whole course of the experiment. Initial growth of flagellates and small ciliates was followed by a predominance of larger protozoa. According to microscopic observations and SSU rRNA molecular analyses, most predominant were the ciliates belonging to Euplotidae and Scuticociliatia. This is the first study to characterise the eukaryotic communities specifically in a large-scale oil bioremediation trial using both microscopy-based and several molecular techniques.

  1. Association of DNA with nuclear matrix in in vitro assembled nuclei induced by rDNA from Tetrahymena shanghaiensis in Xenopus egg extracts

    Institute of Scientific and Technical Information of China (English)

    CHENYING; BOZHANG; 等

    1997-01-01

    The nuclei assembled from exogenous DNA or chromatin in egg extracts resemble their in vivo counterparts in many aspects.However,the distribution pattern of DNA in these nuclei remains unknown.We introduced rDNA from the macronuclei of Tetrahymena into Xenopus cellfree extracts to examine the association of specific DNA sequences with nuclear matrix(NM) in the nuclei assembled in vitro.Our previous works showed the 5'NTS(nontranscription sequences) of the rDNA specifically bind to the NM system in the macronuclei.We show now the rDNA could induce chromatin assembly and nuclear formation in Xenopus cell-free system.When we extracted the NM system and compared the binding affinity of different regions of rDNA with the NM system,we found that the 5'NTS still hold their binding affinity with insoluble structure of the assembled nuclei in the estracts of Xenopus eggs.

  2. Effects of Pluronic F-68 on Tetrahymena cells: protection against chemical and physical stress and prolongation of survival under toxic conditions

    DEFF Research Database (Denmark)

    Hellung-Larsen, P; Assaad, F; Pankratova, Stanislava

    2000-01-01

    concentrations of Ca2+ (70 microM); (c) prolongs the survival of cells exposed to higher ion concentrations (10 mM Ca2+, or Na+ or K+); (d) postpones the death caused by trace metal ions like Zn2+, Fe3+ and, Cu2+; (e) protects cells from the death caused by shearing forces; and (f) prolongs the survival of cells......The effects of the non-ionic surfactant Pluronic F-68 (0.01% w/v) on Tetrahymena cells have been studied. A marked protection against chemical and physical stress was observed. The chemical stress effects were studied in cells suspended in buffer (starvation) or in buffers with added ingredients...... from a chemically defined medium (Ca2+, Mg2+, Na+, K+, trace metal ions). The physical stress was due to mechanical stress or hyperthermia. The data show that Pluronic: (a) prolongs the survival of low concentration cell suspensions during starvation; (b) prevents the cell death caused by low...

  3. Role of essential lipids in copepod nutrition: no evidence for trophic upgrading of food quality by a marine ciliate

    DEFF Research Database (Denmark)

    Klein Breteler, W.; Koski, Marja; Rampen, S.

    2004-01-01

    copepod species consumed S. sulcatum at significant rates, but after 3 d, weight-specific ingestion decreased more than 2-fold. Larvae and copepodites feeding on S. sulcatum developed at suboptimal rates, survived poorly and showed abnormal morphology in comparison to control individuals fed a good......., although in low abundance of unuseful Delta7 sterols. Obviously, S. sulcatum did not biochemically enhance bacterial or algal food for subsequent use at higher trophic levels, and only transferred fatty acids without further conversion. The results indicate a deficiency in the ciliate of HUFAs and sterols...

  4. ON THE MARINE CILIATE, Pseudocohnilembus hargisi (PROTOZOA, CILIOPHORA, SCUTICOCILIATIDA) WITH COMPARISON OF ITS RELATED SPECIES

    Institute of Scientific and Technical Information of China (English)

    龚骏; 马宏伟; 宋微波

    2002-01-01

    The living morphology, nuclear apparatus, infraciliature and silverline system of the poorly-known ciliate Pseudocohnilembus hargisi Evans & Thompson, 1964, collected from a shrimp culture pond in Qingdao, China, were examined by observation of the live specimen ; and by the pyridinated carbonate method and Chatton-Lwoff technique. The main characteristics: 13 - 14 (usually 13) longitudinal or slightly spirally arranged somatic kineties; single contractile vacuole with usually 2 ( 1 - 2) pores at posterior ends of the fourth and fifth somatic kineties to the fight of the buccal cavity. Several related congeners were compared and morphometrically tabulated.

  5. Scuticociliatid ciliate outbreak in Australian potbellied seahorse, Hippocampus abdominalis (Lesson, 1827): clinical signs, histopathologic findings, and treatment with metronidazole.

    Science.gov (United States)

    Di Cicco, Emiliano; Paradis, Erika; Stephen, Craig; Turba, Maria Elena; Rossi, Giacomo

    2013-06-01

    A severe outbreak of scuticociliatosis occurred in Australian pot-bellied seahorse, Hippocampus abdominalis (Lesson, 1872), kept at the Vancouver Aquarium Marine Science Centre (Vancouver, British Columbia, Canada). Clinical signs included anorexia, lethargy, irregular respiration, and death. Cytology and histopathology revealed a high number of histophagous ciliated protozoa within the tissues. The parasite, identified as Philasterides dicentrarchi, was observed in several internal organs that appeared edematous and hemorrhagic upon postmortem examination. Severe histopathologic lesions were reported in particular in the ovary, the kidney, and the intestine. This infection was successfully treated with metronidazole via bath therapy. No further evidence of this parasite was found in the treated fish.

  6. Effect of the rumen ciliates Entodinium caudatum, Epidinium ecaudatum and Eudiplodinium maggii, and combinations thereof, on ruminal fermentation and total tract digestion in sheep.

    Science.gov (United States)

    Zeitz, Johanna O; Amelchanka, Sergej L; Michałowski, Tadeusz; Wereszka, Krzysztof; Meile, Leo; Hartnack, Sonja; Kreuzer, Michael; Soliva, Carla R

    2012-06-01

    The quantitative importance of individual ciliate species and their interaction in the rumen is still unclear. The present study was performed to test whether there are species differences in the influence on ruminal fermentation in vivo and if combinations of ciliates act additive in that respect. Six adult wethers fed a hay-concentrate diet were defaunated, then refaunated either with Entodinium caudatum (EC), Epidinium ecaudatum (EE) or Eudiplodinium maggii (EM) alone, then progressively with all possible species combinations. Feed, faeces, urine, ruminal fluid and gas were sampled for eight days always after at least 21 days of adaptation. With a linear mixed model, accounting for the 2 x 2 x 2 full factorial study design, mean marginal effect sizes, i.e., the magnitude of change in variables as caused by the presence of each ciliate species or of combinations of them, were estimated. The apparent digestibility of organic matter and neutral detergent fibre remained unaffected. The apparent N digestibility increased by 0.054 with EM (0.716 with defaunation). Ruminal ammonia increased by 1.6, 4.0 and 8.7 mmol/l in the presence of EM, EC and EE, respectively, compared to defaunation (6.9 mmol/l). In the EM + EE combination, ruminal ammonia was lower than would have been expected from an additive effect. With EE, total short-chain fatty acids increased by 23 mmol/l (100 mmol/l with defaunation), but not when EE was combined with EM. The acetate-to-propionate ratio decreased by 0.73 units in the presence of EE (4.0 with defaunation), but only when EE was the sole ciliate species in the rumen. In the presence of any ciliate species, the 16S rDNA copies of total Bacteria and major fibrolytic species decreased to 0.52- and 0.22-fold values, respectively of that found without protozoa. Total Archaea were unaffected; however, Methanobacteriales copies increased 1.44-fold with EC. The CH4-to-CO2 ratio of ruminal gas decreased by 0.036 with EM and 0.051 with EE (0.454 with

  7. Coding genes and molecular structures of the diffusible signalling proteins (pheromones) of the polar ciliate, Euplotes nobilii.

    Science.gov (United States)

    Vallesi, Adriana; Alimenti, Claudio; Pedrini, Bill; Di Giuseppe, Graziano; Dini, Fernando; Wüthrich, Kurt; Luporini, Pierangelo

    2012-12-01

    In protozoan ciliates, diffusible signalling proteins (pheromones) regulate the vegetative growth and mating interactions. Here, the coding genes and the structures of the encoded pheromones were studied in genetically distinct wild-type strains representing interbreeding Antarctic and Arctic populations of the marine ciliate Euplotes nobilii. Determination of seven allelic pheromone-coding DNA sequences revealed that an unusual extension and high structural conservation of the 5' non-coding region are peculiar traits of this gene family, implying that this region is directly involved in the mechanism of pheromone gene expression, possibly through phenomena of intron splicing and/or frame-shifting. For four pheromones, the three-dimensional structures were determined by nuclear magnetic resonance spectroscopy in solution. These structures show that the pheromones represent a protein family which adapts to its polar environment by combining a structurally stable core of a three-helix bundle with extended polypeptide segments that are devoid of regular secondary structures and concomitantly show enhanced structural flexibility.

  8. OCT-based quantification of flow velocity, shear force, and power generated by a biological ciliated surface (Conference Presentation)

    Science.gov (United States)

    Huang, Brendan K.; Khokha, Mustafa K.; Loewenberg, Michael; Choma, Michael A.

    2016-03-01

    In cilia-driven fluid flow physiology, quantification of flow velocity, shearing force, and power dissipation is important in defining abnormal ciliary function. The capacity to generate flow can be robustly described in terms of shearing force. Dissipated power can be related to net ATP consumption by ciliary molecular motors. To date, however, only flow velocity can be routinely quantified in a non-invasive, non-contact manner. Additionally, traditional power-based metrics rely on metabolic consumption that reflects energy consumption not just from cilia but also from all active cellular processes. Here, we demonstrate the estimation of all three of these quantities (flow velocity, shear force, and power dissipation) using only optical coherence tomography (OCT). Specifically, we develop a framework that can extract force and power information from vectorial flow velocity fields obtained using OCT-based methods. We do so by (a) estimating the viscous stress tensor from flow velocity fields to estimate shearing force and (b) using the viscous stress tensor to estimate the power dissipation function to infer total mechanical power. These estimates have the advantage of (a) requiring only a single modality, (b) being non-invasive in nature, and (c) being reflective of only the net power work generated by a ciliated surface. We demonstrate our all-optical approach to the estimation of these parameters in the Xenopus animal model system under normal and increased viscous loading. Our preliminary data support the hypothesis that the Xenopus ciliated surface can increase force output under loading conditions.

  9. Ciliary-propelling mechanism, effect of temperature and viscosity on swimming speed, and adaptive significance of ‘jumping’ in the ciliate Mesodinium rubrum

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2009-01-01

    Beating cilia are important organelles, not only for water pumping in many active filter-feeding organisms, but also for the swimming activity of ciliates and other aquatic organisms that use cilia for propulsion. The present study concerns the effect of temperature-dependent viscosity of the amb...

  10. La familia de las metalotioneínas en "Tetrahymena" y su aplicación en el desarrollo de biosensores celulares para la detección de metales pesados

    OpenAIRE

    Amaro Torres , Francisco

    2009-01-01

    La evaluación de la contaminación por metales pesados se debe realizar en base a parámetros como la biodisponibilidad de metales, su toxicidad y genotoxicidad. Para ello se utilizan los llamado biosensores celulares, y los ciliados, como microorganismos eucariotas móviles y sin pared celular, constituyen una excelente herramienta para ello. Aunque T. thermophila presenta un gen codificante (TtPCS) para una proteína homóloga a fitoquelatín sintasas, la ausencia de fitoquelatinas en este ciliad...

  11. Taxonomic Studies on a New Marine Ciliate, Apocoleps magnus gen. nov., spec. nov. (Ciliophora, Colepidae),Isolated from Qingdao, China

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiangrui; Alan Warren; SONG Weibo

    2009-01-01

    The morphology and infraciliature of a new marine colepid ciliate, Apocoleps magnus gen. nov., spee. nov., are described based on living observations and silver impregnations. The new genus Apocoleps is characterized by having 8 (vs. 6 in most other related genera) armour tiers, spines at both ends of the cell, 3 adoral organelles and plates with 4 reniform uni-windows. Apocoleps magnus spec. nov. is defined by the following features: body elongated and slightly curved, about 100-120μm×35-45 μm in vivo; anterior tertiary tier plate with four uni-windows, most secondary and main tier plates with four uni-windows, posterior tertiary tier plate with two uni-windows; left plate margin slightly serrated; on average 23 transverse and 22 longitudinal ciliary rows; one terminal contractile vacuole; marine habitat.

  12. Directed Induction of Functional Multi-ciliated Cells in Proximal Airway Epithelial Spheroids from Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Satoshi Konishi

    2016-01-01

    Full Text Available Multi-ciliated airway cells (MCACs play a role in mucociliary clearance of the lung. However, the efficient induction of functional MCACs from human pluripotent stem cells has not yet been reported. Using carboxypeptidase M (CPM as a surface marker of NKX2-1+-ventralized anterior foregut endoderm cells (VAFECs, we report a three-dimensional differentiation protocol for generating proximal airway epithelial progenitor cell spheroids from CPM+ VAFECs. These spheroids could be induced to generate MCACs and other airway lineage cells without alveolar epithelial cells. Furthermore, the directed induction of MCACs and of pulmonary neuroendocrine lineage cells was promoted by adding DAPT, a Notch pathway inhibitor. The induced MCACs demonstrated motile cilia with a “9 + 2” microtubule arrangement and dynein arms capable of beating and generating flow for mucociliary transport. This method is expected to be useful for future studies on human airway disease modeling and regenerative medicine.

  13. The giant ciliate Zoothamnium niveum and its thiotrophic epibiont Candidatus Thiobios zoothamnicoli: a model system to study interspecies cooperation

    Directory of Open Access Journals (Sweden)

    Monika eBright

    2014-04-01

    Full Text Available Symbioses between chemoautotrophic sulfur-oxidizing (thiotrophic bacteria and protists or animals are among the most diverse and prevalent in the ocean. They are extremely difficult to maintain in aquaria and no thiotrophic symbiosis involving an animal host has ever been successfully cultivated. In contrast, we have cultivated the giant ciliate Zoothamnium niveum and its obligate ectosymbiont Cand. Thiobios zoothamnicoli in small flow-through aquaria. This review provides an overview of the host and the symbiont and their phylogenetic relationships. We summarize our knowledge on the ecology, geographic distribution and life cycle of the host, on the vertical transmission of the symbiont, and on the cultivation of this symbiosis. We then discuss the benefits and costs involved in this cooperation compared with other thiotrophic symbioses and outline our view on the evolution and persistence of this byproduct mutualism.

  14. First Record and Redefinition of the Qingdao Population of Marine Ciliate Cardiostomatella vermiformis (Kahl, 1928) Corliss, 1960 (Protozoa, Ciliophora)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The living morphology and infraciliature of a marine ciliate, Cardiostomatella vermiformis isolated from a sand beach of the Jiaozhou Bay near Qingdao, China, were investigated by live observation, protargol and silver carbonate impregnation methods. Both the morphological and morphometric data largely agree with former records. Based on the data obtained, an improved diagnosis for Cardiostomatella vermiformis is supplied: Large marine Cardiostomatella with cylindrical body shape and several prolonged caudal cilia; cells in vivo about (90-500)μm × (30-120)μm; macronucleus beaded; single contractile vacuole caudally positioned; buccal apparatus conspicuously small, genus typical; three to six postoral kineties; 96-130 somatic kineties. This species is recorded for the first time in China.

  15. Complementary Notes on a‘Well-known' Marine Heterotrichous Ciliate, Folliculinopsis producta (Wright, 1859) Fraure-Fremiet,1936 (Protozoa, Ciliophora)

    Institute of Scientific and Technical Information of China (English)

    JI Daode; LIN Xiaofeng; SONG Weibo

    2004-01-01

    The living morphology and infraciliature of a heterotrichous ciliate, Folliculinopsis producta (Wright, 1859)Fraure-Fremiet, 1936, which was collected from the north coast of China, were investigated by in vivo observation and protargol impregnation techniques. As a new contribution, a redescription is presented: large Folliculinopsis of green to dark green in color, 800-1500μm in size; two peristomial lobes of approximately equal size, 300-400μm in length; adoral zone of membranelles containing about 1000 membranelles, lying along lobe margins and exhibiting two circles within buccal cavity;50-70 somatic kineties in mid-body; macronucleus miniliform, consisting of about 20 beads; lorica smooth, vase-shaped,(300 500)μm ×(90-130)μm in size, with 5-12 spiral ridges on neck tube; marine habitat.

  16. Laminin-332 alters connexin profile, dye coupling and intercellular Ca2+ waves in ciliated tracheal epithelial cells

    Directory of Open Access Journals (Sweden)

    Olsen Colin E

    2006-08-01

    Full Text Available Abstract Background Tracheal epithelial cells are anchored to a dynamic basement membrane that contains a variety of extracellular matrix proteins including collagens and laminins. During development, wound repair and disease of the airway epithelium, significant changes in extracellular matrix proteins may directly affect cell migration, differentiation and events mediated by intercellular communication. We hypothesized that alterations in cell matrix, specifically type I collagen and laminin α3β3γ2 (LM-332 proteins within the matrix, directly affect intercellular communication in ciliated rabbit tracheal epithelial cells (RTEC. Methods Functional coupling of RTEC was monitored by microinjection of the negatively charged fluorescent dyes, Lucifer Yellow and Alexa 350, into ciliated RTEC grown on either a LM-332/collagen or collagen matrix. Coupling of physiologically significant molecules was evaluated by the mechanism and extent of propagated intercellular Ca2+ waves. Expression of connexin (Cx mRNA and proteins were assayed by reverse transcriptase – polymerase chain reaction and immunocytochemistry, respectively. Results When compared to RTEC grown on collagen alone, RTEC grown on LM-332/collagen displayed a significant increase in dye transfer. Although mechanical stimulation of RTEC grown on either LM-332/collagen or collagen alone resulted in intercellular Ca2+ waves, the mechanism of transfer was dependent on matrix: RTEC grown on LM-332/collagen propagated Ca2+waves via extracellular purinergic signaling whereas RTEC grown on collagen used gap junctions. Comparison of RTEC grown on collagen or LM-332/collagen matrices revealed a reorganization of Cx26, Cx43 and Cx46 proteins. Conclusion Alterations in airway basement membrane proteins such as LM-332 can induce connexin reorganizations and result in altered cellular communication mechanisms that could contribute to airway tissue function.

  17. Insights into the phylogeny of sporadotrichid ciliates (Protozoa, Ciliophora: Hypotricha) based on genealogical analyses of multiple molecular markers

    Institute of Scientific and Technical Information of China (English)

    HU Xiaoyan; HU Xiaozhong; Khaled A. S. AL-RASHEID; Saieh A. AL-FARRAJ; SONG Weibo

    2011-01-01

    The sporadotrichid ciliates are an especially diverse group. A number of investigators have studied the morphological, morphogenetic, and molecular relationships among members of this group. Despite this, a consistent classification is still lacking and several important questions about the phylogenetic relationships within this group remain unsolved. To improve our understanding of these relationships, we constructed phylogenetic trees using the nucleotide sequences of the small-subunit rRNA (SSrRNA) gene and amino acid sequences of actin I and -αtubulin. Analyses of SSrRNA gene sequences indicated that: 1) the Sporadotrichida sensu Lynn (2008) and the Oxytrichidae are polyphyletic; 2) the Uroleptus species, which are classified to urostylids, formed a sister group with the oxytrichids; 3) Halteria grandinella, which is grouped morphologically with oligotrich species, clustered within the oxytrichids. These results are congruent with previous studies based on SSrRNA gene sequences. However, the amino acid sequences of actin I and α-tubulin yielded different topologies. The main results are: 1) in all phylogenetic trees, the genus Oxylricha was paraphyletic; 2) Uroleptus was sister to a subset of Urostyla and Holosticha, albeit with low supporting values; 3) Halteria grandinella was separated distantly from the Oxytrichidae in trees inferred from actin I amino acid sequences but clustered with oligotrichids in the α-tubulin analysis. The inconsistency among the trees inferred from these different molecular markers may be caused by rapidly accumulated genetic characterizations of ciliates. Further studies with additional molecular markers and sampling of more taxa are expected to better address the relationships among sporadotrichids.

  18. Insights into the phylogeny of sporadotrichid ciliates (Protozoa, Ciliophora: Hypotricha) based on genealogical analyses of multiple molecular markers

    Science.gov (United States)

    Hu, Xiaoyan; Hu, Xiaozhong; Al-Rasheid, Khaled A. S.; Al-Farraj, Saleh A.; Song, Weibo

    2011-01-01

    The sporadotrichid ciliates are an especially diverse group. A number of investigators have studied the morphological, morphogenetic, and molecular relationships among members of this group. Despite this, a consistent classification is still lacking and several important questions about the phylogenetic relationships within this group remain unsolved. To improve our understanding of these relationships, we constructed phylogenetic trees using the nucleotide sequences of the small-subunit rRNA (SSrRNA) gene and amino acid sequences of actin I and α-tubulin. Analyses of SSrRNA gene sequences indicated that: 1) the Sporadotrichida sensu Lynn (2008) and the Oxytrichidae are polyphyletic; 2) the Uroleptus species, which are classified to urostylids, formed a sister group with the oxytrichids; 3) Halteria grandinella, which is grouped morphologically with oligotrich species, clustered within the oxytrichids. These results are congruent with previous studies based on SSrRNA gene sequences. However, the amino acid sequences of actin I and α-tubulin yielded different topologies. The main results are: 1) in all phylogenetic trees, the genus Oxytricha was paraphyletic; 2) Uroleptus was sister to a subset of Urostyla and Holosticha, albeit with low supporting values; 3) Halteria grandinella was separated distantly from the Oxytrichidae in trees inferred from actin I amino acid sequences but clustered with oligotrichids in the α-tubulin analysis. The inconsistency among the trees inferred from these different molecular markers may be caused by rapidly accumulated genetic characterizations of ciliates. Further studies with additional molecular markers and sampling of more taxa are expected to better address the relationships among sporadotrichids.

  19. Natural products from aquatic eukaryotic microorganisms for cancer therapy: Perspectives on anti-tumour properties of ciliate bioactive molecules.

    Science.gov (United States)

    Catalani, Elisabetta; Proietti Serafini, Francesca; Zecchini, Silvia; Picchietti, Simona; Fausto, Anna Maria; Marcantoni, Enrico; Buonanno, Federico; Ortenzi, Claudio; Perrotta, Cristiana; Cervia, Davide

    2016-11-01

    Several modern drugs, including those for cancer therapy, have been isolated from natural sources, are based on natural products and its derivatives, or mime natural products. Some of them are in clinical use, others in clinical trials. The success of natural products in drug discovery is related to their biochemical characteristics and to the technologic methods used to study their feature. Natural compounds may acts as chemo-preventive agents and as factors that increase therapeutic efficacy of existing drugs, thus overcoming cancer cell drug resistance that is the main factor determining the failure in conventional chemotherapy. Water environment, because of its physical and chemical conditions, shows an extraordinary collection of natural biological substances with an extensive structural and functional diversity. The isolation of bioactive molecules has been reported from a great variety of aquatic organisms; however, the therapeutic application of molecules from eukaryotic microorganisms remains inadequately investigated and underexploited on a systematic basis. Herein we describe the biological activities in mammalian cells of selected substances isolated from ciliates, free-living protozoa common almost everywhere there is water, focusing on their anti-tumour actions and their possible therapeutic activity. In particular, we unveil the cellular and molecular machine mediating the effects of cell type-specific signalling protein pheromone Er-1 and secondary metabolites, i.e. euplotin C and climacostol, in cancer cells. To support the feasibility of climacostol-based approaches, we also present novel findings and report additional mechanisms of action using both in vitro and in vivo models of mouse melanomas, with the scope of highlighting new frontiers that can be explored also in a therapeutic perspective. The high skeletal chemical difference of ciliate compounds, their sustainability and availability, also through the use of new organic synthesis

  20. Tracing the path of DNA substrates in active Tetrahymena telomerase holoenzyme complexes: mapping of DNA contact sites in the RNA subunit.

    Science.gov (United States)

    Goldin, Svetlana; Kertesz Rosenfeld, Karin; Manor, Haim

    2012-08-01

    Telomerase, the enzyme that extends single-stranded telomeric DNA, consists of an RNA subunit (TER) including a short template sequence, a catalytic protein (TERT) and accessory proteins. We used site-specific UV cross-linking to map the binding sites for DNA primers in TER within active Tetrahymena telomerase holoenzyme complexes. The mapping was performed at single-nucleotide resolution by a novel technique based on RNase H digestion of RNA-DNA hybrids made with overlapping complementary oligodeoxynucleotides. These data allowed tracing of the DNA path through the telomerase complexes from the template to the TERT binding element (TBE) region of TER. TBE is known to bind TERT and to be involved in the template 5'-boundary definition. Based on these findings, we propose that upstream sequences of each growing telomeric DNA chain are involved in regulation of its growth arrest at the 5'-end of the RNA template. The upstream DNA-TBE interaction may also function as an anchor for the subsequent realignment of the 3'-end of the DNA with the 3'-end of the template to enable initiation of synthesis of a new telomeric repeat.

  1. Impacts of an uncontrolled phosphogypsum dumpsite on summer distribution of phytoplankton, copepods and ciliates in relation to abiotic variables along the near-shore of the southwestern Mediterranean coast.

    Science.gov (United States)

    Rekik, Amira; Drira, Zaher; Guermazi, Wassim; Elloumi, Jannet; Maalej, Sami; Aleya, Lotfi; Ayadi, Habib

    2012-02-01

    In connection with the Taparura Project, studies of spatial distribution of the crustacean zooplankton community, nutrients, phytoplankton and ciliates were conducted in July 2007 at 45 stations spread over fifteen transects along the coast north of Sfax. The results showed that the N/P ratio was lower than the Redfield ratio, suggesting potential N limitation. Phytoplankton was characterised by the proliferation of several diatoms, while ciliates were largely dominated by spirotrichs. Copepods were the most abundant zooplankton present during the entire study period, comprising 61% of the total zooplankton community. Twelve copepod families were identified at every station, with a high percentage of Oithonidae (77% of copepods) dominated by Oithona nana. The abundance of this species was correlated with that of diatoms, Cocoolithophorideae and ciliated Colpodea, suggesting that O. nana may feed on a wide range of prey. Despite human pressure and industrial activities, the coastal waters north of Sfax showed a wide diversity of phytoplankton, ciliates and zooplankton.

  2. [Morphological variations of the nuclear apparatus of astome ciliates Almophrya bivacuolata and A. maediovacuolata (protozoa: ciliophora) endocommensal of terricolous oligochaetes in Cameroon].

    Science.gov (United States)

    Nana, P A; Ngassam, P; Fokam, Z; Bricheux, G; Bouchard, P; Coffe, G; Sime, Gando T; Zébazé, Togouet S H

    2010-12-01

    The silver impregnation supplemented by DAPI and Feulgen nuclear coloration enabled us to study the morphological variations of the nuclear apparatus of two species of endocommensal Astome ciliates, Almophrya bivacuoloata (de Puytorac & Dragesco, 1968) and A. mediovocuolata (Ngassam, 1983). We highlighted important digitations and the presence of dark bands in the structure of the "H" macronucleus of the small cellular types as well as the presence of intermediate forms between "H" and "X" in these two species.

  3. Can a fermentation gas mainly produced by rumen Isotrichidae ciliates be a potential source of biohydrogen and a fuel for a chemical fuel cell?

    Science.gov (United States)

    Piela, Piotr; Michałowski, Tadeusz; Miltko, Renata; Szewczyk, Krzysztof; Sikora, Radosław; Grzesiuk, Elzbieta; Sikora, Anna

    2010-07-01

    Bacteria, fungi and protozoa inhabiting the rumen, the largest chamber of the ruminants' stomach, release large quantities of hydrogen during the fermentation of carbohydrates. The hydrogen is used by coexisting methanogens to produce methane in energy-yielding processes. This work shows, for the first time, a fundamental possibility of using a hydrogen-rich fermentation gas produced by selected rumen ciliates to feed a low-temperature hydrogen fuel cell. A biohydrogen fuel cell (BHFC) was constructed consisting of (i) a bioreactor, in which a hydrogen-rich gas was produced from glucose by rumen ciliates, mainly of the Isotrichidae family, deprived of intra- and extracellular bacteria, methanogens, and fungi, and (ii) a chemical fuel cell of the polymer-electrolyte type (PEFC). The fuel cell was used as a tester of the technical applicability of the fermentation gas produced by the rumen ciliates for power generation. The average estimated hydrogen yield was ca. 1.15 mol H2 per mol of fermented glucose. The BHFC performance was equal to the performance of the PEFC running on pure hydrogen. No fuel cell poisoning effects were detected. A maximum power density of 1.66 kW/m2 (PEFC geometric area) was obtained at room temperature. The maximum volumetric power density was 128 W/m3 but the coulombic efficiency was only ca. 3.8%. The configuration of the bioreactor limited the continuous operation time of this BHFC to ca. 14 hours.

  4. Morphogenesis of respiratory syncytial virus in human primary nasal ciliated epithelial cells occurs at surface membrane microdomains that are distinct from cilia

    Energy Technology Data Exchange (ETDEWEB)

    Jumat, Muhammad Raihan [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Yan, Yan [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Ravi, Laxmi Iyer [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Wong, Puisan [Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510 (Singapore); Huong, Tra Nguyen [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Li, Chunwei [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Tan, Boon Huan [Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510 (Singapore); Wang, De Yun [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Sugrue, Richard J., E-mail: rjsugrue@ntu.edu.sg [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore)

    2015-10-15

    The distribution of cilia and the respiratory syncytial virus (RSV) nucleocapsid (N) protein, fusion (F) protein, attachment (G) protein, and M2-1 protein in human ciliated nasal epithelial cells was examined at between 1 and 5 days post-infection (dpi). All virus structural proteins were localized at cell surface projections that were distinct from cilia. The F protein was also trafficked into the cilia, and while its presence increased as the infection proceeded, the N protein was not detected in the cilia at any time of infection. The presence of the F protein in the cilia correlated with cellular changes in the cilia and reduced cilia function. At 5 dpi extensive cilia loss and further reduced cilia function was noted. These data suggested that although RSV morphogenesis occurs at non-cilia locations on ciliated nasal epithelial cells, RSV infection induces changes in the cilia body that leads to extensive cilia loss. - Highlights: • Respiratory syncytial virus (RSV) infects nasal ciliated epithelial cells. • Virus morphogenesis occurs within filamentous projections distinct from cilia. • The RSV N protein was not detected in the cilia at any time during infection. • Trafficking of the F protein into the cilia occurred early in infection. • Presence of the F protein in cilia correlated with impaired cilia function.

  5. Impacts of restoration of an uncontrolled phosphogypsum dumpsite on the seasonal distribution of abiotic variables, phytoplankton, copepods, and ciliates in a man-made solar saltern.

    Science.gov (United States)

    Kobbi-Rebai, Rayda; Annabi-Trabelsi, Neila; Khemakhem, Hajer; Ayadi, Habib; Aleya, Lotfi

    2013-03-01

    The restoration of an uncontrolled phosphogypsum landfill was investigated for its effects on the seasonal distribution of phytoplankton, ciliates, and copepods. Sampling was carried out monthly from September 2007 to August 2008 at four ponds of increasing salinity (A1, 41 psu; A5, 46 psu; A16, 67 psu; and C31, 77 psu) in the Sfax solar saltern (southeastern Tunisia). Physicochemical and biological analyses were carried out using standard methods. Results showed drastic reduction of phosphate input and greater diversity of phytoplankton, ciliates, and copepods than before restoration. Pennate diatoms and new ciliates, considered bio-indicators of less-stressed marine ecosystems, proliferated in the A1 pond for the first time after restoration. Copepods appeared to feed on a wide range of prey. Economically, removal of the 1.7 million m(3) of phosphate improved the quality of the site's salt production, enabling the salt company to receive the quality ISO 9001 accreditation.

  6. Coincidental loss of bacterial virulence in multi-enemy microbial communities.

    Directory of Open Access Journals (Sweden)

    Ji Zhang

    Full Text Available The coincidental virulence evolution hypothesis suggests that outside-host selection, such as predation, parasitism and resource competition can indirectly affect the virulence of environmentally-growing bacterial pathogens. While there are some examples of coincidental environmental selection for virulence, it is also possible that the resource acquisition and enemy defence is selecting against it. To test these ideas we conducted an evolutionary experiment by exposing the opportunistic pathogen bacterium Serratia marcescens to the particle-feeding ciliate Tetrahymena thermophila, the surface-feeding amoeba Acanthamoeba castellanii, and the lytic bacteriophage Semad11, in all possible combinations in a simulated pond water environment. After 8 weeks the virulence of the 384 evolved clones were quantified with fruit fly Drosophila melanogaster oral infection model, and several other life-history traits were measured. We found that in comparison to ancestor bacteria, evolutionary treatments reduced the virulence in most of the treatments, but this reduction was not clearly related to any changes in other life-history traits. This suggests that virulence traits do not evolve in close relation with these life-history traits, or that different traits might link to virulence in different selective environments, for example via resource allocation trade-offs.

