Pathogenic bacteriumVibrio harveyi: an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans

Institute of Scientific and Technical Information of China (English)

QIAO Ying; WANG Jun; MAO Yong; LIU Min; CHEN Ruanni; SU Yongquan; KE Qiaozhen; HAN Kunhuang; ZHENG Weiqiang

2017-01-01

Vibrio harveyi, known as a pathogenic bacterium caused severe secondary bacterial infections of the large yellow croaker Larimichthys crocea, was identified as an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans. Meta 16S sequencing method was used to identify the bacterial flora in C. irritans, and V. harveyi was isolated via culture-dependent method.Vibrio harveyi was observed in cytoplasm of C. irritans at the stage of tomont both by transmission electron microscopy and by Fluorescencein situ hybridization; no signal, however, was detected in nucleus area. The relationship betweenV. harveyi and C. irritans and the role of endosymbioticV. harveyi inC. irritans merit further investigation.

Characterization of copper resistant ciliates: Potential candidates for ...

African Journals Online (AJOL)

Jane

2011-08-17

, bioremediation. ... on metal interactions in protist ciliates. Ciliated protozoa .... Generally, protozoan cultures grow in mineral salts me- ... utilizing these metal ions as essential requirement or by ...... Lead resistant yeast.

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

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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.

Galvanotactic behavior of Tetrahymena pyriformis under electric fields

International Nuclear Information System (INIS)

Kim, Dal Hyung; Kim, Paul Seung Soo; Kim, Min Jun; Lee, Kyoungwoo; Kim, JinSeok

2013-01-01

Tetrahymena pyriformis, a eukaryotic ciliate, swims toward a cathode in straight or cross-shaped microchannels under an applied electric field, a behavioral response called cathodal galvanotaxis. In straight channel experiments, a one-dimensional electric field was applied, and the galvanotactic swimming behavior of Tetrahymena pyriformis was observed and described in detail while the polarity of this field is switched. In most individual cases, the cell would immediately switch its direction toward the cathode; however, exceptional cases have been observed where cells exhibit a turning delay or do not turn after a polarity switch. In cross-channel experiments, feedback control using vision-based tracking was used to steer a cell in the microchannel intersection using a two-dimensional electric field generated by four electrodes placed at four ends of the cross channel. The motivation for this work is to study the swimming behavior of Tetrahymena pyriformis as a microrobot under the control of electric fields. (paper)

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

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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

Evolution of the Exon-Intron Structure in Ciliate Genomes.

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Vladyslav S Bondarenko

Full Text Available A typical eukaryotic gene is comprised of alternating stretches of regions, exons and introns, retained in and spliced out a mature mRNA, respectively. Although the length of introns may vary substantially among organisms, a large fraction of genes contains short introns in many species. Notably, some Ciliates (Paramecium and Nyctotherus possess only ultra-short introns, around 25 bp long. In Paramecium, ultra-short introns with length divisible by three (3n are under strong evolutionary pressure and have a high frequency of in-frame stop codons, which, in the case of intron retention, cause premature termination of mRNA translation and consequent degradation of the mis-spliced mRNA by the nonsense-mediated decay mechanism. Here, we analyzed introns in five genera of Ciliates, Paramecium, Tetrahymena, Ichthyophthirius, Oxytricha, and Stylonychia. Introns can be classified into two length classes in Tetrahymena and Ichthyophthirius (with means 48 bp, 69 bp, and 55 bp, 64 bp, respectively, but, surprisingly, comprise three distinct length classes in Oxytricha and Stylonychia (with means 33-35 bp, 47-51 bp, and 78-80 bp. In most ranges of the intron lengths, 3n introns are underrepresented and have a high frequency of in-frame stop codons in all studied species. Introns of Paramecium, Tetrahymena, and Ichthyophthirius are preferentially located at the 5' and 3' ends of genes, whereas introns of Oxytricha and Stylonychia are strongly skewed towards the 5' end. Analysis of evolutionary conservation shows that, in each studied genome, a significant fraction of intron positions is conserved between the orthologs, but intron lengths are not correlated between the species. In summary, our study provides a detailed characterization of introns in several genera of Ciliates and highlights some of their distinctive properties, which, together, indicate that splicing spellchecking is a universal and evolutionarily conserved process in the biogenesis of short

The conjugation-specific Die5 protein is required for development of the somatic nucleus in both Paramecium and Tetrahymena.

Science.gov (United States)

Matsuda, Atsushi; Shieh, Annie Wan-Yi; Chalker, Douglas L; Forney, James D

2010-07-01

Development in ciliated protozoa involves extensive genome reorganization within differentiating macronuclei, which shapes the somatic genome of the next vegetative generation. Major events of macronuclear differentiation include excision of internal eliminated sequences (IESs), chromosome fragmentation, and genome amplification. Proteins required for these events include those with homology throughout eukaryotes as well as proteins apparently unique to ciliates. In this study, we identified the ciliate-specific Defective in IES Excision 5 (DIE5) genes of Paramecium tetraurelia (PtDIE5) and Tetrahymena thermophila (TtDIE5) as orthologs that encode nuclear proteins expressed exclusively during development. Abrogation of PtDie5 protein (PtDie5p) function by RNA interference (RNAi)-mediated silencing or TtDie5p by gene disruption resulted in the failure of developing macronuclei to differentiate into new somatic nuclei. Tetrahymena DeltaDIE5 cells arrested late in development and failed to complete genome amplification, whereas RNAi-treated Paramecium cells highly amplified new macronuclear DNA before the failure in differentiation, findings that highlight clear differences in the biology of these distantly related species. Nevertheless, IES excision and chromosome fragmentation failed to occur in either ciliate, which strongly supports that Die5p is a critical player in these processes. In Tetrahymena, loss of zygotic expression during development was sufficient to block nuclear differentiation. This observation, together with the finding that knockdown of Die5p in Paramecium still allows genome amplification, indicates that this protein acts late in macronuclear development. Even though DNA rearrangements in these two ciliates look to be quite distinct, analysis of DIE5 establishes the action of a conserved mechanism within the genome reorganization pathway.

Dissecting relative contributions of cis- and trans-determinants to nucleosome distribution by comparing Tetrahymena macronuclear and micronuclear chromatin.

Science.gov (United States)

Xiong, Jie; Gao, Shan; Dui, Wen; Yang, Wentao; Chen, Xiao; Taverna, Sean D; Pearlman, Ronald E; Ashlock, Wendy; Miao, Wei; Liu, Yifan

2016-12-01

The ciliate protozoan Tetrahymena thermophila contains two types of structurally and functionally differentiated nuclei: the transcriptionally active somatic macronucleus (MAC) and the transcriptionally silent germ-line micronucleus (MIC). Here, we demonstrate that MAC features well-positioned nucleosomes downstream of transcription start sites and flanking splice sites. Transcription-associated trans-determinants promote nucleosome positioning in MAC. By contrast, nucleosomes in MIC are dramatically delocalized. Nucleosome occupancy in MAC and MIC are nonetheless highly correlated with each other, as well as with in vitro reconstitution and predictions based upon DNA sequence features, revealing unexpectedly strong contributions from cis-determinants. In particular, well-positioned nucleosomes are often matched with GC content oscillations. As many nucleosomes are coordinately accommodated by both cis- and trans-determinants, we propose that their distribution is shaped by the impact of these nucleosomes on the mutational and transcriptional landscape, and driven by evolutionary selection. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

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

International Nuclear Information System (INIS)

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

1987-01-01

Cells of the ciliated protozoan Tetrahymena pyriformis incubated with [ 14 C]glucose were found to synthesize Man-P-dolichol and Glc-P-dolichol, as well as Glc 3 Man 5 GlcNAc 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 2 -P-P-dolichol from pig liver, and GDP-[ 14 C]Man. Under exactly the same conditions but with UDP-[ 14 C]Glc instead of GDP-[ 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

Cell death in Tetrahymena thermophila: new observations on culture conditions.

Science.gov (United States)

Christensen, S T; Sørensen, H; Beyer, N H; Kristiansen, K; Rasmussen, L; Rasmussen, M I

2001-01-01

We previously suggested that the cell fate of the protozoan ciliate, Tetrahymena thermophila, effectively relates to a quorum-sensing mechanism where cell-released factors support cell survival and proliferation. The cells have to be present above a critical initial density in a chemically defined nutrient medium in order to release a sufficient level of these factors to allow a new colony to flourish. At a relatively high rate of metabolism and/or macromolecular synthesis and below this critical density, cells began to die abruptly within 30 min of inoculation, and this death took the form of an explosive disintegration lasting less than 50 milliseconds. The cells died at any location in the culture, and the frequency of cell death was always lower in well-filled vials than those with medium/air interface. Cell death was inhibited by the addition of Actinomycin D or through modifications of the culture conditions either by reducing the oxygen tension or by decreasing the temperature of the growth medium. In addition, plastic caps in well-filled vials release substances, which promote cell survival. The fate of low-density cultures is related to certain 'physical' conditions, in addition to the availability of oxygen within closed culture systems. Copyright 2001 Academic Press.

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.

Two-dimensional gravitactic bioconvection in a protozoan (tetrahymena pyriformis) culture

OpenAIRE

Nguyen-Quang, Tri; Nguyen, The Hung; Guichard, Frederic; Nicolau, Ana; Szatmari, George; LePalec, Georges; Dusser, Martine; Lafossee, Josee; Bonnet, Jean Louis; Bohatier, Jacques

2009-01-01

Gravitactic bioconvective patterns created by Tetrahymena pyriformis in a Hele-Shaw apparatus were realized and compared with theoretical results. There were found to be two thresholds for bioconvection development: the first indicates the transition from the diffusion to the steady convection state; the second corresponds to the transition from the steady to the unsteady convection state. The results showed that the Hele-Shaw apparatus may be used as a physical analogy of poro...

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

expressed during vegetative growth or sexual reorganization. In order to get an overview of medium-sized (40-500¿nt) RNAs expressed from the Tetrahymena genome, we created a size-fractionated cDNA library from macronuclear RNA and analyzed 80 RNAs, most of which were previously unknown. The most abundant...... class was small nucleolar RNAs (snoRNAs), many of which are formed by an unusual maturation pathway. The modifications guided by the snoRNAs were analyzed bioinformatically and experimentally and many Tetrahymena-specific modifications were found, including several in an essential, but not conserved...

Transposon domestication versus mutualism in ciliate genome rearrangements.

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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.

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

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...

Protozoan Predation of Escherichia coli O157:H7 Is Unaffected by the Carriage of Shiga Toxin-Encoding Bacteriophages.

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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.

Tetrahymena metallothioneins fall into two discrete subfamilies.

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Silvia Díaz

2007-03-01

Full Text Available Metallothioneins are ubiquitous small, cysteine-rich, multifunctional proteins which can bind heavy metals.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.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.

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

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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.

A novel mitochondrial nuclease-associated protein: a major executor of the programmed nuclear death in Tetrahymena thermophila.

Science.gov (United States)

Osada, Eriko; Akematsu, Takahiko; Asano, Tomoya; Endoh, Hiroshi

2014-03-01

Programmed nuclear death (PND) in the ciliate Tetrahymena is an apoptosis-like phenomenon that occurs in a restricted space of cytoplasm during conjugation. In the process, only the parental macronucleus is selectively eliminated from the progeny cytoplasm, in conjunction with differentiation of new macronuclei for the next generation. For the last decade, mitochondria have been elucidated to be a crucial executioner like apoptosis: apoptosis-inducing factor and yet-unidentified nucleases localised in mitochondria are major factors for PND. To identify such nucleases, we performed a DNase assay in a PAGE (SDS-DNA-PAGE) using total mitochondrial proteins. Some proteins showed DNase activity, but particularly a 17 kDa protein exhibited the highest and predominant activity. Mass spectrometric analysis revealed a novel mitochondrial nuclease, named TMN1, whose homologue has been discovered only in the ciliate Paramecium tetraurelia, but not in other eukaryotes. Gene disruption of TMN1 led to a drastic reduction of mitochondrial nuclease activity and blocked nuclear degradation during conjugation, but did not affect accumulation of autophagic and lysosomal machinery around the parental macronucleus. These observations strongly suggest that the mitochondrial nuclease-associated protein plays a key role in PND as a major executor. Taking the novel protein specific to ciliates in consideration, Tetrahymena would have diverted a different protein from common apoptotic factors shared in eukaryotes to PND in the course of ciliate evolution. © 2014 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

Monoculture of the ciliate protozoan Euplotes sp. (Ciliophora; Hypotrichia fed with different diets - doi: 10.4025/actascibiolsci.v35i1.11795

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Emílio Mateus Costa Melo

2012-12-01

Full Text Available Ciliate protozoa of the genus Euplotes commonly appears contaminating mass cultures of rotifers but also with potential to be used as live food in the larviculture of marine fish. To obtain a monoculture of Euplotes sp., three diets were tested: 1 microalgae Nannochloropsis oculata, 2 commercial diet for rotifers Culture Selco 3000, and 3 baker’s yeast (Saccharomyces cerevisiae. The ciliates were inoculated at 10 ind. mL-¹. On day 5, protozoa densities in the groups fed the commercial diet (1,911.0 ± 248.7 ind. mL-¹ and the baker’s yeast (2,600.0 ± 195.3 ind. mL-1 did not differ, but were higher than the group fed microalgae (2.0 ± 1.4 ind. mL-1 (p -¹ than in the groups fed microalgae (3.0 ± 1.4 ind. mL-¹ or commercial diet (11,287.0 ± 1,468.0 ind. mL-¹. An exponential growth curve was observed for the protozoa fed baker’s yeast (R² = 0.992; p Euplotes sp. can result in very high densities of this protozoan.  

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

International Nuclear Information System (INIS)

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 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)

Cyc17, a meiosis-specific cyclin, is essential for anaphase initiation and chromosome segregation in Tetrahymena thermophila.

Science.gov (United States)

Yan, Guan-Xiong; Dang, Huai; Tian, Miao; Zhang, Jing; Shodhan, Anura; Ning, Ying-Zhi; Xiong, Jie; Miao, Wei

2016-07-17

Although the role of cyclins in controlling nuclear division is well established, their function in ciliate meiosis remains unknown. In ciliates, the cyclin family has undergone massive expansion which suggests that diverse cell cycle systems exist, and this warrants further investigation. A screen for cyclins in the model ciliate Tetrahymena thermophila showed that there are 34 cyclins in this organism. Only 1 cyclin, Cyc17, contains the complete cyclin core and is specifically expressed during meiosis. Deletion of CYC17 led to meiotic arrest at the diakinesis-like metaphase I stage. Expression of genes involved in DNA metabolism and chromosome organization (chromatin remodeling and basic chromosomal structure) was repressed in cyc17 knockout matings. Further investigation suggested that Cyc17 is involved in regulating spindle pole attachment, and is thus essential for chromosome segregation at meiosis. These findings suggest a simple model in which chromosome segregation is influenced by Cyc17.

Inhibition of the Rumen Ciliate Entodinium caudatum by Antibiotics

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Tansol Park

2017-06-01

Full Text Available Axenic cultures of free-living aerobic ciliates, such as Tetrahymena thermophila and Paramecium aurelia, have been established and routinely used in laboratory research, greatly facilitating, or enabling characterization of their metabolism, physiology, and ecology. Ruminal protozoa are anaerobic ciliates, and they play important roles in feed digestion and fermentation. Although, repeatedly attempted, no laboratory-maintainable axenic culture of ruminal ciliates has been established. When axenic ciliate cultures are developed, antibiotics are required to eliminate the accompanying bacteria. Ruminal ciliates gradually lose viability upon antibiotic treatments, and the resultant axenic cultures can only last for short periods of time. The objective of this study was to evaluate eight antibiotics that have been evaluated in developing axenic cultures of ruminal ciliates, for their toxicity to Entodinium caudatum, which is the most predominant ruminal ciliate species. Scanning and transmission electron microscopy (TEM showed that the antibiotics damaged both the cell surface and nuclei of E. caudatum and increased accumulation of intracellular glycogen. Combinations of the three least toxic antibiotics failed to eliminate the bacteria that are present in the E. caudatum culture. The combination of ampicillin, carbenicillin, streptomycin, and oxytetracycline was able to eliminate all the bacteria, but the resultant axenic E. caudatum culture gradually lost viability. Adding the bacterial fraction (live separated from an untreated E. caudatum culture reversed the viability decline and recovered the growth of the treated E. caudatum culture, whereas feeding nine strains of live bacteria isolated from E. caudatum cells, either individually or in combination, could not. Nutritional and metabolic dependence on its associated bacteria, accompanied with direct and indirect inhibition by antibiotics, makes it difficult to establish an axenic culture of E

Role of apoptosis-inducing factor (AIF in programmed nuclear death during conjugation in Tetrahymena thermophila

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Endoh Hiroshi

2010-02-01

Full Text Available Abstract Background Programmed nuclear death (PND, which is also referred to as nuclear apoptosis, is a remarkable process that occurs in ciliates during sexual reproduction (conjugation. In Tetrahymena thermophila, when the new macronucleus differentiates, the parental macronucleus is selectively eliminated from the cytoplasm of the progeny, concomitant with apoptotic nuclear events. However, the molecular mechanisms underlying these events are not well understood. The parental macronucleus is engulfed by a large autophagosome, which contains numerous mitochondria that have lost their membrane potential. In animals, mitochondrial depolarization precedes apoptotic cell death, which involves DNA fragmentation and subsequent nuclear degradation. Results We focused on the role of mitochondrial apoptosis-inducing factor (AIF during PND in Tetrahymena. The disruption of AIF delays the normal progression of PND, specifically, nuclear condensation and kilobase-size DNA fragmentation. AIF is localized in Tetrahymena mitochondria and is released into the macronucleus prior to nuclear condensation. In addition, AIF associates and co-operates with the mitochondrial DNase to facilitate the degradation of kilobase-size DNA, which is followed by oligonucleosome-size DNA laddering. Conclusions Our results suggest that Tetrahymena AIF plays an important role in the degradation of DNA at an early stage of PND, which supports the notion that the mitochondrion-initiated apoptotic DNA degradation pathway is widely conserved among eukaryotes.

Genetics and Epigenetics of Mating Type Determination in Paramecium and Tetrahymena.

Science.gov (United States)

Orias, Eduardo; Singh, Deepankar Pratap; Meyer, Eric

2017-09-08

While sex is an ancient and highly conserved eukaryotic invention, self-incompatibility systems such as mating types or sexes appear to be derived limitations that show considerable evolutionary plasticity. Within a single class of ciliates, Paramecium and Tetrahymena species have long been known to present a wide variety of mating type numbers and modes of inheritance, but only recently have the genes involved been identified. Although similar transmembrane proteins mediate self/nonself recognition in both ciliates, the mechanisms of mating type determination differ widely, ranging from Mendelian systems to developmental nuclear differentiation, either stochastic or maternally inherited. The non-Mendelian systems rely on programmed editing of the germline genome that occurs during differentiation of the somatic nucleus, and they have co-opted different DNA recombination mechanisms-some previously unknown. Here we review the recent molecular advances and some remaining unsolved questions and discuss the possible implications of these diverse mechanisms for inbreeding/outbreeding balance regulation.

A comparative in-silico analysis of autophagy proteins in ciliates

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Erhan Aslan

2017-01-01

Full Text Available Autophagy serves as a turnover mechanism for the recycling of redundant and/or damaged macromolecules present in eukaryotic cells to re-use them under starvation conditions via a double-membrane structure known as autophagosome. A set of eukaryotic genes called autophagy-related genes (ATGs orchestrate this highly elaborative process. The existence of these genes and the role they play in different eukaryotes are well-characterized. However, little is known of their role in some eukaryotes such as ciliates. Here, we report the computational analyses of ATG genes in five ciliate genomes to understand their diversity. Our results show that Oxytricha trifallax is the sole ciliate which has a conserved Atg12 conjugation system (Atg5-Atg12-Atg16. Interestingly, Oxytricha Atg16 protein includes WD repeats in addition to its N-terminal Atg16 domain as is the case in multicellular organisms. Additionally, phylogenetic analyses revealed that E2-like conjugating protein Atg10 is only present in Tetrahymena thermophila. We fail to find critical autophagy components Atg5, Atg7 and Atg8 in the parasitic ciliate Ichthyophthirius multifiliis. Contrary to previous reports, we also find that ciliate genomes do not encode typical Atg1 since all the candidate sequences lack an Atg1-specific C-terminal domain which is essential for Atg1 complex formation. Consistent with the absence of Atg1, ciliates also lack other members of the Atg1 complex. However, the presence of Atg6 in all ciliates examined here may rise the possibility that autophagosome formation could be operated through Atg6 in ciliates, since Atg6 has been shown as an alternative autophagy inducer. In conclusion, our results highlight that Atg proteins are partially conserved in ciliates. This may provide a better understanding for the autophagic destruction of the parental macronucleus, a developmental process also known as programmed nuclear death in ciliates.

The importance of protozoan bacterivory in a subtropical environment (Lobo-Broa Reservoir, SP, Brazil

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AS Mansano

Full Text Available This study evaluated the importance of heterotrophic nanoflagellates (HNF and ciliates bacterivory in a mesotrophic subtropical environment (Lobo-Broa Reservoir, Brazil by the quantification of their ingestion rates. The in situ experiments using fluorescently labelled bacteria (FLB were carried out bimonthly over one year (three surveys in the dry season and three in the rainy one at the sub-surface of two sampling points that have different trophic degrees. The ingestion rates for both ciliates and HNF were higher in the meso-eutrophic region (point 2 due to the higher water temperatures, which accelerate the metabolism of protozoans and the higher bacteria densities. Concerning total protozoan bacterivory, the HNF had the greatest grazing impact on bacterial community, especially the HNF <5µm. The data showed that HNF grazing, in addition to regulating the bacteria abundance, also induced changes to the bacterial community structure, such as increasing size and numbers of bacterial filaments. The ciliates were also important to the system bacterivory, especially in point 2, where there were high densities and ingestion rates. The protozoan bottom-up control was more important in the dry season and the top-down control was more important in the rainy season, so, these two forces are equally important to the bacterial abundance regulation in this reservoir in an annual basis.

Microfaunal indicators, Ciliophora phylogeny and protozoan population shifts in an intermittently aerated and fed bioreactor

International Nuclear Information System (INIS)

Ntougias, Spyridon; Tanasidis, Spartakos; Melidis, Paraschos

2011-01-01

Microfauna community structure was examined in the mixed liquor of a bench-scale bioreactor equipped with an intermittent aeration and feeding system. The reactor was operated under an intermittent aeration of 25 min in every 1 h and varying feeding conditions (0.264, 0.403 and 0.773 kg BOD 5 /m 3 d). A total of 14 protozoan and metazoan taxa were identified by microscopic examination. Sessile ciliates, followed by crawling ciliates, were the major protozoan groups under 0.403 kg BOD 5 /m 3 d organic loading conditions, while sessile ciliate population was remarkably increased under an organic loading of 0.773 kg BOD 5 /m 3 d. Principal Component Analysis and Pearson correlation coefficient tests were performed in order to reveal relationships between microfauna community and operational parameters. Ciliophora specific-18S rRNA gene clone library was constructed to identify ciliate diversity under 0.773 kg BOD 5 /m 3 d organic loading conditions. Ciliophora diversity consisted of members of Aspidiscidae, Epistylidae, Opisthonectidae and Vorticellidae, with the majority of the clones being associated with the species Vorticella fusca. At least one novel phylogenetic linkage among Ciliophora was identified. Comparisons made after molecular characterization and microscopic examination of Ciliophora community showed that the estimation of broad ciliate groups is useful for ecological considerations and evaluation of the operational conditions in wastewater treatment plants.

Microfaunal indicators, Ciliophora phylogeny and protozoan population shifts in an intermittently aerated and fed bioreactor

Energy Technology Data Exchange (ETDEWEB)

Ntougias, Spyridon, E-mail: sntougia@env.duth.gr [Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67100 Xanthi (Greece); Tanasidis, Spartakos; Melidis, Paraschos [Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67100 Xanthi (Greece)

2011-02-28

Microfauna community structure was examined in the mixed liquor of a bench-scale bioreactor equipped with an intermittent aeration and feeding system. The reactor was operated under an intermittent aeration of 25 min in every 1 h and varying feeding conditions (0.264, 0.403 and 0.773 kg BOD{sub 5}/m{sup 3} d). A total of 14 protozoan and metazoan taxa were identified by microscopic examination. Sessile ciliates, followed by crawling ciliates, were the major protozoan groups under 0.403 kg BOD{sub 5}/m{sup 3} d organic loading conditions, while sessile ciliate population was remarkably increased under an organic loading of 0.773 kg BOD{sub 5}/m{sup 3} d. Principal Component Analysis and Pearson correlation coefficient tests were performed in order to reveal relationships between microfauna community and operational parameters. Ciliophora specific-18S rRNA gene clone library was constructed to identify ciliate diversity under 0.773 kg BOD{sub 5}/m{sup 3} d organic loading conditions. Ciliophora diversity consisted of members of Aspidiscidae, Epistylidae, Opisthonectidae and Vorticellidae, with the majority of the clones being associated with the species Vorticella fusca. At least one novel phylogenetic linkage among Ciliophora was identified. Comparisons made after molecular characterization and microscopic examination of Ciliophora community showed that the estimation of broad ciliate groups is useful for ecological considerations and evaluation of the operational conditions in wastewater treatment plants.

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.

Product analysis illuminates the final steps of IES deletion in Tetrahymena thermophila.

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Saveliev, S V; Cox, M M

2001-06-15

DNA sequences (IES elements) eliminated from the developing macronucleus in the ciliate Tetrahymena thermophila are released as linear fragments, which have now been detected and isolated. A PCR-mediated examination of fragment end structures reveals three types of strand scission events, reflecting three steps in the deletion process. New evidence is provided for two steps proposed previously: an initiating double-stranded cleavage, and strand transfer to create a branched deletion intermediate. The fragment ends provide evidence for a previously uncharacterized third step: the branched DNA strand is cleaved at one of several defined sites located within 15-16 nucleotides of the IES boundary, liberating the deleted DNA in a linear form.

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

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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.

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 H P; Huynen, Martijn A

2006-02-10

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). 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. 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.

Meeting on the Microbiology of Soils, Autumn 2001: Estimation of protozoan diversity in soil

DEFF Research Database (Denmark)

Ekelund, Flemming

2002-01-01

Different methods of estimating protozoan diversity in soil are discussed in this paper, with the major emphasis on heterotrophic flagellates. Although many species of ciliates and testate amoebae seem to be unique to the soil environment, the communities of heterotrophic flagellates and naked am...

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

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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.

Experimental evolution of protozoan traits in response to interspecific competition.

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terHorst, C P

2011-01-01

Decades of experiments have demonstrated the ecological effect of competition, but experimental evidence for competitive effects on trait evolution is rare. I measured the evolution of six protozoan traits in response to competitors from the inquiline community of pitcher plants. Replicate populations of Colpoda, a ciliated protozoan, were allowed to evolve in response to intra- and interspecific competition for 20 days (approximately 100 generations), before traits were measured in two common garden environments. Populations that evolved with interspecific competition had smaller cell sizes, produced fewer cysts and had higher population growth rates relative to populations grown in monoculture. The presence of interspecific competitors led to differential lineage sorting, most likely by increasing the strength of selection. These results are the first to demonstrate protozoan evolution in response to competition and may have implications for species coexistence in this system. © 2010 The Author. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

Molecular characteristics of an immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

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Ichthyophthirius multifiliis, a ciliated protozoan parasite of fish, expresses surface antigens (i-antigens), which react with host antibodies that render them immobile. The nucleotide sequence of an i-antigen gene of Ichthyophthirius multifiliis strain ARS-6 was deduced. The predicted protein of 47...

Exploration of the Germline Genome of the Ciliate Chilodonella uncinata through Single-Cell Omics (Transcriptomics and Genomics

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Xyrus X. Maurer-Alcalá

2018-01-01

Full Text Available Separate germline and somatic genomes are found in numerous lineages across the eukaryotic tree of life, often separated into distinct tissues (e.g., in plants, animals, and fungi or distinct nuclei sharing a common cytoplasm (e.g., in ciliates and some foraminifera. In ciliates, germline-limited (i.e., micronuclear-specific DNA is eliminated during the development of a new somatic (i.e., macronuclear genome in a process that is tightly linked to large-scale genome rearrangements, such as deletions and reordering of protein-coding sequences. Most studies of germline genome architecture in ciliates have focused on the model ciliates Oxytricha trifallax, Paramecium tetraurelia, and Tetrahymena thermophila, for which the complete germline genome sequences are known. Outside of these model taxa, only a few dozen germline loci have been characterized from a limited number of cultivable species, which is likely due to difficulties in obtaining sufficient quantities of “purified” germline DNA in these taxa. Combining single-cell transcriptomics and genomics, we have overcome these limitations and provide the first insights into the structure of the germline genome of the ciliate Chilodonella uncinata, a member of the understudied class Phyllopharyngea. Our analyses reveal the following: (i large gene families contain a disproportionate number of genes from scrambled germline loci; (ii germline-soma boundaries in the germline genome are demarcated by substantial shifts in GC content; (iii single-cell omics techniques provide large-scale quality germline genome data with limited effort, at least for ciliates with extensively fragmented somatic genomes. Our approach provides an efficient means to understand better the evolution of genome rearrangements between germline and soma in ciliates.

Two Tetrahymena G-DNA-binding proteins, TGP1 and TGP3, share novel motifs and may play a role in micronuclear division

OpenAIRE

Lu, Quan; Henderson, Eric

2000-01-01

G-DNA is a four-stranded DNA structure with diverse putative biological roles. We have previously purified and cloned a novel G-DNA-binding protein TGP1 from the ciliate Tetrahymena thermophila. Here we report the molecular cloning of TGP3, an additional G-DNA-binding protein from the same organism. The TGP3 cDNA encodes a 365 amino acid protein that is homologous to TGP1 (34% identity and 44% similarity). The proteins share a sequence pattern that contains two novel repetitive and homologous...

Highly divergent mitochondrial ATP synthase complexes in Tetrahymena thermophila.

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Praveen Balabaskaran Nina

2010-07-01

Full Text Available 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 highly conserved across prokaryotes and eukaryotes. Therefore, it was a surprise that genes encoding the a and b subunits as well as other components of the F(o sector were undetectable in the sequenced genomes of a variety of apicomplexan parasites. While the parasitic existence of these organisms could explain the apparent incomplete nature of ATP synthase in Apicomplexa, genes for these essential components were absent even in Tetrahymena thermophila, a free-living ciliate belonging to a sister clade of Apicomplexa, which demonstrates robust oxidative phosphorylation. This observation raises the possibility that the entire clade of Alveolata may have invented novel means to operate ATP synthase complexes. To assess this remarkable possibility, we have carried out an investigation of the ATP synthase from T. thermophila. Blue native polyacrylamide gel electrophoresis (BN-PAGE revealed the ATP synthase to be present as a large complex. Structural study based on single particle electron microscopy analysis suggested the complex to be a dimer with several unique structures including an unusually large domain on the intermembrane side of the ATP synthase and novel domains flanking the c subunit rings. The two monomers were in a parallel configuration rather than the angled configuration previously observed in other organisms. Proteomic analyses of well-resolved ATP synthase complexes from 2-D BN/BN-PAGE identified orthologs of seven canonical ATP synthase subunits, and at least 13 novel proteins that constitute subunits apparently limited to the ciliate lineage. A mitochondrially encoded protein, Ymf66, with predicted eight transmembrane domains could be a

Protozoan Bacterivory and Escherichia coli Survival in Drinking Water Distribution Systems

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Sibille, I.; Sime-Ngando, T.; Mathieu, L.; Block, J. C.

1998-01-01

The development of bacterial communities in drinking water distribution systems leads to a food chain which supports the growth of macroorganisms incompatible with water quality requirements and esthetics. Nevertheless, very few studies have examined the microbial communities in drinking water distribution systems and their trophic relationships. This study was done to quantify the microbial communities (especially bacteria and protozoa) and obtain direct and indirect proof of protozoan feeding on bacteria in two distribution networks, one of GAC water (i.e., water filtered on granular activated carbon) and the other of nanofiltered water. The nanofiltered water-supplied network contained no organisms larger than bacteria, either in the water phase (on average, 5 × 107 bacterial cells liter−1) or in the biofilm (on average, 7 × 106 bacterial cells cm−2). No protozoa were detected in the whole nanofiltered water-supplied network (water plus biofilm). In contrast, the GAC water-supplied network contained bacteria (on average, 3 × 108 cells liter−1 in water and 4 × 107 cells cm−2 in biofilm) and protozoa (on average, 105 cells liter−1 in water and 103 cells cm−2 in biofilm). The water contained mostly flagellates (93%), ciliates (1.8%), thecamoebae (1.6%), and naked amoebae (1.1%). The biofilm had only ciliates (52%) and thecamoebae (48%). Only the ciliates at the solid-liquid interface of the GAC water-supplied network had a measurable grazing activity in laboratory test (estimated at 2 bacteria per ciliate per h). Protozoan ingestion of bacteria was indirectly shown by adding Escherichia coli to the experimental distribution systems. Unexpectedly, E. coli was lost from the GAC water-supplied network more rapidly than from the nanofiltered water-supplied network, perhaps because of the grazing activity of protozoa in GAC water but not in nanofiltered water. Thus, the GAC water-supplied network contained a functional ecosystem with well-established and

The fate of deleted DNA produced during programmed genomic deletion events in Tetrahymena thermophila.

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Saveliev, S V; Cox, M M

1994-01-01

Thousands of DNA deletion events occur during macronuclear development in the ciliate Tetrahymena thermophila. In two deleted genomic regions, designated M and R, the eliminated sequences form circles that can be detected by PCR. However, the circles are not normal products of the reaction pathway. The circular forms occur at very low levels in conjugating cells, but are stable. Sequencing analysis showed that many of the circles (as many as 50% of those examined) reflected a precise deletion in the M and R regions. The remaining circles were either smaller or larger and contained varying lengths of sequences derived from the chromosomal DNA surrounding the eliminated region. The chromosomal junctions left behind after deletion were more precise, although deletions in either the M or R regions can generate any of several alternative junctions (1). Some new chromosomal junctions were detected in the present study. The results suggest that the deleted segment is released as a linear DNA species that is degraded rapidly. The species is only rarely converted to the stable circles we detect. The deletion mechanism is different from those proposed for deletion events in hypotrichous ciliates (2-4), and does not reflect a conservative site-specific recombination process such as that promoted by the bacteriophage lambda integrase (5). Images PMID:7838724

Impact and control of protozoan parasites in maricultured fishes.

Science.gov (United States)

Buchmann, Kurt

2015-01-01

Aquaculture, including both freshwater and marine production, has on a world scale exhibited one of the highest growth rates within animal protein production during recent decades and is expected to expand further at the same rate within the next 10 years. Control of diseases is one of the most prominent challenges if this production goal is to be reached. Apart from viral, bacterial, fungal and metazoan infections it has been documented that protozoan parasites affect health and welfare and thereby production of fish in marine aquaculture. Representatives within the main protozoan groups such as amoebae, dinoflagellates, kinetoplastid flagellates, diplomonadid flagellates, apicomplexans, microsporidians and ciliates have been shown to cause severe morbidity and mortality among farmed fish. Well studied examples are Neoparamoeba perurans, Amyloodinium ocellatum, Spironucleus salmonicida, Ichthyobodo necator, Cryptobia salmositica, Loma salmonae, Cryptocaryon irritans, Miamiensis avidus and Trichodina jadranica. The present report provides details on the parasites' biology and impact on productivity and evaluates tools for diagnosis, control and management. Special emphasis is placed on antiprotozoan immune responses in fish and a strategy for development of vaccines is presented.

Selecting one of several mating types through gene segment joining and deletion in Tetrahymena thermophila.

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Marcella D Cervantes

Full Text Available The unicellular eukaryote Tetrahymena thermophila has seven mating types. Cells can mate only when they recognize cells of a different mating type as non-self. As a ciliate, Tetrahymena separates its germline and soma into two nuclei. During growth the somatic nucleus is responsible for all gene transcription while the germline nucleus remains silent. During mating, a new somatic nucleus is differentiated from a germline nucleus and mating type is decided by a stochastic process. We report here that the somatic mating type locus contains a pair of genes arranged head-to-head. Each gene encodes a mating type-specific segment and a transmembrane domain that is shared by all mating types. Somatic gene knockouts showed both genes are required for efficient non-self recognition and successful mating, as assessed by pair formation and progeny production. The germline mating type locus consists of a tandem array of incomplete gene pairs representing each potential mating type. During mating, a complete new gene pair is assembled at the somatic mating type locus; the incomplete genes of one gene pair are completed by joining to gene segments at each end of germline array. All other germline gene pairs are deleted in the process. These programmed DNA rearrangements make this a fascinating system of mating type determination.

Dynein light chain family in Tetrahymena thermophila.

Science.gov (United States)

Wilkes, David E; Rajagopalan, Vidyalakshmi; Chan, Clarence W C; Kniazeva, Ekaterina; Wiedeman, Alice E; Asai, David J

2007-02-01

Dyneins are large protein complexes that produce directed movement on microtubules. In situ, dyneins comprise combinations of heavy, intermediate, light-intermediate, and light chains. The light chains regulate the locations and activities of dyneins but their functions are not completely understood. We have searched the recently sequenced Tetrahymena thermophila macronuclear genome to describe the entire family of dynein light chains expressed in this organism. We identified fourteen genes encoding putative dynein light chains and seven genes encoding light chain-like proteins. RNA-directed PCR revealed that all 21 genes were expressed. Quantitative real time reverse transcription PCR showed that many of these genes were upregulated after deciliation, indicating that these proteins are present in cilia. Using the nomenclature developed in Chlamydomonas, Tetrahymena expresses two isoforms each of LC2, LC4, LC7, and Tctex1, three isoforms of p28, and six LC8/LC8-like isoforms. Tetrahymena also expresses two LC3-like genes. No Tetrahymena orthologue was found for Chlamydomonas LC5 or LC6. This study provides a complete description of the different genes and isoforms of the dynein light chains that are expressed in Tetrahymena, a model organism in which the targeted manipulation of genes is straightforward. (c) 2006 Wiley-Liss, Inc.

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

-quality Rhodomonas sp. diet. The specific mass of fatty acids in S. sulcatum was much lower than in the Dunaliella sp. diet, However, the fatty acid composition of the protozoan more or less resembled that of the food, lacking long-chain highly unsaturated fatty acids (HUFAs). Sterols only occurred in Dunaliella sp......The ciliate Strombidium sulcatum was used to feed and grow young stages of the copepods Temora longicornis (Muller) and Pseudocalanus elongatus (Boeck). The ciliate was cultured in the laboratory using either bacteria or the green alga Dunaliella sp. as a food source. Young copepodites of both......., 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...

Induced tubulin synthesis is caused by induced gene transcription in Tetrahymena

International Nuclear Information System (INIS)

Seyfert, H.M.; Kohle, D.; Jenovai, S.

1987-01-01

Tubulin synthesis and tubulin mRNA concentrations increase to variable extents during ciliary regeneration in the ciliate Tetrahymena. Experiments described here were carried out to determine whether the increased tubulin mRNa concentrations are due to induced transcription of tubulin genes or to stabilization of tubulin mRNA. In vivo labeling experiments with [ 3 H]uridine and in vitro transcription assays suggest that under conditions of increased protein and tubulin synthesis the rate of transcription is enhanced. Hybridization assays of in vitro transcribed RNA also demonstrate qualitatively that the tubulin genes are transcribed at higher rates when tubulin synthesis is stimulated during ciliary regeneration. This observation is supported by measurements of the half-life of tubulin mRNA molecules in nondeciliated cells: This is approximately 2 h. Since the concentration of tubulin mRNA in cells engaged in cilia regeneration increases from 5 to 19-fold during the first hour of the regeneration period, even a complete stabilization of the tubulin mRNA molecules could not account for an increase in tubulin mRNA concentration of this magnitude

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

Science.gov (United States)

Catania, Francesco; Lynch, Michael

2010-05-04

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. 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. 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.

Protozoans bacterivory in a subtropical environment during a dry/cold and a rainy/warm season

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Karina F. Hisatugo

2014-01-01

Full Text Available In aquatic ecosystems, bacteria are controlled by several organisms in the food chain, such as protozoa, that use them as food source. This study aimed to quantify the ingestion and clearance rates of bacteria by ciliates and heterotrophic nanoflagellates (HNF in a subtropical freshwater reservoir (Monjolinho reservoir -São Carlos -Brazil during one year period, in order to verify their importance as consumers and controllers of bacteria in two seasons, a dry/cold and a rainy/warm one. For this purpose, in situ bacterivory experiments were carried out bimonthly using fluorescently labeled bacteria with 5-(4,6 diclorotriazin-2yl aminofluorescein (DTAF. Although ciliates have shown the highest individual ingestion and clearance rates, bacterivory was dominated by HNF, who showed higher population ingestion rates (mean of 9,140 bacteria h-1mL-1 when compared to ciliates (mean of 492 bacteria h-1mL-1. The greater predation impact on bacterial communities was caused mainly by the small HNF (< 5 µm population, especially in the rainy season, probably due to the abundances of these organisms, the precipitation, trophic index state and water temperature that were higher in this period. Thus, the protozoan densities together with environmental variables were extremely relevant in determining the seasonal pattern of bacterivory in Monjolinho reservoir.

Ciliate telomerase RNA loop IV nucleotides promote hierarchical RNP assembly and holoenzyme stability.

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Robart, Aaron R; O'Connor, Catherine M; Collins, Kathleen

2010-03-01

Telomerase adds simple-sequence repeats to chromosome 3' ends to compensate for the loss of repeats with each round of genome replication. To accomplish this de novo DNA synthesis, telomerase uses a template within its integral RNA component. In addition to providing the template, the telomerase RNA subunit (TER) also harbors nontemplate motifs that contribute to the specialized telomerase catalytic cycle of reiterative repeat synthesis. Most nontemplate TER motifs function through linkage with the template, but in ciliate and vertebrate telomerases, a stem-loop motif binds telomerase reverse transcriptase (TERT) and reconstitutes full activity of the minimal recombinant TERT+TER RNP, even when physically separated from the template. Here, we resolve the functional requirements for this motif of ciliate TER in physiological RNP context using the Tetrahymena thermophila p65-TER-TERT core RNP reconstituted in vitro and the holoenzyme reconstituted in vivo. Contrary to expectation based on assays of the minimal recombinant RNP, we find that none of a panel of individual loop IV nucleotide substitutions impacts the profile of telomerase product synthesis when reconstituted as physiological core RNP or holoenzyme RNP. However, loop IV nucleotide substitutions do variably reduce assembly of TERT with the p65-TER complex in vitro and reduce the accumulation and stability of telomerase RNP in endogenous holoenzyme context. Our results point to a unifying model of a conformational activation role for this TER motif in the telomerase RNP enzyme.

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

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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.

Synergistic Interactions within a Multispecies Biofilm Enhance Individual Species Protection against Grazing by a Pelagic Protozoan

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Prem K. Raghupathi

2018-01-01

Full Text Available Biofilm formation has been shown to confer protection against grazing, but little information is available on the effect of grazing on biofilm formation and protection in multispecies consortia. With most biofilms in nature being composed of multiple bacterial species, the interactions and dynamics of a multispecies bacterial biofilm subject to grazing by a pelagic protozoan predator were investigated. To this end, a mono and multispecies biofilms of four bacterial soil isolates, namely Xanthomonas retroflexus, Stenotrophomonas rhizophila, Microbacterium oxydans and Paenibacillus amylolyticus, were constructed and subjected to grazing by the ciliate Tetrahymena pyriformis. In monocultures, grazing strongly reduced planktonic cell numbers in P. amylolyticus and S. rhizophila and also X. retroflexus. At the same time, cell numbers in the underlying biofilms increased in S. rhizophila and X. retroflexus, but not in P. amylolyticus. This may be due to the fact that while grazing enhanced biofilm formation in the former two species, no biofilm was formed by P. amylolyticus in monoculture, either with or without grazing. In four-species biofilms, biofilm formation was higher than in the best monoculture, a strong biodiversity effect that was even more pronounced in the presence of grazing. While cell numbers of X. retroflexus, S. rhizophila, and P. amylolyticus in the planktonic fraction were greatly reduced in the presence of grazers, cell numbers of all three species strongly increased in the biofilm. Our results show that synergistic interactions between the four-species were important to induce biofilm formation, and suggest that bacterial members that produce more biofilm when exposed to the grazer not only protect themselves but also supported other members which are sensitive to grazing, thereby providing a “shared grazing protection” within the four-species biofilm model. Hence, complex interactions shape the dynamics of the biofilm and

Molecular aspects of calcium signalling at the crossroads of unikont and bikont eukaryote evolution--the ciliated protozoan Paramecium in focus.

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Plattner, Helmut

2015-03-01

The ciliated protozoan, Paramecium tetraurelia has a high basic Ca(2+) leakage rate which is counteracted mainly by export through a contractile vacuole complex, based on its V-type H(+)-ATPase activity. In addition Paramecium cells dispose of P-type Ca(2+)-ATPases, i.e. a plasmamembrane and a sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (PMCA, SERCA). Antiporter systems are to be expected, as inferred from indirect evidence. Among the best known cytosolic Ca(2+)-binding proteins, calmodulin activates Ca(2+) influx channels in the somatic cell membrane, but inactivates Ca(2+) influx channels in cilia, where it, thus, ends ciliary reversal induced by depolarization via channels in the somatic cell membrane. Centrin inactivates Ca(2+) signals after stimulation by its high capacity/low affinity binding sites, whereas its high affinity sites regulate some other functions. Cortical Ca(2+) stores (alveolar sacs) are activated during stimulated trichocyst exocytosis and thereby mediate store-operated Ca(2+) entry (SOCE). Ca(2+) release channels (CRCs) localised to alveoli and underlying SOCE are considered as Ryanodine receptor-like proteins (RyR-LPs) which are members of a CRC family with 6 subfamilies. These also encompass genuine inositol 1,4,5-trisphosphate receptors (IP3Rs) and intermediates between the two channel types. All IP3R/RyR-type CRCs possess six carboxyterminal transmembrane domains (TMD), with a pore domain between TMD 5 and 6, endowed with a characteristic selectivity filter. There are reasons to assume a common ancestor molecule for such channels and diversification further on in evolution. The distinct distribution of specific CRCs in the different vesicles undergoing intracellular trafficking suggests constitutive formation of very locally restricted Ca(2+) signals during vesicle-vesicle interaction. In summary, essential steps of Ca(2+) signalling already occur at this level of evolution, including an unexpected multitude of CRCs. For dis

J-GLOBAL MeSH Dictionary: Tetrahymena pyriformis [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Tetrahymena pyriformis 名詞 一般 * * * * Tetrahymena... pyriformis ... MeSH D013769 200906097287118996 C LS07 UNKNOWN_2 Tetrahymena pyriformis

J-GLOBAL MeSH Dictionary: Tetrahymena thermophila [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Tetrahymena thermophila 名詞 一般 * * * * Tetrahymena... thermophila ... MeSH D016808 200906086486381246 C LS07 UNKNOWN_2 Tetrahymena thermophila

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

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

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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.

Anti-ulcer, anti-protozoan and anti-cancer activities of irradiated κ-carrageenan: some biological effects of irradiated food grade-carrageenan on various gastrointestinal disorders

International Nuclear Information System (INIS)

Deocaris, Custer C.; Cruz, Angela C; Dela Rosa, Alumanda M.; De Guzman, Roche Ray C.; Abilo, Rhea Mae L.; Gutierrez, Ana Kamila O.; Deocaris, Chester C.