  7. The genealogic tree of mycobacteria reveals a long-standing sympatric life into free-living protozoa.

    Directory of Open Access Journals (Sweden)

    Otmane Lamrabet

    Full Text Available Free-living protozoa allow horizontal gene transfer with and between the microorganisms that they host. They host mycobacteria for which the sources of transferred genes remain unknown. Using BLASTp, we searched within the genomes of 15 mycobacteria for homologous genes with 34 amoeba-resistant bacteria and the free-living protozoa Dictyostelium discoideum. Subsequent phylogenetic analysis of these sequences revealed that eight mycobacterial open-reading frames (ORFs were probably acquired via horizontal transfer from beta- and gamma-Proteobacteria and from Firmicutes, but the transfer histories could not be reliably established in details. One further ORF encoding a pyridine nucleotide disulfide oxidoreductase (pyr-redox placed non-tuberculous mycobacteria in a clade with Legionella spp., Francisella spp., Coxiella burnetii, the ciliate Tetrahymena thermophila and D. discoideum with a high reliability. Co-culturing Mycobacterium avium and Legionella pneumophila with the amoeba Acanthamoeba polyphaga demonstrated that these two bacteria could live together in amoebae for five days, indicating the biological relevance of intra-amoebal transfer of the pyr-redox gene. In conclusion, the results of this study support the hypothesis that protists can serve as a source and a place for gene transfer in mycobacteria.

  8. The membrane skeleton in Paramecium: Molecular characterization of a novel epiplasmin family and preliminary GFP expression results.

    Science.gov (United States)

    Pomel, Sébastien; Diogon, Marie; Bouchard, Philippe; Pradel, Lydie; Ravet, Viviane; Coffe, Gérard; Viguès, Bernard

    2006-02-01

    Previous attempts to identify the membrane skeleton of Paramecium cells have revealed a protein pattern that is both complex and specific. The most prominent structural elements, epiplasmic scales, are centered around ciliary units and are closely apposed to the cytoplasmic side of the inner alveolar membrane. We sought to characterize epiplasmic scale proteins (epiplasmins) at the molecular level. PCR approaches enabled the cloning and sequencing of two closely related genes by amplifications of sequences from a macronuclear genomic library. Using these two genes (EPI-1 and EPI-2), we have contributed to the annotation of the Paramecium tetraurelia macronuclear genome and identified 39 additional (paralogous) sequences. Two orthologous sequences were found in the Tetrahymena thermophila genome. Structural analysis of the 43 sequences indicates that the hallmark of this new multigenic family is a 79 aa domain flanked by two Q-, P- and V-rich stretches of sequence that are much more variable in amino-acid composition. Such features clearly distinguish members of the multigenic family from epiplasmic proteins previously sequenced in other ciliates. The expression of Green Fluorescent Protein (GFP)-tagged epiplasmin showed significant labeling of epiplasmic scales as well as oral structures. We expect that the GFP construct described herein will prove to be a useful tool for comparative subcellular localization of different putative epiplasmins in Paramecium.

  9. Ecological effects of various toxic agents on the aquatic microcosm in comparison with acute ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fuma, S. E-mail: fuma@nirs.go.jp; Ishii, N.; Takeda, H.; Miyamoto, K.; Yanagisawa, K.; Ichimasa, Y.; Saito, M.; Kawabata, Z.; Polikarpov, G.G

    2003-07-01

    The purpose of this study was an evaluation of the effect levels of various toxic agents compared with acute doses of ionizing radiation for the experimental model ecosystem, i.e., microcosm mimicking aquatic microbial communities. For this purpose, the authors used the microcosm consisting of populations of the flagellate alga Euglena gracilis as a producer, the ciliate protozoan Tetrahymena thermophila as a consumer and the bacterium Escherichia coli as a decomposer. Effects of aluminum and copper on the microcosm were investigated in this study, while effects of {gamma}-rays, ultraviolet radiation, acidification, manganese, nickel and gadolinium were reported in previous studies. The microcosm could detect not only the direct effects of these agents but also the community-level effects due to the interspecies interactions or the interactions between organisms and toxic agents. The authors evaluated doses or concentrations of each toxic agent which had the following effects on the microcosm: (1) no effects; (2) recognizable effects, i.e., decrease or increase in the cell densities of at least one species; (3) severe effects, i.e., extinction of one or two species; and (4) destructive effects, i.e., extinction of all species. The resulting effects data will contribute to an ecological risk assessment of the toxic agents compared with acute doses of ionizing radiation.

  10. Comparative study of phenol and cyanide containing wastewater in CSTR and SBR activated sludge reactors.

    Science.gov (United States)

    Papadimitriou, C A; Samaras, P; Sakellaropoulos, G P

    2009-01-01

    The objectives of this work were the examination of the performance of two bench scale activated sludge systems, a conventional Continuous Stirring Tank Reactor (CSTR) and a Sequential Batch Reactor (SBR), for the treatment of wastewaters containing phenol and cyanides and the assessment of the toxicity reduction potential by bioassays. The operation of the reactors was monitored by physicochemical analyses, while detoxification potential of the systems was monitored by two bioassays, the marine photobacterium Vibrio fischeri and the ciliate protozoan Tetrahymena thermophila. The reactors influent was highly toxic to both organisms, while activated sludge treatment resulted in the reduction of toxicity of the influent. An increased toxicity removal was observed in the SBR; however CSTR system presented a lower ability for toxicity reduction of influent. The performance of both systems was enhanced by the addition of powdered activated carbon in the aeration tank; activated carbon upgraded the performance of the systems due to the simultaneous biological removal of pollutants and to carbon adsorption process; almost negligible values of phenol and cyanides were measured in the effluents, while further toxicity reduction was observed in both systems.

  11. Toxicity of five anilines to crustaceans, protozoa and bacteria

    Directory of Open Access Journals (Sweden)

    MARILIIS SIHTMÄE

    2010-09-01

    Full Text Available Aromatic amines (anilines and related derivates are an important class of environmental pollutants that can be released to the aquatic environment as industrial effluents or as breakdown products of pesticides and dyes. The toxicity of aniline, 2-chloroaniline, 3-chloroaniline, 4-chloroaniline and 3,5-dichloroaniline towards a multitrophic test battery comprised of bacteria Aliivibrio fischeri (formerly Vibrio fischeri, a ciliated protozoan Tetrahymena thermophila and two crustaceans (Daphnia magna and Thamnocephalus platyurus were investigated. Under the applied test conditions, the toxicity of the anilines notably varied among the test species. The bacteria and protozoa were much less sensitive towards the anilines than the crustaceans: EC50 values 13–403 mg L-1 versus 0.13–15.2 mg L-1. No general tendency between toxicity and the chemical structure of the anilines (the degree of chloro-substitution and the position of the chloro-substituents was found in the case of all the tested aquatic species. The replacement of the artificial test medium (ATM by the river water remarkably decreased the toxicity of anilines to crustaceans but not to protozoa. This research is part of the EU 6th Framework Integrated Project OSIRIS, in which ecotoxicogenomic studies of anilines (e.g., for Daphnia magna will also be performed that may help to clarify the mechanisms of toxicity of different anilines.

  12. The long-range P3 helix of the Tetrahymena ribozyme is disrupted during folding between the native and misfolded conformations.

    Science.gov (United States)

    Mitchell, David; Jarmoskaite, Inga; Seval, Nikhil; Seifert, Soenke; Russell, Rick

    2013-08-09

    RNAs are prone to misfolding, but how misfolded structures are formed and resolved remains incompletely understood. The Tetrahymena group I intron ribozyme folds in vitro to a long-lived misfolded conformation (M) that includes extensive native structure but is proposed to differ in topology from the native state (N). A leading model predicts that exchange of the topologies requires unwinding of the long-range, core helix P3, despite the presence of P3 in both conformations. To test this model, we constructed 16 mutations to strengthen or weaken P3. Catalytic activity and in-line probing showed that nearly all of the mutants form the M state before folding to N. The P3-weakening mutations accelerated refolding from M (3- to 30-fold) and the P3-strengthening mutations slowed refolding (6- to 1400-fold), suggesting that P3 indeed unwinds transiently. Upon depletion of Mg(2+), the mutations had analogous effects on unfolding from N to intermediates that subsequently fold to M. The magnitudes for the P3-weakening mutations were larger than in refolding from M, and small-angle X-ray scattering showed that the ribozyme expands rapidly to intermediates from which P3 is disrupted subsequently. These results are consistent with previous results indicating unfolding of native peripheral structure during refolding from M, which probably permits rearrangement of the core. Together, our results demonstrate that exchange of the native and misfolded conformations requires loss of a core helix in addition to peripheral structure. Further, the results strongly suggest that misfolding arises from a topological error within the ribozyme core, and a specific topology is proposed.

  13. In silico prediction of toxicity of phenols to Tetrahymena pyriformis by using genetic algorithm and decision tree-based modeling approach.

    Science.gov (United States)

    Abbasitabar, Fatemeh; Zare-Shahabadi, Vahid

    2017-04-01

    Risk assessment of chemicals is an important issue in environmental protection; however, there is a huge lack of experimental data for a large number of end-points. The experimental determination of toxicity of chemicals involves high costs and time-consuming process. In silico tools such as quantitative structure-toxicity relationship (QSTR) models, which are constructed on the basis of computational molecular descriptors, can predict missing data for toxic end-points for existing or even not yet synthesized chemicals. Phenol derivatives are known to be aquatic pollutants. With this background, we aimed to develop an accurate and reliable QSTR model for the prediction of toxicity of 206 phenols to Tetrahymena pyriformis. A multiple linear regression (MLR)-based QSTR was obtained using a powerful descriptor selection tool named Memorized_ACO algorithm. Statistical parameters of the model were 0.72 and 0.68 for Rtraining(2) and Rtest(2), respectively. To develop a high-quality QSTR model, classification and regression tree (CART) was employed. Two approaches were considered: (1) phenols were classified into different modes of action using CART and (2) the phenols in the training set were partitioned to several subsets by a tree in such a manner that in each subset, a high-quality MLR could be developed. For the first approach, the statistical parameters of the resultant QSTR model were improved to 0.83 and 0.75 for Rtraining(2) and Rtest(2), respectively. Genetic algorithm was employed in the second approach to obtain an optimal tree, and it was shown that the final QSTR model provided excellent prediction accuracy for the training and test sets (Rtraining(2) and Rtest(2) were 0.91 and 0.93, respectively). The mean absolute error for the test set was computed as 0.1615.

  14. Infraciliature and morphogenesis in three rumen Diplodinium ciliates, Diplodinium polygonale, Diplodinium leche, and Diplodinium nanum, observed by light microscopy.

    Science.gov (United States)

    Ito, Akira; Imai, Soichi

    2005-01-01

    Infraciliature and morphogenesis of three rumen ophryoscolecid ciliates, Diplodinium polygonale Dogiel, 1925, Diplodinium leche Imai et al., 1992, and Diplodinium nanum Imai, 1988, are described from pyridinated silver carbonate-impregnated specimens. These three species have two polybrachykineties in the buccal area and a polybrachykinety in the dorsal ciliary zone. The vestibular polybrachykinety (VP) of D. polygonale and D. leche arises from the dorsal extremity of the adoral polybrachykinety (AP) as in Entodinium species, extending toward the left in D. polygonale and toward the left posterior in D. leche. The VP of D. nanum arises from the inner side of the AP, separate from its dorsal extremity, as in other Diplodinium species and extends toward the left posterior. These series of the polybrachykinety arrangements in D. polygonale, D. leche, and D. nanum can be regarded as transitional forms in the evolution of an Entodinium-like ancestor to Diplodinium. Morphogenesis of these three Diplodinium species is not different from that of other Diplodinium species.

  15. Estimation of divergence times in litostomatean ciliates (Ciliophora: Intramacronucleata), using Bayesian relaxed clock and 18S rRNA gene.

    Science.gov (United States)

    Vďačný, Peter

    2015-08-01

    The class Litostomatea comprises a diverse assemblage of free-living and endosymbiotic ciliates. To understand diversification dynamic of litostomateans, divergence times of their main groups were estimated with the Bayesian molecular dating, a technique allowing relaxation of molecular clock and incorporation of flexible calibration points. The class Litostomatea very likely emerged during the Cryogenian around 680 Mya. The origin of the subclass Rhynchostomatia is dated to about 415 Mya, while that of the subclass Haptoria to about 654 Mya. The order Pleurostomatida, emerging about 556 Mya, was recognized as the oldest group within the subclass Haptoria. The order Spathidiida appeared in the Paleozoic about 442 Mya. The three remaining haptorian orders evolved in the Paleozoic/Mesozoic periods: Didiniida about 419 Mya, Lacrymariida about 269 Mya, and Haptorida about 194 Mya. The subclass Trichostomatia originated from a spathidiid ancestor in the Mesozoic about 260 Mya. A further goal of this study was to investigate the impact of various settings on posterior divergence time estimates. The root placement and tree topology as well as the priors of the rate-drift model, birth-death process and nucleotide substitution rate, had no significant effect on calculation of posterior divergence time estimates. However, removal of calibration points could significantly change time estimates at some nodes.

  16. Morphology and morphogenesis of a new marine cyrtophorid ciliate, Hartmannula sinica nov. spec. (Protozoa, Ciliophora, Cyrtophorida) from China.

    Science.gov (United States)

    Shao, Chen; Song, Weibo; Gong, Jun

    2008-02-01

    The living morphology, infraciliature and morphogenesis of a new marine cyrtophorid ciliate, Hartmannula sinica nov. spec., collected from Qingdao, north China, have been investigated. The new species is characterized by: size in vivo 90-130 x 40-50 microm, body long elliptical in outline, cilium-free field covered with a conspicuous alveolar layer; 24-31 ventral kineties, the rightmost 6-9 of which extend apically; 20-24 nematodesmal rods; about 15 sparsely distributed contractile vacuoles; a yellowish pigment spot is always present near the anterior tip of the cell. Morphogenetic events exhibit a pattern, which is homologous with that of related cyrtophorids. The main features are as follows: (1) preoral and circumoral kineties of opisthe develop from the oral primordium that forms in mid-body from sections of 3 postoral kineties, while parental preoral and circumoral kineties are retained; (2) parental cytostome and nematodesmal rods are resorbed in middle divisional stages and then replaced by newly formed structures; (3) the heteromerous macronucleus unifies in the late divisional stage.

  17. Morphology, ontogeny and molecular phylogeny of a novel saline soil ciliate, Urosomoida paragiliformis n. sp. (Ciliophora, Hypotrichia).

    Science.gov (United States)

    Wang, Jingyi; Lyu, Zhao; Warren, Alan; Wang, Feng; Shao, Chen

    2016-10-01

    The living morphology, infraciliature and morphogenesis of a new ciliate, Urosomoida paragiliformis n. sp., collected from saline soil in Weinan, China, were studied in vivo and after protargol staining. Urosomoida paragiliformis n. sp. is characterized as follows: body elongate-elliptical with no tail, flexible and slightly contractile; cortical granules dark-brown, 0.5μm across, arranged in short irregular rows; about 33 adoral membranelles; 14 frontoventral-transverse cirri; right and left marginal rows not confluent posteriorly; two macronuclear nodules. Morphogenesis of U. paragiliformis n. sp. corresponds well with that of other Urosomoida-species except that in reorganisers the oral primordium develops membranelles that replace those at the proximal end of the old adoral zone, whereas in dividers the entire parental adoral zone of membranelles is inherited by the proter. Phylogenetic analyses based on SSU rDNA sequence data suggest a close relationship between U. paragiliformis n. sp. and Paraurosomoida indiensis. A new combination is made: Oxytrichella subtropica (Fan et al., 2015) comb. nov. (basionym Urosomoida subtropica).

  18. Tissue mortality by Caribbean ciliate infection and white band disease in three reef-building coral species.

    Science.gov (United States)

    Verde, Alejandra; Bastidas, Carolina; Croquer, Aldo

    2016-01-01

    Caribbean ciliate infection (CCI) and white band disease (WBD) are diseases that affect a multitude of coral hosts and are associated with rapid rates of tissue losses, thus contributing to declining coral cover in Caribbean reefs. In this study we compared tissue mortality rates associated to CCI in three species of corals with different growth forms: Orbicella faveolata (massive-boulder), O. annularis (massive-columnar) and Acropora cervicornis (branching). We also compared mortality rates in colonies of A. cervicornis bearing WBD and CCI. The study was conducted at two locations in Los Roques Archipelago National Park between April 2012 and March 2013. In A. cervicornis, the rate of tissue loss was similar between WBD (0.8 ± 1 mm/day, mean ± SD) and CCI (0.7 ± 0.9 mm/day). However, mortality rate by CCI in A. cervicornis was faster than in the massive species O. faveolata (0.5 ± 0.6 mm/day) and O. annularis (0.3 ± 0.3 mm/day). Tissue regeneration was at least fifteen times slower than the mortality rates for both diseases regardless of coral species. This is the first study providing coral tissue mortality and regeneration rates associated to CCI in colonies with massive morphologies, and it highlights the risks of further cover losses of the three most important reef-building species in the Caribbean.

  19. The water-born protein pheromones of the polar protozoan ciliate, Euplotes nobilii: Coding genes and molecular structures

    Science.gov (United States)

    Vallesi, Adriana; Alimenti, Claudio; Di Giuseppe, Graziano; Dini, Fernando; Pedrini, Bill; Wüthrich, Kurt; Luporini, Pierangelo

    2010-08-01

    The protozoan ciliate Euplotes nobilii found in Antarctic and Arctic coastal waters relies on secretion of water-soluble cell type-specific signal proteins (pheromones) to regulate its vegetative growth and sexual mating. For three of these psychrophilic pheromones we previously determined the three-dimensional structures by nuclear magnetic resonance (NMR) spectroscopy with protein solutions purified from the natural sources, which led to evidence that their adaptation to cold is primarily achieved by increased flexibility through an extension of regions free of regular secondary structures, and by increased exposure of negative charges on the protein surface. Then we cloned the coding genes of these E. nobilii pheromones from the transcriptionally active cell somatic nucleus (macronucleus) and characterized the full-length sequences. These sequences all contain an open reading frame of 252-285 nucleotides, which is specific for a cytoplasmic pheromone precursor that requires two proteolytic cleavages to remove a signal peptide and a pro segment before release of the mature protein into the extracellular environment. The 5‧ and 3‧ non-coding regions are two- to three-fold longer than the coding region and appear to be tightly conserved, probably in relation to the inclusion of intron sequences destined to be alternatively removed to play key regulatory roles in the mechanism of the pheromone gene expression.

  20. Tissue mortality by Caribbean ciliate infection and white band disease in three reef-building coral species

    Directory of Open Access Journals (Sweden)

    Alejandra Verde

    2016-07-01

    Full Text Available Caribbean ciliate infection (CCI and white band disease (WBD are diseases that affect a multitude of coral hosts and are associated with rapid rates of tissue losses, thus contributing to declining coral cover in Caribbean reefs. In this study we compared tissue mortality rates associated to CCI in three species of corals with different growth forms: Orbicella faveolata (massive-boulder, O. annularis (massive-columnar and Acropora cervicornis (branching. We also compared mortality rates in colonies of A. cervicornis bearing WBD and CCI. The study was conducted at two locations in Los Roques Archipelago National Park between April 2012 and March 2013. In A. cervicornis, the rate of tissue loss was similar between WBD (0.8 ± 1 mm/day, mean ± SD and CCI (0.7 ± 0.9 mm/day. However, mortality rate by CCI in A. cervicornis was faster than in the massive species O. faveolata (0.5 ± 0.6 mm/day and O. annularis (0.3 ± 0.3 mm/day. Tissue regeneration was at least fifteen times slower than the mortality rates for both diseases regardless of coral species. This is the first study providing coral tissue mortality and regeneration rates associated to CCI in colonies with massive morphologies, and it highlights the risks of further cover losses of the three most important reef-building species in the Caribbean.

  1. Notes on Two Marine Ciliates from the Yellow Sea, China: Placus salinus and Strombidium apolatum (Protozoa, Ciliophora)

    Institute of Scientific and Technical Information of China (English)

    XU Dapeng; SONG Weibo; HU Xiaozhong

    2005-01-01

    The living morphology and infraciliature of two rare marine ciliates, Placus salinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastal waters near Qingdao, China, were investigated by in vivo observation and protargol impregnation technique. The improved diagnosis for Placus salinus is as follows: medium-sized marine Placus, in vivo (50 -60) μm × (30 -40)μm; cell elliptical to barrel-shaped; 28 -31 somatic kineties; single macronucleus usually ellipsoid and one micronucleus located in the indention of the macronucleus; one contractile vacuole posteriorly positioned. Strombidium apolatum is characterized by: marine strombidium (40-60) μm × (30-45) μm in vivo, cordiform in shape with somewhat pointed posterior end and conspicuous apical protrusion; extrusomes prominent, about 15μm in length and evenly arranged along the circle kinety; about 16 collar and 5-6 buccal membranelles; one elongate macronucleus and one micronucleus; circle and ventral kineties consisting of about 53 and 45 dikinetids respectively.

  2. Morphology of four cyrtophorian ciliates (Protozoa, Ciliophora) from Yangtze Delta, China, with notes on the phylogeny of the genus Phascolodon.

    Science.gov (United States)

    Pan, Hongbo; Wang, Liqing; Jiang, Jiamei; Stoeck, Thorsten

    2016-10-01

    The morphology of four cyrtophorian ciliates, Dysteria ovalis, D. semilunaris, Phascolodon vorticella, and Chlamydonellopsis calkinsi, were investigated using living observation and protargol-staining. The morphology of D. ovalis is revealed in detail for the first time, and it is characterized by the following combination of features: size 40-50×20-30μm in vivo; oval in outline; four right kineties, including two frontoventral kineties and one shortened leftmost right kinety; three left frontal kineties; two ventrally located contractile vacuoles; marine habitat. New Chinese populations of three other species correspond well with previous descriptions, but a well-developed alveolar layer on the cell surface of P. vorticella is reported for the first time. Phylogenetic analyses based on small subunit rRNA gene sequences clustered Dysteria ovalis with Mirodysteria decora, whereas D. semilunaris is grouped with D. lanceolata. Although Phascolodon appeared as sister to Pseudochilodonopsis in the present work, its accurate phylogenetic position is still uncertain because AU test did not reject the possibility that it clustered with Odontochlamys and Chilodonella.

  3. Morphologic and Genetic Variability in the Marine Planktonic Ciliate Laboea strobila Lohmann, 1908 (Ciliophora, Oligotrichia), with Notes on its Ontogenesis

    Science.gov (United States)

    AGATHA, SABINE; STRÜDER-KYPKE, MICHAELA C.; BERAN, ALFRED

    2010-01-01

    Laboea strobila Lohmann, 1908 is a conspicuous oligotrich ciliate in the marine plankton. In order to compare different populations, the morphology of specimens from the Mediterranean Sea, North Sea, and Irish Sea was investigated using live observation, protargol impregnation, and scanning electron microscopy. Furthermore, the PCR-amplified products of the SSrRNA gene from a monoclonal culture of L. strobila from the Mediterranean Sea were sequenced and aligned with sequences of other oligotrichs, including a population of L. strobila from the Atlantic coast of the USA. Finally, the data from the ecological literature were summarized and the cultivation methods were described. The SSrRNA gene sequences of the two distantly located L. strobila populations from the North Atlantic are identical. Likewise, the morphometrics of most populations so far investigated after protargol impregnation (i.e. from the North Atlantic) do not show obvious differences. In all computed phylogenetic trees, L. strobila groups with Strombidium species, forming a monophyletic taxon corresponding to the subclass Oligotrichia. These results are corroborated by the ontogenetic comparison. Since no type species was fixed for Laboea Lohmann, 1908, L. strobila was designated in the present paper. PMID:15218695

  4. Primary and secondary siRNA synthesis triggered by RNAs from food bacteria in the ciliate Paramecium tetraurelia.

    Science.gov (United States)

    Carradec, Quentin; Götz, Ulrike; Arnaiz, Olivier; Pouch, Juliette; Simon, Martin; Meyer, Eric; Marker, Simone

    2015-02-18

    In various organisms, an efficient RNAi response can be triggered by feeding cells with bacteria producing double-stranded RNA (dsRNA) against an endogenous gene. However, the detailed mechanisms and natural functions of this pathway are not well understood in most cases. Here, we studied siRNA biogenesis from exogenous RNA and its genetic overlap with endogenous RNAi in the ciliate Paramecium tetraurelia by high-throughput sequencing. Using wild-type and mutant strains deficient for dsRNA feeding we found that high levels of primary siRNAs of both strands are processed from the ingested dsRNA trigger by the Dicer Dcr1, the RNA-dependent RNA polymerases Rdr1 and Rdr2 and other factors. We further show that this induces the synthesis of secondary siRNAs spreading along the entire endogenous mRNA, demonstrating the occurrence of both 3'-to-5' and 5'-to-3' transitivity for the first time in the SAR clade of eukaryotes (Stramenopiles, Alveolates, Rhizaria). Secondary siRNAs depend on Rdr2 and show a strong antisense bias; they are produced at much lower levels than primary siRNAs and hardly contribute to RNAi efficiency. We further provide evidence that the Paramecium RNAi machinery also processes single-stranded RNAs from its bacterial food, broadening the possible natural functions of exogenously induced RNAi in this organism.

  5. GenBank blastx search result: AK288287 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288287 J090018F21 AY740525.1 AY740525 Tetrahymena thermophila cadmium-inducible m...etallothionein 1 (MTT1) and cadmium-inducible metallothionein 3 (MTT3) genes, complete cds. INV 0.0 0 ...

  6. Pseudomonas aeruginosa adaptation to lungs of cystic fibrosis patients leads to lowered resistance to phage and protist enemies

    DEFF Research Database (Denmark)

    Friman, Ville-Petri; Ghoul, Melanie; Molin, Søren

    2013-01-01

    ) patients affects its survival in the presence of natural phage (14/1, ΦKZ, PNM and PT7) and protist (Tetrahymena thermophila and Acanthamoebae polyphaga) enemies. We found that most of the bacteria isolated from relatively recently intermittently colonised patients (1-25 months), were innately phage...

  7. Dicty_cDB: Contig-U12991-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ( AF272150 ) Dictyostelium discoideum deliriumA (dlrA) gene, c... 2022 0.0 3 ( BJ...39594 ) TT1EP48TV Tetrahymena thermophila SB210 cDNA libr... 38 10.0 2 >( AF272150 ) Dictyostelium discoideum delirium

  8. Dicty_cDB: AFI355 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ead. 599 e-167 1 CN206669 |CN206669.1 Tor7097 Gametophyte rehydration Library Tor...590755.1 TTE00006978 Normalized large Tetrahymena thermophila cDNA, mRNA sequence. 74 3e-09 1 CN206834 |CN206834.1 Tor7258 Game

  9. Dicty_cDB: AFL178 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available e-167 1 CN206669 |CN206669.1 Tor7097 Gametophyte rehydration Library Tortula ruralis cDNA, mRNA sequence. 7... TTE00006978 Normalized large Tetrahymena thermophila cDNA, mRNA sequence. 74 3e-09 1 CN206834 |CN206834.1 Tor7258 Game

  10. Dicty_cDB: AFK889 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 599 e-167 1 CN206669 |CN206669.1 Tor7097 Gametophyte rehydration Library Tortula...55.1 TTE00006978 Normalized large Tetrahymena thermophila cDNA, mRNA sequence. 74 4e-09 1 CN206834 |CN206834.1 Tor7258 Game

  11. Dicty_cDB: AFH816 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ingle read. 599 e-167 1 CN206669 |CN206669.1 Tor7097 Gametophyte rehydration Library Tortula ruralis cDNA, m... Normalized large Tetrahymena thermophila cDNA, mRNA sequence. 74 3e-09 1 CN206834 |CN206834.1 Tor7258 Gam

  12. Dicty_cDB: AFH538 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available e-165 1 CN206669 |CN206669.1 Tor7097 Gametophyte rehydration Library Tortula ruralis cDNA, mRNA sequence. 7...ge Tetrahymena thermophila cDNA, mRNA sequence. 74 3e-09 1 CN206834 |CN206834.1 Tor7258 Game

  13. Dicty_cDB: AFI356 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ad. 599 e-167 1 CN206669 |CN206669.1 Tor7097 Gametophyte rehydration Library Tort...90755.1 TTE00006978 Normalized large Tetrahymena thermophila cDNA, mRNA sequence. 74 3e-09 1 CN206834 |CN206834.1 Tor7258 Game

  14. Rapid prey evolution can alter the structure of predator-prey communities

    NARCIS (Netherlands)

    Friman, V. -P.; Jousset, A.; Buckling, A.

    2014-01-01

    Although microevolution has been shown to play an important role in pairwise antagonistic species interactions, its importance in more complex communities has received little attention. Here, we used two Pseudomonas fluorescens prey bacterial strains (SBW25 and F113) and Tetrahymena thermophila prot

  15. Dicty_cDB: SHH274 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available e 2 map 6245135-6357017 strain AX4, complete sequence. 42 0.72 5 AF435076 |AF435076.2 Tetrahymena thermophila anlage...n stage induced 1 protein (ASI1) and anlagen stage induced 2 protein (ASI

  16. UV Radiation and Visible Light Induce hsp70 Gene Expression in the Antarctic Psychrophilic Ciliate Euplotes focardii.

    Science.gov (United States)

    Fulgentini, Lorenzo; Passini, Valerio; Colombetti, Giuliano; Miceli, Cristina; La Terza, Antonietta; Marangoni, Roberto

    2015-08-01

    The psychrophilic ciliate Euplotes focardii inhabits the shallow marine coastal sediments of Antarctica, where, over millions of years of evolution, it has reached a strict molecular adaptation to such a constant-temperature environment (about -2 °C). This long evolution at sub-zero temperatures has made E. focardii unable to respond to heat stress with the activation of its heat shock protein (hsp) 70 genes. These genes can, however, be expressed in response to other stresses, like the oxidative one, thus indicating that the molecular adaptation has exclusively altered the heat stress signaling pathways, while it has preserved hsp70 gene activation in response to other environmental stressors. Since radiative stress has proved to be affine to oxidative stress in several organisms, we investigated the capability of UV radiation to induce hsp70 transcription. E. focardii cell cultures were exposed to several different irradiation regimes, ranging from visible only to a mixture of visible, UV-A and UV-B. The irradiation values of each spectral band have been set to be comparable with those recorded in a typical Antarctic spring. Using Northern blot analysis, we measured the expression level of hsp70 immediately after irradiation (0-h-labeled samples), 1 h, and 2 h from the end of the irradiation. Surprisingly, our results showed that besides UV radiation, the visible light was also able to induce hsp70 expression in E. focardii. Moreover, spectrophotometric measurements have revealed no detectable endogenous pigments in E. focardii, making it difficult to propose a possible explanation for the visible light induction of its hsp70 genes. Further research is needed to conclusively clarify this point.

  17. Ciliated protists from the nepheloid layer and water column of sites affected by the Deepwater Horizon oil spill in the Northeastern Gulf of Mexico

    Science.gov (United States)

    Moss, Joseph A.; McCurry, Chelsea; Tominack, Sarah; Romero, Isabel C.; Hollander, David; Jeffrey, Wade H.; Snyder, Richard A.

    2015-12-01

    Benthic marine protists have been well documented from shallow marine benthic habitats but remain understudied in deeper habitats on continental shelves and slopes, particularly in the Northeastern Gulf of Mexico (NEGOM). This region was affected by a deep water oil well failure (BP-Deepwater Horizon, 2010). The combination of a lack of information on deep sea microbenthic communities and the potential for benthic microbial petroleum mineralization prompted this investigation. Water column and nepheloid layer samples were obtained via Niskin bottles and a multicorer respectively at stations across the NEGOM to: (1) determine whether nepheloid and water column communities are distinct and (2) assess benthic species richness relative to sediment PAH contamination. Phylum specific 18S rRNA gene amplification was used to construct clone libraries of ciliate assemblages. BLAST searches in the NCBI database indicated that a majority (~75%) of the clone sequences corresponded (94-100% similarity) with listed, yet unclassified sequences. Several putative species were common at most site locations and depths. Many known benthic ciliates, such as Uronychia transfuga, Uronychia setigera, and Spirotrachelostyla tani, were common in the nepheloid layer samples and not recovered in water column samples. Ciliated protist species richness increased with PAH levels found in surface sediments, suggesting a positive microbial response to petroleum enrichment of the benthos. The presence of previously unknown microbenthic communites in the nephaloid layer over oceanic clay-silt muds alters our view of microbial processes in the deep sea and merits investigation of the microbial processes and rates of microbial mineralization and biomass production important to global biogeochemistry.