2001-01-01

κ carrageenan and its radiolytic products are both shown to strongly inhibit pepsin activity based on our in vitro peptic ulcer model. Generated Lineweaver-Burke (LB) plots resemble the trend for competitive inhibition except that the changes in the slopes are too large rendering Km to approach a negative value. Our observations corroborate with the published dual behavior of carrageenan in inhibiting peptic ulcers, that is, by exerting simultaneously both enzyme (E) competitive inhibition and substrate (S) occlusion. Irradiated-carrageenan does not display anti-protozoan activity against Tetrahymena and pathogenic Entamoeba histolytica, and anti-tumor potential based on Artemia salina (brine shrimp) nauplus tests and the MTT assay with human MCF7 breast carcinoma cell line. (Author)

Survey of protozoan, helminth and viral infections in shrimp Litopenaeus setiferus and prawn Macrobrachium acanthurus native to the Jamapa River region, Mexico.

Science.gov (United States)

Domínguez-Machín, Magda E; Hernández-Vergara, Martha P; Jiménez-García, Isabel; Simá-Alvarez, Raúl; Rodríguez-Canul, Rossanna

2011-09-09

We surveyed protozoan and metazoan parasites as well as white spot syndrome virus (WSSV) and infectious hypodermal hematopoietic necrosis virus (IHHNV) in white shrimp Litopenaeus setiferus and the palaemonid prawn Macrobrachium acanthurus native to the lower Jamapa River region of Veracruz, Mexico. The presence of parasites and the infection parameters were evaluated in 113 palaemonid prawns collected during the northwind (n = 45), rainy (n = 38) and dry seasons (n = 30) between October 2007 and July 2008, and in 91 shrimp collected in the rainy season between May and June 2008. In L. setiferus, ciliates of the subclass Apostomatia (Ascophrys sp.) were evident in gills, and third-stage larvae of the nematode Physocephalus sexalatus were evident in the stomach. Cestodes of the genus Prochristianella were evident in the hepatopancreas, while some gregarines of the genus Nematopsis, as well as unidentified larval cestodes, were observed in the intestine. Histology identified Ascophrys sp. in association with gill necrosis and tissue melanization. Slight inflammation was observed in intestinal epithelium near cestode larvae. In M. acanthurus, epibionts of the protozoans Epistylis sp., Acineta sp. and Lagenophrys sp. were observed under uropods, periopods and pleopods. An unidentified ciliate of the Apostomatia was also found in the gills, and Nematopsis was identified in the intestine. No histopathology was observed in association with these parasites. Moreover, neither WSSV nor IHHNV were detected by the polymerase chain reaction (PCR) in any of the L. setiferus or M. acanthurus analysed.

Ciliate protozoa

International Nuclear Information System (INIS)

Dehority, B.A.

2005-01-01

Gruby and Delafond discovered the rumen protozoa in 1843 and suggested that their digestive activity was the primary means by which ruminants could survive on an all-plant diet. However, subsequent studies have clearly shown that bacteria actually play a prominent role in the fermentation of plant materials, and fungi are also involved. The rumen ciliates range in size from 18 to 500 μm and can be enumerated and identified microscopically at relatively low magnifications. On the basis of cell morphology, they have been classified into at least five families containing 24 different genera. Although new species are still being reported yearly, the last summary was compiled in 1992 by Williams and Coleman and listed 257 separate species. Ciliate protozoa belonging to different families are found in most other herbivorous mammals. This includes those animals in which fermentation occurs in the hindgut, such as the horse, elephant, rhinoceros and capybara, as well as in the non-ruminant foregut fomenters, i.e. camelids, hippopotamus and kangaroo. These ciliates can be enumerated and identified using the methods and techniques presented in this chapter, presuming appropriate procedures are used for obtaining representative samples from the animal

Environmental requirements of selected estuarine ciliated Protozoa

International Nuclear Information System (INIS)

Borror, A.C.

1975-05-01

This report addresses species composition and microdistribution of ciliates (Protozoa, Ciliophora) of a tidal marsh at Adams Pt., Great Bay, New Hampshire (1970, 1971) in relationship to temperature, salinity, pH, concentration of oxygen, H 2 S, and bacteria, and occurrence of micrometazoa. Accurate counting and precise identification allowed measurement of tidal effects on ciliate abundance and diversity, and the relationship of ciliates to micrometazoa and bacteria. During 1970, we identified 79 species in 175 collections; during 1971, 83 species in 102 collections. Although in general ciliate distribution was not correlated with temperature, salinity, pH, or oxygen concentration, some species were tolerant of anoxic environments. Ciliates differed in distribution between the upper (Spartina patens) and the lower (S. alterniflora) marsh. We measured responses of bacteria and ciliates to the physical and biological changes in a patens-panne pond caused by tidal flushing, and to the flushing of a channel in the lower marsh by several different tidal cycles. (U.S.)

The Conjugation-Specific Die5 Protein Is Required for Development of the Somatic Nucleus in both Paramecium and Tetrahymena▿

Science.gov (United States)

Matsuda, Atsushi; Shieh, Annie Wan-Yi; Chalker, Douglas L.; Forney, James D.

2010-01-01

Development in ciliated protozoa involves extensive genome reorganization within differentiating macronuclei, which shapes the somatic genome of the next vegetative generation. Major events of macronuclear differentiation include excision of internal eliminated sequences (IESs), chromosome fragmentation, and genome amplification. Proteins required for these events include those with homology throughout eukaryotes as well as proteins apparently unique to ciliates. In this study, we identified the ciliate-specific Defective in IES Excision 5 (DIE5) genes of Paramecium tetraurelia (PtDIE5) and Tetrahymena thermophila (TtDIE5) as orthologs that encode nuclear proteins expressed exclusively during development. Abrogation of PtDie5 protein (PtDie5p) function by RNA interference (RNAi)-mediated silencing or TtDie5p by gene disruption resulted in the failure of developing macronuclei to differentiate into new somatic nuclei. Tetrahymena ΔDIE5 cells arrested late in development and failed to complete genome amplification, whereas RNAi-treated Paramecium cells highly amplified new macronuclear DNA before the failure in differentiation, findings that highlight clear differences in the biology of these distantly related species. Nevertheless, IES excision and chromosome fragmentation failed to occur in either ciliate, which strongly supports that Die5p is a critical player in these processes. In Tetrahymena, loss of zygotic expression during development was sufficient to block nuclear differentiation. This observation, together with the finding that knockdown of Die5p in Paramecium still allows genome amplification, indicates that this protein acts late in macronuclear development. Even though DNA rearrangements in these two ciliates look to be quite distinct, analysis of DIE5 establishes the action of a conserved mechanism within the genome reorganization pathway. PMID:20495055

Biomechanics of Tetrahymena escaping from dead ends

Science.gov (United States)

Ishikawa, Takuji; Kikuchi, Kenji

2017-11-01

Behaviors of swimming microorganisms in complex environments are important in understanding cells' distribution in nature and in industries. Although cell's swimming and spreading in an infinite fluid has been intensively investigated, that in a narrow region bounded by walls is still unclear. Thus, in this study, we used Tetrahymena thermophila as a model microorganism, and experimentally investigated its behavior between flat plates with an angle. The results showed that the cells tended to escape from the narrow region, and the swimming velocity and the radius of curvature of the trajectories decreased as they swam narrower region. We then developed a computational model of swimming Tetrahymena. The results showed that the escaping behavior could be well explained by fluid mechanics. The obtained knowledge is useful in understanding cells' behaviors in complex environments, such as in porous media and in a granular matter. This research was supported by JSPS KAKENHI Grants, numbers 25000008 and 17H00853.

JST Thesaurus Headwords and Synonyms: Tetrahymena [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Tetrahymena 名詞 一般 * * * * テトラヒメナ属... テトラヒメナゾク テトラヒメナゾク Thesaurus2015 200906089871776382 C LS07 UNKNOWN_1 Tetrahymena

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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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

Inhibition of Tetrahymena pyriformis growth by Aliphatic Alcohols ...

African Journals Online (AJOL)

A Quantitative Structure- Activity Relationship (QSAR) study was undertaken to evaluate the relative toxicity of a mixed series of 21 (linear and branched-chain) alcohols and 9 normal aliphatic amines in term of the 50% inhibitory growth concentration (IGC50) of Tetrahymena pyriformis. The applied simple linear regression ...

SPECIES COMPOSITION OF PSAMMOPHILIC CILIATES OF SUMGAIT CASPIAN COAST

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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.

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.

The effect of extracellular environment on the sensitivity of two strains of Tetrahymena to gamma rays

International Nuclear Information System (INIS)

Gebicki, J.M.; Darlington, J.L.; Baumgartner, S.

1980-01-01

The radiosensitivity of two strains of Tetrahymena pyriformis to gamma radiation was studied. Irradiation of mass suspensions of Tetrahymena in their normal growth medium confirmed earlier reports of their very high resistance to gamma rays. However this resistance was lowered when the cells were irradiated singly. Using mass and single cell cultures of Tetrahymena, it was shown that the mass cultures were not protected by anoxia from the effects of gamma radiation. However when lysates of Tetrahymena suspensions were added to single cell isolates just before irradiation, the cells were protected. Thus the high resistance of cells in mass culture might lie in the release of protective substances by other cells lysing spontaneously, or as a result of radiation damage. The absence of proteose-peptone-yeast in the growth medium markedly increased the lethality of the gamma rays for both strains. The most likely explanation appeared to lie in the protection of cells from indirect effects of radiation by organic materials in the external medium. The results of the present study emphasise the role of the indirect component of radiation damage in cell death. It is likely that much of this damage occurs in cell membranes. (U.K.)

The effects of different fertilizers on the ciliate communities of forests

International Nuclear Information System (INIS)

Lehle, E.; Funke, W.

1993-01-01

The influence of lime, mineral fertilizers and different composts on the ciliate communities (Protozoa: Ciliophora) of very acidified spruce forests were tested. In succession culture experiments species range, total numbers, abundance and dominance structure of the ciliate communities showed continued changes over a 90 day period. This method offers the opportunity not only to diagnose, but also to quantify effects of soil treatments. Investigations at the ARINUS-site Schluchsee (Black Forest) showed the following results: Liming led to a greater change in the ciliate communities than fertilization with magnesium-sulphate and ammonia-sulphate. Liming and treatment with compost, made from household garbage, and compost, made from chopped wood on the Beimerstetten site (Swabian Alb) led also to remarkably changes in the ciliate communities. The total ciliate numbers of the household garbage area were very low. In contrast, the ciliate community of the chopped wood compost areas were characterized by a great species number and high abundances of spirotrichuous ciliates, especially Halteria grandinella. (orig./UWA) [de

Experimental and modeling evidence of appendicularian-ciliate interactions

DEFF Research Database (Denmark)

Lombard, Fabien; Eloire, D.; Gobet, A.

occurred simultaneously, resulting in apparent mutualism. The large ciliate Strombidium sp. entered the inlet filters of appendicularian houses (larger than 500 µm body size) by distorting the mesh. Once inside, Strombidium fed on particles concentrated on the filters. When appendicularians were larger...... than 900 µm, both the high flow rate in the buccal tube and their esophagus width allowed the "host" appendicularian to capture and ingest ciliates. Thus, ciliates seem to be sequentially competitors, then parasites or commensal in appendicularian houses, and finally prey for appendicularians...

Genomic organization and developmental fate of adjacent repeated sequences in a foldback DNA clone of Tetrahymena thermophila

International Nuclear Information System (INIS)

Tschunko, A.H.; Loechel, R.H.; McLaren, N.C.; Allen, S.L.

1987-01-01

DNA sequence elimination and rearrangement occurs during the development of somatic cell lineages of eukaryotes and was first discovered over a century ago. However, the significance and mechanism of chromatin elimination are not understood. DNA elimination also occurs during the development of the somatic macronucleus from the germinal micronucleus in unicellular ciliated protozoa such as Tetrahymena thermophila. In this study foldback DNA from the micronucleus was used as a probe to isolate ten clones. All of those tested (4/4) contained sequences that were repetitive in the micronucleus and rearranged in the macronucleus. Inverted repeated sequences were present in one clone. This clone, pTtFBl, was subjected to a detailed analysis of its developmental fate. Subregions were subcloned and used as probes against Southern blots of micronuclear and macronuclear DNA. DNA was labeled with [ 33 P]-labeled dATP. The authors found that all subregions defined repeated sequence families in the micronuclear genome. A minimum of four different families was defined, two of which are retained in the macronucleus and two of which are completely eliminated. The inverted repeat family is retained with little rearrangement. Two of the families, defined by subregions that do not contain parts of the inverted repeat are totally eliminated during macronuclear development-and contain open reading frames. The significance of retained inverted repeats to the process of elimination is discussed

Experimental and modeling evidence of appendicularian-ciliate interactions

DEFF Research Database (Denmark)

Lombard, Fabien; Eloire, Damien; Gobet, Angelique

2010-01-01

occurred simultaneously, resulting in apparent mutualism. The large ciliate Strombidium sp. entered the inlet filters of appendicularian houses (larger than 500 mu m body size) by distorting the mesh. Once inside, Strombidium fed on particles concentrated on the filters. When appendicularians were larger...... than 900 mu m, both the high flow rate in the buccal tube and their esophagus width allowed the "host'' appendicularian to capture and ingest ciliates. Thus, ciliates seem to be sequentially competitors, then parasites or commensal in appendicularian houses, and finally prey for appendicularians...

Binding and internalization of 3H-epinephrine in Tetrahymena

International Nuclear Information System (INIS)

Csaba, G.; Sudar, F.; Pados, R.

1980-01-01

Exposure of Tetrahymena to exogenous epinephrine is followed by appearance of the hormone in the cell membrane, intracytoplasmic vacuoles and nucleus. The intranuclear localization is always heterochromatic. Only a minor proportion of the epinephrine applied gains access to the nucleus, while the bulk of it attaches to the membrane. (author)

Network of interactions between ciliates and phytoplankton during spring

Directory of Open Access Journals (Sweden)

Thomas ePosch

2015-11-01

Full Text Available The annually recurrent spring phytoplankton blooms in freshwater lakes initiate pronounced successions of planktonic ciliate species. Although there is considerable knowledge on the taxonomic diversity of these ciliates, their species-specific interactions with other microorganisms are still not well understood. Here we present the succession patterns of 20 morphotypes of ciliates during spring in Lake Zurich, Switzerland, and we relate their abundances to phytoplankton genera, flagellates, heterotrophic bacteria, and abiotic parameters. Interspecific relationships were analyzed by contemporaneous correlations and time-lagged co-occurrence and visualized as association networks. The contemporaneous network pointed to the pivotal role of distinct ciliate species (e.g., Balanion planctonicum, Rimostrombidium humile as primary consumers of cryptomonads, revealed a clear overclustering of mixotrophic / omnivorous species, and highlighted the role of Halteria / Pelagohalteria as important bacterivores. By contrast, time-lagged statistical approaches (like local similarity analyses, LSA proved to be inadequate for the evaluation of high-frequency sampling data. LSA led to a conspicuous inflation of significant associations, making it difficult to establish ecologically plausible interactions between ciliates and other microorganisms. Nevertheless, if adequate statistical procedures are selected, association networks can be powerful tools to formulate testable hypotheses about the autecology of only recently described ciliate species.

Free-living ciliates from epiphytic tank bromeliads in Mexico.

Science.gov (United States)

Durán-Ramírez, Carlos Alberto; García-Franco, José Guadalupe; Foissner, Wilhelm; Mayén-Estrada, Rosaura

2015-02-01

The ciliate diversity of Mexican bromeliads is poorly known. We studied the ciliate community of two species of epiphytic tank bromeliads from 48 individuals of Tillandsia heterophylla and four of T. prodigiosa. The bromeliads occurred on over 22 tree host species. Samples were collected during 2009 and 2010 in a mountain cloud forest and in two coffee plantations and in a pine-oak forest. The ciliates were identified in live and protargol preparations. We recorded 61 ciliate species distributed in 39 genera grouped in eight classes. Ten species were frequent in the 52 samples (20 ± 3.2) and Leptopharynx bromeliophilus was the most frequent recorded in 25 samples. Thirty-three species are new for the fauna of Mexico, 24 species have been recorded for the first time in tank bromeliads. The classes Spirotrichea, Oligohymenophorea and Colpodea presented the highest number of species, 16, 14, and 12, respectively. Colpoda was the most species-rich genus being present with six species. A low similarity between areas and seasons was obtained with Jaccard's index. We conclude that the two bromeliads species host a rich ciliate diversity whose knowledge contributes to the question of ciliate distribution and specifically, in tank bromeliads. Copyright © 2014 Elsevier GmbH. All rights reserved.

Distinct toxicological characteristics and mechanisms of Hg2+ and MeHg in Tetrahymena under low concentration exposure.

Science.gov (United States)

Liu, Cheng-Bin; Qu, Guang-Bo; Cao, Meng-Xi; Liang, Yong; Hu, Li-Gang; Shi, Jian-Bo; Cai, Yong; Jiang, Gui-Bin

2017-12-01

Inorganic divalent mercury complexes (Hg 2+ ) and monomethylmercury complexes (MeHg) are the main mercury species in aquatic systems and their toxicity to aquatic organisms is of great concern. Tetrahymena is a type of unicellular eukaryotic protozoa located at the bottom of food chain that plays a fundamental role in the biomagnification of mercury. In this work, the dynamic accumulation properties, toxicological characteristics and mechanisms of Hg 2+ and MeHg in five Tetrahymena species were evaluated in detail. The results showed that both Hg 2+ and MeHg were ingested and exhibited inhibitory effects on the proliferation or survival of Tetrahymena species. However, the ingestion rate of MeHg was significantly higher than that of Hg 2+ . The mechanisms responsible for the toxicity of MeHg and Hg 2+ were different, although both chemicals altered mitochondrial membrane potential (MMP). MeHg disrupted the integrity of membranes while Hg 2+ had detrimental effects on Tetrahymena as a result of the increased generation of reactive oxygen species (ROS). In addition, the five Tetrahymena species showed different capacities in accumulating Hg 2+ and MeHg, with T. corlissi exhibiting the highest accumulations. The study also found significant growth-promoting effect on T. corlissi under low concentration exposure (0.003 and 0.01μg Hg/mL (15 and 50nM)), suggesting different effect and mechanism that should be more closely examined when assessing the bioaccumulation and toxicity of mercury in aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

Protozoan growth rates on secondary-metabolite-producing Pseudomonas spp. correlate with high-level protozoan taxonomy

DEFF Research Database (Denmark)

Pedersen, Annette L.; Winding, Anne; Altenburger, Andreas

2011-01-01

Different features can protect bacteria against protozoan grazing, for example large size, rapid movement, and production of secondary metabolites. Most papers dealing with these matters focus on bacteria. Here, we describe protozoan features that affect their ability to grow on secondary-metabol...

Effects of four commonly used UV filters on the growth, cell viability and oxidative stress responses of the Tetrahymena thermophila.

Science.gov (United States)

Gao, Li; Yuan, Tao; Zhou, Chuanqi; Cheng, Peng; Bai, Qifeng; Ao, Junjie; Wang, Wenhua; Zhang, Haimou

2013-11-01

UV filters are increasingly used in sunscreens and other personal care products. Although their residues have been widely identified in aquatic environment, little is known about the influences of UV filters to protozoan. The growth inhibition effects, cell viability and oxidative stress responses of four commonly used UV filters, 2-ethylhexyl 4-methoxycinnamate (EHMC), benzophenone-3 (BP-3), 4-methyl-benzylidene camphor (4-MBC) and octocrylene (OC), to protozoan Tetrahymena thermophila were investigated in this study. The 24-h EC50 values with 95% confidence intervals for BP-3 and 4-MBC were 7.544 (6.561-8.675) mg L(-1) and 5.125 (4.874-5.388) mg L(-1), respectively. EHMC and OC did not inhibit the growth of T. thermophila after 24h exposure at the tested concentrations. The results of cell viability assays with propidium iodide (PI) staining were consistent with that of the growth inhibition tests. As for BP-3 and 4-MBC, the relatively higher concentrations, i.e. of 10.0 and 15.0 mg L(-1), could lead to the cell membranes impairment after 4h exposure. With the increase of the exposure time to 6h, their adverse effects on cell viability of T. thermophila were observed at the relatively lower concentration groups (1.0 mg L(-1) and 5.0 mg L(-1)). In addition, it is noticeable that at environmentally relevant concentration (1.0 μg L(-1)), BP-3 and 4-MBC could lead to the significant increase of catalase (CAT) activities of the T. thermophila cells. Especially for the BP-3, the oxidative injuries were further confirmed by the reduction of glutathione (GSH) content. It is imperative to further investigate the additive action of UV filters and seek other sensitive endpoint, especially at environmentally relevant concentration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Factors driving the seasonal distribution of planktonic and epiphytic ciliates in a eutrophicated Mediterranean Lagoon

Energy Technology Data Exchange (ETDEWEB)

Dhib, Amel [Université de Franche-Comté, Laboratoire de Chrono-Environnement, UMR CNRS 6249 (France); Institut National des Sciences et Technologies de la Mer (INSTM), Laboratoire Milieu Marin, Centre la Goulette (Tunisia); Brahim, Mounir Ben; Ziadi, Boutheina; Akrout, Fourat; Turki, Souad [Institut National des Sciences et Technologies de la Mer (INSTM), Laboratoire Milieu Marin, Centre la Goulette (Tunisia); Aleya, Lotfi [Université de Franche-Comté, Laboratoire de Chrono-Environnement, UMR CNRS 6249 (France)

2013-09-15

Highlights: • Distribution of planktonic and epiphytic ciliates at five stations in Ghar El Melh Lagoon. • 28 planktonic ciliates were identified with spring-early autumn peaks. • 4 epiphytic ciliates of the seagrass Ruppia cirrhosa were recorded with high density. • Significant correlations were found between ciliate assemblages, environmental factors and harmful dinoflagellates. -- Abstract: We studied the distribution of planktonic and epiphytic ciliates coupled with environmental factors and microalgae abundance at five stations in Ghar El Melh Lagoon (Tunisia). Planktonic ciliates were monitored for a year and epiphytic ciliates were sampled during summer 2011 in concordance with the proliferation of the seagrass Ruppia cirrhosa. Ciliate assemblage was largely dominated by Spirotrichea followed respectively by Tintinnida of and Strombidiida. No significant difference was found in the distribution of ciliate species among the stations. Redundancy analysis indicates that abiotic factors (temperature and nutriments) have a significant effect on the dynamics of certain ciliates. For epiphytic ciliates, 4 species were identified: Tintinnopsis campanula, Aspidisca sp., Strombidium acutum and Amphorides amphora. Based on PERMANOVA analyses, ciliates exhibit significant correlations among months and stations. According to ACP, epiphyte distribution follows roughly those of R. cirrhosa and pH. Significant correlations were found between harmful dinoflagellates and both planktonic and epiphytic ciliates.

Factors driving the seasonal distribution of planktonic and epiphytic ciliates in a eutrophicated Mediterranean Lagoon

International Nuclear Information System (INIS)

Dhib, Amel; Brahim, Mounir Ben; Ziadi, Boutheina; Akrout, Fourat; Turki, Souad; Aleya, Lotfi

2013-01-01

Highlights: • Distribution of planktonic and epiphytic ciliates at five stations in Ghar El Melh Lagoon. • 28 planktonic ciliates were identified with spring-early autumn peaks. • 4 epiphytic ciliates of the seagrass Ruppia cirrhosa were recorded with high density. • Significant correlations were found between ciliate assemblages, environmental factors and harmful dinoflagellates. -- Abstract: We studied the distribution of planktonic and epiphytic ciliates coupled with environmental factors and microalgae abundance at five stations in Ghar El Melh Lagoon (Tunisia). Planktonic ciliates were monitored for a year and epiphytic ciliates were sampled during summer 2011 in concordance with the proliferation of the seagrass Ruppia cirrhosa. Ciliate assemblage was largely dominated by Spirotrichea followed respectively by Tintinnida of and Strombidiida. No significant difference was found in the distribution of ciliate species among the stations. Redundancy analysis indicates that abiotic factors (temperature and nutriments) have a significant effect on the dynamics of certain ciliates. For epiphytic ciliates, 4 species were identified: Tintinnopsis campanula, Aspidisca sp., Strombidium acutum and Amphorides amphora. Based on PERMANOVA analyses, ciliates exhibit significant correlations among months and stations. According to ACP, epiphyte distribution follows roughly those of R. cirrhosa and pH. Significant correlations were found between harmful dinoflagellates and both planktonic and epiphytic ciliates

The symbiotic intestinal ciliates and the evolution of their hosts.

Science.gov (United States)

Moon-van der Staay, Seung Yeo; van der Staay, Georg W M; Michalowski, Tadeusz; Jouany, Jean-Pierre; Pristas, Peter; Javorský, Peter; Kišidayová, Svetlana; Varadyova, Zora; McEwan, Neil R; Newbold, C Jamie; van Alen, Theo; de Graaf, Rob; Schmid, Markus; Huynen, Martijn A; Hackstein, Johannes H P

2014-04-01

The evolution of sophisticated differentiations of the gastro-intestinal tract enabled herbivorous mammals to digest dietary cellulose and hemicellulose with the aid of a complex anaerobic microbiota. Distinctive symbiotic ciliates, which are unique to this habitat, are the largest representatives of this microbial community. Analyses of a total of 484 different 18S rRNA genes show that extremely complex, but related ciliate communities can occur in the rumen of cattle, sheep, goats and red deer (301 sequences). The communities in the hindgut of equids (Equus caballus, Equus quagga), and elephants (Elephas maximus, Loxodonta africanus; 162 sequences), which are clearly distinct from the ruminant ciliate biota, exhibit a much higher diversity than anticipated on the basis of their morphology. All these ciliates from the gastro-intestinal tract constitute a monophyletic group, which consists of two major taxa, i.e. Vestibuliferida and Entodiniomorphida. The ciliates from the evolutionarily older hindgut fermenters exhibit a clustering that is specific for higher taxa of their hosts, as extant species of horse and zebra on the one hand, and Africa and Indian elephant on the other hand, share related ciliates. The evolutionary younger ruminants altogether share the various entodiniomorphs and the vestibuliferids from ruminants. Copyright © 2014 Elsevier GmbH. All rights reserved.

Investigating the biodiversity of ciliates in the 'Age of Integration'.

Science.gov (United States)

Clamp, John C; Lynn, Denis H

2017-10-01

Biology is now turning toward a more integrative approach to research, distinguished by projects that depend on collaboration across hierarchical levels of organization or across disciplines. This trend is prompted by the need to solve complex, large-scale problems and includes disciplines that could be defined as integrative biodiversity. Integrative biodiversity of protists, including that of ciliates, is still partially in its infancy. This is the result of a shortage of historical data resources such as curated museum collections. Major areas of integrative biodiversity of ciliates that have begun to emerge can be categorized as integrative systematics, phenotypic plasticity, and integrative ecology. Integrative systematics of ciliates is characterized by inclusion of diverse sources of data in treatment of taxonomy of species and phylogenetic investigations. Integrative research in phenotypic plasticity combines investigation of functional roles of individual species of ciliates with genetic and genomic data. Finally, integrative ecology focuses on genetic identity of species in communities of ciliates and their collective functional roles in ecosystems. A review of current efforts toward integrative research into biodiversity of ciliates reveals a single, overarching concern-rapid progress will be achieved only by implementing a comprehensive strategy supported by one or more groups of active researchers. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Phytoplankton growth inhibited by the toxic and bacterivorous ciliate

NARCIS (Netherlands)

Schaafsma, F.L.; Peperzak, L.

2013-01-01

The ubiquitous marine ciliate Uronema marinum is mainly bacterivorous. It was therefore surprising that in a ciliate-contaminated experiment the growth rate of the phytoplankton species Emiliania huxleyi was significantly reduced. As U. marinum does not ingest E. huxleyi cells, their growth

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.

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.

Effect of the Silica Content of Diatoms on Protozoan Grazing

Directory of Open Access Journals (Sweden)

Shuwen Zhang

2017-06-01

Full Text Available This study examined the effect that silica content in diatom cells has on the behavior of protists. The diatoms Thalassiosira weissflogii and T. pseudonana were cultured in high or low light conditions to achieve low and high silica contents, respectively. These cells were then fed to a heterotrophic dinoflagellate Noctiluca scintillans and a ciliate Euplotes sp. in single and mixed diet experiments. Our results showed that in general, N. scintillans and Euplotes sp. both preferentially ingested the diatoms with a low silica content rather than those with a high silica content. However, Euplotes sp. seemed to be less influenced by the silica content than was N. scintillans. In the latter case, the clearance and ingestion rate of the low silica diatoms were significantly higher, both in the short (6-h and long (1-d duration grazing experiments. Our results also showed that N. scintillans required more time to digest the high silica-containing cells. As the high silica diatoms are harder to digest, this might explain why N. scintillans exhibits a strong preference for the low silica prey. Thus, the presence of high silica diatoms might limit the ability of the dinoflagellate to feed. Our findings suggest that the silica content of diatoms affects their palatability and digestibility and, consequently, the grazing activity and selectivity of protozoan grazers.

Thyrotropin (TSH) regulates triiodothyronine (T3) production in the unicellular Tetrahymena.

Science.gov (United States)

Csaba, G; Pállinger, Eva

2011-09-01

The aim of the experiments was to study the regulation of triiodothyronine (T3) production in the unicellular Tetrahymena. Untreated and troph-hormone treated specimen were prepared and in different timepoints T3 content was measured and compared by immunocytochemical flow cytometry. 0.1 or 0.001 IU TSH in tryptone-yeast medium stimulated T3 synthesis at 10, 20, 30 min, but does not stimulate after 1 h. The overlapping gonadotropic hormone (GTH) also did it, however only at 10 min. In Losina salt solution (physiological for Tetrahymena) the effect was weaker, however outer amino acid source was not absolutely needed for the production of the hormone. The results show that the TSH regulation of thyroid hormone synthesis (storage, secretion) and troph-hormone overlap can be deduced to a unicellular level. This may allow the hypothesis that the endocrine mechanisms proved at a low level of phylogeny are preserved for the higher ranked organisms.

How applicable is the general adaptation syndrome to the unicellular Tetrahymena?

Science.gov (United States)

Csaba, György; Pállinger, Eva

2009-01-01

Hormone receptors, hormones and signal transduction pathways characteristic of higher vertebrates can be observed also in the unicellular Tetrahymena. Previous work showed that stress conditions (starvation, high temperature, high salt concentration, formaldehyde or alcohol treatment) elevated the intracellular level of four hormones (ACTH, endorphin, serotonin and T(3)). Here, the effect of other stressors (CuSO4 poisoning, tryptophan hydroxylase inhibitor parachlorophenylalanine (PCPA) treatment) on the same and other hormones (epinephrine, insulin, histamine) was studied, using immunocytochemistry and flow cytometric analysis. It was found, that each effect increased the intracellular hormone contents, but some hormones (histamine, T(3)) were less reactive. Insulin--which is a life-saving factor for Tetrahymena--itself provoked elevation of hormone amounts in association with a stressor, further increased the level of hormones. It was concluded that the ancestor of Selye's General Adaptation Syndrome (GAS) can be found already at unicellular level, and this possibly has a life saving function. Copyright 2008 John Wiley & Sons, Ltd.

The effect of salinity on some endocommensalic ciliates from shipworms

Digital Repository Service at National Institute of Oceanography (India)

Santhakumari, V.

. Seasonal incidence and relative abundance of these ciliates showed that they were more abundant during the low saline than the high saline periods. Eventhough these ciliates can endure higher salinities through gradual acclimatization of their habitat...

Sources of mycosporine-like amino acids in planktonic Chlorella-bearing ciliates (Ciliophora)

Science.gov (United States)

SONNTAG, BETTINA; SUMMERER, MONIKA; SOMMARUGA, RUBEN

2007-01-01

Mycosporine-like amino acids (MAAs) are a family of secondary metabolites known to protect organisms exposed to solar UV radiation. We tested their distribution among several planktonic ciliates bearing Chlorella isolated from an oligo-mesotrophic lake in Tyrol, Austria. In order to test the origin of these compounds, the MAAs were assessed by high performance liquid chromatography in both the ciliates and their symbiotic algae. Considering all Chlorella-bearing ciliates, we found: (i) seven different MAAs (mycosporine-glycine, palythine, asterina-330, shinorine, porphyra-334, usujirene, palythene); (ii) one to several MAAs per species and (iii) qualitative and quantitative seasonal changes in the MAAs (e.g. in Pelagodileptus trachelioides). In all species tested, concentrations of MAAs were always <1% of ciliate dry weight. Several MAAs were also identified in the Chlorella isolated from the ciliates, thus providing initial evidence for their symbiotic origin. In Uroleptus sp., however, we found evidence for a dietary source of MAAs. Our results suggest that accumulation of MAAs in Chlorella-bearing ciliates represents an additional benefit of this symbiosis and an adaptation for survival in sunlit, UV-exposed waters.

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

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....... These two super orders are phylogenetically distant from each other. Infection with Tetrahymena resulted in parasite invasion of internal organs, skin and muscle in all fish species. A relatively strong inflammatory response was observed in infected goldfish and koi, with negligible response in fish species...... of the Acanthopterygii super order. Guppies were the most susceptible to Tetrahymena infection, exhibiting a mortality rate of 87% and 100% in two separate experiments. A high mortality rate was also observed in platy (77%), while that of molly and angelfish was significantly lower (23% and 33%, respectively). Goldfish...

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

International Nuclear Information System (INIS)

Xiao, Qi; Huang, Shan; Su, Wei; Li, Peiyuan; Liang, Zuocui; Ou, Jianzhen; Ma, Jianqiang; Liu, Yi

2012-01-01

Highlights: ► The toxic effects of QDs to T. thermophila BF 5 using a TAM air microcalorimeter. ► QDs were acutely toxic for T. thermophila BF 5 growth in a dose-dependent manner. ► The toxicity of different ligands-capped QDs on T. thermophila BF 5 was investigated. ► QDs could be ingested by cells and affect the morphology of T. thermophila BF 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 5 (T. thermophila BF 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 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 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 5 was also investigated. The uptake of MAA-CdSe/ZnS QDs and adenosine 5′-monophosphate (AMP)-CdSe/ZnS QDs by cells and the morphological change during the process of T. thermophila BF 5 growth incubated with these QDs were further studied by fluorescence inverted microscopy.

Ciliated protozoa in the impact zone of the Uzhgorod treatment plant

Directory of Open Access Journals (Sweden)

Pliashechnyk Volodimir

2018-01-01

Full Text Available This paper presents the results of studies on the Uzh River (Ukraine, Zakarpattia Oblast near the effluent point of a sewage treatment plant in Uzhgorod. The samples were taken at various sites of the treatment plant along the stages of purification process, as well as in the river, at a number of different points above and below the wastewater discharge. At each of these objects, the temperature and O2 were measured. The structure of ciliate assemblage was analyzed along the stages of the treatment process in the WWTP and in the river before and after the sewage discharge. A total of 26 ciliate taxa were observed and included in the analysis. All the studied stations were considered as a continuum in which populations of protozoa spread freely according to their ecological preferences. The majority of ciliate species were encountered in each of the examined stations, but their quantitative development differed significantly, reflecting their response to the environmental conditions at the stations. The analysis of the qualitative and quantitative distribution of ciliate populations by the stations enabled to group them in respect to the peculiarities of the local conditions. The study showed that the majority of the ciliate species, typical of bioreactors, are equally common at the stations of the Uzh River below wastewater discharges. The ciliate assemblage in the oxygen gradient demonstrated a wide spectrum of ecological tolerance at the species level. These findings confirm that ciliates are very good indicators of the environmental quality, provided that detailed information about their environmental priorities is available.

Ciliated protozoa in the impact zone of the Uzhgorod treatment plant

Science.gov (United States)

Pliashechnyk, Volodimir; Danko, Yaroslav; Łagód, Grzegorz; Drewnowski, Jakub; Kuzmina, Tatiana; Babko, Roman

2018-02-01

This paper presents the results of studies on the Uzh River (Ukraine, Zakarpattia Oblast) near the effluent point of a sewage treatment plant in Uzhgorod. The samples were taken at various sites of the treatment plant along the stages of purification process, as well as in the river, at a number of different points above and below the wastewater discharge. At each of these objects, the temperature and O2 were measured. The structure of ciliate assemblage was analyzed along the stages of the treatment process in the WWTP and in the river before and after the sewage discharge. A total of 26 ciliate taxa were observed and included in the analysis. All the studied stations were considered as a continuum in which populations of protozoa spread freely according to their ecological preferences. The majority of ciliate species were encountered in each of the examined stations, but their quantitative development differed significantly, reflecting their response to the environmental conditions at the stations. The analysis of the qualitative and quantitative distribution of ciliate populations by the stations enabled to group them in respect to the peculiarities of the local conditions. The study showed that the majority of the ciliate species, typical of bioreactors, are equally common at the stations of the Uzh River below wastewater discharges. The ciliate assemblage in the oxygen gradient demonstrated a wide spectrum of ecological tolerance at the species level. These findings confirm that ciliates are very good indicators of the environmental quality, provided that detailed information about their environmental priorities is available.

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.

Protistan Bacterivory in an Oligomesotrophic Lake: Importance of Attached Ciliates and Flagellates

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Carrias; Amblard; Bourdier

1996-05-01

Seasonal and depth variations of the abundance, biomass, and bacterivory of protozoa (heterotrophic and mixotrophic flagellates and ciliates) were determined during thermal stratification in an oligomesotrophic lake (Lake Pavin, France). Maximal densities of heterotrophic flagellates (1.9x10(3) cells ml-1) and ciliates (6.1 cells ml-1) were found in the metalimnion. Pigmented flagellates dominated the flagellate biomass in the euphotic zone. Community composition of ciliated protists varied greatly with depth, and both the abundance and biomass of ciliates was dominated by oligotrichs. Heterotrophic flagellates dominated grazing, accounting for 84% of total protistan bacterivory. Maximal grazing impact of heterotrophic flagellates was 18.9x10(6) bacteria 1(-1)h-1. On average, 62% of nonpigmented flagellates were found to ingest particles. Ciliates and mixotrophic flagellates averaged 13% and 3% of protistan bacterivory, respectively. Attached protozoa (ciliates and flagellates) were found to colonize the diatom Asterionella formosa. Attached bacterivores had higher ingestion rates than free bacterivorous protozoa and may account for 66% of total protozoa bacterivory. Our results indicated that even in low numbers, epibiotic protozoa may have a major grazing impact on free bacteria.

The oxidative stress response of oxytetracycline in the ciliate Pseudocohnilembus persalinus.

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Wang, Chongnv; Pan, Xuming; Fan, Yawen; Chen, Ying; Mu, Weijie

2017-12-01

Oxytetracycline (OTC) is commonly employed in fish farms to prevent bacterial infections in China, and because of their widely and intensive use, the potential harmful effects on organisms in aquatic environment are of great concern. Ciliates play an important role in aquatic food webs as secondary producers, and Pseudocohnilembus persalinus, is one kind of them which are easily found in fish farms, surviving in polluted water. Therefore, using P. persalinus as experimental models, this study investigated the effects of oxytetracycline (OTC) on the growth, antioxidant system and morphological damage in pollution-resistant ciliates species. Our results showed that the 96-h EC 50 values for OTC of P. persalinus was 21.38mgL -1 . The increased level of SOD and GSH during 96h OTC stress was related to an adaptive response under oxidative stress induced in ciliates. Additionally, sod1, sod2 and sod3 exhibited a significant increased expression level compared to control group at 24h treatment, indicating a promoting of dense system in ciliates at this exposure time. However, only sod1 and sod2 showed raised expression level at 48h stress, showing the different sensitive of gene isoforms to some extent. With OTC treatment, damage of regular wrinkles, shrunk, twisted on the cell surface, even forming cyst of scuticociliatid ciliate cells were firstly observed by SEM (scanning electron microscope) in this study. Overall, physiological, molecular and morphological information on the toxicological studies of ciliates and more information on possibility of ciliates as indicators of contamination were provided in this study. Copyright © 2017. Published by Elsevier B.V.

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

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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.

The protozoan associates of some crustaceans

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Santhakumari, V.; Gopalan, U.K.

produced by high turbidity and low oxygen tension in the infested tanaidacean were carried out. Most of the infested tanaidaceans were found dead, showing the potentially harmful nature of this ciliate...

Utility of combining morphological characters, nuclear and mitochondrial genes: An attempt to resolve the conflicts of species identification for ciliated protists.

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Zhao, Yan; Yi, Zhenzhen; Gentekaki, Eleni; Zhan, Aibin; Al-Farraj, Saleh A; Song, Weibo

2016-01-01

Ciliates comprise a highly diverse protozoan lineage inhabiting all biotopes and playing crucial roles in regulating microbial food webs. Nevertheless, subtle morphological differences and tiny sizes hinder proper species identification for many ciliates. Here, we use the species-rich taxon Frontonia and employ both nuclear and mitochondrial loci. We attempt to assess the level of genetic diversity and evaluate the potential of each marker in delineating species of Frontonia. Morphological features and ecological characteristics are also integrated into genetic results, in an attempt to resolve conflicts of species identification based on morphological and molecular methods. Our studies reveal: (1) the mitochondrial cox1 gene, nuclear ITS1 and ITS2 as well as the hypervariable D2 region of LSU rDNA are promising candidates for species delineation; (2) the cox1 gene provides the best resolution for analyses below the species level; (3) the V2 and V4 hypervariable regions of SSU rDNA, and D1 of LSU rDNA as well as the 5.8S rDNA gene do not show distinct barcoding gap due to overlap between intra- and inter-specific genetic divergences; (4) morphological character-based analysis shows promise for delimitation of Frontonia species; and (5) all gene markers and character-based analyses demonstrate that the genus Frontonia consists of three groups and monophyly of the genus Frontonia is questionable. Copyright © 2015 Elsevier Inc. All rights reserved.

Zooxanthellae Harvested by Ciliates Associated with Brown Band Syndrome of Corals Remain Photosynthetically Competent▿

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Ulstrup, Karin E.; Kühl, Michael; Bourne, David G.

2007-01-01

Brown band syndrome is a new coral affliction characterized by a local accumulation of yet-unidentified ciliates migrating as a band along the branches of coral colonies. In the current study, morphologically intact zooxanthellae (= Symbiodinium) were observed in great numbers inside the ciliates (>50 dinoflagellates per ciliate). Microscale oxygen measurements and variable chlorophyll a fluorescence analysis along with microscopic observations demonstrated that zooxanthellae within the ciliates are photosynthetically competent and do not become compromised during the progression of the brown band zone. Zooxanthellae showed similar trends in light acclimation in a comparison of rapid light curve and steady-state light curve measures of variable chlorophyll a fluorescence. Extended light exposure of steady-state light curves resulted in higher quantum yields of photosystem II. The brown band tissue exhibited higher photosynthetically active radiation absorptivity, indicating more efficient light absorption due to a higher density of zooxanthellae in the ciliate-dominated zone. This caused relatively higher gross photosynthesis rates in the zone with zooxanthella-containing ciliates compared to healthy coral tissue. The observation of photosynthetically active intracellular zooxanthellae in the ciliates suggests that the latter can benefit from photosynthates produced by ingested zooxanthellae and from photosynthetic oxygen production that alleviates diffusion limitation of oxic respiration in the densely populated brown band tissue. It remains to be shown whether the zooxanthellae form a stable symbiotic association with the ciliate or are engulfed incidentally during grazing on coral tissue and then maintained as active inside the ciliate for a period before being digested and replaced by new zooxanthellae. PMID:17259357

Zooxanthellae harvested by ciliates associated with brown band syndrome of corals remain photosynthetically competent.

Science.gov (United States)

Ulstrup, Karin E; Kühl, Michael; Bourne, David G

2007-03-01

Brown band syndrome is a new coral affliction characterized by a local accumulation of yet-unidentified ciliates migrating as a band along the branches of coral colonies. In the current study, morphologically intact zooxanthellae (= Symbiodinium) were observed in great numbers inside the ciliates (>50 dinoflagellates per ciliate). Microscale oxygen measurements and variable chlorophyll a fluorescence analysis along with microscopic observations demonstrated that zooxanthellae within the ciliates are photosynthetically competent and do not become compromised during the progression of the brown band zone. Zooxanthellae showed similar trends in light acclimation in a comparison of rapid light curve and steady-state light curve measures of variable chlorophyll a fluorescence. Extended light exposure of steady-state light curves resulted in higher quantum yields of photosystem II. The brown band tissue exhibited higher photosynthetically active radiation absorptivity, indicating more efficient light absorption due to a higher density of zooxanthellae in the ciliate-dominated zone. This caused relatively higher gross photosynthesis rates in the zone with zooxanthella-containing ciliates compared to healthy coral tissue. The observation of photosynthetically active intracellular zooxanthellae in the ciliates suggests that the latter can benefit from photosynthates produced by ingested zooxanthellae and from photosynthetic oxygen production that alleviates diffusion limitation of oxic respiration in the densely populated brown band tissue. It remains to be shown whether the zooxanthellae form a stable symbiotic association with the ciliate or are engulfed incidentally during grazing on coral tissue and then maintained as active inside the ciliate for a period before being digested and replaced by new zooxanthellae.

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

International Nuclear Information System (INIS)

Arany, Eszter; Láng, Júlia; Somogyvári, Dávid; Láng, Orsolya; Alapi, Tünde; Ilisz, István

2014-01-01

The effects of dissolved O 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 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 2 · contribute to the degradation of diclofenac. • Toxicity of VUV-treated samples decreases with increasing rate of mineralization. • Dissolved O 2 enhances the mineralization of diclofenac by affecting the radical set. • Treated samples retain the chemorepellent character of the parent compound

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.

ATP7B detoxifies silver in ciliated airway epithelial cells

International Nuclear Information System (INIS)

Ibricevic, Aida; Brody, Steven L.; Youngs, Wiley J.; Cannon, Carolyn L.

2010-01-01

Silver is a centuries-old antibiotic agent currently used to treat infected burns. The sensitivity of a wide range of drug-resistant microorganisms to silver killing suggests that it may be useful for treating refractory lung infections. Toward this goal, we previously developed a methylated caffeine silver acetate compound, SCC1, that exhibits broad-spectrum antimicrobial activity against clinical strains of bacteria in vitro and when nebulized to lungs in mouse infection models. Preclinical testing of high concentrations of SCC1 in primary culture mouse tracheal epithelial cells (mTEC) showed selective ciliated cell death. Ciliated cell death was induced by both silver- and copper-containing compounds but not by the methylated caffeine portion of SCC1. We hypothesized that copper transporting P-type ATPases, ATP7A and ATP7B, play a role in silver detoxification in the airway. In mTEC, ATP7A was expressed in non-ciliated cells, whereas ATP7B was expressed only in ciliated cells. The exposure of mTEC to SCC1 induced the trafficking of ATP7B, but not ATP7A, suggesting the presence of a cell-specific silver uptake and detoxification mechanisms. Indeed, the expression of the copper uptake protein CTR1 was also restricted to ciliated cells. A role of ATP7B in silver detoxification was further substantiated when treatment of SCC1 significantly increased cell death in ATP7B shRNA-treated HepG2 cells. In addition, mTEC from ATP7B -/- mice showed enhanced loss of ciliated cells compared to wild type. These studies are the first to demonstrate a cell type-specific expression of the Ag + /Cu + transporters ATP7A, ATP7B, and CTR1 in airway epithelial cells and a role for ATP7B in detoxification of these metals in the lung.