  18. Ciliates (Protozoa from dried sediments of a temporary pond from Argentina Ciliados (Protozoa de sedimentos secos de una charca temporaria de la Argentina

    Directory of Open Access Journals (Sweden)

    Gabriela Cristina Küppers

    2009-12-01

    Full Text Available Temporary ponds represent special environments that are inhabited by organisms adapted to changing environmental conditions. Ciliates are able to survive complete loss of water in these transient habitats through cyst formation. However, ciliates from the Neotropical region in general have been poorly studied with modern techniques. The main goal of this study is to describe the ciliates in dried sediments of a temporary pond from Buenos Aires Province, Argentina, through sampling efforts that were performed 2003-2005. Soil samples were obtained during drought phases and re wetted in laboratory to establish raw and enriched cultures. Ciliates were then studied both in vivo and after impregnation with protargol. In this study, we present 4 new records for Argentina (Gonostomum affine (Stein, 1859 Sterki, 1878, Stylonychia bifaria (Stokes, 1887 Berger, 1999, Pleurotricha lanceolata (Ehrenberg, 1835 Stein, 1859, Meseres corlissi Petz and Foissner, 1992, 1 for South America (Blepharisma americanum (Suzuki, 1954 Hirshfield, Isquith and Bhandary, 1965, and 2 for the Neotropical Realm (Gonostomum strenuum (Engelmann, 1862 Sterki, 1878, Stylonychia lemnae Ammermann and Schlegel, 1983.Los cuerpos de agua temporarios son ambientes particulares que se encuentran habitados por organismos adaptados a condiciones fluctuantes. Los ciliados son capaces de sobrevivir a la pérdida completa de agua del ambiente gracias a la formación de estructuras de resistencia. Por otra parte, los ciliados de la región Neotropical han sido poco investigados con técnicas modernas. El objetivo de este estudio es referir los ciliados que se desarrollaron a partir de los sedimentos secos de una charca temporaria de la provincia de Buenos Aires, Argentina, en la que se realizaron muestreos durante el período 2003-2005. Las muestras de suelo fueron obtenidas durante las fases de sequía y luego resuspendidas en el laboratorio para realizar cultivos naturales y enriquecidos. Los

  19. Identification of cAMP-dependent phosphorylated proteins involved in the formation of environment-resistant resting cysts by the terrestrial ciliate Colpoda cucullus

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    Y Sogame

    2014-07-01

    Full Text Available In the terrestrial ciliate Colpoda cucullus, an elevation of the intracellular cAMP concentration was reported to be involved in environment-resistant resting cyst formation. In the present study, cAMP-dependently phosphorylated proteins of encystment-induced C. cucullus were isolated with Phos-tag agarose phosphate-affinity beads and subsequent SDS-PAGE. In a liquid chromatography/tandem mass spectrometry analysis of these phosphoproteins, 27-, 37- and 43-kDa proteins (p27, p37 and p43 were identified as Rieske iron-sulfur protein, histone H4 (hyperacetylated form, and actin, respectively.

  20. Phylogenetic positions of two marine ciliates, Metanophrys similis and Pseudocohnilembus hargisi (Protozoa, Ciliophora, Scuticociliatia), inferred from complete small subunit rRNA gene sequences

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The small subunit rRNA (SSrRNA) gene was sequenced for two marine scuticociliates Metanophrys similis and Pseudocohnilembus hargisi. The results show that this gene comprises 1763 and 1753 nucleotides in the two marine ciliates respectively.Metanophrys similis is phylogenetically closely related to the clade containing Mesanophrys carcini and Anophyroides haemophila, which branches basally to other species within the order Philasterida. Pseudocohnilembus hargisi groups with its congener, P. marinus, with strong bootstrap support. Paranophrys magna groups with the clade including Cohnilembus and Uronema, representing a sister clade to that containing the two Pseudocohnilembus species.

  1. Combined effects of {gamma}-rays and acidification on an experimental model ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Fuma, Shoichi; Ishii, Nobuyoshi; Takeda, Hiroshi [National Inst. of Radiological Sciences, Chiba (Japan); Kawabata, Zen' ichiro [Kyoto Univ. (Japan). Center for Ecological Research; Ichimasa, Yusuke [Ibaraki Univ., Mito (Japan). Faculty of Science

    2002-05-01

    It is necessary to evaluate combined effects of ionizing radiation and other toxic agents on ecosystems, because ecosystems are exposed to these various factors. The authors studied combined effects of {gamma}-rays and acidification on an experimental model ecosystem (microcosm) mimicking aquatic microbial communities. Microcosms, consisted of flagellate algae Euglena gracilis Z as a producer, ciliate protozoa Tetrahymena thermophila B as a consumer and bacteria Escherichia coli DH5{alpha} as a decomposer, were loaded by the following treatments: Irradiation with 100 Gy {sup 60}Co {gamma}-rays; Acidification of culture medium to pH4.0 with the mixture of 0.1 N HNO{sub 3} and 0.1 N H{sub 2}SO{sub 4} (1:1, v/v), which mimicked acid rain; and Irradiation with 100 Gy {gamma}-rays followed by the acidification of the culture medium (pH 4.0). The {gamma}-irradiation induced a temporary decrease in cell densities of E. coli, but did not affect cell densities of the other species. The concentrations of chlorophyll a and ATP in the microcosm were not affected by the {gamma}-irradiation, and chlorophyll a concentrations in a Eu. gracilis cell were not affected, either. The acidification significantly decreased cell densities of T. thermophila, slightly decreased cell densities of E. coli, and slightly increased cell densities of Eu. gracilis. The concentrations of chlorophyll a and ATP in the microcosm were increased by the acidification, although chlorophyll a concentrations in a Eu. gracilis cell were decreased. The combined exposure to {gamma}-rays and acids temporarily decreased cell densities of E. coli, significantly decreased cell densities of T. thermophila, and slightly increased cell densities of Eu. gracilis. The concentrations of chlorophyll a and ATP in the microcosm were increased by the combined exposure, although chlorophyll a concentrations in a Eu. gracilis cell were decreased. The authors therefore conclude that combined exposure to {gamma}-rays and acids

  2. Ku-mediated coupling of DNA cleavage and repair during programmed genome rearrangements in the ciliate Paramecium tetraurelia.

    Directory of Open Access Journals (Sweden)

    Antoine Marmignon

    2014-08-01

    Full Text Available During somatic differentiation, physiological DNA double-strand breaks (DSB can drive programmed genome rearrangements (PGR, during which DSB repair pathways are mobilized to safeguard genome integrity. Because of their unique nuclear dimorphism, ciliates are powerful unicellular eukaryotic models to study the mechanisms involved in PGR. At each sexual cycle, the germline nucleus is transmitted to the progeny, but the somatic nucleus, essential for gene expression, is destroyed and a new somatic nucleus differentiates from a copy of the germline nucleus. In Paramecium tetraurelia, the development of the somatic nucleus involves massive PGR, including the precise elimination of at least 45,000 germline sequences (Internal Eliminated Sequences, IES. IES excision proceeds through a cut-and-close mechanism: a domesticated transposase, PiggyMac, is essential for DNA cleavage, and DSB repair at excision sites involves the Ligase IV, a specific component of the non-homologous end-joining (NHEJ pathway. At the genome-wide level, a huge number of programmed DSBs must be repaired during this process to allow the assembly of functional somatic chromosomes. To understand how DNA cleavage and DSB repair are coordinated during PGR, we have focused on Ku, the earliest actor of NHEJ-mediated repair. Two Ku70 and three Ku80 paralogs are encoded in the genome of P. tetraurelia: Ku70a and Ku80c are produced during sexual processes and localize specifically in the developing new somatic nucleus. Using RNA interference, we show that the development-specific Ku70/Ku80c heterodimer is essential for the recovery of a functional somatic nucleus. Strikingly, at the molecular level, PiggyMac-dependent DNA cleavage is abolished at IES boundaries in cells depleted for Ku80c, resulting in IES retention in the somatic genome. PiggyMac and Ku70a/Ku80c co-purify as a complex when overproduced in a heterologous system. We conclude that Ku has been integrated in the Paramecium

  3. Ku-mediated coupling of DNA cleavage and repair during programmed genome rearrangements in the ciliate Paramecium tetraurelia.

    Science.gov (United States)

    Marmignon, Antoine; Bischerour, Julien; Silve, Aude; Fojcik, Clémentine; Dubois, Emeline; Arnaiz, Olivier; Kapusta, Aurélie; Malinsky, Sophie; Bétermier, Mireille

    2014-08-01

    During somatic differentiation, physiological DNA double-strand breaks (DSB) can drive programmed genome rearrangements (PGR), during which DSB repair pathways are mobilized to safeguard genome integrity. Because of their unique nuclear dimorphism, ciliates are powerful unicellular eukaryotic models to study the mechanisms involved in PGR. At each sexual cycle, the germline nucleus is transmitted to the progeny, but the somatic nucleus, essential for gene expression, is destroyed and a new somatic nucleus differentiates from a copy of the germline nucleus. In Paramecium tetraurelia, the development of the somatic nucleus involves massive PGR, including the precise elimination of at least 45,000 germline sequences (Internal Eliminated Sequences, IES). IES excision proceeds through a cut-and-close mechanism: a domesticated transposase, PiggyMac, is essential for DNA cleavage, and DSB repair at excision sites involves the Ligase IV, a specific component of the non-homologous end-joining (NHEJ) pathway. At the genome-wide level, a huge number of programmed DSBs must be repaired during this process to allow the assembly of functional somatic chromosomes. To understand how DNA cleavage and DSB repair are coordinated during PGR, we have focused on Ku, the earliest actor of NHEJ-mediated repair. Two Ku70 and three Ku80 paralogs are encoded in the genome of P. tetraurelia: Ku70a and Ku80c are produced during sexual processes and localize specifically in the developing new somatic nucleus. Using RNA interference, we show that the development-specific Ku70/Ku80c heterodimer is essential for the recovery of a functional somatic nucleus. Strikingly, at the molecular level, PiggyMac-dependent DNA cleavage is abolished at IES boundaries in cells depleted for Ku80c, resulting in IES retention in the somatic genome. PiggyMac and Ku70a/Ku80c co-purify as a complex when overproduced in a heterologous system. We conclude that Ku has been integrated in the Paramecium DNA cleavage

  4. Morphology, morphogenesis and gene sequence of a freshwater ciliate, Pseudourostyla cristata (Ciliophora, Urostyloidea) from the ancient Lake Biwa, Japan.

    Science.gov (United States)

    Chen, Xumiao; Li, Zicong; Hu, Xiaozhong; Kusuoka, Yasushi

    2010-01-01

    The urostyloid freshwater ciliate Pseudourostyla cristata was recorded for the first time from Lake Biwa, a 4-million-year-old lake located in Shiga Prefecture, Japan. Its morphology and morphogenesis were investigated using live observation and protargol impregnation, and the SSU ribosomal RNA gene was sequenced. Based on the current observations and previous descriptions, this species is readily recognized mainly by the following characters: body slender or broadly oval to elliptical, and dark grey in color; size in vivo about 170-400 x 40-150 microm; pellicle flexible and contractile, with extrusomes forming a hyaline seam underneath; ciliature comprising about 60-130 adoral membranelles, usually 1 buccal cirrus, 20-24 frontal, 2 frontoterminal, 17-26 pairs of midventral, and 5-16 transverse cirri, 4-6 left and 4-5 right marginal rows, and 8-10 dorsal kineties; 15-83 macronuclear nodules and 2-9 micronuclei; freshwater habitat. The main morphogenetic developments are: (1) the oral primordium for the proter originates de novo on the dorsal wall of the buccal cavity, and the dedifferentiated undulating membranes and some parental proximal membranelles join in the primordial development; the old adoral zone will be partly replaced by new structures; (2) the oral primordium for the opisthe occurs epiapokinetally left of the midventral complex between the adoral zone and the transverse cirri; (3) the fronto-midventral transverse cirral (FVT) anlagen develop separately in both dividers by dedifferentiation of most of the midventral cirri; (4) the single buccal cirrus is generated from the posterior end of FVT anlage II; (5) the leftmost frontal cirrus is derived from the anterior end of the undulating membranes anlage (FVT anlage I); (6) the marginal rows of each side are formed from a single anlage which arises within the rightmost row; (7) the dorsal kineties develop by intrakinetal basal body proliferation; and (8) the most posterior FVT anlage contributes the two

  5. Ruminal degradability and ciliates protozoa population in rumen of Nellore steers fed with high concentrated diet supplemented with live yeast, monensin and salinomycin

    Directory of Open Access Journals (Sweden)

    Josiane Hernades Ortolan

    2010-01-01

    Full Text Available Four Nelore steers had been used, with average alive weight of 190±32 kg, in experimental delineation by 4x4 latin square, whith the objective of evaluate the effect of the yeast monensin and salinomycin on the parameters of ruminal degradability and the ciliates protozoa population present in the animals rumen. The diet offered to the animals was composed by sorghum silage and concentrated (30:70, respectively, where the four different treatments had been submitted in accordance with the used additive: 5,0g of yeast culture (Beef Sacc®; 0.42g of salinomycin (Coxistac®; 2.0g of monensin (Rumensin® and the control, without additive. The experimental period was subdivided in 21 days of adaptation and seven of harvest, totalized 28 days of experimental period. It had increase of the value for fraction “b” in the dry matter, the treatment with yeast culture, and the salinomycin treatment (P<0,05. The treatment with yeast significantly increased the number of rumen ciliates protozoa (P<0,05.

  6. Isolation and structural characterization of two water-borne pheromones from Euplotes crassus, a ciliate commonly known to carry membrane-bound pheromones.

    Science.gov (United States)

    Alimenti, Claudio; Vallesi, Adriana; Federici, Sergio; di Giuseppe, Graziano; Fernando, Dini; Carratore, Vitale; Luporini, Pierangelo

    2011-01-01

    Ciliates comprise species synthesizing water-diffusible mating type factors or pheromones and species synthesizing insoluble, cell membrane-bound pheromones. Euplotes crassus has traditionally been placed in the latter group. In contrast with this notion, we found that E. crassus is a constitutive pheromone-secreting ciliate, like other Euplotes species. From cell-free filtrate preparations of the E. crassus strain L-2D, we isolated two distinct pheromones, designated as Ec-α and Ec-1, and determined their complete amino acid sequences by combined chemical and genetic approaches. The Ec-α pheromone sequence extends for 56 amino acid residues with six cysteines and shows a molecular mass of 6,183 Da, while the Ec-1 pheromone sequence extends for 45 amino acid residues with 10 cysteines and shows a molecular mass of 4,840 Da. Marked structural differences distinguish the full-length Ec-α and Ec-1 coding sequences, which have been cloned and characterized from the transcriptionally active macronuclear genome. They were taken as clear indication that the Ec-α and Ec-1 pheromones are specified by genes that are not allelic, but likely derived from a duplicated genetic locus of the transcriptionally silent micronuclear genome.

  7. The Anti-Oxidant Defense System of the Marine Polar Ciliate Euplotes nobilii: Characterization of the MsrB Gene Family

    Directory of Open Access Journals (Sweden)

    Francesca Ricci

    2017-01-01

    Full Text Available Organisms living in polar waters must cope with an extremely stressful environment dominated by freezing temperatures, high oxygen concentrations and UV radiation. To shed light on the genetic mechanisms on which the polar marine ciliate, Euplotes nobilii, relies to effectively cope with the oxidative stress, attention was focused on methionine sulfoxide reductases which repair proteins with oxidized methionines. A family of four structurally distinct MsrB genes, encoding enzymes specific for the reduction of the methionine-sulfoxide R-forms, were identified from a draft of the E. nobilii transcriptionally active (macronuclear genome. The En-MsrB genes are constitutively expressed to synthesize proteins markedly different in amino acid sequence, number of CXXC motifs for zinc-ion binding, and presence/absence of a cysteine residue specific for the mechanism of enzyme regeneration. The En-MsrB proteins take different localizations in the nucleus, mitochondria, cytosol and endoplasmic reticulum, ensuring a pervasive protection of all the major subcellular compartments from the oxidative damage. These observations have suggested to regard the En-MsrB gene activity as playing a central role in the genetic mechanism that enables E. nobilii and ciliates in general to live in the polar environment.

  8. Emergence of the Terrestrial Ciliate Colpoda cucullus from a Resting Cyst: Rupture of the Cyst Wall by Active Expansion of an Excystment Vacuole

    Science.gov (United States)

    Funadani, Ryoji; Suetomo, Yasutaka; Matsuoka, Tatsuomi

    2013-01-01

    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. PMID:23268793

  9. Separate Culture and Morphological Observation of Free Living Amoebae and Ciliates%自生阿米巴和纤毛虫的分离培养与观察

    Institute of Scientific and Technical Information of China (English)

    岳爱梅; 刘营; 谭叶; 丛慧; 林佳慧; 张英杰; 张忠广

    2013-01-01

    Objective To study the methods of cultivation and morphological observation of free living amoebae and ciliates and observe the growth and species change of parasites in different time and vegetables. Methods Various green vegetable juice were prepared for cultivating the amoebae and ciliates at 37℃ The growth of free living amoebae and ciliates were observed using microscope. Results Rotary motion of ciliates was observed after cultivation for 48 hours.Decreased quantity and activity of ciliates and increased quantity and activity of free living amoebae were observed after cultivation for 72 hours. Decreased quantity of free living amoebae and ciliates were observed even disappeared but the cysts appeared after cultivation for 144 hours. And various green vegetable juice showed differences in culturing the amoebae and ciliates; between 72 h to 120 h ciliates could be found in celery juice, while free living amoebae were found between 96 h to 120 h. Ciliates could be easier to observe in rape flower juice between 72 h to 96h and free living amoebae easier to see in caraway juice between 72 h to 120 h. Conclusion This method is simple and convenient to observe the living amoebae and ciliates. It is useful in the parasitology teaching.%目的 研究建立自生阿米巴和纤毛虫的培养方法,观察不同菜种在不同时间寄生虫的生长情况及种类的变化.方法 制作不同蔬菜叶的悬液,37℃恒温培养,镜下观察不同时间自生阿米巴和纤毛虫的生长情况.结果 培养48 h后,可观察到纤毛虫活跃的旋转运动;72 h后纤毛虫数量减少,活动度降低,自生阿米巴出现,蠕动活跃;144 h后自生阿米巴、纤毛虫数量减少甚至观察不到,包囊出现,不同菜种在不同时间自生阿米巴、纤毛虫数量、种类也相应变化,如芹菜中纤毛虫在72~120 h、阿米巴在96~120 h数量最多,最易观察到,油菜中纤毛虫在72~96 h最易观察到,香菜中阿米巴在72~120 h

  10. A case study for effects of operational taxonomic units from intracellular endoparasites and ciliates on the eukaryotic phylogeny: phylogenetic position of the haptophyta in analyses of multiple slowly evolving genes.

    Directory of Open Access Journals (Sweden)

    Hisayoshi Nozaki

    Full Text Available Recent multigene phylogenetic analyses have contributed much to our understanding of eukaryotic phylogeny. However, the phylogenetic positions of various lineages within the eukaryotes have remained unresolved or in conflict between different phylogenetic studies. These phylogenetic ambiguities might have resulted from mixtures or integration from various factors including limited taxon sampling, missing data in the alignment, saturations of rapidly evolving genes, mixed analyses of short- and long-branched operational taxonomic units (OTUs, intracellular endoparasite and ciliate OTUs with unusual substitution etc. In order to evaluate the effects from intracellular endoparasite and ciliate OTUs co-analyzed on the eukaryotic phylogeny and simplify the results, we here used two different sets of data matrices of multiple slowly evolving genes with small amounts of missing data and examined the phylogenetic position of the secondary photosynthetic chromalveolates Haptophyta, one of the most abundant groups of oceanic phytoplankton and significant primary producers. In both sets, a robust sister relationship between Haptophyta and SAR (stramenopiles, alveolates, rhizarians, or SA [stramenopiles and alveolates] was resolved when intracellular endoparasite/ciliate OTUs were excluded, but not in their presence. Based on comparisons of character optimizations on a fixed tree (with a clade composed of haptophytes and SAR or SA, disruption of the monophyly between haptophytes and SAR (or SA in the presence of intracellular endoparasite/ciliate OTUs can be considered to be a result of multiple evolutionary reversals of character positions that supported the synapomorphy of the haptophyte and SAR (or SA clade in the absence of intracellular endoparasite/ciliate OTUs.

  11. Use of the PCR and fluorescent probes to recover SSU rRNA gene sequences from single cells of the ciliate protozoon Spathidium.

    Science.gov (United States)

    Dyal, P L; Hope, S; Roberts, D M; Embley, T M

    1995-08-01

    A two-stage heminested PCR approach was developed to amplify small subunit (SSU) rDNA sequences, via two overlapping fragments, from single cells of microbial eucaryotes. The method was evaluated using the ciliate protozoon Spathidium when PCR products were obtained from nine of 10 cells tested. Southern blotting demonstrated that all fragments contained the same sequence in a region of SSU rDNA which is normally highly variable between species. A fluorescent oligonucleotide probe was used to demonstrate that this sequence also occurred in fixed cells of Spathidium. Fixatives containing mercuric salts preserved cell shape and allowed probe binding with little background autofluorescence. The Spathidium sequence is closely related to that from the haptorid Homalozoon vermiculare.

  12. Rumen ciliates in the African (Cape) buffalo (Syncerus caffer caffer) living in the vicinity of the Orpen Gate entrance into Kruger National Park, South Africa.

    Science.gov (United States)

    Booyse, Dirk G; Dehority, Burk A; Reininghaus, Björn

    2014-07-31

    Samples of rumen contents were obtained from 10 African (Cape) buffalo living in the vicinity of the Orpen Gate entrance into Kruger National Park in South Africa. Total number of ciliate protozoa per animal ranged from 3.15 to 23.25 x 103. Forty three different species and forms were observed, of which 35 are a new host record. The total number of species and forms per animal varied from 10 to 17. Eudiplodinium maggii occurred in all 10 animals, followed by Dasytricha ruminantium in nine animals. Diplodinium posterovesiculatum, Eudiplodinium magnodentatum and Ostracodinium mammosum were present in seven animals with all other species and forms occurring in five or less animals. 

  13. ParameciumDB in 2011: new tools and new data for functional and comparative genomics of the model ciliate Paramecium tetraurelia.

    Science.gov (United States)

    Arnaiz, Olivier; Sperling, Linda

    2011-01-01

    ParameciumDB is a community model organism database built with the GMOD toolkit to integrate the genome and biology of the ciliate Paramecium tetraurelia. Over the last four years, post-genomic data from proteome and transcriptome studies has been incorporated along with predicted orthologs in 33 species, annotations from the community and publications from the scientific literature. Available tools include BioMart for complex queries, GBrowse2 for genome browsing, the Apollo genome editor for expert curation of gene models, a Blast server, a motif finder, and a wiki for protocols, nomenclature guidelines and other documentation. In-house tools have been developed for ontology browsing and evaluation of off-target RNAi matches. Now ready for next-generation deep sequencing data and the genomes of other Paramecium species, this open-access resource is available at http://paramecium.cgm.cnrs-gif.fr.

  14. Temporal variability of the microbial food web (viruses to ciliates under the influence of the Black Sea Water inflow (N. Aegean, E. Mediterranean

    Directory of Open Access Journals (Sweden)

    A. GIANNAKOUROU

    2015-01-01

    Full Text Available Τhe entire pelagic microbial food web was studied during the winter-spring period in the frontal area of the North Aegean Sea. Abundance of viruses, heterotrophic bacteria, cyanobacteria, auto- and hetero-trophic flagellates, and ciliates, as well as bacterial production, were measured at three stations (MD1, MD2, MD3 situated along a N-S transect between the area directly influenced by the inflowing Black Sea water and the area covered by the Levantine water. Samples were collected in December 2009, and January, March, April, and May 2011. Station MD1 exhibited the highest values of abundance and integrated biomass of all microbial groups and bacterial production during all months, and MD3 the lowest. Bacteria dominated the total integrated biomass at all stations and months, followed by cyanobacteria, auto-, hetero-trophic flagellates and ciliates. On a temporal scale, the microbial food web was less important in March as all microbial parameters at all stations showed the lowest values. After the phytoplankton bloom in March, the heterotrophic part of the microbial food web (mainly strongly increased, though the intensity of the phenomenon was diminished from North to South. Pico-sized plankton was found to be heterotrophic whereas nanoplankton was autotrophic. It seems that the influence of the Black Sea water on station MD1, permanent throughout the study period of early winter to late spring, was reflected in all microbial populations studied, and produced a more productive pelagic food web system, with potential consequences for the upper trophic levels.

  15. Effect of high levels of the rotifer Lecane inermis on the ciliate community in laboratory-scale sequencing batch bioreactors (SBRs).

    Science.gov (United States)

    Fyda, Janusz; Babko, Roman; Fiałkowska, Edyta; Pajdak-Stós, Agnieszka; Kocerba-Soroka, Wioleta; Sobczyk, Mateusz; Sobczyk, Łukasz

    2015-10-01

    Due to its ability to feed on filamentous bacteria, the rotifer Lecane inermis has already been recognized as a potential control agent of activated sludge bulking, which is usually caused by the excessive growth of filamentous microorganisms. However, their effectiveness depends, in part, on their abundance. We studied the influence of high densities of L. inermis on the protozoan community in activated sludge from a wastewater treatment plant (WWTP) in 4 laboratory-scale sequencing batch bioreactors (SBRs). Two treatments and two controls were subjected to nutrient removal system in process similar to that used in a WWTP. The experiment lasted 9 days and was repeated in 24-h cycles, including phases of agitation with feeding, aeration and agitation and sedimentation with decantation at the end of the cycle. In total, 32 taxa were identified, among which 25 were ciliated protozoa, 4 were amoebae, 2 were flagellates, and one was a nematode. Rotifers were then introduced to 2 bioreactors at a final concentration of 500ind.mL(-1), and the taxonomic composition and abundance of the activated sludge microfauna were assessed 2, 5 and 8 days thereafter. The mean density of ciliates on the first day of experiment was 12,610ind.mL(-1) and diminished to 4868±432ind.mL-±432ind.mL(-1) in the control and 5496±638ind.mL(-1) in the rotifer-treated group on the last day. Thus, even extremely high densities of artificially introduced rotifers did not negatively affect the protozoan community. On the contrary, the protozoan community was more diverse in the treatment group than in the control.

  16. Ecological impacts of umbrella effects of radiation on the individual members

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Masahiro [Regulatory Sciences Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, 263-8555 (Japan); Kawaguchi, Isao [Regulatory Sciences Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, 263-8555 (Japan)]. E-mail: kawag@nirs.go.jp

    2007-07-15

    In order to study the interactions in a model aquatic microcosm, an individual-based computer simulation model was developed. The microcosm consists of Euglena gracilis as an autotroph algae, Tetrahymena thermophila as a heterotroph protozoa and Escherichia coli as a saprotroph bacteria. There exists a strong interaction between Tetrahymena and E. coli as the first is the predator of the second. Ecological toxicity tests were conducted to test the population level impacts of the biological effects of radiation and toxicants on the lethality and mobility factors that influence directly or indirectly growth and reproduction. Radiological effects on lethality of E. coli individuals were translated to the reduction of the equilibrium population of Tetrahymena. A synergistic effect at the community level was also observed by the simulation of a combined exposure of radiation and a toxicant which reduced the feeding efficiency of Tetrahymena.

  17. Ciliate and mesozooplankton community response to increasing CO2 levels in the Baltic Sea: insights from a large-scale mesocosm experiment

    Science.gov (United States)

    Lischka, Silke; Bach, Lennart T.; Schulz, Kai-Georg; Riebesell, Ulf

    2017-01-01

    Community approaches to investigating ocean acidification (OA) effects suggest a high tolerance of micro- and mesozooplankton to carbonate chemistry changes expected to occur within this century. Plankton communities in the coastal areas of the Baltic Sea frequently experience pH variations partly exceeding projections for the near future both on a diurnal and seasonal basis. We conducted a large-scale mesocosm CO2 enrichment experiment ( ˜ 55 m3) enclosing the natural plankton community in Tvärminne-Storfjärden for 8 weeks during June-August 2012 and studied community and species-taxon response of ciliates and mesozooplankton to CO2 elevations expected for this century. In addition to the response to fCO2, we also considered temperature and chlorophyll a variations in our analyses. Shannon diversity of ciliates significantly decreased with fCO2 and temperature with a greater dominance of smaller species. The mixotrophic Myrionecta rubra seemed to indirectly and directly benefit from higher CO2 concentrations in the post-bloom phase through increased occurrence of picoeukaryotes (most likely Cryptophytes) and Dinophyta at higher CO2 levels. With respect to mesozooplankton, we did not detect significant effects for either total abundance or for Shannon diversity. The cladocera Bosmina sp. occurred at distinctly higher abundance for a short time period during the second half of the experiment in three of the CO2-enriched mesocosms except for the highest CO2 level. The ratio of Bosmina sp. with empty to embryo- or resting-egg-bearing brood chambers, however, was significantly affected by CO2, temperature, and chlorophyll a. An indirect CO2 effect via increased food availability (Cyanobacteria) stimulating Bosmina sp. reproduction cannot be ruled out. Although increased regenerated primary production diminishes trophic transfer in general, the presence of organisms able to graze on bacteria such as cladocerans may positively impact organic matter transfer to higher

  18. Sulphur-cycling bacteria and ciliated protozoans in a Beggiatoaceae mat covering organically enriched sediments beneath a salmon farm in a southern Chilean fjord.

    Science.gov (United States)

    Aranda, Carlos P; Valenzuela, Cristian; Matamala, Yessica; Godoy, Félix A; Aranda, Nicol

    2015-11-15

    The colourless mat covering organically enriched sediments underlying an intensive salmon farm in Estero Pichicolo, southern Chile, was surveyed by combined 454 PyroTag and conventional Sanger sequencing of 16S/18S ribosomal RNA genes for Bacteria and Eukarya. The mat was dominated by the sulphide-oxidizing bacteria (SOB) Candidatus Isobeggiatoa, Candidatus Parabeggiatoa and Arcobacter. By order of their abundances, sulphate-reducing bacteria (SRB) were represented by diverse deltaproteobacterial Desulfobacteraceae, but also within Desulfobulbaceae, Desulfuromonadaceae and Desulfovibrionaceae. The eukaryotic PyroTags were dominated by polychaetes, copepods and nematodes, however, ciliated protozoans were highly abundant in microscopy observations, and were represented by the genera Condylostoma, Loxophyllum and Peritromus. Finally, the abundant Sulfurimonas/Sulfurovum also suggest the occurrence of zero-valence sulphur oxidation, probably derived from Beggiatoaceae as a result of bacteriovorus infaunal activity or generated as free S(0) by the Arcobacter bacteria. The survey suggests an intense and complex sulphur cycle within the surface of salmon-farm impacted sediments.

  19. Description of the rare marine ciliate, Uronychia multicirrus song, 1997 (Ciliophora; Euplotida) based on morphology, morphogenesis and SS rRNA gene sequence.

    Science.gov (United States)

    Shen, Zhuo; Shao, Chen; Gao, Shan; Lin, Xiaofeng; Li, Jiqiu; Hu, Xiaozhong; Song, Weibo

    2009-01-01

    A population of the marine euplotid ciliate, Uronychia multicirrus Song 1997, found in the littoral zone of the Daya Bay, Guangdong, South China, was investigated using live observation and protargol impregnation method. This species is diagnosed by possessing a long row of ventral cirri, which has never been seen in all other known congeners. Divisional process, described based on protargol-impregnated specimens, is typical of the genus regarding its general pattern: (1) the oral primordia in both proter and opisthe develop de novo in two subcortical pouches, while the UM-anlage forms de novo (i.e. does not develop from the oral primordium); (2) five frontoventral-transverse (FVT)-cirral anlagen develop in a primary-mode on the cell surface, and almost all the cirri are derived from the FVT-anlagen, except the first frontal cirri, which are formed de novo in both dividers; (3) the species characteristic ventral row derives from the right-most FVT-anlage; (4) the parental structures do not take part in the construction of the marginal anlagen, and (5) the caudal cirri originate in the right-most two dorsal kineties in a multi-segmentation mode. The small subunit rRNA gene of U. multicirrus (GenBank accession number: EU267929) is 1,773 bp and differs by 0.9-1.41% from its closely related congeners.