Ciliated cells in vitamin A-deprived cultured hamster tracheal epithelium do divide

International Nuclear Information System (INIS)

Rutten, A.A.; Beems, R.B.; Wilmer, J.W.; Feron, V.J.

1988-01-01

The pseudostratified tracheal epithelium, composed of a heterogeneous phenotypically varying cell population, was studied with respect to the in vitro cell proliferative activity of differentiated epithelial cells. Ciliated tracheal epithelial cells so far have been considered to be terminally differentiated, nonproliferating cells. Tracheal organ cultures obtained from vitamin A-deprived Syrian Golden hamsters were cultured in a vitamin A-deficient, serum-free, hormone-supplemented medium. In vitamin A-deprived tracheal epithelium treated with physiologically active all-trans retinol and low cigarette-smoke condensate concentrations it is possible to stimulate the cell proliferation of both basal and columnar cells. Therefore, the probability of finding proliferating columnar cells was increased compared with the in vivo and the vitamin A-deprived situation in which cell proliferative activity is relatively low. In the presence of cigarette-smoke condensate in a noncytotoxic concentration, basal, small mucous granule, ciliated, and indifferent tracheal epithelial cells incorporated [methyl-3H]-thymidine into the DNA during the S phase. The finding that ciliated cells were labeled was supported by serial sections showing the same labeled ciliated cell in two section planes separated by 2 to 3 micron, without labeled epithelial cells next to the ciliated cell. Furthermore, a ciliated tracheal epithelial cell incorporating [methyl- 3 H]thymidine into DNA was also seen in tracheal cultures of vitamin A-deprived hamsters treated with all-trans retinol in a physiologic concentration

Comparing the responses of rumen ciliate protozoa and bacteria to excess carbohydrate.

Science.gov (United States)

Teixeira, César R V; Lana, Rogério de Paula; Tao, Junyi; Hackmann, Timothy J

2017-06-01

When given excess carbohydrate, certain microbial species respond by storing energy (synthesizing reserve carbohydrate), but other species respond by dissipating the energy as heat (spilling energy). To determine the importance of these responses in the rumen microbial community, this study quantified the responses of mixed ciliate protozoa vs bacteria to glucose. We hypothesized that ciliates would direct more glucose to synthesis of reserve carbohydrate (and less to energy spilling) than would bacteria. Ciliates and bacteria were isolated from rumen fluid using filtration and centrifugation, resuspended in nitrogen-free buffer to limit growth, and dosed with 5 mM glucose. Compared with bacteria, ciliates consumed glucose >3-fold faster and synthesized reserve carbohydrate 4-fold faster. They incorporated 53% of glucose carbon into reserve carbohydrate-nearly double the value (27%) for bacteria. Energy spilling was not detected for ciliates, as all heat production (104%) was accounted by synthesis of reserve carbohydrate and endogenous metabolism. For bacteria, reserve carbohydrate and endogenous metabolism accounted for only 68% of heat production, and spilling was detected within 11 min of dosing glucose. These results suggest that ciliates alter the course of ruminal carbohydrate metabolism by outcompeting bacteria for excess carbohydrate, maximizing reserve carbohydrate synthesis, and minimizing energy spilling. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

[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.

Comparative studies on the photosensitizing potency of 5-methoxypsoralen and 8-methoxypsoralen as measured by cytolysis in Paramecium caudatam and Tetrahymena pyriformis, and growth inhibition and survival in Candida albicans

International Nuclear Information System (INIS)

Young, A.R.; Barth, J.

1982-01-01

The photosensitizing potencies of 5-methoxypsoralen and 8-methoxypsoralen were investigated using the following biological end-points for lethality: (i) cytolysis in the protozoans Paramecium caudatum and Tetrahymena pyriformis, (ii) inhibition of growth in the yeast Candida albicans and (iii) survival as measured by colony counts in Candida albicans. In all cases, 5-methoxypsoralen proved to be the more potent photosensitizing agent. The preliminary action spectra of the 2 compounds for growth inhibition in C. albicans were similar and showed maximal spectral efficiency in the 320-340 nm waveband. The molecular basis for the described end-points is unknown. Although it is well known that 5-methoxypsoralen and 8-methoxypsoralen readily photoreact with DNA, it is considered that photoreaction with protein should also be given serious consideration as the possible lethal event. The superior effect of 5-methoxypsoralen is in accordance with some of the physical and photochemical properties of this molecule, but this result is at variance with other studies in different test systems that have been used to compare the photobiological efficacy of these 2 compounds. (author)

Comparative studies on the photosensitizing potency of 5-methoxypsoralen and 8-methoxypsoralen as measured by cytolysis in Paramecium caudatam and Tetrahymena pyriformis, and growth inhibition and survival in Candida albicans

Energy Technology Data Exchange (ETDEWEB)

Young, A.R. (Institute of Dermatology, London (UK)); Barth, J. (Karl-Marx-Universitaet, Leipzig (German Democratic Republic))

1982-01-01

The photosensitizing potencies of 5-methoxypsoralen and 8-methoxypsoralen were investigated using the following biological end-points for lethality: (i) cytolysis in the protozoans Paramecium caudatum and Tetrahymena pyriformis, (ii) inhibition of growth in the yeast Candida albicans and (iii) survival as measured by colony counts in Candida albicans. In all cases, 5-methoxypsoralen proved to be the more potent photosensitizing agent. The preliminary action spectra of the 2 compounds for growth inhibition in C. albicans were similar and showed maximal spectral efficiency in the 320-340 nm waveband. The molecular basis for the described end-points is unknown. Although it is well known that 5-methoxypsoralen and 8-methoxypsoralen readily photoreact with DNA, it is considered that photoreaction with protein should also be given serious consideration as the possible lethal event. The superior effect of 5-methoxypsoralen is in accordance with some of the physical and photochemical properties of this molecule, but this result is at variance with other studies in different test systems that have been used to compare the photobiological efficacy of these 2 compounds.

Gefitinib, an EGFR Tyrosine Kinase inhibitor, Prevents Smoke-Mediated Ciliated Airway Epithelial Cell Loss and Promotes Their Recovery.

Directory of Open Access Journals (Sweden)

Monica Valencia-Gattas

Full Text Available Cigarette smoke exposure is a major health hazard. Ciliated cells in the epithelium of the airway play a critical role in protection against the noxious effects of inhaled cigarette smoke. Ciliated cell numbers are reduced in smokers which weakens host defense and leads to disease. The mechanisms for the loss of ciliated cells are not well understood. The effects of whole cigarette smoke exposure on human airway ciliated ciliated cells were examined using in vitro cultures of normal human bronchial epithelial cells and a Vitrocell® VC 10® Smoking Robot. These experiments showed that whole cigarette smoke causes the loss of differentiated ciliated cells and inhibits differentiation of ciliated cells from undifferentiated basal cells. Furthermore, treatment with the epidermal growth factor receptor (EGFR tyrosine kinase inhibitor, Gefitinib, during smoke exposure prevents ciliated cell loss and promotes ciliated cell differentiation from basal cells. Finally, restoration of ciliated cells was inhibited after smoke exposure was ceased but was enhanced by Gefitinib treatment. These data suggest that inhibition of EGFR activity may provide therapeutic benefit for treating smoke related diseases.

Open Veterinary Journal - Vol 3, No 2 (2013)

African Journals Online (AJOL)

Involvement of a putative intercellular signal-recognizing G protein-coupled receptor in the engulfment of Salmonella by the protozoan Tetrahymena · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. PN Agbedanu, MT Brewer, TA Day, MJ Kimber, KL Anderson, SK ...

Protozoan predation in soil slurries compromises determination of contaminant mineralization potential

International Nuclear Information System (INIS)

Badawi, Nora; Johnsen, Anders R.; Brandt, Kristian K.; Sørensen, Jan; Aamand, Jens

2012-01-01

Soil suspensions (slurries) are commonly used to estimate the potential of soil microbial communities to mineralize organic contaminants. The preparation of soil slurries disrupts soil structure, however, potentially affecting both the bacterial populations and their protozoan predators. We studied the importance of this “slurry effect” on mineralization of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA, 14 C-labelled), focussing on the effects of protozoan predation. Mineralization of MCPA was studied in “intact” soil and soil slurries differing in soil:water ratio, both in the presence and absence of the protozoan activity inhibitor cycloheximide. Protozoan predation inhibited mineralization in dense slurry of subsoil (soil:water ratio 1:3), but only in the most dilute slurry of topsoil (soil:water ratio 1:100). Our results demonstrate that protozoan predation in soil slurries may compromise quantification of contaminant mineralization potential, especially when the initial density of degrader bacteria is low and their growth is controlled by predation during the incubation period. - Highlights: ► We studied the protozoan impact on MCPA mineralization in soil slurries. ► Cycloheximide was used as protozoan inhibitor. ► Protozoa inhibited MCPA mineralization in dilute topsoil slurry and subsoil slurry. ► Mineralization potentials may be underestimated when using soil slurries. - Protozoan predation may strongly bias the quantification of mineralization potential when performed in soil slurries, especially when the initial density of degrader bacteria is low such as in subsoil or very dilute topsoil slurries.

Prevalence of ciliated epithelium in apical periodontitis lesions.

Science.gov (United States)

Ricucci, Domenico; Loghin, Simona; Siqueira, José F; Abdelsayed, Rafik A

2014-04-01

This article reports on the morphologic features and the frequency of ciliated epithelium in apical cysts and discusses its origin. The study material consisted of 167 human apical periodontitis lesions obtained consecutively from patients presenting for treatment during a period of 12 years in a dental practice operated by one of the authors. All of the lesions were obtained still attached to the root apices of teeth with untreated (93 lesions) or treated canals (74 lesions). The former were obtained by extraction and the latter by extraction or apical surgery. Specimens were processed for histopathologic and histobacteriologic analyses. Lesions were classified, and the type of epithelium, if present, was recorded. Of the lesions analyzed, 49 (29%) were diagnosed as cysts. Of these, 26 (53%) were found in untreated teeth, and 23 (47%) related to root canal-treated teeth. Ciliated columnar epithelium was observed partially or completely lining the cyst wall in 4 cysts, and all of them occurred in untreated maxillary molars. Three of these lesions were categorized as pocket cysts, and the other was a true cyst. Ciliated columnar epithelium-lined cysts corresponded to approximately 2% of the apical periodontitis lesions and 8% of the cysts of endodontic origin in the population studied. This epithelium is highly likely to have a sinus origin in the majority of cases. However, the possibility of prosoplasia or upgraded differentiation into ciliated epithelium from the typical cystic lining squamous epithelium may also be considered. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

JST Thesaurus Headwords and Synonyms: Tetrahymena pyriformis [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Tetrahymena pyriformis 名詞 一般 * * ...* * Ｔｅｔｒａｈｙｍｅｎａ　ｐｙｒｉｆｏｒｍｉｓ Ｔｅｔｒａｈｙｍｅｎａ　ｐｙｒｉｆｏｒｍｉｓ ティーイーティーアールエイエイチワイエムイーエヌエイ　ピーワイアールアイエフオーアールエムアイエス Thesaurus2015 200906097287118996 C LS07 UNKNOWN_2 Tetrahymena pyriformis

JST Thesaurus Headwords and Synonyms: Tetrahymena thermophila [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Tetrahymena thermophila 名詞 一般 * *... * * Ｔｅｔｒａｈｙｍｅｎａ　ｔｈｅｒｍｏｐｈｉｌａ Ｔｅｔｒａｈｙｍｅｎａ　ｔｈｅｒｍｏｐｈｉｌａ ティーイーティーアールエイエイチワイエムイーエヌエイ　ティーエイチイーアールエムオーピーエイチアイエルエイ Thesaurus2015 200906086486381246 C LS07 UNKNOWN_2 Tetrahymena thermophila

Rumen ciliate protozoal fauna of native sheep, friesian cattle and dromedary camel in Libya.

Science.gov (United States)

Selim, H M; Imai, S; el Sheik, A K; Attia, H; Okamoto, E; Miyagawa, E; Maede, Y

1999-03-01

Rumen ciliate species and composition were surveyed on the native sheep, Friesian-cattle and dromedary (one-humped) camels kept in Libya. As a result of survey, 5 genera including 14 species with 5 formae in native sheep, 9 genera including 27 species with 6 formae in Friesian-cattle and 6 genera including 13 species and 7 formae in dromedary camels were identified. All of the ciliate species and their percentage composition detected from the Libyan sheep and cattle in this examination were similar to those found from corresponding animals in the other countries. Libyan camels lacked some peculiar ciliate species found from camels in the other countries, but had many cosmopolitan species common with those in the domestic ruminants, suggesting that ciliate faunae of camel are easily affected by the other domestic ruminants kept together. The ciliate density was estimated as 105/ml in every host species.

Deep-sea ciliates: Recorded diversity and experimental studies on pressure tolerance

Science.gov (United States)

Schoenle, Alexandra; Nitsche, Frank; Werner, Jennifer; Arndt, Hartmut

2017-10-01

Microbial eukaryotes play an important role in biogeochemical cycles not only in productive surface waters but also in the deep sea. Recent studies based on metagenomics report deep-sea protistan assemblages totally different from continental slopes and shelf waters. To give an overview about the ciliate fauna recorded from the deep sea we summarized the available information on ciliate occurrence in the deep sea. Our literature review revealed that representatives of the major phylogenetic groups of ciliates were recorded from the deep sea (> 1000 m depth): Karyorelictea, Heterotrichea, Spirotrichea (Protohypotrichia, Euplotia, Oligotrichia, Choreotrichia, Hypotrichia), Armophorea (Armophorida), Litostomatea (Haptoria), Conthreep (Phyllopharyngea incl. Cyrtophoria, Chonotrichia, Suctoria; Nassophorea incl. Microthoracida, Synhymeniida, Nassulida; Colpodea incl. Bursariomorphida, Cyrtolophosidida; Prostomatea; Plagiopylea incl. Plagiopylida, Odontostomatida; Oligohymenophorea incl. Peniculia, Scuticociliatia, Hymenostomatia, Apostomatia, Peritrichia, Astomatia). Species occurring in both habitats, deep sea and shallow water, are rarely found to our knowledge to date. This indicates a high deep-sea specific ciliate fauna. Our own studies of similar genotypes (SSU rDNA and cox1 gene) revealed that two small scuticociliate species (Pseudocohnilembus persalinus and Uronema sp.) could be isolated from surface as well as deep waters (2687 m, 5276 m, 5719 m) of the Pacific. The adaptation to deep-sea conditions was investigated by exposing the ciliate isolates directly or stepwise to different hydrostatic pressures ranging from 1 to 550 atm at temperatures of 2 °C and 13 °C. Although the results indicated no general barophilic behavior, all four isolated strains survived the highest established pressure. A better survival at 550 atm could be observed for the lower temperature. Among microbial eukaryotes, ciliates should be considered as a diverse and potentially

Ciliates from ancient permafrost: Assessment of cold resistance of the resting cysts.

Science.gov (United States)

Shatilovich, Anastasia; Stoupin, Daniel; Rivkina, Elizaveta

2015-06-01

There is evidence that resting cysts of soil ciliates and numerous taxa of other protists can survive in permafrost for thousands of years at subzero temperatures; however, our knowledge about mechanisms of long term cryobiosis remains incomplete. In order to better understand the means by which ancient cysts survive, we investigated resistance to cyclical supercooling stress of resting cysts of the soil ciliate Colpoda steinii (Colpodida, Ciliophora). Three clonal strains were used for comparison, isolated from Siberian tundra soil, ancient Holocene (5-7,000 y) and late Pleistocene (32-35,000 y) permafrost sediments. To determine the viability of the ancient and contemporary ciliate cysts we improved and validated a cultivation-independent method of vital fluorescent staining with a combination of two nucleic acid binding dyes, acridine orange and propidium iodide. The viability of Colpoda steinii cysts during low-temperature experiments was measured using both the proposed vital fluorescent staining method and standard germination test. Our results indicate that the dual-fluorescence technique is a more accurate, rapid, and efficient method for estimating cyst viability. We found that cysts of ancient ciliates display lower tolerance to the impact of cyclical cold compared to cysts of contemporary ciliates from Siberian permafrost affected soils. Copyright © 2015 Elsevier GmbH. All rights reserved.

Molecular detection of protozoan parasites in ticks infesting cattle ...

African Journals Online (AJOL)

An assessment of protozoan parasite load in the ticks infesting cattle entering the country by hooves through a major trans-boundary route in Ogun State was carried out using ... This is the first report on protozoan parasites detected in ticks infesting cattle entering Nigeria through a major trans-boundary route in Nigeria.

Report of a case of surgical ciliated cyst in the left maxillary sinus

Directory of Open Access Journals (Sweden)

Amirhossein Pakravan

2017-06-01

Full Text Available Surgical ciliated cyst happens as a delayed complication in the maxillary sinus, and is more frequent in Asia in comparison with Western countries. We report a case of surgical ciliated cyst in maxillary sinus in a male patient after 30 years of surgery for sinusitis treatment. The patient had swelling and pain in the region, and his radiographic views showed a cystic lesion. Incisional biopsy was performed and surgical ciliated cyst was reported as diagnosis. Then, Enucleation with curettage was performed for him as treatment.

Acute toxicity of heavy metals towards freshwater ciliated protists

International Nuclear Information System (INIS)

Madoni, Paolo; Romeo, Maria Giuseppa

2006-01-01

The acute toxicity of five heavy metals to four species of freshwater ciliates (Colpidium colpoda, Dexiotricha granulosa, Euplotes aediculatus, and Halteria grandinella) was examined in laboratory tests. After exposing the ciliates to soluble compound of cadmium, copper, chromium, lead, and nickel at several selected concentrations, the mortality rate was registered and the LC 5 values (with 95% confidence intervals) were calculated. Large differences appeared in sensitivities of the four species to the metals. H. grandinella showed the highest sensitivity for cadmium (0.07 mg l -1 , LC 5 ) and lead (0.12 mg l -1 , LC 5 ), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l -1 , LC 5 ). The comparison with data obtained with other species indicate that Halteria grandinella and Euplotes aediculatus are excellent and convenient bioindicator for evaluating the toxicity of waters and wastewaters polluted by heavy metals. The short time (24 h) and simplicity of the test procedure enable this test to be used in laboratory studies. - Ciliated protozoa are suitable bioindicators of heavy metal pollution in freshwater environments

Phytoplankton growth inhibited by the toxic and bacterivorous ciliate Uronema marinum (Protozoa, Ciliophora)

NARCIS (Netherlands)

Schaafsma, F. L.; Peperzak, L.

2013-01-01

The ubiquitous marine ciliate Uronema marinum is mainly bacterivorous. It was therefore surprising that in a ciliate-contaminated experiment the growth rate of the phytoplankton species Emiliania huxleyi was significantly reduced. As U. marinum does not ingest E. huxleyi cells, their growth

[Ciliate diversity and spatiotemporal variation in surface sediments of Yangtze River estuary hypoxic zone].

Science.gov (United States)

Feng, Zhao; Kui-Dong, Xu; Zhao-Cui, Meng

2012-12-01

By using denaturing gradient gel electrophoresis (DGGE) and sequencing as well as Ludox-QPS method, an investigation was made on the ciliate diversity and its spatiotemporal variation in the surface sediments at three sites of Yangtze River estuary hypoxic zone in April and August 2011. The ANOSIM analysis indicated that the ciliate diversity had significant difference among the sites (R = 0.896, P = 0.0001), but less difference among seasons (R = 0.043, P = 0.207). The sequencing of 18S rDNA DGGE bands revealed that the most predominant groups were planktonic Choreotrichia and Oligotrichia. The detection by Ludox-QPS method showed that the species number and abundance of active ciliates were maintained at a higher level, and increased by 2-5 times in summer, as compared with those in spring. Both the Ludox-QPS method and the DGGE technique detected that the ciliate diversity at the three sites had the similar variation trend, and the Ludox-QPS method detected that there was a significant variation in the ciliate species number and abundance between different seasons. The species number detected by Ludox-QPS method was higher than that detected by DGGE bands. Our study indicated that the ciliates in Yangtze River estuary hypoxic zone had higher diversity and abundance, with the potential to supply food for the polyps of jellyfish.

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.

On the methods for the estimation of salinity tolerance of ciliates

OpenAIRE

Smurov, Alexei

2000-01-01

Critical review of research methods for tolerance and potential tolerance of ciliates is given. Using several Paramecium species as an example the original approaches to potential tolerance estimation is presented. Connection between resistance, tolerance and potential tolerance is shown. Model for explanation of the connection is proposed. Several application aspects of diagrams of the connection between acclimation salinity and value of upper salinity tolerant limit in the ciliates are cons...

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

International Nuclear Information System (INIS)

Fuma, S.; Ishii, N.; Takeda, H.; Miyamoto, K.; Yanagisawa, K.; Ichimasa, Y.; Saito, M.; Kawabata, Z.; Polikarpov, G.G.

2003-01-01

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 γ-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

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 ...... 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.......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...

Acute toxicity of heavy metals towards freshwater ciliated protists

Energy Technology Data Exchange (ETDEWEB)

Madoni, Paolo [Dipartimento di Scienze Ambientali, Universita degli Studi di Parma, Parco Area delle Scienze 11/A, 43100 Parma (Italy)]. E-mail: paolo.madoni@unipr.it; Romeo, Maria Giuseppa [Dipartimento di Scienze Ambientali, Universita degli Studi di Parma, Parco Area delle Scienze 11/A, 43100 Parma (Italy)

2006-05-15

The acute toxicity of five heavy metals to four species of freshwater ciliates (Colpidium colpoda, Dexiotricha granulosa, Euplotes aediculatus, and Halteria grandinella) was examined in laboratory tests. After exposing the ciliates to soluble compound of cadmium, copper, chromium, lead, and nickel at several selected concentrations, the mortality rate was registered and the LC{sub 5} values (with 95% confidence intervals) were calculated. Large differences appeared in sensitivities of the four species to the metals. H. grandinella showed the highest sensitivity for cadmium (0.07 mg l{sup -1}, LC{sub 5}) and lead (0.12 mg l{sup -1}, LC{sub 5}), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l{sup -1}, LC{sub 5}). The comparison with data obtained with other species indicate that Halteria grandinella and Euplotes aediculatus are excellent and convenient bioindicator for evaluating the toxicity of waters and wastewaters polluted by heavy metals. The short time (24 h) and simplicity of the test procedure enable this test to be used in laboratory studies. - Ciliated protozoa are suitable bioindicators of heavy metal pollution in freshwater environments.

Apoptotic markers in protozoan parasites

Directory of Open Access Journals (Sweden)

Fasel Nicolas

2010-11-01

Full Text Available Abstract The execution of the apoptotic death program in metazoans is characterized by a sequence of morphological and biochemical changes that include cell shrinkage, presentation of phosphatidylserine at the cell surface, mitochondrial alterations, chromatin condensation, nuclear fragmentation, membrane blebbing and the formation of apoptotic bodies. Methodologies for measuring apoptosis are based on these markers. Except for membrane blebbing and formation of apoptotic bodies, all other events have been observed in most protozoan parasites undergoing cell death. However, while techniques exist to detect these markers, they are often optimised for metazoan cells and therefore may not pick up subtle differences between the events occurring in unicellular organisms and multi-cellular organisms. In this review we discuss the markers most frequently used to analyze cell death in protozoan parasites, paying special attention to changes in cell morphology, mitochondrial activity, chromatin structure and plasma membrane structure/permeability. Regarding classical regulators/executors of apoptosis, we have reviewed the present knowledge of caspase-like and nuclease activities.

Effects of resource supplements on mature ciliate biofilms: an empirical test using a new type of flow cell.