  20. The use of protozoa in ecotoxicology: application of multiple endpoint tests of the ciliate E. crassus for the evaluation of sediment quality in coastal marine ecosystems.

    Science.gov (United States)

    Gomiero, A; Dagnino, A; Nasci, C; Viarengo, A

    2013-01-01

    Despite an increasing number of surveys describing adverse effects of contaminated sediments on marine organisms, few studies have addressed protists. In this study, the free-crawling marine ciliate Euplotes crassus was evaluated as the test organism for the screening of sediment toxicity using sediments from both coastal and estuarine sites of the Venice Lagoon (Marghera harbour [MH], Valle Millecampi [MV], Murano island [MI] and Lido inlet [LI]). Two endpoints of high ecological value, mortality (Mry) and replication rate (RpR), were assessed in combination with the two sublethal biomarkers of stress, endocytotic rate (Ecy) and lysosomal membrane stability (NRRT). The results showed a significant inhibition of RpR, Ecy and NRRT paralleled by a small and insignificantly increased Mry of the exposed specimens. Our results thus demonstrate that only a combination of mortality and sublethal biomarkers was able to characterise an exposure-related stress syndrome. The suite of biomarkers described here was also able to detect and resolve a pollution-induced stress syndrome at an early stage of pollution. The contamination level of the sediments was assessed using chemical analysis, by estimating bioavailability and by computing a toxic pressure coefficient (TPC) to account for potential additive effects of different pollutants. The observed biological responses were consistent with the contamination levels in sediments, suggesting a high potential for using Protozoa in bioassays to assess environmental risk in coastal marine systems.

  1. The water-borne protein signals (pheromones) of the Antarctic ciliated protozoan Euplotes nobilii: structure of the gene coding for the En-6 pheromone.

    Science.gov (United States)

    La Terza, Antonietta; Dobri, Nicoleta; Alimenti, Claudio; Vallesi, Adriana; Luporini, Pierangelo

    2009-01-01

    The marine Antarctic ciliate, Euplotes nobilii, secretes a family of water-borne signal proteins, denoted as pheromones, which control vegetative proliferation and mating in the cell. Based on the knowledge of the amino acid sequences of a set of these pheromones isolated from the culture supernatant of wild-type strains, we designed probes to identify their encoding genes in the cell somatic nucleus (macronucleus). The full-length gene of the pheromone En-6 was determined and found to contain an open-reading frame specific for the synthesis of the En-6 cytoplasmic precursor (pre-pro-En-6), which requires 2 proteolytic cleavages to remove the signal peptide (pre) and the prosegment before secretion of the mature protein. In contrast to the sequence variability that distinguishes the secreted pheromones, the pre- and pro-sequences appear to be tightly conserved and useful for the construction of probes to clone every other E. nobilii pheromone gene. Potential intron sequences in the coding region of the En-6 gene imply the synthesis of more En-6 isoforms.

  2. The protein pheromone Er-1 of the ciliate Euplotes raikovi stimulates human T-cell activity: involvement of interleukin-2 system.

    Science.gov (United States)

    Cervia, Davide; Catalani, Elisabetta; Belardinelli, Maria Cristina; Perrotta, Cristiana; Picchietti, Simona; Alimenti, Claudio; Casini, Giovanni; Fausto, Anna Maria; Vallesi, Adriana

    2013-02-01

    Water-soluble protein signals (pheromones) of the ciliate Euplotes have been supposed to be functional precursors of growth factors and cytokines that regulate cell-cell interaction in multi-cellular eukaryotes. This work provides evidence that native preparations of the Euplotes raikovi pheromone Er-1 (a helical protein of 40 amino acids) specifically increases viability, DNA synthesis, proliferation, and the production of interferon-γ, tumor necrosis factor-α, interleukin (IL)-1β, IL-2, and IL-13 in human Jurkat T-cells. Also, Er-1 significantly decreases the mRNA levels of the β and γ subunits of IL-2 receptor (IL-2R), while the mRNA levels of the α subunit appeared to be not affected. Jurkat T-cell treatments with Er-1 induced the down-regulation of the IL-2Rα subunit by a reversible and time-dependent endocytosis, and increased the levels of phosphorylation of the extracellular signal-regulated kinases (ERK). The cell-type specificity of these effects was supported by the finding that Er-1, although unable to directly influence the growth of human glioma U-373 cells, induced Jurkat cells to synthesize and release factors that, in turn, inhibited the U-373 cell proliferation. Overall, these findings imply that Er-1 coupling to IL-2R and ERK immuno-enhances T-cell activity, and that this effect likely translates to an inhibition of glioma cell growth.

  3. Phylogeny and establishment of a new ciliate family, Wilbertomorphidae fam. nov. (Ciliophora, Karyorelictea), a highly specialized taxon represented by Wilbertomorpha colpoda gen. nov., spec. nov.

    Science.gov (United States)

    Xu, Yuan; Li, Jiamei; Song, Weibo; Warren, Alan

    2013-01-01

    The morphology and molecular phylogeny of a new marine interstitial karyorelictean ciliate, Wilbertomorpha colpoda gen. nov., spec. nov., isolated from a sandy beach at Qingdao, China, are investigated. The ciliature is mainly on the right surface with the left surface barren except for a single marginal kinety, which is typical of the order Loxodida. Nevertheless, other morphological features, such as the highly reduced buccal structure, the absence of a buccal cavity and the presence of extremely specialized cortical granules, prevent its assignation to any known family. Furthermore, the secondary structure of the variable region 2 of the SSU rRNA gene is unique among loxodids. Thus, we establish a new family, Wilbertomorphidae fam. nov. for the genus Wilbertomorpha. Phylogenetic analyses based on SSU rRNA gene sequence data suggest that this taxon is a sister group to the family Geleiidae which belongs to the order Protoheterotrichida. However, morphologically Wilbertomorpha bears a much stronger resemblance to Loxodidae which belongs to the order Loxodida. Based on these findings, we tentatively place Wilbertomorphidae nov. fam. incertae sedis within Karyorelictea.

  4. 纤毛类原生动物中宿主-共生体系统的研究%Studies on the Host-Symbiont System in Ciliates

    Institute of Scientific and Technical Information of China (English)

    顾福康; 孙军; 何远; 田沁

    2001-01-01

    目前已经在100多种纤毛虫中观察到细菌、藻类和其他微生物等共生体。对纤毛虫中宿主-共生体系统的研究表明,双小核草履虫中卡巴粒的遗传为细胞质遗传理论提供了例证;含细菌共生体的许多厌氧纤毛虫无线粒体,共生体对宿主代谢有重要作用;尾草履虫-钝状全孢螺菌共生作用中,共生菌感染形式的39kDa、15kDa周质蛋白可分别与IF-3-1、IF-3-2两种单抗反应,其共生体早期感染过程中两种抗原的量发生显著变化,并且共生体生殖 形式选择性地合成63kDa蛋白质,该蛋白质可能是与共生作用有联系的关键分子;绿草履虫-小球藻共生系统中,共生藻中存在葡糖胺硬性壁是其与草履虫发生共生关系的基本条件,其中,共生藻参与宿主代谢,与宿主形成相互受益的专一性关系,并且藻类共生体的作用可能影响了宿主草履虫基因组有关结构,改变了其基因表达。作者推测,探索共生体对宿主基因结构及其表达产物的影响可能是对纤毛虫中共生作用研究的主要趋势,这对于深入了 解真核细胞中宿主-共生体双方的相互作用、物质交流在分子水平上的调控机理、细胞结构与功能的关系等细胞生命活动规律是有意义的。%To date, bacterial,algal and other microbial symbionts have been found in more than 100 species of ciliates. The study of the host-symbiont system in ciliates shows that: ( 1 ) The inheritance of kappa particles in the cytoplasm of Paramecium aurelia is a classic example of the cytoplasmic inheritance theory. (2) Bacterial symbionts in some anerobic ciliates that lack mitochondria play the major role in the host's metabolism. (3) In the P. Caudatum-Holospora obtusa system, 39- and 15-kDa periplasmic pro teins of the infectious H. Obtusa reacted with IF-3-1 and IF-3-2 monoclonal antibodies respectively. The amounts of both antigens were reduced during

  5. Morphology, morphogenesis and small subunit rRNA gene sequence of a soil hypotrichous ciliate, Perisincirra paucicirrata (Ciliophora, Kahliellidae), from the shoreline of the Yellow River, North China.

    Science.gov (United States)

    Li, Fengchao; Xing, Yi; Li, Jiamei; Al-Rasheid, Khaled A S; He, Songke; Shao, Chen

    2013-01-01

    The morphology, morphogenesis, and 18S rRNA gene sequence of a soil hypotrichous ciliate Perisincirra paucicirrata, isolated from north China, were investigated. Perisincirra paucicirrata differs from its congeners in: (1) having a body length to width ratio in vivo of 4:1, (2) its adoral zone occupying between 15% and 25% of the total body length, and (3) the presence of two parabuccal cirri, three left (with 10-16 cirri each) and two right marginal rows (with 14-24 cirri each), and three dorsal kineties. Our study offers a first attempt to begin to map the morphogenetic processes of the genus, which are mainly characterised by the following: the formation of four frontal ventral transverse anlagens for each daughter cell, with the proter's anlage I originating from the reorganised anterior part of the parental paroral; the paroral and endoral anlage developed from the reorganised old endoral and do not contribute the first frontal cirrus; the frontoventral transverse anlage I contributing the left frontal cirrus; anlage II generating the middle frontal and the buccal cirri; anlage III developing the right frontal cirrus and the anterior parabuccal cirrus; and anlage IV contributing the posterior parabuccal cirrus. As an additional contribution, we judge that the inner one or the two right rows of P. kahli and P. longicirrata are marginal rows. Phylogenetic analysis based on SSU rDNA sequences suggests that Perisincirra is related to sporadotrichids, but provides no credible evidence for its taxonomic position.

  6. Morphology and SSU rDNA sequence analysis of two hypotrichous ciliates (Protozoa, Ciliophora, Hypotrichia) including the new species Metaurostylopsis parastruederkypkeae n. sp.

    Science.gov (United States)

    Lu, Borong; Wang, Chundi; Huang, Jie; Shi, Yuhong; Chen, Xiangrui

    2016-10-01

    The morphology and phylogeny of two hypotrichous ciliates, Metaurostylopsis parastruederkypkeae n. sp. and Neourostylopsis flavicana (Wang et al., 2011) Chen et al., 2013 were investigated based on morphology, infraciliature and the small subunit (SSU) ribosomal RNA gene (rRNA) sequence. The new species, M. parastruederkypkeae n. sp. was identified according to its characteristics: body shape ellipsoidal, size about (165-200) × (45-60) μm in vivo, cell color reddish; two types of cortical granules including wheat grain-like and yellow-greenish larger ones along the marginal cirri rows and dorsal kineties and dot-like and reddish smaller ones, grouped around marginal cirri on ventral side and arranged in short lines on dorsal side; 26-41 adoral membranelles; three frontal and one parabuccal, five to seven frontoterminal, one buccal, and three to six transverse cirri; seven to thirteen midventral pairs; five to nine unpaired ventral cirri, five to seven left and three to five right marginal rows; and three complete dorsal kineties. Phylogenetic analysis based on SSU rDNA sequences showed that both Metaurostylopsis and Neourostylopsis are monophyletic. As the internal relationship between and within both genera are not clear, further studies on the species in these two genera are necessary. The key characteristics of all known twelve Metaurostylopsis-Apourostylopsis-Neourostylopsis species complex were updated.

  7. Morphology of four new solitary sessile peritrich ciliates from the Yellow Sea, China, with description of an unidentified species of Paravorticella (Ciliophora, Peritrichia).

    Science.gov (United States)

    Sun, Ping; Al-Farraj, Saleh A; Warren, Alan; Ma, Honggang

    2017-02-01

    Sessile peritrichs are a large assemblage of ciliates that have a wide distribution in soil, freshwater and marine waters. Here, we document four new and one unidentified species of solitary sessile peritrichs from aquaculture ponds and coastal waters of the northern Yellow Sea, China. Based on their living morphology, infraciliature and silverline system, four of the five forms were identified as new members belonging to one of three genera, Vorticella, Pseudovorticella and Scyphidia, representing two families, Vorticellidae and Scyphidiidae. The other isolate was found to be an unidentified species of the poorly known genus Paravorticella. Vorticella chiangi sp. nov. is characterized by its inverted bell-shaped zooid, short row 3 in infundibular polykinety 3 and marine habitat. Pseudovorticella liangae sp. nov. posseses a thin, broad peristomial lip and a granular pellicle. Pseudovorticella haiboensis sp. nov. is differentiated from its congeners by having an elongated zooid that is covered by a layer of thin pellicular vesicles, and two rows of kineties in infundibular polykinety 3. Scyphidia perezuzae sp. nov. and Paravorticella sp. are stalkless ectoparasites or ectocommensals of aquatic animals. The former has a short, plump body, a narrow peristomial lip and a conspicuous, flattened, disc-shaped scopula for adhesion. Paravorticella sp. has an extremely elongated clavate body, a broad peristomial lip, and a narrow scopula.

  8. Dicty_cDB: AFK467 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 599 e-167 1 CN206669 |CN206669.1 Tor7097 Gametophyte rehydration Library Tortula ruralis cDNA, mRNA sequenc....1 Tor7258 Gametophyte rehydration Library Tortula ruralis cDNA, mRNA sequence. 70 5e-08 1 CK030146 |CK03014...55.1 TTE00006978 Normalized large Tetrahymena thermophila cDNA, mRNA sequence. 74 3e-09 1 CN206834 |CN206834

  9. La estria supranuclear de las células ciliadas en la rinitis alérgica Supranuclear stria of ciliated cells in allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Ana Zerdiew

    2007-08-01

    Full Text Available Se estudiaron 80 pacientes adultos alérgicos, que cursaron con los siguientes cuadros clínicos: 16 casos de rinitis intermitente y 64 de rinitis persistente. Se realizó el recuento porcentual de la estría supranuclear de las células ciliadas, respecto de los leucocitos presentes en los extendidos obtenidos por toma endonasal. Con los datos obtenidos se clasificaron los extendidos en 4 grupos; Grupo A (N=23: predominio leucocitario eosinófilo con eosinofilia nasal >10%, Grupo B (N=15: abundantes leucocitos neutrófilos y eosinofilia nasal >10%, Grupo C (N=29: con escasos leucocitos, Grupo D (N=13: con abundantes leucocitos de predominio neutrófilo sin eosinofilia. Se observó que el incremento porcentual de estría supranuclear se correlacionó con eosinofilia nasal >10% y con las muestras que presentaron escasos leucocitos. Sin embargo se evidenció una marcada disminución del porcentaje de estría supranuclear en la leucocitosis neutrófila de etiología bacteriana.Nasal secretions were studied in 80 allergic adults patients: 16 with intermittent rhinitis and 64 with persistent rhinitis. The percentage of supranuclear stria of ciliated cells with regard to leucocytes was studied by nasal scraping. Four groups of patients were classified according to nasal leucocytic predominance: patients with eosinophilic predominance with eosinophils > 10% in Group A (N=23, patients with abundant neutrophils and eosinophils >10% in Group B (N=15, patients with scant leucocytes in Group C (N=29, patients with neutrophilic predominance without eosinophils in Group D (N=13. An increase of supranuclear stria percentage was correlated to eosinophils > 10% and also correlated to scant leucocytes. Nevertheless, a significant decrease of supranuclear stria percentage was observed in neutrophilic leukocytosis of bacterial etiology.

  10. Role of four conserved aspartic acid residues of EF-loops in the metal ion binding and in the self-assembly of ciliate Euplotes octocarinatus centrin.

    Science.gov (United States)

    Liu, Wen; Duan, Lian; Sun, Tijian; Yang, Binsheng

    2016-12-01

    Ciliate Euplotes octocarinatus centrin (EoCen) is an EF-hand calcium-binding protein closely related to the prototypical calcium sensor protein calmodulin. Four mutants (D37K, D73K, D110K and D146K) were created firstly to elucidate the importance of the first aspartic acid residues (Asp37, Asp73, Asp110 and Asp146) in the beginning of the four EF-loops of EoCen. Aromatic-sensitized Tb(3+) fluorescence indicates that the aspartic acid residues are very important for the metal-binding of EoCen, except for Asp73 (in EF-loop II). Resonance light scattering (RLS) measurements for different metal ions (Ca(2+) and Tb(3+)) binding proteins suggest that the order of four conserved aspartic acid residues for contributing to the self-assembly of EoCen is Asp37 > Asp146 > Asp110 > Asp73. Cross-linking experiment also exhibits that Asp37 and Asp146 play critical role in the self-assembly of EoCen. Asp37, in site I, which is located in the N-terminal domain, plays the most important role in the metal ion-dependent self-assembly of EoCen, and there is cooperativity between N-terminal and C-terminal domain (especially the site IV). In addition, the dependence of Tb(3+) induced self-assembly of EoCen and the mutants on various factors, including ionic strength and pH, were characterized using RLS. Finally, 2-p-toluidinylnaphthalene-6-sulfonate (TNS) binding, ionic strength and pH control experiments indicate that in the process of EoCen self-assembly, molecular interactions are mediated by both electrostatic and hydrophobic forces, and the hydrophobic interaction has the important status.

  11. The protein pheromone Er-1 of the ciliate Euplotes raikovi stimulates human T-cell activity: Involvement of interleukin-2 system

    Energy Technology Data Exchange (ETDEWEB)

    Cervia, Davide, E-mail: d.cervia@unitus.it [Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo (Italy); Department of Biomedical and Clinical Sciences, “Luigi Sacco” University Hospital, University of Milan, Milano (Italy); Catalani, Elisabetta; Belardinelli, Maria Cristina [Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo (Italy); Perrotta, Cristiana [Department of Biomedical and Clinical Sciences, “Luigi Sacco” University Hospital, University of Milan, Milano (Italy); Picchietti, Simona [Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo (Italy); Alimenti, Claudio [Department of Environmental and Natural Sciences, University of Camerino, Camerino (Italy); Casini, Giovanni; Fausto, Anna Maria [Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo (Italy); Vallesi, Adriana [Department of Environmental and Natural Sciences, University of Camerino, Camerino (Italy)

    2013-02-01

    Water-soluble protein signals (pheromones) of the ciliate Euplotes have been supposed to be functional precursors of growth factors and cytokines that regulate cell–cell interaction in multi-cellular eukaryotes. This work provides evidence that native preparations of the Euplotes raikovi pheromone Er-1 (a helical protein of 40 amino acids) specifically increases viability, DNA synthesis, proliferation, and the production of interferon-γ, tumor necrosis factor-α, interleukin (IL)-1β, IL-2, and IL-13 in human Jurkat T-cells. Also, Er-1 significantly decreases the mRNA levels of the β and γ subunits of IL-2 receptor (IL-2R), while the mRNA levels of the α subunit appeared to be not affected. Jurkat T-cell treatments with Er-1 induced the down-regulation of the IL-2Rα subunit by a reversible and time-dependent endocytosis, and increased the levels of phosphorylation of the extracellular signal-regulated kinases (ERK). The cell-type specificity of these effects was supported by the finding that Er-1, although unable to directly influence the growth of human glioma U-373 cells, induced Jurkat cells to synthesize and release factors that, in turn, inhibited the U-373 cell proliferation. Overall, these findings imply that Er-1 coupling to IL-2R and ERK immuno-enhances T-cell activity, and that this effect likely translates to an inhibition of glioma cell growth. -- Highlights: ► Euplotes pheromone Er-1 increases the growth of human Jurkat T-cells. ► Er-1 increases the T-cell production of specific cytokines. ► Er-1 activates interleukin-2 receptor and extracellular signal-regulated kinases. ► The immuno-enhancing effect of Er-1 on Jurkat cells translates to an inhibition of human glioma cell growth.

  12. Moss ciliated protozoa as bioindicators. A study on the urban area of Pisa (Italy); Protozoi ciliati del muschio come biondicatori. Uno studio nell'area urbana di Pisa

    Energy Technology Data Exchange (ETDEWEB)

    Verni, F.; Rosati, G. [Pisa Univ., Pisa (Italy). Dipt. di Etologia, Ecologia, Evoluzione

    2000-07-01

    Samples of moss were collected, every month for 7 months, from five zones of Pisa (S2, S3, S4, S5, S6) and a woody zone (S1) as control. For each sample the type and the number of the ciliate species as well as the number of individuals for each species were determined. Lead content was also measured. The data were statistically elaborated and compared. The diversity Shannon index (H) was calculated to determine the health state of ciliate communities. In any case an inverse correlation between H and the lead content was reported; the highest the H value, the lowest the lead content and vice versa. On the basis of the results here reported the use of Ciliates as biondicators appears suitable for the control of urban soil. An analysis like this appears advantageous as it is rather simple and cheap and allows to determine the possible variations in a real time. [Italian] Sono stati analizzati campioni di muschio prelevati, con cadenza mensile per 7 mesi, in 5 stazioni di Pisa (S2, S3, S4, S5, S6) e da una zona boscosa (S1), come controllo. Per ogni campione si e' proceduto all'identificazione dei Ciliati presenti, al conteggio delle specie e del numero di individui per specie, nonche' alla misurazione del piombo presente. I dati sono stati confrontati dopo elaborazione statistica. L'indice della diversita' di Shannon ha fornito informazioni sulla salute della comunita' dei Protozoi delle varie stazioni. In ogni caso risulta una correlazione inversa tra i valori dell'indice di Shannon e la quantita' di piombo: S5, la stazione piu' esposta al traffico, risulta quella piu' degradata. L'uso dei Ciliati come biondicatori risulta quindi appropriato e vantaggioso considerando che e' semplice, poco costoso e permette di valutare in tempi reali variazioni nell'ambiente.

  13. [Revision of of the subfamily of Metaracoelophryinae de Puytorac 1972 (Oligohymenophora: Hoplytophryida: Hoplytophryidae), astome ciliates of the digestive tract of Oligochaeta worms of Africa: description of five new species].

    Science.gov (United States)

    Fokam, Z; Ngassam, P; Nana, P A; Bricheux, G; Bouchard, P; Sime Ngando, T

    2012-02-01

    Five new species belonging to the astome ciliates, living in the digestive tract of Oligochaeta worms belonging to the genus Alma from Cameroon, have been described. The techniques used are: vital staining, staining of the nucleus with Diamidino Phenyl Indol (DAPI), scanning electron microscopy and silver staining method (Fernandez Galiano, 1976, 1994). This work confirms the presence of the genus Paracoelophrya and Dicoelophrya in the digestive track of the oligochaete Alma from Gabon and Cameroon; it helps to understand the general taxonomy of this Metaracoelophryinae subfamily. Moreover, the homogeneity of this group is confirmed and the phylogenetic relationship inside the Hoplitophryida order need more studies to be solved.

  14. Protocruzia,a highly ambiguous ciliate(Protozoa;Ciliophora):Very likely an ancestral form for Heterotrichea,Colpodea or Spirotrichea? With reevaluation of its evolutionary position based on multigene analyses

    Institute of Scientific and Technical Information of China (English)

    Thorsten; STOECK; Shin; Mann; Kyoon; Al-Rasheid; Khaled; A.; S.; Al-Khedhairy; Abdulaziz; A.

    2010-01-01

    The ciliate genus Protocruzia belongs to one of the most ambiguous taxa considering its systematic position,possibly as a member of the classes Heterotrichea,Spirotrichea or Karyorelictea,which is tentatively placed into Spirotrichea in Lynn’s 2008 system.To test these hypotheses,multigene trees(Bayesian inference,evolutionary distance,maximum parsimony,and maximum likelihood) were constructed using the small subunit rRNA(SSU rRNA) gene,internal transcribed spacer 2(ITS2) and a protein coding gene(histone H4).All analyses agree that:(1) four morphotypes of Protocruzia from different geographical origins group together and form a monophyletic clade,which cannot be assigned to any of the eleven described ciliate classes;(2) it is invariably positioned on an isolated branch separated from the class Spirotrichea suggesting that this clade should be clearly removed from Spirotrichea;(3) this leads us to hypothesize that this taxon may indeed represent a lineage on a class rank.Based on the fact that it is,both morphologically and in molecular features,closely related to the heterotrichs,Colpodea and Oligohymenophorea,Protocruziida might be an ancestral form for the subphylum Intramacronucleata in the evolutionary line from the class Heterotrichea(subphylum Postciliodesmatophora) to higher taxa.

  15. ABUNDANCE AND BIOMASS OF COPEPOD NAUPLII AND CILIATES IN JIAOZHOU BAY%胶州湾桡足类幼虫和浮游生纤毛虫的丰度与生物量

    Institute of Scientific and Technical Information of China (English)

    张武昌; 王荣

    2001-01-01

    This paper presents data of ciliates and copepod nauplii abundance and biomass from eight cruises (September, December, 1997; February, April, August, November, 1998; February, May, 1999) in Jiaozhou Bay. Water samples were taken by 2L Niskin Bottles at ten stations during every cruise. One liter water was preserved in plastic bottle with Lugol's (1%). The sample scheme of water layer was surface, middle and bottom according to water depth. The samples were examined with the method of Utermohl (1958) one month after sampling. Carbon:volumn ratio was 0.05 pgC/μm3 for copepod nauplii (Mullin, 1969), 0.19pgC/μm3 for ciliates (Putt et al, 1989). Body volume of tintinnids was assumed to be 50% of that of the lorica (Beers et al, 1969).   Copepod nauplii dominated in September 1997. The aloricate oligotrichous ciliates were dominant through December 1997 to February 1999. Tintinnids dominated in May 1999. The maximum abundance of copepod nauplii, aloricate ciliates and tintinnids were 850 (August, 1998), 21300 (August, 1998) and 1720 ind/L (May, 1999) respectively. The total abundance of the above three in the surface layer was 10—22350 ind/L, with larger abundance in the inner part of the bay. There was no obvious trend in the vertical distribution. The total biomass of copepod nauplii, aloricate ciliates and tintinnids in the surface layer was in the range of 0.10—380.27μgC/L, water column biomass 0.20—1426.02mgC/m2.%1997年9月、12月,1998年2月、4月、8月、11月以及1999年2月和5月在胶州湾采集桡足类幼虫和浮游生纤毛虫的样品。样品用Lugol's试剂固定(最后浓度1%),用显微镜计数桡足类幼虫和浮游生纤毛虫的丰度,并计算总生物量(表层生物量和水体生物量)。桡足类幼虫、无壳纤毛虫和砂壳纤毛虫的最大丰度分别为850ind/L(1998年8月)、21300ind/L(1998年8月)和1720ind/L(1999年5月)。表层的总丰度为10—22630ind/L,水平分布湾内比湾外多。表层纤

  16. Protozoa: a novel Campylobacter reservoir?

    Science.gov (United States)

    In previous in vitro studies we found that Campylobacter jejuni remained viable for longer periods of time when they were cultivated in the presence of Tetrahymena pyriformis (ciliate) and Acanthamoeba castellanii (amoeba) than when they were in an independent planktonic state. Increased survival t...

  17. GENETIC RELATIONSHIPS OF FIVE PERITRICHOUS CILIATES INFERRED FROM INTER SIMPLE SEQUENCE REPEAT (ISSR) MOLECULAR MARKERS%五种缘毛类纤毛虫遗传关系的ISSR研究

    Institute of Scientific and Technical Information of China (English)

    张文静; 余育和; 沈韫芬

    2005-01-01

    In this study, ISSR (inter simple sequence repeat) molecular markers were used to clarify genetic relationships of five peritrichous ciliates: Carchesium polypinum, Epistylis chrysemydis, E. plicatilis, E. urceolata and Vorticella campanula.From 34 primers, 13 polymorphic primers were selected and tested. The genetic distance values going from 0.6667 to 1. 0000 among the five species show the ISSR-PCR method has a high resolution. In the phylogenetic tree constructed with the unweighted pair group method using arithmetic averages (UPGMA), V. campanula was separated from other species firstly; C.polypinum and E. chrysemydis were closely related; in the group of Epistylis species, E. plicatilis and E. urceolata were first clustered together and then grouped with E. chrysemydis. These results were compared with the phylogenetic tree from the complete small subunit ribosomal RNA (SSrRNA) gene sequences. We found that: 1) ISSR primers can give the informative profiles in peritrichous ciliates; 2) C. polypinum has a nearer relation with Epistylis than V. campanula. The colonial or solitary status might be a more important phylogenetic character within peritrichs than the characters of stalk and the myoneme; 3) E.urceolata shared closer relationship with E. plicatilis than E. chrysemydis. The hollow nature of the stalk is a useful phylogenetic and taxonomic character in the genus Epistylis. This study demonstrated that ISSR-PCR method was a new useful method to reveal the relationships among related or similar species in ciliates.%应用ISSR分子标记揭示了5种缘毛类纤毛虫(Carchesium polypinum,Epistylis chrysemydis,E.plicatilis,E.urceolata和Vorticella campanula)的遗传关系.从34个引物中筛选到13个多态性高的引物进行研究.得到的遗传距离(0.666 7~1.000 0)显示ISSR技术具有较高的分辨率.依据构建的UPGMA聚类树,V.campanula首先和其他种类分开;C.polypinum和E.chrysemydis聚在了一起;在3种Epistylis纤毛虫中,E

  18. Predação e canibalismo entre protozoários ciliados (Ciliophora: Entodiniomorphida: Ophryoscolecidae no rúmen de ovinos (Ovis aries Predation and cannibalism among ciliate protozoans (Ciliophora: Entodiniomorphida: Ophryoscolecidae in the rumen of sheep (Ovis aries

    Directory of Open Access Journals (Sweden)

    Isabel Martinele

    2008-09-01

    Full Text Available O objetivo deste trabalho foi registrar ocorrências de predação e canibalismo em protozoários ciliados no rúmen de ovinos. Foram analisadas amostras de conteúdo ruminal de cinco ovinos mestiços Santa Inês, fistulados no rúmen, mantidos em pastagem natural de caatinga, no município de Sertânia, Pernambuco. Foram obtidas seis amostras de conteúdo ruminal de cada ovino, totalizando 30 amostras, as quais foram fixadas em formalina 18,5% (v/v. De cada amostra foi retirada uma alíquota de 1 ml de conteúdo ruminal ao qual se adicionaram três gotas de solução de lugol para a coloração e identificação dos protozoários ciliados. Estas alíquotas foram analisadas utilizando-se lâminas e lamínulas, em campos determinados randomicamente. Constatou-se a ocorrência de interações do tipo predador-presa entre ciliados de Ophryoscolecidae Stein, 1859, onde Elytroplastron bubali (Dogiel, 1928 apresentou comportamento predatório sobre Enoploplastron triloricatum (Dogiel, 1925 e sobre outras espécies de Epidinium Crawley, 1923 e de Entodinium Stein, 1859. Foram ainda observados casos de canibalismo entre espécimes de E. bubali, o que consiste no primeiro registro deste tipo de interação nesta espécie. Registra-se, ainda, pela primeira vez a ocorrência de E. bubali no rúmen de ovinos no Brasil.The objective of the present study was to record the occurrence of predation and cannibalism among ciliate protozoans in the rumen of sheep. The analyzed samples consisted of ruminal contents of five fistulated Santa Inez crossbred sheep, maintained in a natural caatinga (scrubland pasture in the municipality of Sertânia, Pernambuco. Six samples of ruminal content were obtained from each sheep (total of 30 samples and fixed in formalin at 18.5% (v/v. One 1 ml aliquot was obtained from each sample of ruminal content and received tree drops of a lugol solution for staining and identification of protozoa ciliates. These aliquots were analyzed in

  19. Morphological Studies of a Ciliate from the External Ulcerative Japanese Flounder, Paralichthys Olivaceus%一种纤毛虫的分类及形态研究 ——寄生于牙鲆体表溃烂组织中的指状拟舟虫

    Institute of Scientific and Technical Information of China (English)

    周丽; 徐奎栋; 战文斌; 宋微波

    2001-01-01

    报道从牙鲆(Paralichthysolivaceus)体表溃烂组织分离的一种纤毛虫,通过活体观察、扫描电镜、蛋白银染色法、银浸法,对其形态学及纤毛图式做了研究。经鉴定,该纤毛虫为指状拟舟虫(Paralembus digitiformis Kahl,1933),隶属于寡膜纲、盾纤目、嗜污科、拟舟虫属。这是指状拟舟虫在牙鲆上兼性寄生的首次报道。%An external ulcerative disease frequently occurred in Ja paneseflounder, Paralichthys olivaceus, cultured in artificial propagation facilities along the coasts of Shandong, China, has caused mass mortalities in r ecent years. The ciliate was a pathogen to flounder and was identified as Para lembus digitiformis Kahl 1933, a marine facultative parasitic scuticociliatid ciliate. Morphological studies were made on living observations and specimens tr eated with protargol-impregnation techniques and Chatton-Lwoff silver impregna tion techniques as well as scanning electron microscopy. The ciliate, Paralemb us digitiformis Kahl 1933, as an opportunistic pathogen of cultured flounder, is first reported in this paper.