Science.gov (United States)

Norf, Helge; Arndt, Hartmut; Weitere, Markus

2009-11-01

Biofilm-dwelling consumer communities play an important role in the matter flux of many aquatic ecosystems. Due to their poor accessibility, little is as yet known about the regulation of natural biofilms. Here, a new type of flow cell is presented which facilitates both experimental manipulation and live observation of natural, pre-grown biofilms. These flow cells were used to study the dynamics of mature ciliate biofilms in response to supplementation of planktonic bacteria. The results suggest that enhanced ciliate productivity could be quickly transferred to micrometazoans (ciliate grazers), making the effects on the standing stock of the ciliates detectable only for a short time. Likewise, no effect on ciliates appeared when micrometazoan consumers were ab initio abundant. This indicates the importance of 'top-down' control of natural ciliate biofilms. The flow cells used here offer great potential for experimentally testing such control mechanisms within naturally cultivated biofilms.

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.

Protozoan Diversity in a productive fishpond of a tropical plateau ...

African Journals Online (AJOL)

A survey of the Protozoan species diversity in a productive fishpond of the Jos Plateau, Nigeria was investigated at 7 day interval over a period of 11 months. Samples were collected from water column and sediment. Protozoans were found to compose of the flagellates sarcodines and cilliates. There was a significant ...

Beyond the "Code": A Guide to the Description and Documentation of Biodiversity in Ciliated Protists (Alveolata, Ciliophora).

Science.gov (United States)

Warren, Alan; Patterson, David J; Dunthorn, Micah; Clamp, John C; Achilles-Day, Undine E M; Aescht, Erna; Al-Farraj, Saleh A; Al-Quraishy, Saleh; Al-Rasheid, Khaled; Carr, Martin; Day, John G; Dellinger, Marc; El-Serehy, Hamed A; Fan, Yangbo; Gao, Feng; Gao, Shan; Gong, Jun; Gupta, Renu; Hu, Xiaozhong; Kamra, Komal; Langlois, Gaytha; Lin, Xiaofeng; Lipscomb, Diana; Lobban, Christopher S; Luporini, Pierangelo; Lynn, Denis H; Ma, Honggang; Macek, Miroslav; Mackenzie-Dodds, Jacqueline; Makhija, Seema; Mansergh, Robert I; Martín-Cereceda, Mercedes; McMiller, Nettie; Montagnes, David J S; Nikolaeva, Svetlana; Ong'ondo, Geoffrey Odhiambo; Pérez-Uz, Blanca; Purushothaman, Jasmine; Quintela-Alonso, Pablo; Rotterová, Johana; Santoferrara, Luciana; Shao, Chen; Shen, Zhuo; Shi, Xinlu; Song, Weibo; Stoeck, Thorsten; La Terza, Antonietta; Vallesi, Adriana; Wang, Mei; Weisse, Thomas; Wiackowski, Krzysztof; Wu, Lei; Xu, Kuidong; Yi, Zhenzhen; Zufall, Rebecca; Agatha, Sabine

2017-07-01

Recent advances in molecular technology have revolutionized research on all aspects of the biology of organisms, including ciliates, and created unprecedented opportunities for pursuing a more integrative approach to investigations of biodiversity. However, this goal is complicated by large gaps and inconsistencies that still exist in the foundation of basic information about biodiversity of ciliates. The present paper reviews issues relating to the taxonomy of ciliates and presents specific recommendations for best practice in the observation and documentation of their biodiversity. This effort stems from a workshop that explored ways to implement six Grand Challenges proposed by the International Research Coordination Network for Biodiversity of Ciliates (IRCN-BC). As part of its commitment to strengthening the knowledge base that supports research on biodiversity of ciliates, the IRCN-BC proposes to populate The Ciliate Guide, an online database, with biodiversity-related data and metadata to create a resource that will facilitate accurate taxonomic identifications and promote sharing of data. © 2017 The Authors Journal of Eukaryotic Microbiology published by Wiley Periodicals, Inc. on behalf of International Society of Protistologists.

Characterization of copper resistant ciliates: Potential candidates for ...

African Journals Online (AJOL)

Jane

2011-08-17

Aug 17, 2011 ... algae (Rehman and Shakoori, 2001), yeast (Shakoori et al., 2005) ... organisms, this study was undertaken to determine the efficiency of ...... copper, mercury and zinc to ciliates from activated sludge plants. Bull. Environ.

A Holotrichous ciliate from the coelom of Chaetognaths

Digital Repository Service at National Institute of Oceanography (India)

Santhakumari, V.

A holotrichous ciliate was observed from the body cavity of Chaetognaths Sagitta enflata and S. bedoti collected from the zooplankton samples at Cape Comorin and Tuticorin (Tamil Nadu, India). Species were examined for infected parasites...

Evolution of apoptosis-like programmed cell death in unicellular protozoan parasites.

Science.gov (United States)

Kaczanowski, Szymon; Sajid, Mohammed; Reece, Sarah E

2011-03-25

Apoptosis-like programmed cell death (PCD) has recently been described in multiple taxa of unicellular protists, including the protozoan parasites Plasmodium, Trypanosoma and Leishmania. Apoptosis-like PCD in protozoan parasites shares a number of morphological features with programmed cell death in multicellular organisms. However, both the evolutionary explanations and mechanisms involved in parasite PCD are poorly understood. Explaining why unicellular organisms appear to undergo 'suicide' is a challenge for evolutionary biology and uncovering death executors and pathways is a challenge for molecular and cell biology. Bioinformatics has the potential to integrate these approaches by revealing homologies in the PCD machinery of diverse taxa and evaluating their evolutionary trajectories. As the molecular mechanisms of apoptosis in model organisms are well characterised, and recent data suggest similar mechanisms operate in protozoan parasites, key questions can now be addressed. These questions include: which elements of apoptosis machinery appear to be shared between protozoan parasites and multicellular taxa and, have these mechanisms arisen through convergent or divergent evolution? We use bioinformatics to address these questions and our analyses suggest that apoptosis mechanisms in protozoan parasites and other taxa have diverged during their evolution, that some apoptosis factors are shared across taxa whilst others have been replaced by proteins with similar biochemical activities.

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.

Human parasitic protozoan infection to infertility: a systematic review.

Science.gov (United States)

Shiadeh, Malihe Nourollahpour; Niyyati, Maryam; Fallahi, Shirzad; Rostami, Ali

2016-02-01

Protozoan parasitic diseases are endemic in many countries worldwide, especially in developing countries, where infertility is a major burden. It has been reported that such infections may cause infertility through impairment in male and female reproductive systems. We searched Medline, PubMed, and Scopus databases and Google scholar to identify the potentially relevant studies on protozoan parasitic infections and their implications in human and animal model infertility. Literature described that some of the protozoan parasites such as Trichomonas vaginalis may cause deformities of the genital tract, cervical neoplasia, and tubal and atypical pelvic inflammations in women and also non-gonoccocal urethritis, asthenozoospermia, and teratozoospermia in men. Toxopalasma gondii could cause endometritis, impaired folliculogenesis, ovarian and uterine atrophy, adrenal hypertrophy, vasculitis, and cessation of estrus cycling in female and also decrease in semen quality, concentration, and motility in male. Trypanosoma cruzi inhibits cell division in embryos and impairs normal implantation and development of placenta. Decrease in gestation rate, infection of hormone-producing glands, parasite invasion of the placenta, and overproduction of inflammatory cytokines in the oviducts and uterine horns are other possible mechanisms induced by Trypanosoma cruzi to infertility. Plasmodium spp. and Trypanosoma brucei spp. cause damage in pituitary gland, hormonal disorders, and decreased semen quality. Entamoeba histolytica infection leads to pelvic pain, salpingitis, tubo-ovarian abscess, and genital ulcers. Cutaneous and visceral leishmaniasis can induce genital lesion, testicular amyloidosis, inflammation of epididymis, prostatitis, and sperm abnormality in human and animals. In addition, some epidemiological studies have reported that rates of protozoan infections in infertile patients are higher than healthy controls. The current review indicates that protozoan parasitic

Protozoan Bacterivory in the Ice and the Water Column of a Cold Temperate Lagoon.

Science.gov (United States)

Sime-Ngando; Demers; Juniper

1999-02-01

> Abstract Bacterial abundance and bacterivorous protist abundance and activity were examined in ice-brine and water column communities of a cold temperate Japanese lagoon (Saroma-Ko Lagoon, Hokkaido, 44 degreesN, 144 degreesE), during the late winter phase of ice community development (February-March 1992). Bacterial abundance averaged 6 and 1 x 10(5) cells ml-1 in the ice-brine and plankton samples, respectively, and generally decreased during the sampling period. Bacterivorous protists, identified based on direct observation of short-term (Protist abundance averaged 4 x 10(3) and 8.1 cells ml-1 in the ice-brine and 0.3 x 10(3) and 1.2 cells ml-1 in the plankton, for flagellates and ciliates, respectively. In contrast to bacteria, the abundance of protists generally increased throughout the sampling period, indicating predator-prey interactions. Protistan bacterivory, measured from the rate of FLB disappearance over 24 h, averaged 36% (ice) and 24% (plankton) of bacterial standing stock and exhibited the same seasonal pattern as for protist abundance. The calculated specific clearance (range, 2-67 nl protozoa-1 h-1) and ingestion (protists" on nonbacterial food items were also provided. Although alternative sources of bacterial loss are likely to be of importance, this study provides evidence for the potential of protozoan assemblages as bacterial grazers in both sea ice-brine biota and water column at the southern limit of sea ice in the northern hemisphere.

Further studies on the role of protozoa in landfill

Energy Technology Data Exchange (ETDEWEB)

Finlay, B.J.; Clarke, K.J.; Cranwell, P.A.; Embley, T.M.; Hindle, R.M.; Simon, B.M.

1993-11-01

The specific objectives of this study were: to determine the growth requirements of methanogen-bearing protozoa living in landfill; to measure the rate of methane generation by these `protozoan consortia`; to quantify the role of protozoan grazing in stimulating overall microbial activity; to determine the identity of both symbiotic methanogens and host ciliates in different landfill sites. The results showed that the landfill ciliated protozoon, Metopus palaeformis, showed net growth in the temperature range 7-35{sup o}C, if the landfill material contained at least 40% water by weight. The methanogens living inside one cell of M.palaeformis produced, on average, 0.37 x 10{sup -12}mol CH{sub 4}/hour. In laboratory studies, the initial rate of methane generation from landfill material was twice as great when ciliates were present. There was no experimental evidence that this was due to ciliate grazing activity stimulating the re-cycling of essential nutrients to free-living bacteria. It is theoretically possible that acetate excreted by ciliates was converted to methane by free-living methanogens and that this was the source of ciliate-enhanced methane production. It was shown that the methanogenic bacteria living symbiotically within the ciliates are quite distinct from free-living methanogens previously described from landfill refuse. It is unlikely that the ciliates act as vectors for the transmission of methanogens between landfill sites. In conclusion, protozoon may be an important component of the landfill microbial community because they stimulate the rate of anaerobic decomposition and hence the rate of methane production. But protozoa are important only when the landfill material is wet (> 40% water) and when the temperature of the landfill does not exceed 30{sup o}C. (author)

Patchiness of Ciliate Communities Sampled at Varying Spatial Scales along the New England Shelf.

Directory of Open Access Journals (Sweden)

Jean-David Grattepanche

Full Text Available Although protists (microbial eukaryotes provide an important link between bacteria and Metazoa in food webs, we do not yet have a clear understanding of the spatial scales on which protist diversity varies. Here, we use a combination of DNA fingerprinting (denaturant gradient gel electrophoresis or DGGE and high-throughput sequencing (HTS to assess the ciliate community in the class Spirotrichea at varying scales of 1-3 km sampled in three locations separated by at least 25 km-offshore, midshelf and inshore-along the New England shelf. Analyses of both abundant community (DGGE and the total community (HTS members reveal that: 1 ciliate communities are patchily distributed inshore (i.e. the middle station of a transect is distinct from its two neighboring stations, whereas communities are more homogeneous among samples within the midshelf and offshore stations; 2 a ciliate closely related to Pelagostrobilidium paraepacrum 'blooms' inshore and; 3 environmental factors may differentially impact the distributions of individual ciliates (i.e. OTUs rather than the community as a whole as OTUs tend to show distinct biogeographies (e.g. some OTUs are restricted to the offshore locations, some to the surface, etc.. Together, these data show the complexity underlying the spatial distributions of marine protists, and suggest that biogeography may be a property of ciliate species rather than communities.

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

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'

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium "Candidatus Holospora parva".

Science.gov (United States)

Lanzoni, Olivia; Fokin, Sergei I; Lebedeva, Natalia; Migunova, Alexandra; Petroni, Giulio; Potekhin, Alexey

2016-01-01

Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of "green" ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name "Candidatus Holospora parva" for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis.

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium "Candidatus Holospora parva".

Directory of Open Access Journals (Sweden)

Olivia Lanzoni

Full Text Available Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of "green" ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name "Candidatus Holospora parva" for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis.

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’

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

Homologous Recombination in Protozoan Parasites and Recombinase Inhibitors

Directory of Open Access Journals (Sweden)

Andrew A. Kelso

2017-09-01

Full Text Available Homologous recombination (HR is a DNA double-strand break (DSB repair pathway that utilizes a homologous template to fully repair the damaged DNA. HR is critical to maintain genome stability and to ensure genetic diversity during meiosis. A specialized class of enzymes known as recombinases facilitate the exchange of genetic information between sister chromatids or homologous chromosomes with the help of numerous protein accessory factors. The majority of the HR machinery is highly conserved among eukaryotes. In many protozoan parasites, HR is an essential DSB repair pathway that allows these organisms to adapt to environmental conditions and evade host immune systems through genetic recombination. Therefore, small molecule inhibitors, capable of disrupting HR in protozoan parasites, represent potential therapeutic options. A number of small molecule inhibitors were identified that disrupt the activities of the human recombinase RAD51. Recent studies have examined the effect of two of these molecules on the Entamoeba recombinases. Here, we discuss the current understandings of HR in the protozoan parasites Trypanosoma, Leishmania, Plasmodium, and Entamoeba, and we review the small molecule inhibitors known to disrupt human RAD51 activity.

Ciliate diversity, community structure, and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica.

Science.gov (United States)

Xu, Yuan; Vick-Majors, Trista; Morgan-Kiss, Rachael; Priscu, John C; Amaral-Zettler, Linda

2014-10-01

We report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and March 2008). We tested hypotheses on the relationship between species richness and environmental conditions including environmental extremes, nutrient status, and day length. On the basis of the unique environment that exists in these high-latitude lakes, we expected that novel taxa would be present. Alpha diversity analyses showed that extreme conditions-that is, high salinity, low oxygen, and extreme changes in day length-did not impact ciliate richness; however, ciliate richness was 30% higher in samples with higher dissolved organic matter. Beta diversity analyses revealed that ciliate communities clustered by dissolved oxygen, depth, and salinity, but not by season (i.e., day length). The permutational analysis of variance test indicated that depth, dissolved oxygen, and salinity had significant influences on the ciliate community for the abundance matrices of resampled data, while lake and season were not significant. This result suggests that the vertical trends in dissolved oxygen concentration and salinity may play a critical role in structuring ciliate communities. A PCR-based strategy capitalizing on divergent eukaryotic V9 hypervariable region ribosomal RNA gene targets unveiled two new genera in these lakes. A novel taxon belonging to an unknown class most closely related to Cryptocaryon irritans was also inferred from separate gene phylogenies. © 2014 Marine Biological Laboratory.

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.

Studies on the microzooplankton from the central and eastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Gauns, M; Mohanraju, R.; Madhupratap, M

Numerical abundance and composition of microzooplankton in the upper 200 m were studied from the central and eastern Arabian Sea during three seasons. Protozoans, comprising of ciliates (loricates and aloricates), flagellates and sarcodines were...

A brief history of ciliate studies (late XVII the first third of the XX century)

OpenAIRE

Fokin, Sergei

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.

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

exposed to hyperthermia (43 degrees C). The cellular survival is increased at reduced temperatures (e.g. 4 degrees C instead of 36 degrees C) and at increased cellular concentrations (e.g. 100 cells ml(-1) instead of 25 or 10 cells ml(-1)). There is no effect of pre-incubation with Pluronic......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....... The protective effect of Pluronic towards Tetrahymena is observed for concentrations in the range from 0.001 to 0.1% w/v....

Description of Diploplastron dehorityi sp. nov. (Entodiniomorphida, Ophryoscolecidae), a new rumen ciliate from Brazilian sheep (Ovis aries).

Science.gov (United States)

Cedrola, Franciane; Dias, Roberto Júnio Pedroso; Martinele, Isabel; D'Agosto, Marta

2017-05-03

To date the genus Diploplastron comprised only one species of ophryoscolecid ciliate, Diploplastron affine, which is characterized by having two retractable ciliary zones in the anterior end of the body, two slender and juxtaposed skeletal plates on the right side, a rod shape macronucleus, and two contractile vacuoles. During study on the characterization of rumen ciliate community composition in Brazilian domestic sheep, we observed ciliates with atypical morphology but with diagnostic features of genus Diploplastron. This study describes Diploplastron dehorityi, a new species of ophryoscolecid ciliate, that differs from D. affine, primarily, in the morphology of skeletal plates, morphology of nuclear apparatus and body shape. In addition to the similarities between the new species and congener species, D. dehorityi has some morphological similarities to species of genus Eremoplastron.

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium “Candidatus Holospora parva”

Science.gov (United States)

Lebedeva, Natalia; Migunova, Alexandra; Petroni, Giulio

2016-01-01

Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of “green” ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name “Candidatus Holospora parva” for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis. PMID:27992463

Some ciliates from the marine wood boring isopod Sphaeroma treubia

Digital Repository Service at National Institute of Oceanography (India)

Santhakumari, V.; Nair, N.B.

Seven ectocommensalic ciliates, namely, Vorticella companula, Zoothamnium rigidum, Cothurnia gammari, Legenophrys cochinensis sp. nov., Epistylis gammari, Folliculina producta and Foliculina boltoni, all first-time recorded from the wood...

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 unsaturated fatty acids, but the amount of fatty acids compared to their carbon weight was very low and, therefore, it was considered as a poor food source. We propose a short-term interruption of food supply to copepod cultures in order to mitigate bloom formation of ciliates. This will force copepods...

Molecular characterization of intestinal protozoan parasites from ...

African Journals Online (AJOL)

Koffi Mathurin

2014-02-17

Feb 17, 2014 ... three major protozoan parasites which cause diarrhea. Out of ... 2010) regarding the under 5 mortality rate (U5MR) and .... Positive (%) Negative Total ..... Checkley W, Epstein LD, Gilman RH, Black RE, Cabrera L, Sterling CR.

A decade of intestinal protozoan epidemiology among settled immigrants in Qatar.

Science.gov (United States)

Abu-Madi, Marawan A; Behnke, Jerzy M; Boughattas, Sonia; Al-Thani, Asma; Doiphode, Sanjay H

2016-08-05

The World Health Organization estimates that about 3.5 billion people worldwide are affected by intestinal parasitic infections. Reports have already emphasized the role of immigrants in outbreaks of parasitic diseases in industrialized countries. With the mass influx of immigrants to Qatar, patent intestinal parasitic infections have been observed. Herein, the prevalence of intestinal protozoan infections was analysed in 29,286 records of subjects referred for stool examination at the Hamad Medical Corporation over the course of a decade (2005 to 2014, inclusive). Overall prevalence of combined protozoan infections was 5.93 % but there were significant temporal trends, age and sex effects and those arising from the region of origin of the subjects. The most common protozoan was Blastocystis hominis (overall prevalence 3.45 %). Giardia duodenalis, Chilomastix mesnili, Entamoeba coli, Entamoeba hartmanni, Endolimax nana, Iodamoeba butschlii, Entamoeba histolytica/dispar, Cryptosporidium sp. and a single case of Isospora were also detected. The prevalence of combined protozoan infections, G. duodenalis and the non-pathogenic amoebae all declined significantly across the decade. That of B. hominis varied between years but showed no directional trend across years and there was no evidence that prevalence of E. histolyitica/dispar changed significantly. Protozoan infections were observed among all regional groups, but prevalence was higher among subjects from the Arabian Peninsula, Africa and Asia compared to those from the Eastern Mediterranean and Qatar. Prevalence was higher among male subjects in all cases, but age-prevalence profiles differed between the taxa. These results offer optimism that prevalence will continue to decline in the years ahead.

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

NARCIS (Netherlands)

Ricard, G.N.S.; McEwan, N.R.; Dutilh, B.E.; Jouany, J.P.; Macheboeuf, D.; Mitsumori, M.; McIntosh, F.M.; Michalowski, T.; Nagamine, T.; Nelson, N.; Newbold, C.J.; Nsabimana, E.; Takenaka, A; Thomas, N.A.; Ushida, K.; Hackstein, J.H.P.; Huynen, M.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

On the nature of species: insights from Paramecium and other ciliates

Science.gov (United States)

Hall, Meaghan S.; Katz, Laura A.

2011-01-01

The multiple species concepts currently in use by the scientific community (e.g. Morphological, Biological, Phylogenetic) are united in that they all aim to capture the process of divergence between populations. For example, the Biological Species Concept (BSC) defines a species as a natural group of organisms that is reproductively isolated from other such groups. Here we synthesize nearly a century of research on the ciliate genus Paramecium that highlights the shortcomings of our prevailing notions on the nature of species. In this lineage, there is discordance between morphology, mating behavior, and genetics, features assumed to be correlated, at least after sufficient time has passed, under all species concepts. Intriguingly, epigenetic phenomena are well documented in ciliates where they influence features such as germline/soma differentiation and mating type determination. Consequently, we hypothesize that divergence within ciliate populations is due to a dynamic interaction between genetic and epigenetic factors. The growing list of examples of epigenetic phenomena that potentially impact speciation (i.e. by influencing the dynamics of sex chromosomes, fate of hybrids, zygotic drive and genomic conflicts) suggests that interactions between genetics and epigenetics may also drive divergence in other eukaryotic lineages. PMID:21505762

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. © 2014 The Authors The Journal of Eukaryotic Microbiology published by Wiley Periodicals, Inc. on behalf of International Society of Protistologists.

Bioaccumulation of ultraviolet sunscreen compounds (mycosporine-like amino acids) by the heterotrophic freshwater ciliate Bursaridium living in alpine lakes

Science.gov (United States)

Sonntag, Bettina; Kammerlander, Barbara; Summerer, Monika

2017-01-01

Abstract Ciliates in shallow alpine lakes are exposed to high levels of incident solar ultraviolet radiation (UVR). We observed the presence of specific sunscreen compounds, the mycosporine-like amino acids (MAAs), in several populations of Bursaridium, a relatively large ciliate species found in such lakes. The populations from 3 highly UV transparent lakes revealed the presence of 7 MAAs (MG, SH, PR, PI, AS, US, and PE) in total concentrations of 3.6–52.4 10−5 μg μg−1 dry weight (DW) per individual, whereas in one glacially turbid and less UV transparent lake, no MAAs were detected in the Bursaridium population. The MAAs in the ciliates generally reflected the composition and relative amounts of the lakes’ seston MAAs, assuming that the ciliates fed on MAA-rich plankton. We experimentally found that naturally acquired MAAs prevented ciliate mortality under simulated UVR and photosynthetically active radiation (PAR) conditions. We further tested the dietary regulation of the MAAs-content in the ciliates under artificial UVR and PAR exposure and found an increase in MAAs concentrations in all treatments. Our assumption was that several stress factors other than irradiation were involved in the synthesis or up-regulation of MAAs. PMID:28690781

Dependence of the cytotoxicity of multi-walled carbon nanotubes on the culture medium

International Nuclear Information System (INIS)

Zhu Ying; Ran Tiecheng; Li Yuguo; Guo Jinxue; Li Wenxin

2006-01-01

This study examined the influence of multi-walled carbon nanotubes (MWNTs) on the growth of the unicellular protozoan Tetrahymena pyriformis. Contrary to the findings from most other investigations, our experiment indicated that MWNTs stimulated growth of the cells cultured in proteose peptone yeast extract medium (PPY). Atomic force microscopy images and thermogravimetric analysis showed the spontaneous formation of peptone-MWNT conjugates in the medium by noncovalent binding. Uptake of large amounts of the conjugates by Tetrahymena pyriformis was responsible for growth stimulation, evidenced by images with fluorescently labelled peptone. After the PPY medium was replaced by a filtrated pond water medium (FPW), however, inhibition of the growth of cells exposed to MWNTs occurred. Measurements of the level of malondialdehyde and superoxide dismutase activity demonstrated further that MWNTs might be either toxic or nontoxic, depending on the medium used to cultivate Tetrahymena pyriformis. The biological effects of the interaction of MWNTs with some composites in culture media would be helpful for understanding the mechanisms of the toxicity of carbon nanotubes to living systems

Toxicity of Chlorpyrifos and Dimethoate to the Ciliate Urostyla grandis, with Notes on Their Effects on Cell Ultrastructure

Science.gov (United States)

Mu, Weijie; Warren, Alan; Pan, Xuming; Ying, Chen

2018-06-01

Chlorpyrifos and dimethoate are overused agricultural pesticides that can trigger trophic cascades, resulting in toxicity to both terrestrial and aquatic organisms as well as altered ecosystems. In previous studies, substantial attention has been given to the effects of pesticides on vertebrate species and, to a lesser extent, species of zooplankton. The present study was designed to show that the fission time effective concentration in ciliates is a potential aquatic detection index for environmental monitoring. The ciliate Urostyla grandis was treated with doses of chlorpyrifos and dimethoate. After exposed to the pesticides, the LC 50 ( i.e., concentration that killed 50% of the ciliate cells within 24 h) values were 0.029 mg L-1 for chlorpyrifos and 0.0685 mg L-1 for dimethoate. The fission time effective concentrations after 168 h of exposure were 0.0075-0.0093 mg L-1 for chlorpyrifos and 0.2640-0.2750 mg L-1 for dimethoate. These results show that the fission time effective concentration is lower than the LC 50 value in ciliates, indicating that fission time effective concentration is more suitable than the LC 50 value for environmental monitoring using ciliates. The effects of chlorpyrifos and dimethoate on ciliate cell ultrastructures included agglutination of chromatin in the macronucleus, protruded and discontinuous macronuclear and micronuclear membranes, loss of integrity of mitochondrial membranes and contents, and abscission and deformation of the adoral zone of membranelles.

Assessment of potential sources of protozoan contamination ...

African Journals Online (AJOL)

Occasional screening of food and water quality available to organisms in protected areas could be beneficial to their successful conservation. This is important for areas receiving regular human visitors and exhibiting activities that may be detrimental to ecosystem health. This study determined the intestinal protozoan ...

First record of entodiniomorph ciliates in a carnivore, the maned wolf (Chrysocyon brachyurus), from Brazil.

Science.gov (United States)

Vynne, Carly; Kinsella, John M

2009-06-01

The entodiniomorph ciliates (Ciliophora: Entodiniomorphida) are endosymbiotes widely found in the intestines of herbivorous mammals. These commensals commonly occur in the Artiodactyla and Perissodactyla and have also been described in the Proboscidea, Primates, Rodentia, and Diprotodontia. This study reports the first finding of a ciliate in a member of order Carnivora, the maned wolf (Chrysocyon brachyurus). Fecal samples from wild and captive maned wolves were screened using ethyl acetate sedimentation. Prevalence in fecal samples collected from free-ranging maned wolves in Brazil was 40% (6 of 15). Fecal samples from two of four captive individuals from the St. Louis Zoo also had the same species of ciliate. The largely frugivorous diet of the maned wolf likely explains the occurrence of these normally herbivore-associated endosymbiotes in a carnivore.

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

Potential effect of some environmental factors on the phage removal during wastewater treatment. Study in vitro

International Nuclear Information System (INIS)

Benhyahya, M.; Bohatier, J.; Laveran, H.; Ettayebi, M.; Senaud, J.

2000-01-01

caused by the dissolved matters. But the process was progressively more marked (24 hours later, it was 98.8% and 38% respectively for MS2 and øX-174). With solar radiations, an important inactivation of the somatic coliphage was obtained at the earlier exposition times to the sunlight. Later, the effect was amplified. øX-174 phage titer decreased almost 2 log units after exposition of 1.5 hour and more than 5 log units after 12 hours. In the case of MS2, decrease titer was less important at the first exposition times but tended to 5 log units at the last one (12 hours). The infection of the protozoan culture medium by any of the phages was followed by microscopic observations. The morphology and the mobility of the ciliate were no affected by the presence of phages. The biological cycle was also comparable to the control. The ciliate culture medium seems to have an inactivation effect mainly in the case of øX-174. Predation by Tetrahymena pyriformis cannot be considered as an important factor of phage removal from the medium [fr

The D1-D2 region of the large subunit ribosomal DNA as barcode for ciliates.

Science.gov (United States)

Stoeck, T; Przybos, E; Dunthorn, M

2014-05-01

Ciliates are a major evolutionary lineage within the alveolates, which are distributed in nearly all habitats on our planet and are an essential component for ecosystem function, processes and stability. Accurate identification of these unicellular eukaryotes through, for example, microscopy or mating type reactions is reserved to few specialists. To satisfy the demand for a DNA barcode for ciliates, which meets the standard criteria for DNA barcodes defined by the Consortium for the Barcode of Life (CBOL), we here evaluated the D1-D2 region of the ribosomal DNA large subunit (LSU-rDNA). Primer universality for the phylum Ciliophora was tested in silico with available database sequences as well as in the laboratory with 73 ciliate species, which represented nine of 12 ciliate classes. Primers tested in this study were successful for all tested classes. To test the ability of the D1-D2 region to resolve conspecific and congeneric sequence divergence, 63 Paramecium strains were sampled from 24 mating species. The average conspecific D1-D2 variation was 0.18%, whereas congeneric sequence divergence averaged 4.83%. In pairwise genetic distance analyses, we identified a D1-D2 sequence divergence of DNA amplification of single cells and voucher deposition. In conclusion, the presented data pinpoint the D1-D2 region as an excellent candidate for an official CBOL barcode for ciliated protists. © 2013 John Wiley & Sons Ltd.

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

Science.gov (United States)

Clark, Kevin B

2013-01-01

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 non-modal 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 social

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

Phylogenetic evidence for the acquisition of ribosomal RNA introns subsequent to the divergence of some of the major Tetrahymena groups

DEFF Research Database (Denmark)

Sogin, M L; Ingold, A; Karlok, M

1986-01-01

. In an attempt to evaluate the evolutionary origins of the intervening sequences, we have now determined complete small subunit ribosomal RNA gene sequences from 13 species of Tetrahymena and the absolute number of nucleotide differences between the sequences was used to construct a phylogenetic tree...

Effects of a ciliate protozoa predator on microbial communities in pitcher plant (Sarracenia purpurea leaves.

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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.

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. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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...

Act together – implications of symbioses in aquatic ciliates

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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

Stress and Protists: No life without stress.

Science.gov (United States)

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

2016-08-01

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. Copyright © 2016 Elsevier GmbH. All rights reserved.

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. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Protozoa in a stressed area of the Egyptian Mediterranean coast of Damietta, Egypt

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Mohamed Moussa Dorgham

2013-08-01

Full Text Available The Damietta coast is part of the Egyptian Mediterranean coast off the Nile Delta and has recently been polluted as a result of intensive human activities.The environmental parameters and protozoan community in the area were studied biweekly from January to December 2007. The results of the environmentalparameters indicated low salinity, oxic and anoxic conditions, high nutrient levels and intensive phytoplankton growth. A total of 69 protozoan specieswere identified, belonging to Amoebozoa (8 species, Foraminifera (12 species, non-tintinnid ciliates (22 species and tintinnids (27 species. The numerical density of protozoans was high over the whole area, with annual averages between 8.2 × 103 cells m-3 and 51.4 × 103 cells m-3.Spring was the most productive season for protozoans, but several distinct peaks were observed during the year at the sampling sites. The protozoangroups showed clearly different spatial patterns in both composition and abundance: whereas amoebozoans and non-tintinnid ciliates were dominant in themore polluted areas (sites IV and V, tintinnids dominated in the less polluted areas (sites, I, II and III. Several pollution indicators wererecorded: amoebozoans - Centropyxis aculeata, Centropyxis sp., Cochliopodium sp.,Difflugia sp.; non-tintinnids - Bursaridium sp., Frontonia atra,Holophrya sp., Paramecium sp., Paramecium bursaria,Vasicola ciliata, Vorticella sp., Strombidium sp.; tintinnids- Favella ehrenbergii, Helicostomella subulata, Leprotintinnus nordgvisti,Tintinnopsis beroidea, Stenosemella ventricosa, Tintinnopsis campanula,T. cylindrica, T. lobiancoi, Eutintinnus lusus-undae.

Upwelling dynamics in the Baltic Sea studied by a combined SAR/infrared satellite data and circulation model analysis

Directory of Open Access Journals (Sweden)

Evgenia Gurova

2013-08-01

Full Text Available The Damietta coast is part of the Egyptian Mediterranean coast off the Nile Delta and has recently been polluted as a result of intensive human activities.The environmental parameters and protozoan community in the area were studied biweekly from January to December 2007. The results of the environmentalparameters indicated low salinity, oxic and anoxic conditions, high nutrient levels and intensive phytoplankton growth. A total of 69 protozoan specieswere identified, belonging to Amoebozoa (8 species, Foraminifera (12 species, non-tintinnid ciliates (22 species and tintinnids (27 species. The numerical density of protozoans was high over the whole area, with annual averages between 8.2 × 103 cells m-3 and 51.4 × 103 cells m-3.Spring was the most productive season for protozoans, but several distinct peaks were observed during the year at the sampling sites. The protozoangroups showed clearly different spatial patterns in both composition and abundance: whereas amoebozoans and non-tintinnid ciliates were dominant in themore polluted areas (sites IV and V, tintinnids dominated in the less polluted areas (sites, I, II and III. Several pollution indicators wererecorded: amoebozoans - Centropyxis aculeata, Centropyxis sp., Cochliopodium sp.,Difflugia sp.; non-tintinnids - Bursaridium sp., Frontonia atra,Holophrya sp., Paramecium sp., Paramecium bursaria,Vasicola ciliata, Vorticella sp., Strombidium sp.; tintinnids- Favella ehrenbergii, Helicostomella subulata, Leprotintinnus nordgvisti,Tintinnopsis beroidea, Stenosemella ventricosa, Tintinnopsis campanula,T. cylindrica, T. lobiancoi, Eutintinnus lusus-undae.

The symbiotic intestinal ciliates and the evolution of their hosts

NARCIS (Netherlands)

Moon-van der Staay, S.Y.; Staay, G.W. van der; Michalowski, T.; Jouany, J.P.; Pristas, P.; Javorsky, P.; Kisidayova, S.; Varadyova, Z.; McEwan, N.R.; Newbold, C.J.; Alen, T. van; Graaf, R. de; Schmid, M.; Huynen, M.A.; Hackstein, J.H.

2014-01-01

The evolution of sophisticated differentiations of the gastro-intestinal tract enabled herbivorous mammals to digest dietary cellulose and hemicellulose with the aid of a complex anaerobic microbiota. Distinctive symbiotic ciliates, which are unique to this habitat, are the largest representatives

Functional diversity of benthic ciliate communities in response to environmental gradients in a wetland of Yangtze Estuary, China.

Science.gov (United States)

Xu, Yuan; Fan, Xinpeng; Warren, Alan; Zhang, Liquan; Xu, Henglong

2018-02-01

Researches on the functional diversity of benthic ecosystems have mainly focused on macrofauna, and studies on functional structure of ciliate communities have been based only on trophic- or size-groups. Current research was carried out on the changing patterns of classical and functional diversity of benthic ciliates in response to environmental gradients at three sites in a wetland in Yangtze Estuary. The results showed that changes of environmental factors (e.g. salinity, sediment grain size and hydrodynamic conditions) in the Yangtze Estuary induce variability in species composition and functional trait distribution. Furthermore, increased species richness and diversity did not lead to significant changes in functional diversity due to functional redundancy. However, salt water intrusion of Yangtze Estuary during the dry season could cause reduced functional diversity of ciliate communities. Current study provides the first insight into the functional diversity of ciliate communities in response to environmental gradients. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

OpenAIRE

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

2006-01-01

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...

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 the population may be encysted. The factors governing the dynamics of active and encysted cells in the soil are not well understood. Our objective was to determine the dynamics of active and encysted populations of ciliates during the decomposition of freshly added organic material. We monitored, in soil...... microcosms, the active and total populations of ciliates, their potential prey (bacteria and small protozoa), their potential competitors (amoebae, flagellates, and nematodes), and their potential predators (nematodes). We sampled with short time intervals (2 to 6 days) and generated a data set, suitable...

Social biases determine spatiotemporal sparseness of ciliate mating heuristics.

Science.gov (United States)

Clark, Kevin B

2012-01-01

Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate's initial subjective bias, responsiveness, or preparedness, as defined by Stevens' Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The present

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 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.

Assessing phagotrophy in the mixotrophic ciliate Paramecium bursaria using GFP-expressing yeast cells.

Science.gov (United States)

Miura, Takashi; Moriya, Hisao; Iwai, Sosuke

2017-07-03

We used cells of the yeast Saccharomyces cerevisiae expressing green fluorescent protein (GFP) as fluorescently labelled prey to assess the phagocytic activities of the mixotrophic ciliate Paramecium bursaria, which harbours symbiotic Chlorella-like algae. Because of different fluorescence spectra of GFP and algal chlorophyll, ingested GFP-expressing yeast cells can be distinguished from endosymbiotic algal cells and directly counted in individual P. bursaria cells using fluorescence microscopy. By using GFP-expressing yeast cells, we found that P. bursaria altered ingestion activities under different physiological conditions, such as different growth phases or the presence/absence of endosymbionts. Use of GFP-expressing yeast cells allowed us to estimate the digestion rates of live prey of the ciliate. In contrast to the ingestion activities, the digestion rate within food vacuoles was not affected by the presence of endosymbionts, consistent with previous findings that food and perialgal vacuoles are spatially and functionally separated in P. bursaria. Thus, GFP-expressing yeast may provide a valuable tool to assess both ingestion and digestion activities of ciliates that feed on eukaryotic organisms. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Application of the denaturing gradient gel electrophoresis (DGGE) technique as an efficient diagnostic tool for ciliate communities in soil.

Science.gov (United States)

Jousset, Alexandre; Lara, Enrique; Nikolausz, Marcell; Harms, Hauke; Chatzinotas, Antonis

2010-02-01

Ciliates (or Ciliophora) are ubiquitous organisms which can be widely used as bioindicators in ecosystems exposed to anthropogenic and industrial influences. The evaluation of the environmental impact on soil ciliate communities with methods relying on morphology-based identification may be hampered by the large number of samples usually required for a statistically supported, reliable conclusion. Cultivation-independent molecular-biological diagnostic tools are a promising alternative to greatly simplify and accelerate such studies. In this present work a ciliate-specific fingerprint method based on the amplification of a phylogenetic marker gene (i.e. the 18S ribosomal RNA gene) with subsequent analysis by denaturing gradient gel electrophoresis (DGGE) was developed and used to monitor community shifts in a polycyclic aromatic hydrocarbon (PAH) polluted soil. The semi-nested approach generated ciliate-specific amplification products from all soil samples and allowed to distinguish community profiles from a PAH-polluted and a non-polluted control soil. Subsequent sequence analysis of excised bands provided evidence that polluted soil samples are dominated by organisms belonging to the class Colpodea. The general DGGE approach presented in this study might thus in principle serve as a fast and reproducible diagnostic tool, complementing and facilitating future ecological and ecotoxicological monitoring of ciliates in polluted habitats. Copyright 2009 Elsevier B.V. All rights reserved.

Intestinal protozoan and helminthic diarrheal infections in children ...

African Journals Online (AJOL)

Intestinal protozoan and helminthic diarrheal infections in children under five years old in Agasha, Benue State, north-central Nigeria. ... creation particularly on proper hand washing with soap or ash and water for children and their parents/care-givers. Keywords: diarrhea, protozoa, helminthes, hygiene and hand hygiene.

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.

COMPLEXITY OF ECOLOGICAL SYSTEMS (THE CASE OF MARINE CILIATE COMMUNITY

Directory of Open Access Journals (Sweden)

I.V. Burkovsky

2016-03-01

Full Text Available The paper analyzes the seasonal and long-term dynamics of marine interstitial ciliates communities as a result of the processes of system self-organization (of increasing complexity in constantly fluctuating environment. The traits of simple structure of ciliate community include substantial variability in the composition (even in case of stable environment and the lack of sustainable combinations of species. The mechanism of the current state maintenance is the lack of energy supply in certain periods or in specific loci of space, as well as large amplitude and unpredictable fluctuations of environmental factors. An indication of the community’s complexity is availability of stable combinations of species in time and space. The mechanisms of formation of stable species combinations are a constant flow of external energy, optimal values and stability of environmental factors (including repeatability of seasonal cycles and the use of space resources by species according the principle of complementarity of ecological niches.

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

Ecological effects of ionizing radiation and other toxic agents on the aquatic microcosm

International Nuclear Information System (INIS)

Fuma, Shoichi; Ishii, Nobuyoshi; Tanaka, Nobuyuki; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei; Kawabata, Zen'ichiro

2004-01-01

The purpose of this study was comparative evaluation of effects of ionizing radiation and other various toxic agents on aquatic microbial communities. For this purpose, the authors investigated effects of γ-rays, ultraviolet (UV) radiation, acidification, aluminum, manganese, nickel, copper and gadolinium on the microcosm, i.e., the experimental model ecosystem consisting of populations of the flagellate alga Euglena gracilis as a producer, the ciliate protozoan Tetrahymena thermophila as a consumer and the bacterium Eseherichia coli as a decomposer. Effects of toxic agents in the microcosm were not only direct effects but also community-level effects due to interactions among the constituting species or between organisms and toxic agents. In general, the degrees of effects observed in the microcosm could be categorized as follows: no effects; recognizable effects, i.e., decrease or increase in the cell densities of at least one species; severe effects, i.e., extinction of one or two species; and destructive effects, i.e., extinction of all species. These results were analyzed by the ecological effect index (EEI), in which differences in the cell densities between exposed and control microcosm were represented by the Euclidean distance function. A 50% effect doses for the microcosm (ED M50 ), at which the EEI became 50%, were evaluated to be 530 Gy for γ-rays, 2100 J m -2 for UV, 4100 μM for manganese, 45 μM for nickel, 110 μM for copper and 250 μM for gadolinium. (author)

Zooplankton community of Bhayandar and Thane salt pans around Bombay

Digital Repository Service at National Institute of Oceanography (India)

Mustafa, S.; Nair, V.R.; Govindan, K.

. The protozoan ciliate Fabrea salina dominated the microzooplankton community. The mesomacrozooplankton standing stock was more at Thane (av 1.7 g wet wt/m sup(3)) as compared to Bhayandar (av 1.4 g wet wt/m sup(3)). However, group diversity was more at Bhayandar...

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

The secondary structure of the large-subunit ribosomal RNA (24-26S rRNA) has been studied with emphasis on comparative analysis of the folding patterns of the divergent domains in the available protist sequences, that is Prorocentrum micans (dinoflagellate), Saccharomyces carlsbergensis (yeast......), 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...

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.

Photosensory transduction in unicellular eukaryotes: a comparison between related ciliates Blepharisma japonicum and Stentor coeruleus and photoreceptor cells of higher organisms.

Science.gov (United States)

Sobierajska, Katarzyna; Fabczak, Hanna; Fabczak, Stanisław

2006-06-01

Blepharisma japonicum and Stentor coeruleus are related ciliates, conspicuous by their photosensitivity. They are capable of avoiding illuminated areas in the surrounding medium, gathering exclusively in most shaded places (photodispersal). Such behaviour results mainly from motile photophobic response occurring in ciliates. This light-avoiding response is observed during a relatively rapid increase in illumination intensity (light stimulus) and consists of cessation of cell movement, a period of backward movement (ciliary reversal), followed by a forward swimming, usually in a new direction. The photosensitivity of ciliates is ascribed to their photoreceptor system, composed of pigment granules, containing the endogenous photoreceptor -- blepharismin in Blepharisma japonicum, and stentorin in Stentor coeruleus. A light stimulus, applied to both ciliates activates specific stimulus transduction processes leading to the electrical changes at the plasma membrane, correlated with a ciliary reversal during photophobic response. These data indicate that both ciliates Blepharisma japonicum and Stentor coeruleus, the lower eukaryotes, are capable of transducing the perceived light stimuli in a manner taking place in some photoreceptor cells of higher eukaryotes. Similarities and differences concerning particular stages of light transduction in eukaryotes at different evolutional levels are discussed in this article.

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

Science.gov (United States)

Vďačný, Peter

2017-10-01

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. Copyright © 2017 The Author. Published by Elsevier GmbH.. All rights reserved.

Off the hook - how bacteria survive protozoan grazing

DEFF Research Database (Denmark)

Matz, Carsten; Kjelleberg, S.

2005-01-01

Bacterial growth and survival in numerous environments are constrained by the action of bacteria-consuming protozoa. Recent findings suggest that bacterial adaptations against protozoan predation might have a significant role in bacterial persistence and diversification. We argue that selective p...... for microbial ecology and evolution at the interface of prokaryotes and eukaryotes....

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

Transcriptional program of ciliated epithelial cells reveals new cilium and centrosome components and links to human disease.

Directory of Open Access Journals (Sweden)

Ramona A Hoh

Full Text Available Defects in the centrosome and cilium are associated with a set of human diseases having diverse phenotypes. To further characterize the components that define the function of these organelles we determined the transcriptional profile of multiciliated tracheal epithelial cells. Cultures of mouse tracheal epithelial cells undergoing differentiation in vitro were derived from mice expressing GFP from the ciliated-cell specific FOXJ1 promoter (FOXJ1:GFP. The transcriptional profile of ciliating GFP+ cells from these cultures was defined at an early and a late time point during differentiation and was refined by subtraction of the profile of the non-ciliated GFP- cells. We identified 649 genes upregulated early, when most cells were forming basal bodies, and 73 genes genes upregulated late, when most cells were fully ciliated. Most, but not all, of known centrosome proteins are transcriptionally upregulated early, particularly Plk4, a master regulator of centriole formation. We found that three genes associated with human disease states, Mdm1, Mlf1, and Dyx1c1, are upregulated during ciliogenesis and localize to centrioles and cilia. This transcriptome for mammalian multiciliated epithelial cells identifies new candidate centrosome and cilia proteins, highlights similarities between components of motile and primary cilia, and identifies new links between cilia proteins and human disease.

Detection and prevalence of protozoan parasites in ready-to-eat packaged salads on sale in Italy.

Science.gov (United States)

Caradonna, Tiziana; Marangi, Marianna; Del Chierico, Federica; Ferrari, Nicola; Reddel, Sofia; Bracaglia, Giorgia; Normanno, Giovanni; Putignani, Lorenza; Giangaspero, Annunziata

2017-10-01

To investigate the prevalence of protozoan contamination by Giardia duodenalis, Cryptosporidium spp., Toxoplasma gondii and Cyclospora cayetanensis, in 'ready to eat' (RTE) salads on sale in Italy, 648 packages were purchased from industrial and local brands. Nine individual packages from each brand were collected per month, pooled and subjected to microscopy and molecular analyses. Microscopic examination of 864 slides detected Cryptosporidium spp. but also Blastocystis hominis and Dientamoeba fragilis. Molecular tools identified G. duodenalis assemblage A, Cryptosporidium parvum and Cryptosporidium ubiquitum, T. gondii Type I and C. cayetanensis. B. hominis and D. fragilis were also molecularly confirmed. The overall prevalence of each protozoan species was 0.6% for G. duodenalis, 0.8% for T. gondii, 0.9% for Cryptosporidium spp., and 1.3% for C. cayetanensis, while prevalence for B. hominis was 0.5% and for D. fragilis 0.2%. Microscopy and/or molecular tools revealed that 4.2% of the samples were contaminated by at least one protozoan species, and 0.6% of samples presented contamination by two protozoan species, with a number of oocysts ranging from 62 to 554 per g of vegetable matter for T. gondii, and 46 to 1.580 for C. cayetanensis. This is Europe's first large-scale study on the presence of protozoans in packaged salads, and shows that RTE sanitation processes do not guarantee a product free from protozoans of fecal origin. Copyright © 2017 Elsevier Ltd. All rights reserved.