  20. 显示纤毛虫细胞微管骨架的两种荧光标记方法%Two fluorescent labeling methods for revealing microtubular cytoskeleton in ciliates

    Institute of Scientific and Technical Information of China (English)

    余齐耀; 张萌; 陈季武; 倪兵

    2012-01-01

    应用直接荧光标记和免疫荧光标记显微术显示了几种原生动物纤毛虫(如尾草履虫、大尾柱虫、阔口游仆虫)的细胞微管骨架,并据结果提出了用所述方法制备标本时需注意的几个方面:对游仆虫,可以忽略某些步骤;对大尾柱虫各种药品的浓度以及处理时间以较小为宜.%The direct fluorescent labeling and the immunofluorescent labeling with antibody against a-tubulin were used to show the mi-crotubular cytoskeleton of several ciliate protozoans such as Paramecium caudatum, Euplotes eurystomus and Urostyla grandis. Based on the results, the study also proposed some points which should be noted in the preparation of specimen with the methods mentioned a-bove (I.e. , some steps can be ignored in Euplotes; a lower concentration of various drugs and a less processing time will be appropriate for Urostyla species).

  1. Classification of the peritrich ciliate Opisthonecta matiensis (Martín-Cereceda et al. 1999) as Telotrochidium matiense nov. comb., based on new observations and SSU rDNA phylogeny.

    Science.gov (United States)

    Martín-Cereceda, Mercedes; Guinea, Almudena; Bonaccorso, Elisa; Dyal, Patricia; Novarino, Gianfranco; Foissner, Wilhelm

    2007-11-01

    New observations on Opisthonecta matiensis Martín-Cereceda et al. [1999. Description of Opisthonecta matiensis n. sp. (Protozoa, Ciliophora), a new peritrich ciliate from wastewater. J. Eukaryot. Microbiol. 46, 283-289] especially the lack of an epistomial membrane, reveal that the species does not belong to the genus Opisthonecta, but to Telotrochidium, the other genus within the family Opisthonectidae Foissner, 1975. The contractile vacuole and the cytopyge are on the dorsal wall of the vestibulum and the trochal band is limited distally and proximally by rows of narrowly spaced pellicular pores. Thus the species is redefined as Telotrochidium matiense nov. comb. The morphological, cortical and nuclear events occurring during conjugation are illustrated, compared with those in other species, and phylogenetically discussed. Invariably, the microconjugants attach to and penetrate the lateral side of the macroconjugants. Nuclear processes are very similar to those reported from other peritrichs. The small subunit rRNA gene (SSU rDNA) is sequenced and the phylogeny within Opisthonectidae and peritrichs examined. T. matiense is more closely related to Epistylis (63% Maximum Parsimony (MP), 85% Maximum Likelihood (ML)) than to any other genus, while another representative of the family, viz., Opisthonecta henneguyi, is closely related to Vorticella microstoma, Astylozoon enriquesi and clone RT3n18 (100% MP, 100% ML). Morphology and gene sequences suggest that Telotrochidium and Opisthonecta have derived from different lineages of stalked peritrichs: Opisthonecta could have arisen from peritrichs with stalk myonemes, while Telotrochidium probably evolved from peritrichs without stalk myonemes.

  2. T. thermophila group I introns that cleave amide bonds

    Science.gov (United States)

    Joyce, Gerald F. (Inventor)

    1997-01-01

    The present invention relates to nucleic acid enzymes or enzymatic RNA molecules that are capable of cleaving a variety of bonds, including phosphodiester bonds and amide bonds, in a variety of substrates. Thus, the disclosed enzymatic RNA molecules are capable of functioning as nucleases and/or peptidases. The present invention also relates to compositions containing the disclosed enzymatic RNA molecule and to methods of making, selecting, and using such enzymes and compositions.

  3. COMMUNITY STRUCTURE AND DISTRIBUTION OF PELAGIC NANOFLAGELLATES AND CILIATES AND THEIR RELATIONSHIP WITH JELLYFISH OCCURRENCE IN SOUTHERN YELLOW SEA%黄海水母旺发区浮游鞭毛虫和纤毛虫群落结构分布及其与水母发生关系初探

    Institute of Scientific and Technical Information of China (English)

    丁军军; 徐奎栋

    2012-01-01

    The role of nanoflagellates and ciliates during jellyfish bloom remains unexplored. We investigated the changes of the community structure and distribution of planktonic nanoflagellates and ciliates collected from the transects E, G and I in the southern Yellow Sea in April and August of 2011. The nanoflagellates and ciliates were studied using DAPI epifluorescence microscopy and the quantitative protargol stain. The abundance of total nanoflagellates was high in the coastal area and decreased towards the offshore area, Vertically, nanoflagellates mainly distributed in the surface and near the bottom layers in water. Compared with those in spring, the total abundance and biomass of nanoflagellates in- creased in summer. The abundance of ciliates increased from inshore to offshore area. This was different from that of nan- oflagellates. Ciliates in the surface layer contributed up to 80% of total abundance and abruptly decreased below the 30 m depth. Compared with those in spring, the overall ciliate abundance and biomass decreased by about 50% in summer when jellyfish appeared. The ciliate abundance in summer was only 30%--40% of that in spring at transects E and G, while the ciliate abundance at the transect I, where there was no jellyfish observed, highly increased in summer. Jellyfish can cause direct and indirect changes to nano- and microzooplankton through cascading effects. The sharp decreases of ciliates at transects E and G were likely attributed to the predation pressure from increasing jellyfish, and consequently resulted in the increase of nanoflagellates. In contrast, ciliates increased at transect I without the impact of jellyfish.%鞭毛虫和纤毛虫在海洋微食物环和经典食物链间的能量流动中起着重要的枢纽作用,但其在水母暴发过程中的作用仍然不明。本研究基于2011年春季以及水母旺发的夏季黄海专项航次,通过荧光染色技术和定量蛋白银法研究了南黄海水母频发海域3

  4. Potential distribution of sycamore lace bug, Corythucha ciliate in China (Hemiptera : Tingidae)%悬铃木方翅网蝽在我国的潜在分布分析

    Institute of Scientific and Technical Information of China (English)

    朱耿平; 王晓静; 刘国卿; 卜文俊

    2012-01-01

    运用生态位模型MaxEnt和GARP对悬铃木方翅网蝽Corythucha ciliate (Say)在我国的潜在分布进行了模拟,并结合其寄主植物悬铃木在我国的分布进行了分析.实验采用悬铃木方翅网蝽在我国的分布数据,结合6种气候变量和海拔数据构建模型,并将MaxEnt和GARP的输出结果进行合意.研究显示MaxEnt和GARP的模拟结果基本一致,均能较好的模拟悬铃木方翅网蝽在我国的分布,二者均显示山东西南部和中部、四川中部和东部、重庆、陕西中部、河南中部和东部、安徽、江苏、上海、贵州、湖南、江西、浙江、福建中部和北部、云南中部等地区为悬铃木方翅网蝽的适宜分布区,此外,河北中部和南部、山东东部,广东和广西的北部亦具潜在分布的可能性.与MaxEnt输出结果相比,GARP相对较为保守.MaxEnt输出结果显示年平均气温和极端低温对悬铃木方翅网蝽地理分布的限制作用最大.考虑到该虫对高低温度的耐受性,我国二球悬铃木栽培的南界(南宁和广州)和北界(大连、北京、石家庄、太原)需要重视和监控起来.%Potential distribution of Corythucha ciliate (Say) in China were predicted using two ecological niche modelling algorithms (i.e. , MaxEnt and GARP). The models were calibrated using domestic records and 6 bioclimatic variables plus elevation. These potential distributions were then evaluated with respect to the distribution of pest host plant ( i. e. , Platanus spp. ). Significant variables associating with the bug' s occurrence were identified. Both models performed good discriminability compared to random prediction. Result of GARP was a little conservative compared to MaxEnt. High suitable areas identified by the consensus of two models including; southwestern and central Shandong, eastern and central Sichuan, Chongqing, central Shaanxi, eastern and central Henan, Anhui, Jiangsu, Shanghai, Guizhou, Hunan, Jiangxi, Zhejiang

  5. 汉中市兴元湖纤毛虫群落结构与水质评价%Study on Community Structure of Ciliates and Water Evaluation in Xingyuan Lake of Hanzhong

    Institute of Scientific and Technical Information of China (English)

    刘智峰

    2015-01-01

    2014年3~5月,利用PFU法对汉中市兴元湖水中纤毛虫群落进行调查,从3个采样点共观察到56种纤毛虫,隶属1门,3纲,11目,32属。优势种为纵长板壳虫(Coleps elonqatus)、钝漫游虫(Litonotus obtusus)、钩刺斜管虫(Chilodonella uncinata)、珍珠映毛虫(Cinetochilum margaritaceum)、沟钟虫(Vorti-cella convallaria)、尾瘦尾虫(Uroleptus candatus)、伪尖毛虫(Oxyticha fallax)、阔口游仆虫(Euplotes eurys-tomus)。通过计算水体纤毛虫的多样性指数,大小关系为3号采样点﹤1号采样点﹤2号采样点。水质评价结果,1号采样点属于β-中污型,2号采样点属于寡污型,3号采样点属于a-中污型。%The investigation on ciliates community and water quality assessment in Xingyuan Lake was carried out from April to May in 2014. Fifty-six species belonging to three classes of eleven orders of thirty genuses are discovered from three test sites. The dominant spices were Coleps elonqatus, Litonotus obtusus, Chilodonella uncinata, Cinetochilum margaritaceum, Vorticella convallaria, Uroleptus candatus, Oxyticha fallax and Euplotes eurystomus. Using species diversity index to assess water quality of Xingyuan Lake, the results showed that site one belonged to β-mesosaprobic zone; site two belonged to oligosaprobic zone; and site three belonged to a-mesosaprobic zone.

  6. Dicty_cDB: Contig-U10863-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 1( AB220161 |pid:none) Tetrahymena thermophila BNI2 mRNA ... 87 2e-15 (Q0GNC1) RecName: Full=Inverted formin...80;A41724)limb deformity (ld) protein - chicken 85 9e-15 (Q27J81) RecName: Full=Inverted...1H8, c... 79 5e-13 ( O22824 ) RecName: Full=Formin-like protein 2; Short=AtF... 75 6e-13 (Q6NTV6) RecName: Full=Inverted

  7. Three dimension quantitative structure toxicity relationship study of cytoxicitic phenolic analogues against Tetrahymena pyriformis%梨形四膜虫细胞毒性苯酚类似物的三维定量结构毒性相关研究

    Institute of Scientific and Technical Information of China (English)

    王远强; 刘跃辉; 丁元; 张娅; 林治华

    2012-01-01

    目的 使用比较分子相似性指数分析(CoMSIA)方法 对梨形四膜虫细胞毒性苯酚类似物进行三维定量结构毒性相关(3D-QSTR)研究.方法 系统分析了立体场、静电场、疏水场对三维结构毒性模型的影响,并建立相应的3D-QSTR预测模型.结果 使用静电场与疏水场协同作用建立了具有良好可靠性和预测能力的3D-QSTR模型(Q2=0.767,r2=0.933).结论 模型具有良好的预测能力,对苯酚类似物的结构修饰具有指导作用.%Objective To use the comparative molecular similarity indices analysis (CoMSIA) for constructing three dimension quantitative structure-toxicity relationship (3D-QSTR) models of phenolic analogues with cytotoxicity against Tetrahymena pyri-formis. Methods The contribution of hydrophobic,electrostatic and steric property to 3D-QSTR models were analyzed comprehensively. The optimized 3D-QSTR model was constructed by CoMSIA using electrostatic and hydrophobic properties for phenolic ana-loguesResults The model had good stability (Q2 =0. 767) and predictive ability (r2 =0. 933). Conclusion The electrostatic and hydrophobic counter maps from CoMSIA could guide the structural modification of phenolic analogues directly.

  8. 夏季蓝藻水华期间太湖河口区和敞水区纤毛虫群落组成及水平分布%COMMUNITY COMPOSITIONS AND HORIZONTAL DISTRIBUTION OF CILIATES IN LAKE TAIHU DURING THE CYANOBACTERIAL BLOOM IN SUMMER

    Institute of Scientific and Technical Information of China (English)

    李静; 卢文轩; 张雷燕; 陈非洲

    2014-01-01

    In the present study, ciliate samples were collected from 10 sites in the estuary zones and 14 sites in the pe-lagic zones in the northern area of Lake Taihu in July 2009. The ciliate species and their horizontal distribution were analyzed with quantitative protargol stain (QPS) method. We also explored the relationship between the ciliate commu-nity compositions and the environmental variables. We observed 105 species that represented 60 genera, 15 orders and 3 classes. The numbers of the species in different order were counted and compared. Orders Haptorida (21 species) and Oligotrichida (20 species) ranked the first and second, followed by orders Prostomatida (12 species), Peritrichida (11 species), and Hypotrichida (11 species). These five orders were predominant in the samples, while less species belonged to the other ten orders -- Karyorelictida, Pleurostomatida, Colpodida, Nassulida, Cyrophorida, Suctoria, Hy-menostomatida, Synhymeniida, Scuticociliatida, and Heterotrichida. Halteria bifurcate Tamar, H. grandinella Dujardin, Rimostrombidium brachykinetum Krainer, Tintinnopsis cylindrata Kofoid & Campbell and Cyclidium glaucoma Müller were the dominant species in both estuary (3.1%-12.3% in abundance) and pelagic (4.5%-18.1%) zones, followed by Urotricha farcta Claparède & Lachmann, Codonella cratera Leidy, R. humile Penard, Strombidium mirabile Penard, Tintinnidium pusillum Entz, Vorticella aquadulcis complex and V. campanula Ehrenberg. The abundance of ciliate was higher in the estuary zones than that in the pelagic zones, which fell in the range of 1600 to 80900 cells/L (average 31407 cells/L) and 1225 cells/L to 36000 cells/L (average 18618 cells/L), respectively. The biomass of ciliate showed the same pattern which was 1322.6μg/L and 543.6μg/L on average in the estuary and pelagic zones, respectively. Nei-ther the abundance nor the biomass of ciliates showed significant differences (P>0.05). Among the functional feeding groups, bactivorous and

  9. Seasonal and spatial dynamics of a ciliate assemblage in a warm-monomictic Lake Alchichica (Puebla, Mexico Dinámica temporal y espacial de la comunidad de ciliados en un lago monomíctico-cálido Alchichica (Puebla, México

    Directory of Open Access Journals (Sweden)

    Miroslav Macek

    2008-08-01

    Full Text Available The distribution of the ciliate assemblage was surveyed along a depth gradient in the maar crater, athalassohaline, warm monomictic Lake Alchichica (Puebla, Mexico from June 2003 to October 2006 (monthly. DAPI staining was employed to count ciliates while the Quantitative Protargol Staining was used for their identification. Peritrichs often numerically dominated the ciliate assemblage; a maximum of 54 cells ml-1 (Rhabdostyla sp. was observed in the surface layer at the end of the mixing period, during the development of diatoms (Cyclotella alchichicana, cyanobacterial (Nodularia sp. bloom and its decay. Minute spirotrichs (particularly Halteria grandinella and a haptorid, Belonophrya pelagica occasionally dominated the epilimnion while mixotrophic Euplotes cf. daidaleos and Pelagothrix sp. were important round the oxycline along with haptorids, particularly Phialina sp. Scuticociliates Cyclidium glaucoma, Uronema nigricans, and anaerobic ciliates Isocyclidium globosum and Caenomorpha sp. dominated within the hypolimnetic assemblages.De junio de 2003 a diciembre de 2006 se estudió mensualmente la distribución de la comunidad de ciliados en el gradiente de profundidades del Lago Alchichica (Puebla, México, un lago cráter, tipo maar, atalasohalino de comportamiento monomíctico-cálido. La tinción de DAPI fue empleada para el recuento de los ciliados y la tinción de protargol cuantitativa para su identificación. Frecuentemente los ciliados perítricos dominaron numéricamente la comunidad. Al final del periodo de estratificación y durante el desarrollo de las diatomeas (Cyclotella alchichicana y el florecimiento y posterior decaimiento de las cianobacterias filamentosas (Nodularia sp., se observó un máximo de 54 cél. ml-¹ de Rhabdostyla sp. en la superficie del lago. Los espirotricos pequeños (particularmente Halteria grandinella y los haptóridos como Belonophrya pelagica, dominaron ocasionalmente en el epilimnion, mientras que los

  10. Methylation of histone H3K23 blocks DNA damage in pericentric heterochromatin during meiosis

    Science.gov (United States)

    Papazyan, Romeo; Voronina, Ekaterina; Chapman, Jessica R; Luperchio, Teresa R; Gilbert, Tonya M; Meier, Elizabeth; Mackintosh, Samuel G; Shabanowitz, Jeffrey; Tackett, Alan J; Reddy, Karen L; Coyne, Robert S; Hunt, Donald F; Liu, Yifan; Taverna, Sean D

    2014-01-01

    Despite the well-established role of heterochromatin in protecting chromosomal integrity during meiosis and mitosis, the contribution and extent of heterochromatic histone posttranslational modifications (PTMs) remain poorly defined. Here, we gained novel functional insight about heterochromatic PTMs by analyzing histone H3 purified from the heterochromatic germline micronucleus of the model organism Tetrahymena thermophila. Mass spectrometric sequencing of micronuclear H3 identified H3K23 trimethylation (H3K23me3), a previously uncharacterized PTM. H3K23me3 became particularly enriched during meiotic leptotene and zygotene in germline chromatin of Tetrahymena and C. elegans. Loss of H3K23me3 in Tetrahymena through deletion of the methyltransferase Ezl3p caused mislocalization of meiosis-induced DNA double-strand breaks (DSBs) to heterochromatin, and a decrease in progeny viability. These results show that an evolutionarily conserved developmental pathway regulates H3K23me3 during meiosis, and our studies in Tetrahymena suggest this pathway may function to protect heterochromatin from DSBs. DOI: http://dx.doi.org/10.7554/eLife.02996.001 PMID:25161194

  11. Sex determination: ciliates' self-censorship.

    Science.gov (United States)

    Bloomfield, Gareth

    2014-07-07

    Differentiation involves the expression of certain latent cellular characteristics and the repression of others. A new study has revealed how Paramecium uses short RNAs to delete information from the somatic genome of one of its two sexes.

  12. Ciliates as engineers of phototrophic biofilms

    NARCIS (Netherlands)

    Weerman, Ellen J.; van der Geest, Harm G.; van der Meulen, Myra D.; Manders, Erik M. M.; van de Koppel, Johan; Herman, Peter M. J.; Admiraal, Wim

    2011-01-01

    1. Phototrophic biofilms consist of a matrix of phototrophs, non-photosynthetic bacteria and extracellular polymeric substances (EPS) which is spatially structured. Despite widespread exploitation of algae and bacteria within phototrophic biofilms, for example by protozoans, the 'engineering' effect

  13. Ciliates as engineers of phototrophic biofilms.

    NARCIS (Netherlands)

    Weerman, E.J.; Geest, H.G.; Meulen, M.D.; Manders, E.M.M.; Van de Koppel, J.; Herman, P.M.J.; Admiraal, W.

    2011-01-01

    1.Phototrophic biofilms consist of a matrix of phototrophs, non-photosynthetic bacteria and extracellular polymeric substances (EPS) which is spatially structured. Despite widespread exploitation of algae and bacteria within phototrophic biofilms, for example by protozoans, the ‘engineering’ effects

  14. Ciliates as engineers of phototrophic biofilms.

    NARCIS (Netherlands)

    Weerman, E.J.; van der Geest, H.G.; van der Meulen, M.D; Manders, E.M.M.; van de Koppel, J.; Herman, P.M.J.; Admiraal, W.

    2011-01-01

    1. Phototrophic biofilms consist of a matrix of phototrophs, non-photosynthetic bacteria and extracellular polymeric substances (EPS) which is spatially structured. Despite widespread exploitation of algae and bacteria within phototrophic biofilms, for example by protozoans, the ‘engineering’ effect

  15. Using the Ciliate Protozoan Vorticella in Teaching.

    Science.gov (United States)

    Jones, Alick R.

    1980-01-01

    Describes methods for collection, culture, observation, and making permanent stained preparations of the protozoan vorticella. Suggestions are made for experiments to investigate growth, reproduction, settlement, ecology, feeding, and osmoregulation. (CS)

  16. 甘肃徽县水阳江铅锌污染段纤毛虫群落特征及对水质的评价%Community Characteristics of Ciliates and Water Quality Assessment in the Pb-Zn-Contaminated Section of the Shuiyangjiang River in Huixian County,Gansu Province

    Institute of Scientific and Technical Information of China (English)

    马正学; 贺鹏辉; 杨镇; 宁应之

    2009-01-01

    2006年10月至2008年5月,在甘肃徽县水阳江铅锌污染段选择4个样点,分别在3个水期采集水样,研究了纤毛虫物种多样性及群落结构.共鉴定到纤毛虫52种,隶属于3纲12目29科33属.利用纤毛虫群落特征指标对水阳江铅锌污染段的水质进行了初步评价.综合评价结果显示,4个样点受污染程度为县城>厂区>牟坝>对照,污染级别为中度至重度.初步筛选出瓜形膜袋虫(Cyclidium citrullus)、尾草履虫(Paramoecium caudatum)、薄漫游虫(Litonotus lamella)作为铅锌污染水体的指示物种.%Species diversity and community structure of ciliates in the Pb-Zn-Contaminated section of the Shuiyangjiang River were studied during the period from October 2006 to May 2008,using water samples collected from 4 sampling sites in that section in 3 different periods.In the water samples,52 species of ciliates,sorted into 3 classes,12 orders,29 family and 33 genus,were identified,based on which water quality of that section of the Shuiyangjiang River was preliminarily evaluated.Results show that pollution of the water varied in degree between the four sampling sites in the section,following a decreasing order of Xiancheng>Changqu>Muba>Duizhao,from severe to moderate.Ciliates of Cyclidium citrullus,Paramecium caudatum,and Litonotus lamella were screened out to be indicators of Pb-Zn-contamination of water bodies.

  17. 广东沿海的砂壳纤毛虫及3种国内新纪录%TINTINNID CILIATES FROM COASTAL WATERS OFF GUANGDONG, WITH NOTES ON THREE NEW RECORDS OF CHINA (PROTOZOA, CILIOPHORA)

    Institute of Scientific and Technical Information of China (English)

    张伟; 姜勇; 李继秋; 马洪钢; 许恒龙

    2012-01-01

    Tintinnid ciliates are an important component of plankton communities and widely distribute in the coastal waters. However, in morphological studies, the tintinnids belonged to the poorly known groups, especially in the water of the South China Sea. In the winter of 2008, the tintinnids sampled from the coastal waters in the South China Sea (Guangdong) were investigated. The water temperature was 17-20℃ and the salinity was about 30‰-31‰. Samples were collected by a horizontal tow net from 1.5 m under the water surface. Part of samples were immediately stored in 4℃ for in vivo observation and the others were fixed in formalin at a final concentration of 5% for future observations of lorica characteristics. The morphological characteristics including lorica features were observed and described by using light microscopical method. In this present study, 16 species were indentified and they belonged to Tintinnopsis, Codonella, Stenosemella and Favella. Three of them were believed to be the first records of China, Codonella apicata Kofoid & Campbell, 1929, Tintinnopsis turbo Meunier, 1919 and Stenosemella expansa Wailes, 1925. In addition, another three species were the first records in the semi-tropical and tropical areas of China, Tintinnopsis tubulosoides Meunier, 1910; Tintinnopsis lohmanni (Jorgensen, 1927) Laackmann, 1906, and Codonella rapa Kofoid & Campbell, 1929. The other 10 species included Tintinnopsis beroidea Stein, 1867, Tintinnopsis acuminata (Daday, 1887) Kofoid & Campbell, 1929, Tintinnopsis tocantinensis Kofoid & Campbell, 1929, Tintinnopsis tubulosoides Meunier, 1910, Tintinnopsis tublosa Levander, 1900, Tintinnopsis clongata Daday, 1887, Tintinnopsis lohmanni (Jorgensen, 1927) Laackmann,, 1906, Stenosemella parvicollis (Marshall, 1934) Hada, 1935, Favella campanula (Schmidt, 1901)J(o)rgensen, 1924, and Codonella rapa Kofoid & Campbell, 1929.%对广东沿海的砂壳纤毛虫进行了初步研究,涉及7属16种,其中3种确定为中

  18. Structure-Function Studies Link Class II Viral Fusogens with the Ancestral Gamete Fusion Protein HAP2.

    Science.gov (United States)

    Pinello, Jennifer Fricke; Lai, Alex L; Millet, Jean K; Cassidy-Hanley, Donna; Freed, Jack H; Clark, Theodore G

    2017-03-06

    The conserved transmembrane protein, HAP2/GCS1, has been linked to fertility in a wide range of taxa and is hypothesized to be an ancient gamete fusogen. Using template-based structural homology modeling, we now show that the ectodomain of HAP2 orthologs from Tetrahymena thermophila and other species adopt a protein fold remarkably similar to the dengue virus E glycoprotein and related class II viral fusogens. To test the functional significance of this predicted structure, we developed a flow-cytometry-based assay that measures cytosolic exchange across the conjugation junction to rapidly probe the effects of HAP2 mutations in the Tetrahymena system. Using this assay, alterations to a region in and around a predicted "fusion loop" in T. thermophila HAP2 were found to abrogate membrane pore formation in mating cells. Consistent with this, a synthetic peptide corresponding to the HAP2 fusion loop was found to interact directly with model membranes in a variety of biophysical assays. These results raise interesting questions regarding the evolutionary relationships of class II membrane fusogens and harken back to a long-held argument that eukaryotic sex arose as the byproduct of selection for the horizontal transfer of a "selfish" genetic element from cell to cell via membrane fusion.

  19. Níveis de proteína degradável para novilhas em crescimento sobre a concentração de protozoários ciliados e outros parâmetros ruminais Levels of degradable protein given to heifers for the ciliate protozoa concentration and other ruminal parameters

    Directory of Open Access Journals (Sweden)

    Joaquim Balcells

    2001-05-01

    Full Text Available Em um ensaio de controle de parâmetros ruminais (pH, ritmo de trânsito (%h, volume ruminal (l, e concentração de protozoários ciliados, foram utilizadas quatro novilhas Holstein, canuladas no rúmen e duodeno, recebendo dietas com 4 níveis de proteína degradável, sem suplementar ou suplementadas com 25, 50 e 75 gramos de proteína degradável por quilo de concentrado em forma de uréia e caseína (98,2 e 93,2% de matéria orgânica e proteína bruta, respectivamente. As rações experimentais foram compostas por 25% de palha de cevada sem tratar e 75% de concentrado formulado em base a diferentes proporções (25/75 e 75/25 de milho/cevada, com 5% de resíduo de trigo e 5% de suplemento vitamínico mineral. Uma contínua infusão de marcador de fluxo de fase líquida (Cr-EDTA foi executada. Os oito tratamentos experimentais (2 dietas x 4 níveis de infusão foram administrados em 8 períodos de balanço em um delineamento cross-over, em esquema fatorial. O nível de infusão de N degradável afetou de forma significativa os valores médios ponderados de pH, que decresceram ao aumentar a suplementação (p 3/mL que de cevada (59,5 x 103/mL; p Entodinium alcançou 87,8% da população total. O gênero Epidinium apresentou menores valores com a dieta de cevada (3,73 vs. 1,89x103/mL, p 3/mL, p 5/mL, p In this experiment four Holstein heifers fitted with rumen and duodenum canulae were utilized to evaluate the rumen parameters as pH, passage rate (%/h, volume (L and ciliated protozoa concentration, when fed diets with four levels of rumen degradable protein. This was achieved supplementing 0, 25, 50 or 75 grams of degradable protein per kg of concentrate as a urea and casein (98.2% OM and 93.2% CP. The diets had 25% of barley straw without treatment and 75% concentrate formulated to contain different proportions (25/75 and 75/25 of corn and barley and also 5% of wheat residue and 5% of mineral and vitamin supplement. A continuous infusion of

  20. Abundância de ciliados planctônicos em reservatórios em cascata do rio Paranapanema, Brasil- DOI: 10.4025/actascibiolsci.v26i4.1532 Abundance of planktonic ciliates in a cascading reservoirs of the Paranapanema River, Brazil - DOI: 10.4025/actascibiolsci.v26i4.1532

    Directory of Open Access Journals (Sweden)

    Maysa Cláudia Zolin Perenha

    2004-04-01

    Full Text Available O presente estudo teve como objetivo investigar os padrões de distribuição espacial e temporal da densidade e biomassa dos ciliados planctônicos em reservatórios em cascata do rio Paranapanema (22o 18’ - 23o 35’ S; 49o 30’ - 52o 50’ W. Pretende-se testar a hipótese de que, ao longo da série de reservatórios, observa-se um decréscimo da abundância desses organismos no sentido montante-jusante. Para tal, foram coletadas amostras em sete reservatórios, no ano de 2001, em dois períodos hidrológicos distintos, à sub-superfície da região lacustre, com o auxílio de uma garrafa de Van Dorn de 5 litros. Alíquotas de um litro foram obtidas e sua fixação realizada com solução fixadora composta de lugol alcalino, formol e tiossulfeto de sódio. Os valores obtidos para a abundância (densidade e biomassa de ciliados nos diferentes reservatórios (0,4 a 16,6 células.mL-1; 0,23 a 20,7 µg.C.L-1, respectivamente foram inferiores aos resultados encontrados em ambientes eutróficos, porém similares àqueles registrados em ambientes oligo-mesotróficos. A análise dos resultados de distribuição da abundância ao longo da série de reservatórios não corroborou a hipótese preconizada de uma diminuição de densidade e biomassa no sentido montante-jusante, em função da expectativa de uma possível oligotrofização rio abaixo. Em relação aos diferentes grupos funcionais de ciliados, foi constatada a dominância dos Oligotrichida, principalmente os de menor porte (The present study aimed to investigate the spatial and temporal distribution patterns of density and biomass of the planktonic ciliates, in a reservoir serie of the Paranapanema River (22o 18’ - 23o 35’ S; 49o 30’ - 52o 50’ W. We intend to test the hypothesis that, along reservoirs serie, there is a decrease of abundance from river towards the dam. Samplings were carried out in seven reservoirs, during 2001, in two distinct hydrological periods, at subsurface

  1. A New Method of Sample Preparation for Scanning Electron Microscope Used to Observe the Structure under Pellicle in Ciliates%一种用于观察纤毛虫表膜下结构的扫描电镜样品制备新方法

    Institute of Scientific and Technical Information of China (English)

    高晶; 周围; 乔良; 陈瑛; 邱子健

    2011-01-01

    A new method of observing three-dimensional structure under pellicle of ciliates by scanning electron microscope was established. The suitable concentration of KMnO4 was used to fix cell pellicle. The cell bursts and the cytoplasm overflows in the hypotonic solution by adjusting the osmotic pressure of fixative. Then the pellicle peels off and the inside out. After removing the cytoplasm and dehydration, freeze drying and spraying gold, the structure under pellicle was observed by scanning electron microscope in Climacostomum sp., Parame-cium caudatum and Paraurostyla weissei. The result shows that a clearly and stratified three-dimensional images of structure under pellicle can be observed by this method. It could provide a new way for the study on the pellicle of ciliates and other cell memberanes.%该实验摸索出通过扫描电镜观察纤毛虫表膜下三维结构的新方法:用适当浓度的KMnO4作为固定剂,固定虫体细胞表膜,调整固定液的渗透压使细胞在低渗溶液中胀破,细胞质溶出,表膜剥落下来、内外翻转,经脱水、冷冻干燥、喷金后,在扫描电镜下对爽口虫(Climacostomum sp.)、尾草履虫(Paramecium caudatum)及拟尾柱虫(Paraurostyla weissei)的表膜下结构进行了观察.结果表明:利用此方法能够观察到表膜下层次分明而又清晰的三维立体构象.此方法可为纤毛虫表膜及其它细胞质膜的研究提供可借鉴的样品制备新方法.

  2. Efeito da monensina e do óleo de soja sobre os protozoários ciliados do rúmen e correlação dos protozoários com parâmetros da fermentação ruminal e digestivos Effect of monensin and soybean oil on rumen ciliate protozoa and correlation between protozoa with ruminal fermentation and digestive parameters

    Directory of Open Access Journals (Sweden)

    Isabel Martinele

    2008-06-01

    lactating cows on the counting of ciliate protozoa beyond establishing correlations between number of protozoa with some parameters of digestion and ruminal fermentation. The treatments consisted of the inclusion of 33 ppm of sodium monensin or soybean oil at 4% DM, as following: control diet, without oil or monensin - CT; diet with monensin - MN; diet with soybean oil - OL; diet with the combination of 33 ppm of monensin and 4% of soybean oil - OM. Occurrence of 11 ciliate genera was observed, being Entodinium the predominant in all treatments. No significant soybean oil × monensin interaction was observed on protozoa number and genera. The genera Entodinium, Dasytricha, Eremoplastron and Isotricha reduced in the diets with oil, while monensin reduced the counting of Dasytricha, Eremoplastron and Epidinium. The total number of ciliate protozoa and cellulolytics protozoa was reduced by soybean oil and monensin effects, showing a defaunatory additive effect when combined the oil and the monensin. The ciliate cellulolytics was reduced by linoleic acid intake and was related positively with NDF ruminal digestibility and ruminal ammonia. The total number of protozoa was correlated with the molar proportion of propionate in the ruminal liquid, suggesting that monensin and soybean oil, due their defaunatory effect, can reduce the loss of methane in the rumen.

  3. The structure and function of the eukaryotic ribosome.

    Science.gov (United States)

    Wilson, Daniel N; Doudna Cate, Jamie H

    2012-05-01

    Structures of the bacterial ribosome have provided a framework for understanding universal mechanisms of protein synthesis. However, the eukaryotic ribosome is much larger than it is in bacteria, and its activity is fundamentally different in many key ways. Recent cryo-electron microscopy reconstructions and X-ray crystal structures of eukaryotic ribosomes and ribosomal subunits now provide an unprecedented opportunity to explore mechanisms of eukaryotic translation and its regulation in atomic detail. This review describes the X-ray crystal structures of the Tetrahymena thermophila 40S and 60S subunits and the Saccharomyces cerevisiae 80S ribosome, as well as cryo-electron microscopy reconstructions of translating yeast and plant 80S ribosomes. Mechanistic questions about translation in eukaryotes that will require additional structural insights to be resolved are also presented.

  4. Preliminary study on applicability of microsatellite DNA primers from parasite protozoa Trypanosoma cruzi in free-living protozoa

    Science.gov (United States)

    Zhang, Wenjing; Yu, Yuhe; Shen, Yunfen; Miao, Wei; Feng, Weisong

    2004-04-01

    In this paper, we took the lead in studying on specificity of the microsatellite DNA loci and applicability of microsatellite DNA primers in protozoa. In order to study characters of microsatellites in free-living protozoa, eight microsatellite loci primers developed from Trypanosoma cruzi (MCLE01, SCLE10, MCLE08, SCLE11, MCLF10, MCLG10, MCL03, MCL05) were employed to amplify microsatellite in four free-living protozoa, including Bodo designis, Euglena gracilis FACHB848, Paramecium bruzise and Tetrahymena thermophila BF1. In the amplification systems of P. bruzise, four loci (SCLE10, SCLE11, MCLF10, MCL03) were amplified successfully, and four amplification fragments were in proper size. In genome of E. gracilis FACHB848, five of eight primers brought five clear amplification bands. In B. designis, three (No.4, 5 and 7) of eight loci produced clear and sharp products without stutter bands, whereas no bands appeared in T. thermophila BF1. Further, eight 300 500 bp amplification fragments were cloned and sequenced. Nevertheless, all sequenced products did not contain corresponding microsatellite sequence, although Bodo is in the same order and has the nearest phylogenetic relation with Trypanosoma among these four species. Thus, the microsatellite DNA primers can not be applied among order or more far taxa, and the specificity of microsatellite DNA is very high in protozoa. The results of this study will contribute to our understanding of microsatellite DNA in protozoa.

  5. Preliminary Study on Applicability of Microsatellite DNA Primers from Parasite Protozoa Trypanosoma cruzi in Free-living Protozoa

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wenjing; YU Yuhe; SHEN Yunfen; MIAO Wei; FENG Weisong

    2004-01-01

    In this paper, we took the lead in studying on specificity of the microsatellite DNA loci and applicability of microsatellite DNA primers in protozoa. In order to study characters of microsatellites in free-living protozoa, eight microsatellite loci primers developed from Trypanosoma cruzi (MCLE01, SCLE10, MCLE08, SCLE11, MCLF10, MCLG10,MCL03, MCL05) were employed to amplify microsatellite in four free-living protozoa, including Bodo designis, Euglena gracilis FACHB848, Paramecium bruzise and Tetrahymena thermophila BF1. In the amplification systems of P. bruzise, four loci (SCLE10, SCLE1 1, MCLF10, MCL03) were amplified successfully, and four amplification fragments were in proper size. In genome of E. gracilis FACHB848, five of eight primers brought five clear amplification bands. In B. designis, three (No.4, 5 and 7) of eight loci produced clear and sharp products without stutter bands, whereas no bands appeared in T.thermophila BF1. Further, eight 300-500bp amplification fragments were cloned and sequenced. Nevertheless, all sequenced products did not contain corresponding microsatellite sequence, although Bodo is in the same order and has the nearest phylogenetic relation with Trypanosoma among these four species. Thus, the microsatellite DNA primers can not be applied among order or more far taxa, and the specificity of microsatellite DNA is very high in protozoa. The results of this study will contribute to our understanding of microsatellite DNA in protozoa.

  6. The nonhistone, N-terminal tail of an essential, chimeric H2A variant regulates mitotic H3-S10 dephosphorylation.

    Science.gov (United States)

    Song, Xiaoyuan; Bowen, Josephine; Miao, Wei; Liu, Yifan; Gorovsky, Martin A

    2012-03-15

    H2A.Y is an essential, divergent Tetrahymena thermophila histone variant. It has a long nonhistone N terminus that contains leucine-rich repeats (LRR) and an LRR cap domain with similarity to Sds22p, a regulator of yeast protein phosphatase 1 (PP1) activity in the nucleus. In growing cells, H2A.Y is incorporated into micronuclei only during S phase, which occurs immediately after micronuclear mitosis. Depletion of H2A.Y causes prolonged retention of mitosis-associated histone H3-S10 phosphorylation and mitotic abnormalities that mimic S10E mutation. In cells where H2A.Y is depleted, an inducible chimeric gene, in which the H2A.Y N terminus is attached to H2A.X, is shown to regulate micronuclear H3-S10 phosphorylation. H2A.Y can also be specifically coimmunoprecipitated with a Tetrahymena PP1 ortholog (Ppo1p). Taken together, these results argue that the N terminus of H2A.Y functions to regulate H3-S10 dephosphorylation. This striking in vivo case of "cross-talk" between a H2A variant and a specific post-translational modification of another histone demonstrates a novel function for a histone variant.

  7. Act together - implications of symbioses in aquatic ciliates

    DEFF Research Database (Denmark)

    Dziallas, Claudia; Allgaier, Martin; Monaghan, Michael T.;

    2012-01-01

    are globally distributed and have been intensively studied in the context of plastid evolution. Their relatively large cell size offers an ideal habitat for numerous microorganisms with different functional traits including commensalism and parasitism. Phagocytosis facilitates the formation of symbiotic...... relationships, particularly since some ingested microorganisms can escape the digestion. For example, photoautotrophic algae and methanogens represent endosymbionts that greatly extend the biogeochemical functions of their hosts. Consequently, symbiotic relationships between protists and prokaryotes...

  8. Stomatogenesis in the ditransversal ciliate Homalozoon vermiculare (Ciliophora, Rhabdophora).

    Science.gov (United States)

    Leipe, D D; Oppelt, A; Hausmann, K; Foissner, W

    1992-05-22

    H. vermiculare possesses about 10 somatic kineties on the right lateral side, 3 somatic kineties on the left lateral side and a single circumoral kinety. The somatic kineties are composed of monokinetids exc\\~ept for the anterior ends of the brush kineties which are composed of dikinetids. The circumoral kinety consists of paired kinetosomes one of which is nonciliated and associated with a microtubular lamella and a nematodesma. Stomatogenesis commences when the anteriormost somatic kinetosomes in the opisthe are transformed into the nonciliated kinetosomes of the future oral dikinetid. They lose the somatic infraciliary fibers and the ciliary shaft and each gives rise to a nematodesma and a microtubular ribbon. Adjacent to each of the transformed somatic kinetosomes, a new kinetosome is assembled, thus producing an oral dikinetid anlage. The new anterior kinetosome bears a cilium and becomes the ciliferous kinetosome of the oral wreath of cilia. In protargol stained specimens, proliferation of kinetosomes can first be observed in the left lateral kineties but, eventually, each of the somatic kineties produces one kinetofragment. Thus, H. vermiculare has a holotelokinetal type of stomatogenesis. The cirumoral kinety arises from a counter-clockwise rotation (as viewed from outside the cell) of all 15 dikinetid kinetofragments and subsequent "head to tail" fusion of the fragments after cell division has been completed. The oral apparatus of the proter seems to be largely conserved during division. Some aspects of the evolution of the oral apparatus and the origin of the oral microtubular ribbons are discussed.

  9. Unsteady feeding and optimal strokes of model ciliates

    CERN Document Server

    Michelin, Sebastien

    2012-01-01

    The flow field created by swimming microorganisms not only enables their locomotion but also leads to advective transport of nutrients. In this paper we address analytically and computationally the link between unsteady feeding and unsteady swimming on a model microorganism, the spherical squirmer, actuating the fluid in a time-periodic manner. We start by performing asymptotic calculations at low P\\'eclet number (Pe) on the advection-diffusion problem for the nutrients. We show that the mean rate of feeding as well as its fluctuations in time depend only on the swimming modes of the squirmer up to order Pe^(3/2), even when no swimming occurs on average, while the influence of non-swimming modes comes in only at order Pe^2. We also show that generically we expect a phase delay between feeding and swimming of 1/8th of a period. Numerical computations for illustrative strokes at finite Pe confirm quantitatively our analytical results linking swimming and feeding. We finally derive, and use, an adjoint-based opt...

  10. A new peritrichous Ciliate as a symphoriont on a Tardigrade

    NARCIS (Netherlands)

    Land, van der J.

    1964-01-01

    INTRODUCTION On 24 September 1962 a number of Tardigrada was obtained from a sample of lichens from the French Alps. The lichens had been collected Figs. 1, 2. Pyxidium tardigradum n. sp. on Hypsibius oberhaeuseri (Doy.). on 27 June 1961 from a rock in the department Haute Savoie and had been preser

  11. Effects of irradiation on the peritrich ciliates Vorticella and Telotrochidium

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, W.W.

    1976-07-01

    Vorticella microstoma and Telotrochidium henneguyi were exposed to doses of x- and gamma-radiation ranging from 46 r to 120 Kr. Irradiation was applied to freshly excysted motile organisms. Doses below 2 Kr did not induce noticeable morphological effects in either peritrich. Doses between 2 and 5 Kr induced Pellicular blisters in Vorticella but to a very limited extent; the blisters were more prevalent 12 hr post-irradiation. Pellicular blisters were not induced in Telotrochidium, regardless of the dose. A 30 Kr dose caused both peritrichs to become more rounded than the control animals. Doses above 2 Kr altered the normal life cycle of both peritrichs as follows. The post-excystment binary fission stage was extended beyond the normal 18 yr. Post-excystment conjugation occurred later than the usual 18 to 36 hr period. A 38 Kr dose depressed Vorticella's population growth curve during the first 24 hr after irradiation, but recovery and growth was almost complete between 24 to 48 hr post-irradiation. A 57 Kr dose also depressed the population growth curve during the 24 hr following irradiation, but recovery to near normal did not occur until 60 hr post-irradiation. Telotrochidium's response was different and inconsistent in comparison with Vorticella's response. In some experiments only 10% of the Telotrochidium population survived a single 38 Kr dose and growth occurred. Likewise, 57 Kr gave inconsistent results in that it was lethal to the total population in some experiments but merely retarded growth and recovery of the total population in other experiments.

  12. Persistent disruption of ciliated epithelium following paediatric lung transplantation.

    Science.gov (United States)

    Thomas, Biju; Aurora, Paul; Spencer, Helen; Elliott, Martin; Rutman, Andrew; Hirst, Robert A; O'Callaghan, Christopher

    2012-11-01

    It is unclear whether ciliary function following lung transplantation is normal or not. Our aim was to study the ciliary function and ultrastructure of epithelium above and below the airway anastomosis and the peripheral airway of children following lung transplantation. We studied the ciliary beat frequency (CBF) and beat pattern, using high speed digital video imaging and ultrastructure by transmission electron microscopy, of bronchial epithelium from above and below the airway anastomosis and the peripheral airway of 10 cystic fibrosis (CF) and 10 non-suppurative lung disease (NSLD) paediatric lung transplant recipients. Compared to epithelium below the anastomosis, the epithelium above the anastomosis in the CF group showed reduced CBF (median (interquartile range): 10.5 (9.0-11.4) Hz versus 7.4 (6.4-9.2) Hz; pepithelium above the anastomosis, the epithelium below the anastomosis showed marked ultrastructural abnormalities (median duration post-transplant 7-12 months). Ciliary dysfunction is a feature of native airway epithelium in paediatric CF lung transplant recipients. The epithelium below the airway anastomosis shows profound ultrastructural abnormalities in both CF and NSLD lung transplant recipients, many months after transplantation.

  13. Effect of an energy-deficient diet on populations of ciliate protozoans in bovine rumen Efeito da deficiência de energia na dieta sobre a população de protozoários ciliados do rúmen de bovinos

    Directory of Open Access Journals (Sweden)

    P.C. Soares

    2008-02-01

    Full Text Available Ten young rumen-cannulated crossbred steers were randomly divided into two groups: a control group (C; n=4, which was fed a balanced diet for daily weight gain of 900g; and a pronounced energy-deprived group (PED; n=6, receiving 30% less of the required energy for maintenance. After 140 days of these alimentary regimes, rumen fluid and urine samples were collected for biochemical and functional tests, before feeding and at 1, 3, 6, and 9 hours after feeding. The energy-deprivation diet caused a significant reduction in the number of Entodinium, Eodinium, Isotricha, Dasytricha, Eremoplastron, Eudiplodinium, Metadinium, Charonina, Ostracodinium, and Epidinium protozoa. There was no effect of the time of sampling in both groups on the total number of ciliates in rumen fluid. A higher number of protozoan forms in binary division were recorded in the control group, at the 6th and 9th hours after feeding (PForam utilizados 10 novilhos mestiços com cânula ruminal, distribuídos em dois grupos: no grupo controle (C; n=4 receberam dieta balanceada para ganho diário de 900g; no grupo tratado com carência pronunciada de energia (CP; n=6, receberam dieta com 30% a menos do nível de mantença em energia. Após 140 dias sob esses regimes de alimentação, foram coletadas amostras do fluido ruminal e urina, para realização de provas bioquímicas e funcionais, antes e às 1, 3, 6 e 9 horas após o fornecimento do alimento. A carência energética resultou em diminuição significativa na quantidade dos protozoários Entodinium, Eodinium, Isotricha, Dasytricha, Eremoplastron, Eudiplodinium, Metadinium, Charonina, Ostracodinium e Epidinium. Não houve efeito da hora de coleta sobre o total de ciliados nos grupos C e CP. Maior número de formas em divisão binária foi registrado no grupo C, na sexta e nona horas pós-alimentação (P<0,019. Observaram-se altas correlações positivas entre a contagem total de protozoários e a fermentação de glicose, am

  14. Protozoan colonization on artificial substrates in relation to water quality in a tropical Indian harbour

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A field study was conducted to evaluate the protozoancolonization patterns on artificial substrates in relation to organic pollution within a tropical harbour. The composition of protozoans and their succession rates on artificial substrates(polyurethane foam units) were compared between two field stations(A and B), and their presence were considered with regards to the prevailing water quality conditions at the study sites. Altogether 44 genera of flagellates and ciliates were documented. The common genera of flagellates and ciliates were documented. The common genera of flagellates encountered included Monas, Polytoma,and Chromalina. Among the ciliates, the predominant genera were Tetrahymena, Vorticella, Lagynophyra, and Heloiphyra. These groups exhibited characteristic successional patterns in relation to ambient water quality. At Station A, located close to the sewage outfall, the water quality parameters included poor Secchi-disc transparency(0.48m), dissolved oxygen of 1.93 mg/ml, salinity of 18 psu, and temperature 31.3 鳦. Here, thenanoflagellates(spumella)colonized first, followed by microcilliate(Tetrahymena) and sessile form(Vorticella). Station B, located on the seaward side, was characterized by relatively less-stressed environmental conditions with transparency 1.85m and dissolved oxygen value of 6.04 mg/ml. Salinity of 27.27 psu, and mean temperature of 30鳦 were recordedat "B". At this station, the nanoflagellate Polytoma was first documented to colonize on the substrate, followed by microcilliate(Lagynophra) and suctorid(Heliophyra). These findings support the use of protozoans as indicator species for evaluating the hazards posed by organic pollution to natural estuarine communities.

  15. Ecological impacts of environmental toxicants and radiation on the microbial ecosystem: a model simulation of computational microbiology

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Masahiro; Sakashita, Tetsuya; Ishii, Nobuyoshi; Fuma, Shoichi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, K.; Nakamura, Yuji [National Institute of Radiological Sciences, Inage, Chiba (Japan); Kawabata, Zenichiro [Center for Ecological Research, Kyoto Univ., Otsu, Shiga (Japan)

    2000-05-01

    This study explores a microorganic closed-ecosystem by computer simulation to illustrate symbiosis among populations in the microcosm that consists of heterotroph protozoa, Tetrahymena thermophila B as a consumer, autotroph algae, Euglena gracilis Z as a primary producer and saprotroph Bacteria, Escherichia coli DH5 as decomposer. The simulation program is written as a procedure of StarLogoT1.5.1, which is developed by Center for Connected Learning and Computer-Based Modeling, Tufts University. The virtual microcosm is structured and operated by the following rules; (1) Environment is defined as a lattice model, which consists of 10,201 square patches, 300 micron Wide, 300 micron Length and 100 micron Hight. (2) Each patch has its own attributes, Nutrient, Detritus and absolute coordinates, (3) Components of the species, Tetrahymena, Euglena and E-coli are defined as sub-system, and each sub-system has its own attributes as location, heading direction, cell-age, structured biomass, reserves energy and demographic parameters (assimilation rate, breeding threshold, growth rate, etc.). (4) Each component of the species, Tetrahymena, Euglena and E-coli, lives by foraging (Tetrahymena eats E-coli), excreting its metabolic products to the environment (as a substrate of E-coli), breeding and dying according vital condition. (5) Euglena utilizes sunlight energy by photosynthesis process and produces organic compounds. E-coli breaks down the organic compounds of dead protoplasm or metabolic wastes (Detritus) and releases inorganic substances to construct down stream of food cycle. Virtual ecosystem in this study is named SIM-COSM, a parallel computing model for self-sustaining system of complexity. It found that SIM-COSM is a valuable to illustrate symbiosis among populations in the microcosm, where a feedback mechanism acts in response to disturbances and interactions among species and environment. In the simulation, microbes increased demographic and environmental

  16. Transposon Invasion of the Paramecium Germline Genome Countered by a Domesticated PiggyBac Transposase and the NHEJ Pathway

    Directory of Open Access Journals (Sweden)

    Emeline Dubois

    2012-01-01

    Full Text Available Sequences related to transposons constitute a large fraction of extant genomes, but insertions within coding sequences have generally not been tolerated during evolution. Thanks to their unique nuclear dimorphism and to their original mechanism of programmed DNA elimination from their somatic nucleus (macronucleus, ciliates are emerging model organisms for the study of the impact of transposable elements on genomes. The germline genome of the ciliate Paramecium, located in its micronucleus, contains thousands of short intervening sequences, the IESs, which interrupt 47% of genes. Recent data provided support to the hypothesis that an evolutionary link exists between Paramecium IESs and Tc1/mariner transposons. During development of the macronucleus, IESs are excised precisely thanks to the coordinated action of PiggyMac, a domesticated piggyBac transposase, and of the NHEJ double-strand break repair pathway. A PiggyMac homolog is also required for developmentally programmed DNA elimination in another ciliate, Tetrahymena. Here, we present an overview of the life cycle of these unicellular eukaryotes and of the developmentally programmed genome rearrangements that take place at each sexual cycle. We discuss how ancient domestication of a piggyBac transposase might have allowed Tc1/mariner elements to spread throughout the germline genome of Paramecium, without strong counterselection against insertion within genes.

  17. Study of cilia assembly in Tetrahymena and the role of cytosolic chaperonin CCT

    OpenAIRE

    Seixas, Ana Cecília Fernandes, 1974-

    2008-01-01

    Tese de doutoramento em Biologia (Biologia Molecular), apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2008 Os cílios são organelos conservados evolutivamente que são requeridos num vasto número de processos celulares tais como locomoção, quimiotaxia, movimento de fluídos e transdução de sinais. Nos últimos anos, um grande número de publicações tem demonstrado o impacto que pequenas alterações no correcto funcionamento dos cílios tem no Homem. Várias doenças humanas ...

  18. Comparative use of bacterial, algal and protozoan tests to study toxicity of azo- and anthraquinone dyes.

    Science.gov (United States)

    Novotný, Cenek; Dias, Nicolina; Kapanen, Anu; Malachová, Katerina; Vándrovcová, Marta; Itävaara, Merja; Lima, Nelson

    2006-06-01

    Toxicity of two azo dyes (Reactive Orange 16 (RO16); Congo Red (CR)) and two anthraquinone dyes (Remazol Brilliant Blue R (RBBR); Disperse Blue 3 (DB3)) were compared using bacterium Vibrio fischeri, microalga Selenastrum capricornutum and ciliate Tetrahymena pyriformis. The following respective endpoints were involved: acute toxicity measured as bacterial luminescence inhibition, algal growth inhibition, and the effects on the protozoa including viability, growth inhibition, grazing effect and morphometric effects. In addition, mutagenicity of the dyes was determined using Ames test with bacterium Salmonella typhimurium His(-). DB3 dye was the most toxic of all dyes in the bacterial, algal and protozoan tests. In contrast to other dyes, DB3 exhibited mutagenic effects after metabolic activation in vitro in all S. typhimurium strains used. Of the methods applied, the algal test was the most sensitive to evaluate toxicity of the dyes tested.

  19. The nuclear pore complex acts as a master switch for nuclear and cell differentiation

    Science.gov (United States)

    Iwamoto, Masaaki; Hiraoka, Yasushi; Haraguchi, Tokuko

    2015-01-01

    Cell differentiation is associated with the functional differentiation of the nucleus, in which alteration of the expression profiles of transcription factors occurs to destine cell fate. Nuclear transport machineries, such as importin-α, have also been reported as critical factors that induce cell differentiation. Using various fluorescence live cell imaging methods, including time-lapse imaging, FRAP analysis and live-cell imaging associated correlative light and electron microscopy (Live CLEM) of Tetrahymena, a unicellular ciliated protozoan, we have recently discovered that type switching of the NPC is the earliest detectable event of nuclear differentiation. Our studies suggest that this type switching of the NPC directs the fate of the nucleus to differentiate into either a macronucleus or a micronucleus. Our findings in this organism may provide new insights into the role of the NPC in controlling nuclear functions in general in eukaryotes, including controlling cell fate leading to cell differentiation in multicellular metazoa. PMID:26479399

  20. Impacts of radiation exposure on the experimental microbial ecosystem: a particle-based model simulation approach

    Energy Technology Data Exchange (ETDEWEB)

    Doi, M.; Tanaka, N.; Fuma, S.; Kawabata, Z.

    2004-07-01

    Well-designed experimental model ecosystem could be a simple reference of the actual environment and complex ecological systems. For ecological toxicity test of radiation and other environmental toxicants, we investigated and aquatic microbial ecosystem (closed microcosm) in the test tube with initial substrates,autotroph flagellate algae (Euglena, G.), heterotroph ciliate protozoa (Tetrahymena T.) and saprotroph bacteria (E, coli). These species organizes by itself to construct the ecological system, that keeps the sustainable population dynamics for more than 2 years after inoculation only by adding light diurnally and controlling temperature at 25 degree Celsius. Objective of the study is to develop the particle-based computer simulation by reviewing interactions among microbes and environment, and analyze the ecological toxicities of radiation on the microcosm by replicating experimental results in the computer simulation. (Author) 14 refs.

  1. Taxonomy, distribution and prevalence of parasites of tigerfish, Hydrocynus vittatus (Castelnau, 1861) in the Sanyati basin, Lake Kariba, Zimbabwe.

    Science.gov (United States)

    Mabika, Nyasha; Barson, Maxwell; Van Dyk, Cobus; Avenant-Oldewage, Annemariè

    2016-09-01

    Parasites of the tigerfish (Hydrocynus vittatus) were investigated in the period October 2014 to July 2015 in the Sanyati Basin, Lake Kariba. The fish were collected using seine netting and also during the annual Kariba International Tiger Fishing Tournament. A total of 80 fish specimens (24 males and 56 females) were collected and were infected with the following seven parasite taxa: Monogenea (Annulotrema sp.1 from the gills and Annulotrema sp.2 from the skin), Nematoda (Contracaecum larvae), Cestoda (bothriocephalid, larval cyclophyllid), Copepoda (Lamproglena hemprichii), pentastomid, Myxosporea (Myxobolus sp.,) and unicellular ciliate parasites (Trichodina sp., Tetrahymena sp., and unidentified). Annulotrema sp. 1 was observed in all fish and had the highest prevalence, mean intensity and abundance. The fish organs infected were gills, skin, fin, body cavity, stomach, intestines, mesentery, liver, kidney, brain cavity and swim bladder. No parasites were observed in the muscle, eyes and blood. The distribution of the parasites was highest in the gills and lowest in the brain cavity and swimbladder. Bothriocephalids, pentastomes and Trichodina sp. were not observed in male fish. Sex was not related to the intensity of parasites. The results of the study showed that H. vittatus has a richer parasite community than other previous investigated alestids. Pentastomes, Myxobolus sp., Trichodina sp., Tetrahymena sp. and bothriocephalid cestodes are new records for H. vittatus in Zimbabwe.

  2. Hormonal actions in the Protozoan stress: A review.

    Science.gov (United States)

    Csaba, György

    2015-12-01

    In the higher ranked animals the alteration of the environment can provoke a uniform reaction named general adaptation system (GAS), which is a manifestation of stress, caused by different stressors. During GAS certain organs show typical reactions and two members of the hormonal system are activated: epinephine and glucocorticoids. As the unicellular ciliate Tetrahymena also synthesize most of the mammalian-like hormones (except steroids), it can respond to stress by a hormonal reaction. The main differences, related to the mammalian GAS hormonal reaction are, that 1) in Tetrahymena the level of all of the hormones studied significantly elevates under the effect of heat, osmotic or chemical stress and 2) the single stress effect is durable. It is manifested at least to the 100th generations, which means that it is inherited epigenetically. Not only hormone synthesis but the receptorial hormone binding is also elevated, which means that the whole hormonal system is activated. The stress reaction (GAS) phylogenetically can be deduced to a unicellular (Protozoan) level however, prokaryotes - which are also stress-reactive - are using another mechanisms.

  3. Separation of Bacteria, Protozoa and Carbon Nanotubes by Density Gradient Centrifugation

    Directory of Open Access Journals (Sweden)

    Monika Mortimer

    2016-10-01

    Full Text Available Sustainable production and use of carbon nanotube (CNT-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa from unbound multiwall carbon nanotubes (MWCNTs and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstrate separation of protozoa (Tetrahymena thermophila from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. The optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation.

  4. Separation of Bacteria, Protozoa and Carbon Nanotubes by Density Gradient Centrifugation

    Science.gov (United States)

    Mortimer, Monika; Petersen, Elijah J.; Buchholz, Bruce A.; Holden, Patricia A.

    2016-01-01

    Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstrate separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. The optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation. PMID:27917301

  5. Distinct Contribution of Electrostatics, Initial Conformational Ensemble, and Macromolecular Stability in RNA Folding

    Energy Technology Data Exchange (ETDEWEB)

    Laederach,A.; Shcherbakova, I.; Jonikas, M.; Altman, R.; Brenowitz, M.

    2007-01-01

    We distinguish the contribution of the electrostatic environment, initial conformational ensemble, and macromolecular stability on the folding mechanism of a large RNA using a combination of time-resolved 'Fast Fenton' hydroxyl radical footprinting and exhaustive kinetic modeling. This integrated approach allows us to define the folding landscape of the L-21 Tetrahymena thermophila group I intron structurally and kinetically from its earliest steps with unprecedented accuracy. Distinct parallel pathways leading the RNA to its native form upon its Mg2+-induced folding are observed. The structures of the intermediates populating the pathways are not affected by variation of the concentration and type of background monovalent ions (electrostatic environment) but are altered by a mutation that destabilizes one domain of the ribozyme. Experiments starting from different conformational ensembles but folding under identical conditions show that whereas the electrostatic environment modulates molecular flux through different pathways, the initial conformational ensemble determines the partitioning of the flux. This study showcases a robust approach for the development of kinetic models from collections of local structural probes.

  6. Life history trade-offs and relaxed selection can decrease bacterial virulence in environmental reservoirs.

    Science.gov (United States)

    Mikonranta, Lauri; Friman, Ville-Petri; Laakso, Jouni

    2012-01-01

    Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we measured changes in bacterial traits related to both anti-predator defence and virulence. We found that anti-predator adaptation (producing predator-resistant biofilm) caused a correlative attenuation in virulence. Even though the direct mechanism was not found, reduction in virulence was most clearly connected to a predator-driven loss of a red bacterial pigment, prodigiosin. Moreover, life-history trait evolution was more divergent among replicate populations in the absence of predation, leading also to lowered virulence in some of the 'predator absent' selection lines. Together these findings suggest that the virulence of non-obligatory, opportunistic bacterial pathogens can decrease in environmental reservoirs through life history trade-offs, or random accumulation of mutations that impair virulence traits under relaxed selection.

  7. Mapping the kinetic barriers of a Large RNA molecule's folding landscape.

    Directory of Open Access Journals (Sweden)

    Jörg C Schlatterer

    Full Text Available The folding of linear polymers into discrete three-dimensional structures is often required for biological function. The formation of long-lived intermediates is a hallmark of the folding of large RNA molecules due to the ruggedness of their energy landscapes. The precise thermodynamic nature of the barriers (whether enthalpic or entropic that leads to intermediate formation is still poorly characterized in large structured RNA molecules. A classic approach to analyzing kinetic barriers are temperature dependent studies analyzed with Eyring's transition state theory. We applied Eyring's theory to time-resolved hydroxyl radical (•OH footprinting kinetics progress curves collected at eight temperature from 21.5 °C to 51 °C to characterize the thermodynamic nature of folding intermediate formation for the Mg(2+-mediated folding of the Tetrahymena thermophila group I ribozyme. A common kinetic model configuration describes this RNA folding reaction over the entire temperature range studied consisting of primary (fast transitions to misfolded intermediates followed by much slower secondary transitions, consistent with previous studies. Eyring analysis reveals that the primary transitions are moderate in magnitude and primarily enthalpic in nature. In contrast, the secondary transitions are daunting in magnitude and entropic in nature. The entropic character of the secondary transitions is consistent with structural rearrangement of the intermediate species to the final folded form. This segregation of kinetic control reveals distinctly different molecular mechanisms during the two stages of RNA folding and documents the importance of entropic barriers to defining rugged RNA folding landscapes.

  8. Pulsed-resource dynamics increase the asymmetry of antagonistic coevolution between a predatory protist and a prey bacterium.

    Science.gov (United States)

    Friman, V-P; Laakso, J; Koivu-Orava, M; Hiltunen, T

    2011-12-01

    Temporal resource fluctuations could affect the strength of antagonistic coevolution through population dynamics and costs of adaptation. We studied this by coevolving the prey bacterium Serratia marcescens with the predatory protozoa Tetrahymena thermophila in constant and pulsed-resource environments for approximately 1300 prey generations. Consistent with arms race theory, the prey evolved to be more defended, whereas the predator evolved to be more efficient in consuming the bacteria. Coevolutionary adaptations were costly in terms of reduced prey growth in resource-limited conditions and less efficient predator growth on nonliving resource medium. However, no differences in mean coevolutionary changes or adaptive costs were observed between environments, even though resource pulses increased fluctuations and mean densities of coevolving predator populations. Interestingly, a surface-associated prey defence mechanism (bacterial biofilm), to which predators were probably unable to counter-adapt, evolved to be stronger in pulsed-resource environment. These results suggest that temporal resource fluctuations can increase the asymmetry of antagonistic coevolution by imposing stronger selection on one of the interacting species.

  9. Pseudomonas aeruginosa adaptation to lungs of cystic fibrosis patients leads to lowered resistance to phage and protist enemies.

    Directory of Open Access Journals (Sweden)

    Ville-Petri Friman

    Full Text Available Pathogenic life styles can lead to highly specialized interactions with host species, potentially resulting in fitness trade-offs in other ecological contexts. Here we studied how adaptation of the environmentally transmitted bacterial pathogen, Pseudomonas aeruginosa, to cystic fibrosis (CF patients affects its survival in the presence of natural phage (14/1, ΦKZ, PNM and PT7 and protist (Tetrahymena thermophila and Acanthamoebae polyphaga enemies. We found that most of the bacteria isolated from relatively recently intermittently colonised patients (1-25 months, were innately phage-resistant and highly toxic for protists. In contrast, bacteria isolated from long time chronically infected patients (2-23 years, were less efficient in both resisting phages and killing protists. Moreover, chronic isolates showed reduced killing of wax moth larvae (Galleria mellonella probably due to weaker in vitro growth and protease expression. These results suggest that P. aeruginosa long-term adaptation to CF-lungs could trade off with its survival in aquatic environmental reservoirs in the presence of microbial enemies, while lowered virulence could reduce pathogen opportunities to infect insect vectors; factors that are both likely to result in poorer environmental transmission. From an applied perspective, phage therapy could be useful against chronic P. aeruginosa lung infections that are often characterized by multidrug resistance: chronic isolates were least resistant to phages and their poor growth will likely slow down the emergence of beneficial resistance mutations.

  10. Phylogenetic Analysis of Peritrichs Inferred from Cytosolic Hsp70 Gene Partial Sequences%两种缘毛类纤毛虫胞质Hsp70基因序列的克隆及其系统发育分析

    Institute of Scientific and Technical Information of China (English)

    傅诚杰; 缪炜; 沈韫芬; 万明亮

    2004-01-01

    克隆得到2种缘毛类纤毛虫--钟形钟虫(Vorticella campanula)和螅状独缩虫(Carchesium polypinum)的胞质Hsp70基因部分序列,长度均为438 bp,编码146个氨基酸.以细菌为外类群,利用最大似然法和邻接法构建包括其他5种纤毛虫在内的共26个物种的Hsp70基因氨基酸序列系统发育树,其拓扑结构显示:V.campanula和C.polypinum聚在一起,并与另2种寡膜纲的嗜热四膜虫(Tetrahymena thermophila)及草履虫(Paramecium tetraurelia)聚为姊妹枝,提示了缘毛类纤毛虫为单系,且隶属于寡膜纲的系统发育地位.

  11. Life history trade-offs and relaxed selection can decrease bacterial virulence in environmental reservoirs.

    Directory of Open Access Journals (Sweden)

    Lauri Mikonranta

    Full Text Available Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we measured changes in bacterial traits related to both anti-predator defence and virulence. We found that anti-predator adaptation (producing predator-resistant biofilm caused a correlative attenuation in virulence. Even though the direct mechanism was not found, reduction in virulence was most clearly connected to a predator-driven loss of a red bacterial pigment, prodigiosin. Moreover, life-history trait evolution was more divergent among replicate populations in the absence of predation, leading also to lowered virulence in some of the 'predator absent' selection lines. Together these findings suggest that the virulence of non-obligatory, opportunistic bacterial pathogens can decrease in environmental reservoirs through life history trade-offs, or random accumulation of mutations that impair virulence traits under relaxed selection.

  12. Ecotoxicity of nanoparticles of CuO and ZnO in natural water

    Energy Technology Data Exchange (ETDEWEB)

    Blinova, I., E-mail: irina.blinova@kbfi.e [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Ivask, A. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Heinlaan, M. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Estonian University of Life Sciences, Kreutzwaldi 5, Tartu 51014 (Estonia); Mortimer, M. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia); Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618 (Estonia); Kahru, A. [Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618 (Estonia)

    2010-01-15

    The acute toxicity of CuO and ZnO nanoparticles in artificial freshwater (AFW) and in natural waters to crustaceans Daphnia magna and Thamnocephalus platyurus and protozoan Tetrahymena thermophila was compared. The L(E)C{sub 50} values of nanoCuO for both crustaceans in natural water ranged from 90 to 224 mg Cu/l and were about 10-fold lower than L(E)C{sub 50} values of bulk CuO. In all test media, the L(E)C{sub 50} values for both bulk and nanoZnO (1.1-16 mg Zn/l) were considerably lower than those of nanoCuO. The natural waters remarkably (up to 140-fold) decreased the toxicity of nanoCuO (but not that of nanoZnO) to crustaceans depending mainly on the concentration of dissolved organic carbon (DOC). The toxicity of both nanoCuO and nanoZnO was mostly due to the solubilised ions as determined by specific metal-sensing bacteria. - Natural waters remarkably reduced the toxicity of nanoCuO but not nanoZnO.

  13. Pseudomonas aeruginosa adaptation to lungs of cystic fibrosis patients leads to lowered resistance to phage and protist enemies.

    Science.gov (United States)

    Friman, Ville-Petri; Ghoul, Melanie; Molin, Søren; Johansen, Helle Krogh; Buckling, Angus

    2013-01-01

    Pathogenic life styles can lead to highly specialized interactions with host species, potentially resulting in fitness trade-offs in other ecological contexts. Here we studied how adaptation of the environmentally transmitted bacterial pathogen, Pseudomonas aeruginosa, to cystic fibrosis (CF) patients affects its survival in the presence of natural phage (14/1, ΦKZ, PNM and PT7) and protist (Tetrahymena thermophila and Acanthamoebae polyphaga) enemies. We found that most of the bacteria isolated from relatively recently intermittently colonised patients (1-25 months), were innately phage-resistant and highly toxic for protists. In contrast, bacteria isolated from long time chronically infected patients (2-23 years), were less efficient in both resisting phages and killing protists. Moreover, chronic isolates showed reduced killing of wax moth larvae (Galleria mellonella) probably due to weaker in vitro growth and protease expression. These results suggest that P. aeruginosa long-term adaptation to CF-lungs could trade off with its survival in aquatic environmental reservoirs in the presence of microbial enemies, while lowered virulence could reduce pathogen opportunities to infect insect vectors; factors that are both likely to result in poorer environmental transmission. From an applied perspective, phage therapy could be useful against chronic P. aeruginosa lung infections that are often characterized by multidrug resistance: chronic isolates were least resistant to phages and their poor growth will likely slow down the emergence of beneficial resistance mutations.

  14. Paramecium aurelia revisited.

    Science.gov (United States)

    Coleman, A W

    2005-01-01

    The species Paramecium aurelia sensu latu, containing 15 sexually isolated subspecies (syngens), is the classic example of a sibling species complex in the ciliates. Using DNA sequence comparison, it is now possible to see whether this example parallels other studied sibling species complexes. We sequenced the internal transcribed spacer (ITS) region of the nuclear ribosomal cistron for 13 of the syngens plus two other Paramecium species and several Tetrahymena spp. Using available spirotrich sequences of the internal transcribed spacer 2 (ITS2), we established the RNA transcript folding pattern for ciliates. Ciliates exhibit the two highly conserved helices in their RNA transcript folding pattern in common with other eukaryotes, despite their unusual nuclear behavior and their presumed low copy number of micronuclear ribosomal repeats. Consequently, the set of 111-116 ITS2 nucleotide positions that are relatively conserved in evolution can be derived and used for comparative analysis. Mating behavior (i.e. gamete agglutination and fusion) is the character showing greatest correlation with the degree of ITS2 evolution in the P. aurelia complex, as also found in other eukaryotes. The degree of change in the ITS2 relatively conserved sequences found among the sibling species of P. aurelia is the same degree as found among the sibling species of the Drosophila melanogaster-mauritania-sechellia-simulans-yakuba species complex. The relatively conserved subregion of ITS2, determined from transcript secondary structure, is a tool for identifying the level of the biological species in the absence of knowledge of sexual compatibility in both micro- and macro-eukaryote species complexes.

  15. Contribution by the methanogenic endosymbionts of anaerobic ciliates to methane production in Dutch freshwater sediments

    NARCIS (Netherlands)

    Hoek, van A.H.A.M.; Alen, T.A.; Vogels, G.D.; Hackstein, J.H.P.

    2006-01-01

    Biogenic methane contributes substantially to the atmospheric methane concentration and thus to global warming. This trace gas is predominantly produced by strictly anaerobic methanogenic archaea, which thrive in the most divergent ecological niches, e. g. paddy fields, sediments, landfills, and the

  16. The influence of flap inclination angle on fluid transport at ciliated walls

    Science.gov (United States)

    Rockenbach, A.; Schnakenberg, U.

    2017-01-01

    In optimizing fluid flow at walls, research has turned to artificial cilia to mimic the propulsion of their whip-like beat of a metachronal traveling wave. Recently we developed a pneumatically actuated micro-membrane device which has rows of long flaps positioned off-center on membranes over a row of cavities, much like the comb row of a ctenophore. As little is known about how the flap inclination angle influences the fluid transport near the wall of such devices, this paper presents a detailed modeling and experimental investigation of this question using combined FEM-FVM (finite element method-finite volume method)-based simulations for inclination angles of 0°, 20°, 30°, and 45°. The experimental results agree well with those of the FEM-FVM simulations. Antiplectic fluid transport was observed for flap inclination angles lower than 20° whereas symplectic fluid transport was determined for those higher than 20°. In conclusion, the inclination angle of the flaps decisively affects the fluid transport direction and velocity.

  17. Navigation organs of the oriental hornet : the ocelli and ciliated sensory epithelium of the head

    NARCIS (Netherlands)

    Rosenzweig, Eyal

    2000-01-01

    This thesis deals with the structure and the role of the orientation and navigation organs in the Oriental hornet Vespa orientalis L. 1771 (Hymenoptera, Vespinae), with special reference to the ocelli. The role of the cuticle, acting as a voltaic system providing the energy for the hornet to fly and

  18. The ciliate Paramecium shows higher motility in non-uniform chemical landscapes.

    Directory of Open Access Journals (Sweden)

    Carl Giuffre

    Full Text Available We study the motility behavior of the unicellular protozoan Paramecium tetraurelia in a microfluidic device that can be prepared with a landscape of attracting or repelling chemicals. We investigate the spatial distribution of the positions of the individuals at different time points with methods from spatial statistics and Poisson random point fields. This makes quantitative the informal notion of "uniform distribution" (or lack thereof. Our device is characterized by the absence of large systematic biases due to gravitation and fluid flow. It has the potential to be applied to the study of other aquatic chemosensitive organisms as well. This may result in better diagnostic devices for environmental pollutants.

  19. An overview of Suctorian ciliates (Ciliophora, Suctorea) as epibionts of halacarid mites (Acari, Halacaridae)

    Digital Repository Service at National Institute of Oceanography (India)

    Dovgal, I.; Chatterjee, T.; Ingole, B.S.

    dedicated to 90 th anniversary of T. I. Vyazemsky Karadag Scientific Station and 25 th anniversary of Karadag Natural Reserve of Ukrainian National Academy of Sciences). Book 2. Simferopol: Sonat. pp. 313–316. (In Rus- sian). Chatterjee, T., De Troch, M... Videnskabers Selskabs Skrifter, 7, pp. 1–17. Dovgal, I.V. (1996) Keys for identification of tentaculous infusoria (Ciliophora,Suctoria) of the Ukrainian fauna. Vestnik Zoologii, Suppl., N2, 1–42. (In Russian). Dovgal, I.V. (2002) Evolution, phylogeny...

  20. Ciliate protozoa of the forestomach of llamas (Lama glama) from locations at different altitude in Argentina.

    Science.gov (United States)

    Cucchi, María Cerón; Marcoppido, Gisela; Dekker, Anna; Fondevila, Manuel; Fuente, Gabriel De La; Morici, Gabriel; Cravero, Silvio

    2016-01-20

    This study describes the diversity and concentration of the protozoal population from the forestomach of llamas in Argentina at three altitudinal locations. Protozoal diversity was studied in samples from eight llamas from Hurlingham (Buenos Aires, 43 m altitude), four from Tilcara (Jujuy, 2465 m altitude) and six llamas from Cieneguillas (Jujuy, 3800 m altitude). The total concentrations of protozoa in the forestomach contents were 7.9, 9.1 and 4.1 cells x 104 ml-1 in Hurlingham, Tilcara and Cieneguillas, respectively (P>0.05). Entodinium spp. represented 97.9, 92.3 and 71.4% of the protozoal community in Hurlingham, Tilcara and Cieneguillas, respectively, and the remaining protozoa belonged to the Eudiplodinium genus. Entodinium spp. were identified as E. caudatum (mostly morphotype dubardi), E. longinucleatum, E. parvum, E. bovis, E. exiguum, E. dubardi, and a minor presence of E. bimastus (in three animals) and E. ovibos (in one animal). In regards to the rest of protozoal species, Eudiplodinium maggii is the first reported host record for the genus in llamas. This species was present in the forestomach of 14 out of 18 llamas tested, and in one case it was the unique protozoal species. The vestibuliferids, Dasytricha and Isotricha were absent from the forestomach of llamas. Similarly, other species such as those from the Caloscolex genus, Diplodinium cameli and Entodinium ovumrajae, commonly found in Old World Camelids, were also absent from llamas.

  1. Effects of a ciliate protozoa predator on microbial communities in pitcher plant (Sarracenia purpurea leaves.

    Directory of Open Access Journals (Sweden)

    Taylor K Paisie

    Full Text Available The aquatic communities found within the water filled leaves of the pitcher plant, Sarracenia purpurea, have a simple trophic structure providing an ideal system to study microscale interactions between protozoan predators and their bacterial prey. In this study, replicate communities were maintained with and without the presence of the bactivorous protozoan, Colpoda steinii, to determine the effects of grazing on microbial communities. Changes in microbial (Archaea and Bacteria community structure were assessed using iTag sequencing of 16S rRNA genes. The microbial communities were similar with and without the protozoan predator, with>1000 species. Of these species, Archaea were negligible, with Bacteria comprising 99.99% of the microbial community. The Proteobacteria and Bacteroidetes were the most dominant phyla. The addition of a protozoan predator did not have a significant effect on microbial evenness nor richness. However, the presence of the protozoan did cause a significant shift in the relative abundances of a number of bacterial species. This suggested that bactivorous protozoan may target specific bacterial species and/or that certain bacterial species have innate mechanisms by which they evade predators. These findings help to elucidate the effect that trophic structure perturbations have on predator prey interactions in microbial systems.

  2. Structures linking the myonemes, endoplasmic reticulum, and surface membranes in the contractile ciliate Vorticella.

    Science.gov (United States)

    Allen, R D

    1973-02-01

    An electron microscope investigation of the interface between the myonemes of Vorticella convallaria and their associated endoplasmic reticulum (ER) has revealed structures of a complex morphology linking these two organelles. These structures are named "linkage complexes". Each complex contains a spindle-shaped midpiece which lies in a groove of the ER membrane. Microfilaments splay out from the tips of the midpiece and may come in contact with the inner alveolar sac membrane. Three to six raillike structures lie on each side of the midpiece and parallel it. The ER membrane appears to pass through the sides of the rails. In the lumen of the ER these rails are associated with a meshwork of filaments. A cradle of five rods lies within the groove under the midpiece. The ER membrane also passes through these rods which contact the same meshwork. In the scopular region and in the stalk the microfilaments from the midpiece form a bundle which passes into the lumen of modified basal bodies. These basal bodies are connected to the alveolar sac which, in the stalk, passes as a flattened tube along its length. The parts of the dissociated linkage complex are scattered throughout the spasmoneme of the stalk along membranes of the intraspasmonemal tubules. Thus, both stalk and body contractile bundles have linkage complexes that link their associated membrane systems to the microfibrils and, in turn, connect this membrane-microfibrillar interface to the pellicular membranes. The arrangement of the linkage complex suggests an involvement in the control of the transport of calcium ions between ER and microfibrils, and possibly the transfer of a message from the surface membranes to the sites of calcium release to trigger myonemal contraction.

  3. Discomorphella pedroeneasi sp. nov. (Ciliophora, Odontostomatida): An anaerobic ciliate hosting multiple cytoplasmic and macronuclear endocytobionts.

    Science.gov (United States)

    da Silva Paiva, Thiago; Küppers, Gabriela Cristina; Lahr, Daniel José Galafasse; Schweikert, Michael; da Silva-Neto, Inácio Domingos

    2017-01-19

    Odontostomatids are among the less studied representatives of the Ciliophora. They are anaerobic microeukaryotes usually occurring as rare species in sapropelic environments. Here we describe a novel species of Discomorphella, named Discomorphella pedroeneasi sp. nov., using light and electron microscopy observations. Discomorphella pedroeneasi displays many complex morphological features, for which new terms are introduced, such as the auricules, epistomial fringe spacer, frontal awning, odontostomatid ciliary sockets, oral lips and ventral flap. Remarkably, D. pedroeneasi has at least six types of endocytobionts, including intramacronuclear ones, and organelles ultrastructurally similar to the M/H bodies of the odontostomatid Saprodinium dentatum. Based on the new data and revision of the literature, we propose two new diagnostic characters for species separation within Discomorphella: the fringe spacer ratio and the posterior fringe ratio. The taxonomy of Discomorphella is revised and an identification key is provided.

  4. Preliminary identification schemes for some unicellular ciliated and flagellated parasites of warmwater fishes

    Science.gov (United States)

    There are few keys for the identification of small unicellular parasites of warmwater fishes and few experts who can confidently identify these parasites to species. Molecular identification tools for these parasites are largely unavailable. For fishery biologists and even fish health diagnosticia...

  5. The ciliate Paramecium shows higher motility in non-uniform chemical landscapes.

    Science.gov (United States)

    Giuffre, Carl; Hinow, Peter; Vogel, Ryan; Ahmed, Tanvir; Stocker, Roman; Consi, Thomas R; Strickler, J Rudi

    2011-04-11

    We study the motility behavior of the unicellular protozoan Paramecium tetraurelia in a microfluidic device that can be prepared with a landscape of attracting or repelling chemicals. We investigate the spatial distribution of the positions of the individuals at different time points with methods from spatial statistics and Poisson random point fields. This makes quantitative the informal notion of "uniform distribution" (or lack thereof). Our device is characterized by the absence of large systematic biases due to gravitation and fluid flow. It has the potential to be applied to the study of other aquatic chemosensitive organisms as well. This may result in better diagnostic devices for environmental pollutants.

  6. Reduced fecundity in small populations of the rare plant Gentianopsis ciliate (Gentianaceae)

    Science.gov (United States)

    Kery, M.; Matthies, D.

    2004-01-01

    Habitat destruction is the main cause for the biodiversity crisis. Surviving populations are often fragmented, i.e., small and isolated from each other. Reproduction of plants in small populations is often reduced, and this has been attributed to inbreeding depression, reduced attractiveness for pollinators, and reduced habitat quality in small populations. Here we present data on the effects of fragmentation on the rare, self-compatible perennial herb Gentianopsis ciliata (Gentianaceae), a species with very small and presumably well-dispersed seeds. We studied the relationship between population size, plant size, and the number of flowers produced in 63 populations from 1996-1998. In one of the years, leaf and flower size and the number of seeds produced per fruit was studied in a subset of 25 populations. Plant size, flower size, and the number of seeds per fruit and per plant increased with population size, whereas leaf length and the number of flowers per plant did not. The effects of population size on reproduction and on flower size remained significant if the effects were adjusted for differences in plant size, indicating that they could not be explained by differences in habitat quality. The strongly reduced reproduction in small populations may be due to pollination limitation, while the reduced flower size could indicate genetic effects.

  7. Notes on the use of invertebrates, especially ciliates, in studies on pollution and toxicity.

    Science.gov (United States)

    Komala, Z

    1995-01-01

    After treatment of the paramecia with 0.0005% cartap solution a high mortality of the paramecia in the postautogamic experimental group was observed. In the studied postautogamic experimental daily isolation line some defective paramecia were found. The abnormality was manifested by a defective separation of animals during binary fission resulting in the formation of chain forms.

  8. Ciliated cultured dermal fibroblasts in a patient with hyperornithinemia, hyperammonemia and homocitrullinuria (HHH) syndrome.

    Science.gov (United States)

    Haust, M D

    1995-10-01

    Hyperornithinemia, hyperammonemia and homocitrullinuria (HHH)-syndrome is a rare autosomal recessive disorder of the urea cycle, probably caused by a defect in ornithine transport across the hepatic inner mitochondrial membrane. Single rudimentary cilia were present in approximately ten percent of post-divisional or dividing fibroblasts cultured from the skin of a patient with the HHH-syndrome, whereas no such organelles were observed in dermal fibroblasts cultured from normal controls. Since single rudimentary ("primary," "oligo," "solitary") cilia have been observed in a variety of cells in animals and men but the stimuli for their formation and their significance remain controversial, a brief report on their presence in the as yet unreported condition (HHH-syndrome) was considered of interest; hopefully, it might contribute to the ultimate unravelling of some of the unresolved problems. It is of note that unlike the author's previous findings of these unusual organelles in cells affected by a pathological process (atherosclerosis), the rudimentary cilia were observed in the present instance in dividing or postdivisional cells. The implications of these (and other) observations must await further work.

  9. Evidence for a relationship between bovine erythrocyte lipid membrane peculiarities and immune pressure from ruminal ciliates

    Science.gov (United States)

    Erythrocytes of bovines and other ruminants have a strikingly anomalous phospholipid composition, with low or absent phosphatidylcholine (PC) together with high sphingomyelin (SM) content. Here, we report the presence in normal bovine serum of high levels of anti-phospholipid antibodies of IgM isoty...

  10. A NEW METHOD TO ASSESS FUNCTIONAL ACTIVITY OF SERUM COMPLEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    E. G. Cheremnykh

    2015-01-01

    Full Text Available Complement system is an important component of innate immunity, providing primary protection against pathogens invading the body. In addition, it was shown that the complement system is associated with many diseases, not only autoimmune and infectious, but also mental disorders. In this regard, it is necessary to develop affordable and fast method of measuring activity of the complement system in real-time mode. We present a new semi-automated method for assessment of serum complement activity. The assay is based on cytolytic action of complement system upon the ciliate organism Tetrahymena pyriformis. This method consists in repeated counting of live Tetrahymena motile cells by means of specially developed Biolat device, which consists of two video cameras, light sources, and movable round plate. The plate has two rows of holes. The device also includes microprocessor control unit based on AutoCiliata software, intended for control of operation module and counting the surviving cell. The calculations are based on fixation of two sequential video-frames, with subsequent software image processing. Cell death events were observed upon incubation in triethanolamine (TEA buffer containing 5% of blood serum. We have also compared complement activity in different buffers, i.e., standard medium for culturing of ciliates, Veronal-Medinalum buffer, and the TEA buffer. TEA buffer was found superior to the Veronal buffer when applied in the test system. The time of cell death in the TEA-buffered medium containing 5% serum was < 15 minutes for all the sera studied. The parameters denoting serum complement activity were as follows: a half-life time for the moving cells (TLD50, and a similar value for 100% cell inactivation (1/TLD50, functional activity of the complement system, ACS. The sensitivity of this assay was calculated from dependencies between TLD50 and ACS, and actual serum concentrations. We have suggested an opportunity for evaluation of an

  11. Comparative cytotoxicity and accumulation of Roxarsone and its photodegradates in freshwater Protozoan Tetrahymenathermophila

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenzhong; Xu, Fang, E-mail: fang.xu.zh@gmail.com; Han, Jingjing; Sun, Qun; Yang, Kai

    2015-04-09

    Highlights: • Released roxarsone (ROX) readily photolyzed into iAs{sup III}/iAs{sup V} bearing derivatives. • Clear cytotoxicity by ROX photodegradates but not by ROX in Tetrahymena cell. • As uptake in cell membrane by ROX exposure but in cytoplasm by ROX photodegradates. • Biomimetic membrane structure for assessing membrane permeability and cytotoxicity. • ROX photodegradates exposure associated intracellular 15 protein over expression. - Abstract: Roxarsone (ROX) remains to be as an organoarsenical feed additive used widely in developing countries. However, most of the ROX is excreted unchanged in manure, which could be readily photodegraded into inorganic arsenic derivatives. In this study, the comparative cytotoxicity and arsenic accumulation were evaluated after the exposure of Tetrahymenathermophila (T. thermophila) cell model to ROX and its photodegradates. The cytotoxic effects were estimated according to the relevant cell growth curves, morphologies and MTT assays. The 36 h median effective concentrations for ROX and its photodegradates at various photolysis times (10, 20, and 30 min) are 39.0, 2.08, 1.88, and 1.82 mg (total arsenic) L{sup −1}, respectively. In parallel, the cellular arsenic uptakes were determined by hydride generation-atomic fluorescence spectrometry. Phospholipid layer as basic membrane structure was mimicked to assess the correlation between membrane permeability and cytotoxicity. The biocompatibility of ROX was dependent on its tendency to interact with cell membrane while the cytotoxicity was induced by the trans-membrane of the inorganic arsenic species present in the photodegradates of ROX. Furthermore, the photodegradates of ROX-associated alterations of intracellular protein profiles were analyzed using a proteomic approach. Overall, the significance was clarified that the control of arsenic emission caused by the application of ROX needs to be imposed.

  12. Local Kinetic Measures of Macromolecular Structure Reveal Partitioning Among Multiple Parallel Pathways from the Earliest Steps in the Folding of a Large RNA Molecule

    Energy Technology Data Exchange (ETDEWEB)

    Laederach,A.; Shcherbakova, I.; Liang, M.; Brenowitz, M.; Altman, R.

    2006-01-01

    At the heart of the RNA folding problem is the number, structures, and relationships among the intermediates that populate the folding pathways of most large RNA molecules. Unique insight into the structural dynamics of these intermediates can be gleaned from the time-dependent changes in local probes of macromolecular conformation (e.g. reports on individual nucleotide solvent accessibility offered by hydroxyl radical ({center_dot}OH) footprinting). Local measures distributed around a macromolecule individually illuminate the ensemble of separate changes that constitute a folding reaction. Folding pathway reconstruction from a multitude of these individual measures is daunting due to the combinatorial explosion of possible kinetic models as the number of independent local measures increases. Fortunately, clustering of time progress curves sufficiently reduces the dimensionality of the data so as to make reconstruction computationally tractable. The most likely folding topology and intermediates can then be identified by exhaustively enumerating all possible kinetic models on a super-computer grid. The folding pathways and measures of the relative flux through them were determined for Mg{sup 2+} and Na{sup +}-mediated folding of the Tetrahymena thermophila group I intron using this combined experimental and computational approach. The flux during Mg{sup 2+}-mediated folding is divided among numerous parallel pathways. In contrast, the flux during the Na{sup +}-mediated reaction is predominantly restricted through three pathways, one of which is without detectable passage through intermediates. Under both conditions, the folding reaction is highly parallel with no single pathway accounting for more than 50% of the molecular flux. This suggests that RNA folding is non-sequential under a variety of different experimental conditions even at the earliest stages of folding. This study provides a template for the systematic analysis of the time-evolution of RNA structure

  13. RNA folding and catalysis mediated by iron (II.

    Directory of Open Access Journals (Sweden)

    Shreyas S Athavale

    Full Text Available Mg²⁺ shares a distinctive relationship with RNA, playing important and specific roles in the folding and function of essentially all large RNAs. Here we use theory and experiment to evaluate Fe²⁺ in the absence of free oxygen as a replacement for Mg²⁺ in RNA folding and catalysis. We describe both quantum mechanical calculations and experiments that suggest that the roles of Mg²⁺ in RNA folding and function can indeed be served by Fe²⁺. The results of quantum mechanical calculations show that the geometry of coordination of Fe²⁺ by RNA phosphates is similar to that of Mg²⁺. Chemical footprinting experiments suggest that the conformation of the Tetrahymena thermophila Group I intron P4-P6 domain RNA is conserved between complexes with Fe²⁺ or Mg²⁺. The catalytic activities of both the L1 ribozyme ligase, obtained previously by in vitro selection in the presence of Mg²⁺, and the hammerhead ribozyme are enhanced in the presence of Fe²⁺ compared to Mg²⁺. All chemical footprinting and ribozyme assays in the presence of Fe²⁺ were performed under anaerobic conditions. The primary motivation of this work is to understand RNA in plausible early earth conditions. Life originated during the early Archean Eon, characterized by a non-oxidative atmosphere and abundant soluble Fe²⁺. The combined biochemical and paleogeological data are consistent with a role for Fe²⁺ in an RNA World. RNA and Fe²⁺ could, in principle, support an array of RNA structures and catalytic functions more diverse than RNA with Mg²⁺ alone.

  14. Cooperation-mediated plasticity in dispersal and colonization.

    Science.gov (United States)

    Jacob, Staffan; Wehi, Priscilla; Clobert, Jean; Legrand, Delphine; Schtickzelle, Nicolas; Huet, Michele; Chaine, Alexis

    2016-10-01

    Kin selection theory predicts that costly cooperative behaviors evolve most readily when directed toward kin. Dispersal plays a controversial role in the evolution of cooperation: dispersal decreases local population relatedness and thus opposes the evolution of cooperation, but limited dispersal increases kin competition and can negate the benefits of cooperation. Theoretical work has suggested that plasticity of dispersal, where individuals can adjust their dispersal decisions according to the social context, might help resolve this paradox and promote the evolution of cooperation. Here, we experimentally tested the hypothesis that conditional dispersal decisions are mediated by a cooperative strategy: we quantified the density-dependent dispersal decisions and subsequent colonization efficiency from single cells or groups of cells among six genetic strains of the unicellular Tetrahymena thermophila that differ in their aggregation level (high, medium, and low), a behavior associated with cooperation strategy. We found that the plastic reaction norms of dispersal rate relative to density differed according to aggregation level: highly aggregative genotypes showed negative density-dependent dispersal, whereas low-aggregation genotypes showed maximum dispersal rates at intermediate density, and medium-aggregation genotypes showed density-independent dispersal with intermediate dispersal rate. Dispersers from highly aggregative genotypes had specialized long-distance dispersal phenotypes, contrary to low-aggregation genotypes; medium-aggregation genotypes showing intermediate dispersal phenotype. Moreover, highly aggregation genotypes showed evidence for beneficial kin-cooperation during dispersal. Our experimental results should help to resolve the evolutionary conflict between cooperation and dispersal: cooperative individuals are expected to avoid kin-competition by dispersing long distances, but maintain the benefits of cooperation by dispersing in small groups.

  15. Personal care product preservatives: risk assessment and mixture toxicities with an industrial wastewater.

    Science.gov (United States)

    Carbajo, Jose B; Perdigón-Melón, Jose A; Petre, Alice L; Rosal, Roberto; Letón, Pedro; García-Calvo, Eloy

    2015-04-01

    The aquatic toxicity of eight preservatives frequently used in personal care products (PCPs) (iodopropynyl butylcarbamate, bronopol, diazolidinyl urea, benzalkonium chloride, zinc pyrithione, propylparaben, triclosan and a mixture of methylchloroisothiazolinone and methylisothiazolinone) was assessed by means of two different approaches: a battery of bioassays composed of single species tests of bacteria (Vibrio fischeri and Pseudomonas putida) and protozoa (Tetrahymena thermophila), and a whole biological community resazurin-based assay using activated sludge. The tested preservatives showed considerable toxicity in the studied bioassays, but with a marked difference in potency. In fact, all biocides except propylparaben and diazolidinyl urea had EC50 values lower than 1 mg L(-1) in at least one assay. Risk quotients for zinc pyrithione, benzalkonium chloride, iodopropynyl butylcarbamate and triclosan as well as the mixture of the studied preservatives exceeded 1, indicating a potential risk for the process performance and efficiency of municipal sewage treatment plants (STPs). These four single biocides explained more than 95% of the preservative mixture risk in all bioassays. Each individual preservative was also tested in combination with an industrial wastewater (IWW) from a cosmetics manufacturing facility. The toxicity assessment was performed on binary mixtures (preservative + IWW) and carried out using the median-effect principle, which is a special case of the concept of Concentration Addition (CA). Almost 70% of all experiments resulted in EC50 values within a factor of 2 of the values predicted by the median-effect principle (CI values between 0.5 and 2). The rest of the mixtures whose toxicity was mispredicted by CA were assessed with the alternative concept of Independent Action (IA), which showed higher predictive power for the biological community assay. Therefore, the concept used to accurately predict the toxicity of mixtures of a preservative

  16. Protozoan Predation of Escherichia coli O157:H7 Is Unaffected by the Carriage of Shiga Toxin-Encoding Bacteriophages.

    Science.gov (United States)

    Schmidt, Carrie E; Shringi, Smriti; Besser, Thomas E

    2016-01-01

    Escherichia coli O157:H7 is a food-borne bacterium that causes hemorrhagic diarrhea and hemolytic uremic syndrome in humans. While cattle are a known source of E. coli O157:H7 exposure resulting in human infection, environmental reservoirs may also be important sources of infection for both cattle and humans. Bacteriophage-encoded Shiga toxins (Stx) carried by E. coli O157:H7 may provide a selective advantage for survival of these bacteria in the environment, possibly through their toxic effects on grazing protozoa. To determine Stx effects on protozoan grazing, we co-cultured Paramecium caudatum, a common ciliate protozoon in cattle water sources, with multiple strains of Shiga-toxigenic E. coli O157:H7 and non-Shiga toxigenic cattle commensal E. coli. Over three days at ambient laboratory temperature, P. caudatum consistently reduced both E. coli O157:H7 and non-Shiga toxigenic E. coli populations by 1-3 log cfu. Furthermore, a wild-type strain of Shiga-toxigenic E. coli O157:H7 (EDL933) and isogenic mutants lacking the A subunit of Stx 2a, the entire Stx 2a-encoding bacteriophage, and/or the entire Stx 1-encoding bacteriophage were grazed with similar efficacy by both P. caudatum and Tetrahymena pyriformis (another ciliate protozoon). Therefore, our data provided no evidence of a protective effect of either Stx or the products of other bacteriophage genes on protozoan predation of E. coli. Further research is necessary to determine if the grazing activity of naturally-occurring protozoa in cattle water troughs can serve to decrease cattle exposure to E. coli O157:H7 and other Shiga-toxigenic E. coli.

  17. Protozoan Predation of Escherichia coli O157:H7 Is Unaffected by the Carriage of Shiga Toxin-Encoding Bacteriophages.

    Directory of Open Access Journals (Sweden)

    Carrie E Schmidt

    Full Text Available Escherichia coli O157:H7 is a food-borne bacterium that causes hemorrhagic diarrhea and hemolytic uremic syndrome in humans. While cattle are a known source of E. coli O157:H7 exposure resulting in human infection, environmental reservoirs may also be important sources of infection for both cattle and humans. Bacteriophage-encoded Shiga toxins (Stx carried by E. coli O157:H7 may provide a selective advantage for survival of these bacteria in the environment, possibly through their toxic effects on grazing protozoa. To determine Stx effects on protozoan grazing, we co-cultured Paramecium caudatum, a common ciliate protozoon in cattle water sources, with multiple strains of Shiga-toxigenic E. coli O157:H7 and non-Shiga toxigenic cattle commensal E. coli. Over three days at ambient laboratory temperature, P. caudatum consistently reduced both E. coli O157:H7 and non-Shiga toxigenic E. coli populations by 1-3 log cfu. Furthermore, a wild-type strain of Shiga-toxigenic E. coli O157:H7 (EDL933 and isogenic mutants lacking the A subunit of Stx 2a, the entire Stx 2a-encoding bacteriophage, and/or the entire Stx 1-encoding bacteriophage were grazed with similar efficacy by both P. caudatum and Tetrahymena pyriformis (another ciliate protozoon. Therefore, our data provided no evidence of a protective effect of either Stx or the products of other bacteriophage genes on protozoan predation of E. coli. Further research is necessary to determine if the grazing activity of naturally-occurring protozoa in cattle water troughs can serve to decrease cattle exposure to E. coli O157:H7 and other Shiga-toxigenic E. coli.

  18. 纤毛虫中的编程性翻译移码%Programmed translational frameshifting in ciliates

    Institute of Scientific and Technical Information of China (English)

    李禄琴; 胡苗清; 梁爱华

    2014-01-01

    编程性翻译移码现象存在于病毒、原核生物和真核生物中.单细胞真核生物游仆虫基因组中含有的编程性翻译移码基因远远高于其他真核生物基因组.游仆虫中已经报道的编程性翻译移码基因的滑动序列特征为AAA-UAR-V,其上游都有SD(Shine-Dalgarno sequence)相似序列CAAGAA.同时,编程性移码的发生受肽链释放因子eRF1和tRNALys的影响.

  19. The Advances on the Pheromone of Ciliates%纤毛虫信息素研究进展

    Institute of Scientific and Technical Information of China (English)

    张志云; 梁爱华

    2003-01-01

    信息素(pheromone)在纤毛虫的生长分裂和接合生殖中起重要的信号传导作用,由典型的多结构域"信号肽-前体片段-成熟信息素"组成.本文着重阐述了信息素及其受体的结构、功能及作用机制等方面的研究进展.

  20. X-ray microanalysis in cryosections of natively frozen Paramecium caudatum with regard to ion distribution in ciliates

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, M.; Meyer, R.; Zierold, K.

    1985-01-01

    Cells of Paramecium caudatum were shock-frozen without pretreatment for cryoultramicrotomy and freeze-dried for subsequent X-ray microanalysis. Na, Mg, P, S, Cl, K, and Ca were detected in different amounts in several subcellular compartments. In particular, calcium was localized below the cell surface (pellicle). Trichocysts were found to contain significant amounts of Na in their base but not in the tip. Na, Mg, P, S, Cl, K, Ca were found in electron dense deposits within the lumen of the contractile vacuole. A small K concentration was found in the cytoplasm and in the mitochondria. X-ray microanalysis of the element distribution in different subcellular compartments provides information for the understanding of cellular functions such as exocytosis, locomotion, and ion regulation.

  1. MORPHOLOGY OF SIX FRESHWATER CILIATES%六种淡水纤毛虫形态学研究

    Institute of Scientific and Technical Information of China (English)

    王丽卿; 郝瑞娟; 李雪琪; 潘宏博

    2016-01-01

    借助活体观察和银染法对6种淡水纤毛虫(纵长板壳虫Coleps elongatus、瓜形原膜袋虫Protocyclidium citrullus、亨氏累枝虫Epistylis hentscheli、钟形钟虫Vorticella campanula、长柄球吸管虫Metacineta macrocaulis、四分锤吸管虫Tokophrya quadripatita)的形态和纤毛图式进行了详尽研究.本工作首次描述了亨氏累枝虫、四分锤吸管虫、纵长板壳虫的中国种群,同时揭示了亨氏累枝虫长期未知的纤毛图式特征并给出该种类的新定义:虫体高钟形,活体大小约(100-130)μm×(60-65)μm;伸缩泡1个,腹位;大小核各1枚,大核“C”型;群体为规则对称二叉分枝;口区三片小膜均由三列动基列组成,第三小膜由三列等长的动基列组成,其终止处高于第一小膜下端;虫体前端到反口纤毛环间的银线约71-74条,反口纤毛环到帚胚间的银线约35-47条;淡水生境.此外,本研究对长柄球吸管虫、钟形钟虫、瓜形原膜袋虫进行了重新描述,补充了显微照片.

  2. Identification and characterization of a putative agglutination/immobilization antigen on the surface of Cryptocaryon irritans.

    Science.gov (United States)

    Hatanaka, A; Umeda, N; Yamashita, S; Hirazawa, N

    2007-08-01

    The ciliated protozoan Cryptocaryon irritans, a parasite of seawater fishes, was found to express an antigen that elicits antibodies in rabbits and tiger puffer (Takifugu ruburipes). Serum from rabbits and fish immunized with theronts had agglutination/immobilization activity against theronts in vitro; fish serum antibody levels (measured by enzyme-linked immunosorbent assays: ELISA) correlated with this activity. Anti-theront antibody levels in fish were significantly higher in the immunized group as compared with control fish at 2 weeks after booster immunization (injection of bovine serum albumin; Student's t-test, Pagglutination/immobilization antigen. Indirect immunofluorescence staining of theronts suggested that this 32 kDa antigen was expressed on the surface of cilia. The full-length 32 kDa antigen cDNA contained 1147 basepairs, encoding a 328-amino acid protein including hydrophobic N- and C-termini. As with Tetrahymena and Paramecium spp., TAA and TAG appear to be used as glutamine codons in the 32 kDa antigen gene.

  3. Unicellular eukaryotes as models in cell and molecular biology: critical appraisal of their past and future value.

    Science.gov (United States)

    Simon, Martin; Plattner, Helmut

    2014-01-01

    Unicellular eukaryotes have been appreciated as model systems for the analysis of crucial questions in cell and molecular biology. This includes Dictyostelium (chemotaxis, amoeboid movement, phagocytosis), Tetrahymena (telomere structure, telomerase function), Paramecium (variant surface antigens, exocytosis, phagocytosis cycle) or both ciliates (ciliary beat regulation, surface pattern formation), Chlamydomonas (flagellar biogenesis and beat), and yeast (S. cerevisiae) for innumerable aspects. Nowadays many problems may be tackled with "higher" eukaryotic/metazoan cells for which full genomic information as well as domain databases, etc., were available long before protozoa. Established molecular tools, commercial antibodies, and established pharmacology are additional advantages available for higher eukaryotic cells. Moreover, an increasing number of inherited genetic disturbances in humans have become elucidated and can serve as new models. Among lower eukaryotes, yeast will remain a standard model because of its peculiarities, including its reduced genome and availability in the haploid form. But do protists still have a future as models? This touches not only the basic understanding of biology but also practical aspects of research, such as fund raising. As we try to scrutinize, due to specific advantages some protozoa should and will remain favorable models for analyzing novel genes or specific aspects of cell structure and function. Outstanding examples are epigenetic phenomena-a field of rising interest.

  4. Introducing Spectral Structure Activity Relationship (S-SAR Analysis. Application to Ecotoxicology

    Directory of Open Access Journals (Sweden)

    Ana-Maria Lacrămă

    2007-05-01

    Full Text Available A novel quantitative structure-activity (property relationship model, namelySpectral-SAR, is presented in an exclusive algebraic way replacing the old-fashionedmulti-regression one. The actual S-SAR method interprets structural descriptors as vectorsin a generic data space that is further mapped into a full orthogonal space by means of theGram-Schmidt algorithm. Then, by coordinated transformation between the data andorthogonal spaces, the S-SAR equation is given under simple determinant form for anychemical-biological interactions under study. While proving to give the same analyticalequation and correlation results with standard multivariate statistics, the actual S-SARframe allows the introduction of the spectral norm as a valid substitute for the correlationfactor, while also having the advantage to design the various related SAR models throughthe introduced “minimal spectral path” rule. An application is given performing a completeS-SAR analysis upon the Tetrahymena pyriformis ciliate species employing its reportedeco-toxicity activities among relevant classes of xenobiotics. By representing the spectralnorm of the endpoint models against the concerned structural coordinates, the obtainedS-SAR endpoints hierarchy scheme opens the perspective to further design the eco-toxicological test batteries with organisms from different species.

  5. Mean, fluctuations and predictability in biological dispersal

    Science.gov (United States)

    Giometto, A.; Altermatt, F.; Carrara, F.; Rinaldo, A.

    2013-12-01

    Dispersal is a key ecological phenomenon, fundamental to the understanding of the dynamics of invasive species, spread of epidemics and range shifts due to climate or environmental change. Additionally, organisms' spread drives species distribution and affects their coexistence. Despite its relevance, replicated experimentation on biological dispersal is inconclusive to date and current assessments point at inherent limitations to predictability owing to large fluctuations even in the simplest ecological settings. In contrast, we show by replicated experimentation on the spread of the ciliate Tetrahymena sp. in linear landscapes, that information on local unconstrained movement and reproduction of individuals allows to predict reliably the existence and speed of traveling waves of invasion at the macroscopic scale. Furthermore, a theoretical approach introducing demographic stochasticity in the Fisher-Kolmogorov framework of reaction-diffusion processes is shown to capture both the mean and the observed fluctuations in range expansions between replicated invasions. Thus, the predictability of the phenomenon overcomes the inherent stochasticity. Notably, predictions on the spread of organisms are based on local, short-time and independent observations of the two processes affecting dispersal, namely individuals' movement and reproduction. Our results establish a causal link from the short-term individual level to the long-term, broad-scale population patterns and may be generalized to sort whether the variability observed in nature or in experimental ensembles might be accounted for by systematic differences between landscapes or by stochasticity affecting basic vital rates of the organisms involved.

  6. Free-living protozoa in the gastrointestinal tract and feces of pigs: Exploration of an unknown world and towards a protocol for the recovery of free-living protozoa.

    Science.gov (United States)

    Chavatte, N; Lambrecht, E; Van Damme, I; Sabbe, K; Houf, K

    2016-07-30

    Associations with free-living protozoa (FLP) have been implicated in the persistence of foodborne pathogenic bacteria in food-related environments. To date however no information is available on the presence of FLP in the gastrointestinal tract (GIT) of pigs, which represents an important reservoir for zoonotic foodborne bacteria and hence a potential location for associations with FLP. This is at least partly due to the lack of adequate protocols to recover FLP from intestinal content and feces. In the present study different protocols to recover FLP from the porcine GIT and feces were tested. The most effective protocols were then applied to explore the presence of live FLP in the pig GIT and feces. A filtration based protocol was identified as the most suitable method to recover viable FLP from the porcine GIT and feces. Cultivable FLP were recovered from different parts of the GIT, suggesting at least a transient presence of FLP in this habitat. Free-living amoebae species (Acanthamoeba spp., Hyperamoeba sp., Vannella sp., Vermamoeba vermiformis, hartmannellids and vahlkampfiids) but also ciliates (Colpoda sp. and Tetrahymena/Glaucoma lookalike) and flagellates (cercomonads, bodonids and glissomonads) were recovered and cultured from pig intestinal content. Acanthamoeba hatchetti and Filamoeba sinensis were isolated for the first time from pig intestinal content. Despite high gastric acidity, non-cyst forming amoeba species were also detected which suggests survival of their trophozoites in the animal GIT.

  7. Abundance, diversity and community composition of free-living protozoa on vegetable sprouts.

    Science.gov (United States)

    Chavatte, N; Lambrecht, E; Van Damme, I; Sabbe, K; Houf, K

    2016-05-01

    Interactions with free-living protozoa (FLP) have been implicated in the persistence of pathogenic bacteria on food products. In order to assess the potential involvement of FLP in this contamination, detailed knowledge on their occurrence, abundance and diversity on food products is required. In the present study, enrichment and cultivation methods were used to inventory and quantify FLP on eight types of commercial vegetable sprouts (alfalfa, beetroot, cress, green pea, leek, mung bean, red cabbage and rosabi). In parallel, total aerobic bacteria and Escherichia coli counts were performed. The vegetable sprouts harbored diverse communities of FLP, with Tetrahymena (ciliate), Bodo saltans and cercomonads (flagellates), and Acanthamoeba and Vannella (amoebae) as the dominant taxa. Protozoan community composition and abundance significantly differed between the sprout types. Beetroot harbored the most abundant and diverse FLP communities, with many unique species such as Korotnevella sp., Vannella sp., Chilodonella sp., Podophrya sp. and Sphaerophrya sp. In contrast, mung bean sprouts were species-poor and had low FLP numbers. Sampling month and company had no significant influence, suggesting that seasonal and local factors are of minor importance. Likewise, no significant relationship between protozoan community composition and bacterial load was observed.

  8. Re-evaluation of the phylogenetic position of the genus Dexiotrichides (Protozoa, Ciliophora, Scuticociliatida) inferred from stomatogenetic and molecular information for Dexiotrichides pangi

    Institute of Scientific and Technical Information of China (English)

    SONG Weibo; Alan WARREN; David ROBERTS; SHANG Huimin; MA Hongwei; Norbert WILBERT; MIAO Miao; YI Zhenzhen

    2005-01-01

    The divisional process and systematic position of the marine scuticociliate Dexiotrichides pangi are studied. Based on both stomatogenetic data and 18S rDNA gene sequences, the phylogeny and morphogenetic characteristics of this taxon, and of other related genera, are analyzed and discussed. Both the divisionary events and the molecular biological data indicate that this species/genus, together with certain other genera in the Dexiotricha-complex, occupies an intermediate position between the tetrahymenids and the "typical" scuticociliate, which suggests that the Dexiotricha-like taxa should be excluded from the "true" scuticociliates. As a further contribution, the process of stomatogenesis in D. pangican be summarized as follows: (1) The oral primordia in the opisthe are formed only by the proliferation of basal bodies in the scutica field, which subsequently develop intothree membranelles, while the new paroral membrane seems to be generated by the sub-anterior portion of somatic kinety 1 (the 1st postoral intercalary kinety). The latter character exhibits a mode similar to Tetrahymena. (2) In the proter the parental membranelles are retained and remain unchanged throughout the entire division process; only the old paroral membrane is disassembled and differentiated into the anlage, which then gives rise to the new paroral membrane and the scutica of the proter. The 18S rRNA gene sequence reported here isthe first one for a ciliate in the Dexiotricha-complex.

  9. ABC转运蛋白提升四膜虫对DDT的耐受能力%ATP-binding cassette transporter enhances Tetrahymena tolerance to DDT

    Institute of Scientific and Technical Information of China (English)

    宁应之; 党怀; 刘光龙; 熊杰; 袁冬霞; 冯立芳; 缪炜

    2014-01-01

    世界卫生组织允许DDT在部分国家和地区使用.大规模频繁使用杀虫剂造成了蚊子的抗药性,大大降低了DDT的防治效果.目前对于DDT的耐受主要集中在蚊子,但对于喷洒的DDT进入水生态系统后,造成食物链底层水生生物体对DDT耐受还未见报道.本研究对DDT胁迫下的四膜虫全基因组中筛选出一个ATP结合盒转运蛋白基因(abcb15),它能够识别DDT作为其转运的底物.绿色荧光蛋白标记显示ABCB 15蛋白定位于细胞膜上,是一个细胞膜泵蛋白.基因敲降技术造成的abcb15基因敲降株在DDT胁迫下表现出更低的生长速率,这表明ABCB15膜泵蛋白能够将进入细胞内的DDT转运至细胞膜外,藉以提高四膜虫对DDT的耐受能力,以减轻DDT对细胞的损伤.

  10. Tetrahymena gene encodes a protein that is homologous with the liver-specific F-antigen and associated with membranes of the Golgi apparatus and transport vesicles

    DEFF Research Database (Denmark)

    Hummel, R; Nørgaard, P; Andreasen, P H

    1992-01-01

    of the Golgi apparatus and transport vesicles pointing to a role of TF-ag in membrane trafficking. Transcription of the TF-ag gene, as determined by run-on analyses, was only detectable in growing cells, and following transfer to starvation condition pre-existing TF-ag mRNA was rapidly degraded. The abundance...

  11. 77 FR 9618 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the...

    Science.gov (United States)

    2012-02-17

    ... to the same species as) their T. thermophila, although here the petition paraphrased this statement... generic descriptions, nor does it provide any other morphological, ecological, distributional, genetic,...

  12. Targeting of highly conserved Dengue virus sequences with anti-Dengue virus trans-splicing group I introns

    Directory of Open Access Journals (Sweden)

    Fraser Tresa S

    2010-11-01

    Full Text Available Abstract Background Dengue viruses (DENV are one of the most important viral diseases in the world with approximately 100 million infections and 200,000 deaths each year. The current lack of an approved tetravalent vaccine and ineffective insecticide control measures warrant a search for alternatives to effectively combat DENV. The trans-splicing variant of the Tetrahymena thermophila group I intron catalytic RNA, or ribozyme, is a powerful tool for post-transcriptional RNA modification. The nature of the ribozyme and the predictability with which it can be directed makes it a powerful tool for modifying RNA in nearly any cell type without the need for genome-altering gene therapy techniques or dependence on native cofactors. Results Several anti-DENV Group I trans-splicing introns (αDENV-GrpIs were designed and tested for their ability to target DENV-2 NGC genomes in situ. We have successfully targeted two different uracil bases on the positive sense genomic strand within the highly conserved 5'-3' cyclization sequence (CS region common to all serotypes of DENV with our αDENV-GrpIs. Our ribozymes have demonstrated ability to specifically trans-splice a new RNA sequence downstream of the targeted site in vitro and in transfected insect cells as analyzed by firefly luciferase and RT-PCR assays. The effectiveness of these αDENV-GrpIs to target infecting DENV genomes is also validated in transfected or transformed Aedes mosquito cell lines upon infection with unattenuated DENV-2 NGC. Conclusions Analysis shows that our αDENV-GrpIs have the ability to effectively trans-splice the DENV genome in situ. Notably, these results show that the αDENV-GrpI 9v1, designed to be active against all forms of Dengue virus, effectively targeted the DENV-2 NGC genome in a sequence specific manner. These novel αDENV-GrpI introns provide a striking alternative to other RNA based approaches for the transgenic suppression of DENV in transformed mosquito cells and

  13. Nanomaterials' Influences on the Emergence of Life and Their Toxic Effects on Bacteria and Protozoa

    Science.gov (United States)

    Mielke, Randall Edward

    This research investigates the unique properties of nanomaterials (NMs) with highly catalytic surfaces that make them ideal for the production of organic molecules but also confer toxic properties of some NMs. Iron-sulphide NMs were used in a hydrothermal reactor that released hydrogen sulphide and other metal ions in the effluent, as analyzed by inductively-coupled plasma (ICP) spectrometry. Using an environmental scanning electron microscope (ESEM), iron sulphide NM surfaces indicate severe weathering as a result of environmental conditions including high pressure (100 bar H2) and moderate temperatures (130°C). The effluent's chemical properties from the reactor experiment generated chimney structures from newly formed iron-sulphide NMs in a ferrous rich 'Hadean Ocean' solution. Using ESEM, we show that structural changes occur under different pHs, temperatures, and silicate concentrations. The presence of 5-mer peptides also shows distinct structural differences during the formation of iron-sulphide NM chimneys. Nano-titanium dioxide NMs (nTiO2) were used to show the toxicity of nTiO2 encrusted Pseudomonas aeruginosa (PA) fed to Tetrahymena thermophila (TT) protozoa under aerobic conditions. The control TT showed limited toxicity when grown in the presence of nTiO2, and scanning transmission electron microscopy (STEM) revealed the initial accumulation of nTiO2 in food vacuoles (FVs) of control TT cells that were not observed in the TT grown with nTiO2-encrusted PA. After 22 h, very little nTiO2 is observed in the control TT FVs as compared with the TT grown with nTiO2-encrusted PA FVs which had about 30% of the FV filled with nTiO2. Toxicity to nTiO2 was observed as reduced growth yields for both the control and the PA fed TT, but also as a reduction in growth rate for TT grown with nTiO2-encrusted PA. To understand biological weathering of NMs, the use of STEM energy dispersive spectroscopy (EDS) was enhanced to analyze single nano-sized particles

  14. A new family of giardial cysteine-rich non-VSP protein genes and a novel cyst protein.

    Directory of Open Access Journals (Sweden)

    Barbara J Davids

    Full Text Available Since the Giardia lamblia cyst wall is necessary for survival in the environment and host infection, we tested the hypothesis that it contains proteins other than the three known cyst wall proteins. Serial analysis of gene expression during growth and encystation revealed a gene, "HCNCp" (High Cysteine Non-variant Cyst protein, that was upregulated late in encystation, and that resembled the classic Giardia variable surface proteins (VSPs that cover the trophozoite plasmalemma. HCNCp is 13.9% cysteine, with many "CxxC" tetrapeptide motifs and a transmembrane sequence near the C-terminus. However, HCNCp has multiple "CxC" motifs rarely found in VSPs, and does not localize to the trophozoite plasmalemma. Moreover, the HCNCp C-terminus differed from the canonical VSP signature. Full-length epitope-tagged HCNCp expressed under its own promoter was upregulated during encystation with highest expression in cysts, including 42 and 21 kDa C-terminal fragments. Tagged HCNCp targeted to the nuclear envelope in trophozoites, and co-localized with cyst proteins to encystation-specific secretory vesicles during encystation. HCNCp defined a novel trafficking pathway as it localized to the wall and body of cysts, while the cyst proteins were exclusively in the wall. Unlike VSPs, HCNCp is expressed in at least five giardial strains and four WB subclones expressing different VSPs. Bioinformatics identified 60 additional large high cysteine membrane proteins (HCMp containing > or = 20 CxxC/CxC's lacking the VSP-specific C-terminal CRGKA. HCMp were absent or rare in other model or parasite genomes, except for Tetrahymena thermophila with 30. MEME analysis classified the 61 gHCMp genes into nine groups with similar internal motifs. Our data suggest that HCNCp is a novel invariant cyst protein belonging to a new HCMp family that is abundant in the Giardia genome. HCNCp and the other HCMp provide a rich source for developing parasite-specific diagnostic reagents

  15. Transcriptome analysis of the Cryptocaryon irritans tomont stage identifies potential genes for the detection and control of cryptocaryonosis

    Directory of Open Access Journals (Sweden)

    Wan Kiew-Lian

    2010-01-01

    Full Text Available Abstract Background Cryptocaryon irritans is a parasitic ciliate that causes cryptocaryonosis (white spot disease in marine fish. Diagnosis of cryptocaryonosis often depends on the appearance of white spots on the surface of the fish, which are usually visible only during later stages of the disease. Identifying suitable biomarkers of this parasite would aid the development of diagnostic tools and control strategies for C. irritans. The C. irritans genome is virtually unexplored; therefore, we generated and analyzed expressed sequence tags (ESTs of the parasite to identify genes that encode for surface proteins, excretory/secretory proteins and repeat-containing proteins. Results ESTs were generated from a cDNA library of C. irritans tomonts isolated from infected Asian sea bass, Lates calcarifer. Clustering of the 5356 ESTs produced 2659 unique transcripts (UTs containing 1989 singletons and 670 consensi. BLAST analysis showed that 74% of the UTs had significant similarity (E-value -5 to sequences that are currently available in the GenBank database, with more than 15% of the significant hits showing unknown function. Forty percent of the UTs had significant similarity to ciliates from the genera Tetrahymena and Paramecium. Comparative gene family analysis with related taxa showed that many protein families are conserved among the protozoans. Based on gene ontology annotation, functional groups were successfully assigned to 790 UTs. Genes encoding excretory/secretory proteins and membrane and membrane-associated proteins were identified because these proteins often function as antigens and are good antibody targets. A total of 481 UTs were classified as encoding membrane proteins, 54 were classified as encoding for membrane-bound proteins, and 155 were found to contain excretory/secretory protein-coding sequences. Amino acid repeat-containing proteins and GPI-anchored proteins were also identified as potential candidates for the development of

  16. The calpains: modular designs and functional diversity.

    Science.gov (United States)

    Croall, Dorothy E; Ersfeld, Klaus

    2007-01-01

    The calpain family is named for the calcium dependence of the papain-like, thiol protease activity of the well-studied ubiquitous vertebrate enzymes calpain-1 (mu-calpain) and calpain-2 (m-calpain). Proteins showing sequence relatedness to the catalytic core domains of these enzymes are included in this ancient and diverse eukaryotic protein family. Calpains are examples of highly modular organization, with several varieties of amino-terminal or carboxy-terminal modules flanking a conserved core. Acquisition of the penta-EF-hand module involved in calcium binding (and the formation of heterodimers for some calpains) seems to be a relatively late event in calpain evolution. Several alternative mechanisms for binding calcium and associating with membranes/phospholipids are found throughout the family. The gene family is expanded in mammals, trypanosomes and ciliates, with up to 26 members in Tetrahymena, for example; in striking contrast to this, only a single calpain gene is present in many other protozoa and in plants. The many isoforms of calpain and their multiple splice variants complicate the discussion and analysis of the family, and challenge researchers to ascertain the relationships between calpain gene sequences, protein isoforms and their distinct or overlapping functions. In mammals and plants it is clear that a calpain plays an essential role in development. There is increasing evidence that ubiquitous calpains participate in a variety of signal transduction pathways and function in important cellular processes of life and death. In contrast to relatively promiscuous degradative proteases, calpains cleave only a restricted set of protein substrates and use complex substrate-recognition mechanisms, involving primary and secondary structural features of target proteins. The detailed physiological significance of both proteolytically active calpains and those lacking key catalytic residues requires further study.

  17. [The importance of model organisms to study cilia and flagella biology].

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    Vincensini, Laetitia; Blisnick, Thierry; Bastin, Philippe

    2011-01-01

    Cilia and flagella are ubiquitous organelles that protrude from the surfaces of many cells, and whose architecture is highly conserved from protists to humans. These complex organelles, composed of over 500 proteins, can be either immotile or motile. They are involved in a myriad of biological processes, including sensing (non-motile cilia) and/or cell motility or movement of extracellular fluids (motile cilia). The ever-expanding list of human diseases linked to defective cilia illustrates the functional importance of cilia and flagella. These ciliopathies are characterised by an impressive diversity of symptoms and an often complex genetic etiology. A precise knowledge of cilia and flagella biology is thus critical to better understand these pathologies. However, multi-ciliated cells are terminally differentiated and difficult to manipulate, and a primary cilium is assembled only when the cell exits from the cell cycle. In this context the use of model organisms, that relies on the high degree of structural but also of molecular conservation of these organelles across evolution, is instrumental to decipher the many facets of cilia and flagella biology. In this review, we highlight the specific strengths of the main model organisms to investigate the molecular composition, mode of assembly, sensing and motility mechanisms and functions of cilia and flagella. Pioneering studies carried out in the green alga Chlamydomonas established the link between cilia and several genetic diseases. Moreover, multicellular organisms such as mouse, zebrafish, Xenopus, C. elegans or Drosophila, and protists like Paramecium, Tetrahymena and Trypanosoma or Leishmania each bring specific advantages to the study of cilium biology. For example, the function of genes involved in primary ciliary dyskinesia (due to defects in ciliary motility) can be efficiently assessed in trypanosomes.

  18. Digestion, ruminal fermentation, ciliate protozoal populations, and milk production from dairy cows fed cinnamaldehyde, quebracho condensed tannin, or Yucca schidigera saponin extracts.

    Science.gov (United States)

    Benchaar, C; McAllister, T A; Chouinard, P Y

    2008-12-01

    Four ruminally cannulated lactating cows were used in a 4 x 4 Latin square design (28-d periods) to determine the effects of cinnamaldehyde (CIN; 1 g/cow per day), condensed tannins from quebracho trees (QCT, containing 70% tannins, 150 g/cow per day), and saponins from Yucca schidigera extract (YSE, containing 10% saponins; 60 g/cow per day) on digestion, ruminal fermentation characteristics, protozoal populations, and milk production. Intake of dry matter was not affected by the addition of CIN or QCT, but cows fed YSE had lesser intake than cows fed the control diet (21.8 vs. 23.2 kg/d). Apparent total-tract digestibilities of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber were unaffected by dietary treatments. Supplementation with CIN, QTE, or YSE did not affect in situ ruminal degradation of soybean meal, grass silage, or corn grain. Ruminal pH (6.67), total volatile fatty acid concentration (135 mM), and molar proportions (mol/100 mol of total volatile fatty acid) of acetate (65.0), propionate (19.6), and butyrate (11.2) were similar among treatments. Ruminal NH(3)-N concentration was not changed by the addition of CIN and YSE, but tended to decrease in cows fed QCT compared with cows fed the control diet (132 vs. 160 mg/L). Total numbers of ruminal protozoa were not changed by adding CIN, QCT, or YSE in the diet (5.85 log(10)/mL). However, the number of Isotricha was greater in ruminal fluid of cows fed CIN than in ruminal fluid of cows fed the control diet (4.46 vs. 4.23 log(10)/mL). Milk production (33.1 kg/d), milk fat (4.3%), and milk protein (3.5%) remained unchanged between dietary treatments. Results of this study show that under our experimental conditions, supplementing dairy cow diets with CIN, QCT, or YSE had limited effects on digestion, ruminal fermentation characteristics, and protozoal populations. The lack of effects observed in this study suggests that these antimicrobials require administration at greater doses to favorably alter rumen microbial fermentation.

  19. Design and validation of four new primers for next-generation sequencing to target the 18S rRNA genes of gastrointestinal ciliate protozoa.

    Science.gov (United States)

    Ishaq, Suzanne L; Wright, André-Denis G

    2014-09-01

    Four new primers and one published primer were used to PCR amplify hypervariable regions within the protozoal 18S rRNA gene to determine which primer pair provided the best identification and statistical analysis. PCR amplicons of 394 to 498 bases were generated from three primer sets, sequenced using Roche 454 pyrosequencing with Titanium, and analyzed using the BLAST database (NCBI) and MOTHUR version 1.29. The protozoal diversity of rumen contents from moose in Alaska was assessed. In the present study, primer set 1, P-SSU-316F and GIC758R (amplicon of 482 bases), gave the