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. © 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.

15-30, 2016 15 Prevalence of diarrhea causing protozoan infections

African Journals Online (AJOL)

protozoal infection was recorded and therefore public health education about diarrhea causing protozoans and ..... individuals serve as unidentified carriers and may .... Web GIS for tourism devel- ... CSA [Ethiopia] and ICF International; 2012.

Rapid detection of predation of Escherichia coli O157:H7 and sorting of bacterivorous Tetrahymena by flow cytometry

Directory of Open Access Journals (Sweden)

Bradley J. Hernlem

2014-05-01

Full Text Available Protozoa are known to harbor bacterial pathogens, alter their survival in the environment and make them hypervirulent. Rapid non-culture based detection methods are required to determine the environmental survival and transport of enteric pathogens from point sources such as dairies and feedlots to food crops grown in proximity. Grazing studies were performed on a soil isolate of Tetrahymena fed green fluorescent protein (GFP expressing Escherichia coli O157:H7 to determine the suitability of the use of such fluorescent prey bacteria to locate and sort bacterivorous protozoa by flow cytometry. In order to overcome autofluorescence of the target organism and to clearly discern Tetrahymena with ingested prey versus those without, a ratio of prey to host of at least 100:1 was determined to be preferable. Under these conditions, we successfully sorted the two populations using short 5 to 45 min exposures of the prey and verified the internalization of E. coli O157:H7 cells in protozoa by confocal microscopy. This technique can be easily adopted for environmental monitoring of rates of enteric pathogen destruction versus protection in protozoa.

Temperature-dependent changes in the swimming behaviour of Tetrahymena pyriformis-NT1 and their interrelationships with electrophysiology and the state of membrane lipids.

Science.gov (United States)

Connolly, J G; Brown, I D; Lee, A G; Kerkut, G A

1985-01-01

The swimming velocity and the amplitude of the helical swimming path of T. pyriformis-NT1 cells grown at 20 degrees C (Tg 20 degrees C) and 38 degrees C (Tg 38 degrees C) were monitored between 0 and 40 degrees C in the presence and absence of electric fields. Within physiological limits the swimming velocity increased and the amplitude decreased as temperature was raised. The temperature profiles of these properties were not linear, and showed discontinuities at different temperatures for the different cultures. The break points in Arrhenius plots of the resting potential, regenerative spike magnitude, repolarization time, swimming velocity and swimming amplitude are tabulated and compared. The initial breakpoints upon cooling were clustered about the breakpoints in fluorescence polarization of D.P.H. in extracted phospholipids, and around the transition temperatures estimated from the literature for the pellicular membrane of these cells. The average of the initial breakpoints on cooling was 22.9 degrees C for Tg 38 degrees C cells and 13.7 degrees C for Tg 20 degrees C cells, a shift of 9.2 degrees C. Unlike Paramecium there is no depolarizing receptor potential in Tetrahymena upon warming. It is suggested that this may be the basis of a behavioural difference between Tetrahymena and Paramecium--namely that in Tetrahymena maximum swimming velocity occurs above growth temperature whereas in Paramecium the two points coincide. Swimming velocity and resting potential were correlated with membrane fluidity within physiological limits, but for other parameters the relationship with fluidity was more complex.(ABSTRACT TRUNCATED AT 250 WORDS)

A study on protozoan infections (Giardia, Entamoeba, Isoapora and Cryptosporidium in stray dogs in Ilam province

Directory of Open Access Journals (Sweden)

S Kakekhani

2011-11-01

Full Text Available Giardia, Entamoeba, Isospora and Cryptosporidium are important protozoan parastites that caused diarrhea in human and animals. In the present study, fecal samples were collected fresh, directly from the rectum of 112 stray dogs in Ilam province. Giardia and Entamoeba were concentrated by using the formalin ether sedimentation method followed by the trichrome and iodine staining technique andCryptosporidium  oocysts  were  concentrated  by  using  the  formalin  ether  sedimentation  method  followed by the modified Ziehl-Neelsen staining technique. Of 112 stray dogs, protozoan infections were detected from feces of 46 dogs (41.07% that Giardia infection was detected from feces of 21 dogs (18.75%, Isospora 17 (15.17%, Cryptosporidium 8 (7.14% and synchronization infection to 2 protozoan in 9 dogs (8.03% and to 3 protozoan in 3 (2.67%. In the present study not observed to Entamoeba. No statistically significant differences in prevalence of protozoan parasites occurred between female (34.21 % and male (55.5 % stray dogs (p>0/05. But statistically significant differences in prevalence occurred between 1≥0 and 0 ≥1 stray dogs (p>0/05. So that stray dogs of Ilam province can cause infection of human water and food sources.

Photodynamic therapy in the cattle protozoan Tritrichomonas foetus cultivated on superhydrophilic carbon nanotube

Energy Technology Data Exchange (ETDEWEB)

Machado, Susane Moreira [Laboratory of Tissue and Cell Biology, Development and Research Institute (IP and D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, Urbanova, 12244-000 São José dos Campos, SP (Brazil); Pacheco-Soares, Cristina [Laboratory of Tissue and Cell Biology, Development and Research Institute (IP and D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, Urbanova, 12244-000 São José dos Campos, SP (Brazil); Laboratory of Dynamics of Cellular Compartments, Development and Research Institute (IP and D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, Urbanova, 12244-000 São José dos Campos, SP (Brazil); Marciano, Fernanda Roberta; Lobo, Anderson Oliveira [Laboratory of Biomedical Nanotechnology, Development and Research Institute (IP and D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, Urbanova, 12244-000 São José dos Campos, SP (Brazil); Soares da Silva, Newton, E-mail: nsoares@univap.br [Laboratory of Tissue and Cell Biology, Development and Research Institute (IP and D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, Urbanova, 12244-000 São José dos Campos, SP (Brazil); Laboratory of Dynamics of Cellular Compartments, Development and Research Institute (IP and D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, Urbanova, 12244-000 São José dos Campos, SP (Brazil)

2014-03-01

Superhydrophilic vertically aligned carbon nanotubes (VACNT-O{sub 2}) were used for the first time as scaffolds for photodynamic therapy (PDT) to induce inhibition of cell division in eukaryotic cells. VACNT-O{sub 2} scaffolds were produced on Ti substrates using plasma enhanced chemical vapor deposition technique and functionalized by oxygen plasma. Scanning electron microscopy (SEM) analysis was performed to characterize the surface changes of the protozoan and interaction with VACNT-O{sub 2}. Characterization of lipid and total protein expression was performed with protozoa that were or not treated with PDT. Quantification of protein was conducted using Qubit fluorometer and separated on a polyacrylamide gel. SEM analysis showed the release of lipid vesicles by protozoa after the PDT. These vesicles were characterized by the PKH26 fluorescent probe. The results demonstrated a greater amount of protein released after PDT than in the control. When analyzing the protein material in polyacrylamide gel, a significant protein expression of approximately 65 kDa was found. A model identified the programmed death of Tritrichomonas foetus after the PDT was also proposed. - Highlights: • VAMWCNT-O{sub 2} used for the first time as scaffolds for study in parasitic protozoan. • VAMWCNT-O{sub 2} films applied to understand spreading mechanisms of parasitic protozoan. • A release of a protein of approximately 65kDa of protozoan was also observed.

Photodynamic therapy in the cattle protozoan Tritrichomonas foetus cultivated on superhydrophilic carbon nanotube

International Nuclear Information System (INIS)

Machado, Susane Moreira; Pacheco-Soares, Cristina; Marciano, Fernanda Roberta; Lobo, Anderson Oliveira; Soares da Silva, Newton

2014-01-01

Superhydrophilic vertically aligned carbon nanotubes (VACNT-O 2 ) were used for the first time as scaffolds for photodynamic therapy (PDT) to induce inhibition of cell division in eukaryotic cells. VACNT-O 2 scaffolds were produced on Ti substrates using plasma enhanced chemical vapor deposition technique and functionalized by oxygen plasma. Scanning electron microscopy (SEM) analysis was performed to characterize the surface changes of the protozoan and interaction with VACNT-O 2 . Characterization of lipid and total protein expression was performed with protozoa that were or not treated with PDT. Quantification of protein was conducted using Qubit fluorometer and separated on a polyacrylamide gel. SEM analysis showed the release of lipid vesicles by protozoa after the PDT. These vesicles were characterized by the PKH26 fluorescent probe. The results demonstrated a greater amount of protein released after PDT than in the control. When analyzing the protein material in polyacrylamide gel, a significant protein expression of approximately 65 kDa was found. A model identified the programmed death of Tritrichomonas foetus after the PDT was also proposed. - Highlights: • VAMWCNT-O 2 used for the first time as scaffolds for study in parasitic protozoan. • VAMWCNT-O 2 films applied to understand spreading mechanisms of parasitic protozoan. • A release of a protein of approximately 65kDa of protozoan was also observed

Bovine Tick-borne Protozoan Diseases: Emerging Threats

OpenAIRE

El-Ashker MR

2013-01-01

Tick-borne protozoan diseases, Theileriosis and Babesiosis, are major health and management problems of cattle, small ruminants and buffaloes in Africa, Asia and Latin America. Recently, tickborne diseases were ranked high in terms of their impact on poor farming communities in developing countries. Whereas the global economic importance of ticks is particularly high for livestock, there is also a relevant impact on public health in the northern hemisphere.

Purification, characterization and molecular cloning of TGP1, a novel G-DNA binding protein from Tetrahymena thermophila.

OpenAIRE

Lu, Q; Schierer, T; Kang, S G; Henderson, E

1998-01-01

G-DNA, a polymorphic family of four-stranded DNA structures, has been proposed to play roles in a variety of biological processes including telomere function, meiotic recombination and gene regulation. Here we report the purification and cloning of TGP1, a G-DNA specific binding protein from Tetrahymena thermophila. TGP1 was purified by three-column chromatographies, including a G-DNA affinity column. Two major proteins (approximately 80 and approximately 40 kDa) were present in the most high...

The effects of temperature upon the electrophysiological properties of Tetrahymena pyriformis-NT1.

Science.gov (United States)

Connolly, J G; Brown, I D; Lee, A G; Kerkut, G A

1985-01-01

Cells of Tetrahymena pyriformis--NT1 were cultured at 38 degrees C (Tg 38 degrees C) and 20 degrees C (Tg 20 degrees C) and their properties investigated over the range 0-40 degrees C. Tg 20 degrees C cells were viable in the range 3-33 degrees C and changes in their properties were readily reversible between 10 degrees C and 30 degrees C. Tg 38 degrees cells were viable in the range 40-10 degrees C and their property changes were immediately reversible in the range 40-23 degrees C. The I-V relations of Tg 38 degrees C cells showed increased excitability as the cells were cooled from 40 degrees C. At 10 degrees C there was a considerable loss of excitability and slope resistance. Cooling Tg 20 degrees C cells from 20 degrees C gave a similar pattern, although over a narrower temperature range. Warming Tg 20 degrees C Tetrahymena above 20 degrees C led to a progressive loss of excitability and the cells were markedly less viable above 35 degrees C. Within physiological limits the regenerative spike magnitude, repolarization time, time to peak and input resistance increased as temperature was lowered, whereas resting potential was diminished. When compared at their growth temperatures and most intermediate temperatures, the value of the various parameters monitored were generally different for the two cultures. The Q10 value for resting potential changes of Tg 20 degrees C cells about 20 degrees C was 1.20. As in T. vorax this was significantly (P less than 0.01) greater than that predicted for a diffusion potential and suggested that T. pyriformis--NT1 may have an electrogenic pump component in its membrane potential.

Factors Associated with High Prevalence of Intestinal Protozoan Infections among Patients in Sana'a City, Yemen

Science.gov (United States)

Alyousefi, Naelah A.; Mahdy, Mohammed A. K.; Mahmud, Rohela; Lim, Yvonne A. L.

2011-01-01

Background Intestinal protozoan diseases in Yemen are a significant health problem with prevalence ranging from 18% to 27%. The present study is a cross-sectional study aimed at determining the factors associated with the high prevalence of intestinal protozoan infections among patients seeking health care in Sana'a City, the capital of Yemen. Methodology/Principal Findings Stool samples were collected from 503 patients aged between 1 and 80 years old; 219 were males and 284 females. Biodata were collected via pretested standard questionnaire. Faecal samples were processed and examined for (oo)cysts or ova using a wet mount preparation after formal-ether concentration technique. Cryptosporidium oocysts were detected using the Ziehl-Neelsen staining technique. The overall prevalence of intestinal protozoan infections was 30.9%. Infection rates of Giardia duodenalis, Entamoeba histolytica/dispar and Cryptosporidium were 17.7%, 17.1% and 1%, respectively. Other parasites detected included Ascaris lumbricoides (2.4%), Schistosoma mansoni (0.3%), Hymenolepis nana (1.4%) and Enterobius vermicularis (0.4%). Multivariate analysis using forward stepwise logistic regression based on intestinal protozoan infections showed that contact with animals (OR = 1.748, 95% CI = 1.168–2.617) and taking bath less than twice a week (OR = 1.820, 95% CI = 1.192–2.779) were significant risk factors of protozoan infections. Conclusions/Significance This present study indicated that intestinal protozoan infections are still a public health problem in Yemen, with Giardia and Entamoeba infections being most common. Statistical analysis indicated that low personal hygiene and contact with animals were important predictors for intestinal protozoan infections. As highlighted in this study, in order to effectively reduce these infections, a multi-sectoral effort is needed. Preventive measures should include good hygienic practices, good animal husbandry practices, heightened

Morphology and Phylogeny of a New Species of Anaerobic Ciliate, Trimyema finlayi n. sp., with Endosymbiotic Methanogens.

Science.gov (United States)

Lewis, William H; Sendra, Kacper M; Embley, T Martin; Esteban, Genoveva F

2018-01-01

Many anaerobic ciliated protozoa contain organelles of mitochondrial ancestry called hydrogenosomes. These organelles generate molecular hydrogen that is consumed by methanogenic Archaea, living in endosymbiosis within many of these ciliates. Here we describe a new species of anaerobic ciliate, Trimyema finlayi n. sp., by using silver impregnation and microscopy to conduct a detailed morphometric analysis. Comparisons with previously published morphological data for this species, as well as the closely related species, Trimyema compressum , demonstrated that despite them being similar, both the mean cell size and the mean number of somatic kineties are lower for T. finlayi than for T. compressum , which suggests that they are distinct species. This was also supported by analysis of the 18S rRNA genes from these ciliates, the sequences of which are 97.5% identical (6 substitutions, 1479 compared bases), and in phylogenetic analyses these sequences grouped with other 18S rRNA genes sequenced from previous isolates of the same respective species. Together these data provide strong evidence that T. finlayi is a novel species of Trimyema , within the class Plagiopylea. Various microscopic techniques demonstrated that T. finlayi n. sp. contains polymorphic endosymbiotic methanogens, and analysis of the endosymbionts' 16S rRNA gene showed that they belong to the genus Methanocorpusculum , which was confirmed using fluorescence in situ hybridization with specific probes. Despite the degree of similarity and close relationship between these ciliates, T. compressum contains endosymbiotic methanogens from a different genus, Methanobrevibacter . In phylogenetic analyses of 16S rRNA genes, the Methanocorpusculum endosymbiont of T. finlayi n. sp. grouped with sequences from Methanomicrobia, including the endosymbiont of an earlier isolate of the same species, ' Trimyema sp.,' which was sampled approximately 22 years earlier, at a distant (∼400 km) geographical location

Morphology and Phylogeny of a New Species of Anaerobic Ciliate, Trimyema finlayi n. sp., with Endosymbiotic Methanogens

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William H. Lewis

2018-02-01

Full Text Available Many anaerobic ciliated protozoa contain organelles of mitochondrial ancestry called hydrogenosomes. These organelles generate molecular hydrogen that is consumed by methanogenic Archaea, living in endosymbiosis within many of these ciliates. Here we describe a new species of anaerobic ciliate, Trimyema finlayi n. sp., by using silver impregnation and microscopy to conduct a detailed morphometric analysis. Comparisons with previously published morphological data for this species, as well as the closely related species, Trimyema compressum, demonstrated that despite them being similar, both the mean cell size and the mean number of somatic kineties are lower for T. finlayi than for T. compressum, which suggests that they are distinct species. This was also supported by analysis of the 18S rRNA genes from these ciliates, the sequences of which are 97.5% identical (6 substitutions, 1479 compared bases, and in phylogenetic analyses these sequences grouped with other 18S rRNA genes sequenced from previous isolates of the same respective species. Together these data provide strong evidence that T. finlayi is a novel species of Trimyema, within the class Plagiopylea. Various microscopic techniques demonstrated that T. finlayi n. sp. contains polymorphic endosymbiotic methanogens, and analysis of the endosymbionts’ 16S rRNA gene showed that they belong to the genus Methanocorpusculum, which was confirmed using fluorescence in situ hybridization with specific probes. Despite the degree of similarity and close relationship between these ciliates, T. compressum contains endosymbiotic methanogens from a different genus, Methanobrevibacter. In phylogenetic analyses of 16S rRNA genes, the Methanocorpusculum endosymbiont of T. finlayi n. sp. grouped with sequences from Methanomicrobia, including the endosymbiont of an earlier isolate of the same species, ‘Trimyema sp.,’ which was sampled approximately 22 years earlier, at a distant (∼400 km

Ciliated median raphe cyst of perineum presenting as perianal polyp: a case report with immunohistochemical study, review of literature, and pathogenesis.

Science.gov (United States)

Sagar, Jayesh; Sagar, Bethani; Patel, Adam F; Shak, D K

2006-03-05

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.

Phytoplankton/protozoan dynamics in the Nyara Estuary, a small ...

African Journals Online (AJOL)

Phytoplankton/protozoan dynamics in the Nyara Estuary, a small temporarily open system in the Eastern Cape (South Africa) ... freshwater inflow, the Nyara is best described as a predominantly low nutrient, low phytoplankton biomass, stratified system, dominated by the microbial food-web and possibly fed by detritus.

DETECTION OF PROTOZOAN PARASITES IN SOURCE AND FINISHED WATER - 3RD EDITION ASM'S METHODS IN ENVIRONMENTAL MICROBIOLOGY

Science.gov (United States)

Protozoans are eukaryotic organisms which can live either a free-living or parasitic existence. Some free-living forms, under the right conditions, can become opportunistic parasites. Enteric pathogenic protozoans, like Giardia and Cryptosporidium, which are now known to be tra...

The Occurrence of Some Nonblood Protozoan Parasites in Wild and Domestic Mammals in South Africa.

Science.gov (United States)

Lukášová, Radka; Halajian, Ali; Bártová, Eva; Kobédová, Kateřina; Swanepoel, Lourens H; O'Riain, M Justin

2018-04-01

Relatively little is known about protozoan parasites in African animals. Here we investigated the occurrence of protozoan parasites in mammals from South Africa. Oocysts of protozoan parasites were detected in 13 of 56 (23%) fecal samples using conventional microscopic examination methods. Cryptosporidium spp. and Cystoisospora spp. were detected in eight (14%) and five (9%) samples, respectively. Mixed parasitic infection of Cryptosporidium spp. and Cystoisospora spp. was recorded in banded mongoose ( Mungos mungo). Cryptosporidium spp. was detected for the first time in cheetah ( Acinonyx jubatus), spotted hyena ( Crocuta crocuta), and African polecat ( Ictonyx striatus). Antibodies to Toxoplasma gondii and Neospora caninum were not detected by enzyme-linked immunosorbent assay in any of 32 sera tested. We detected T. gondii by PCR in tissues of five of 243 (2%) animals: domestic dog ( Canis lupus familiaris), gerbil ( Gerbilliscus spp.), greater kudu ( Tragelaphus strepsiceros), honey badger ( Mellivora capensis), and white-tailed mongoose ( Ichneumia albicauda). Our isolation of T. gondii from white-tailed mongoose and honey badger was a unique finding. All tissue samples were negative for N. caninum. The study increases our knowledge on the occurrence of protozoan parasites in populations of wild and domestic animals in South Africa.

Intestinal protozoan parasites with zoonotic potential in birds.

Science.gov (United States)

Marietto-Gonçalves, G A; Fernandes, T M; Silva, R J; Lopes, R S; Andreatti Filho, R L

2008-10-01

The aim of this study was to evaluate the occurrence of potentially zoonotic intestinal protozoan infections in exotic and wildlife Brazilian birds. Fecal samples from 207 birds of 45 species were examined. Infections by Balantidium sp., Entamoeba sp., and Blastocystis sp. were observed in 17 individuals (8.2%) of Gnorimopsar chopi, Oryzoborus angolensis, Sporophila caerulescens, Ramphastos toco, Aratinga leucophtalmus, and Pavo cristatus.

Application of the denaturing gradient gel electrophoresis (DGGE) technique as an efficient diagnostic tool for ciliate communities in soil

OpenAIRE

Jousset, Alexandre; Lara, Enrique; Nikolausz, Marcell; Harms, Hauke; Chatzinotasa, Antonis

2010-01-01

Ciliates (or Ciliophora) are ubiquitous organisms which can be widely used as bioindicators in ecosystems exposed to anthropogenic and industrial influences. The evaluation of the environmental impact on soil ciliate communities with methods relying on morphology-based identification may be hampered by the large number of samples usually required for a statistically supported, reliable conclusion. Cultivation-independent molecular-biological diagnostic tools are a promising alternative to gre...

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.

Free-Living Marine Interstitial Hypotrichid Ciliates from Jubail Marine Wildlife Sanctuary in the Arabian Gulf

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K.A.S. AL-Rasheid

1999-01-01

Full Text Available Sediment samples were collected at low tide from various localities of the Jubail Marine Wildlife Sanctuary in the Arabian Gulf on several occasions during l996-l997 for the study of the marine interstitial ciliate fauna of the Sanctuary. Twenty three species belonging to the order Hypotrichida were identified after protargol impregnation, 20 of which represent new records of the fauna of Saudi Arabia, and of the Arabian Gulf at large. The distribution of each species is compared to those in similar habitats worldwide. The present study increases the total known number of hypotrichid ciliates species in Saudi Arabia to 40 species.

Ecology of a heterotrichous ciliate Fabrea salina from salterns of Bombay Coast, India

Digital Repository Service at National Institute of Oceanography (India)

Rattan, P.; Ansari, Z.A.; Sreepada, R.A.

The abundance and population size structure of a heterotrichous ciliate @iFabrea salina@@, was studied in relation to hydrochemical and hydrobiological variables in three hypersaline ponds of Bombay, west coast of India There was a clear seasonal...

Nuclear dualism.

Science.gov (United States)

Karrer, Kathleen M

2012-01-01

Nuclear dualism is a characteristic feature of the ciliated protozoa. Tetrahymena have two different nuclei in each cell. The larger, polyploid, somatic macronucleus (MAC) is the site of transcriptional activity in the vegetatively growing cell. The smaller, diploid micronucleus (MIC) is transcriptionally inactive in vegetative cells, but is transcriptionally active in mating cells and responsible for the genetic continuity during sexual reproduction. Although the MICs and MACs develop from mitotic products of a common progenitor and reside in a common cytoplasm, they are different from one another in almost every respect. Copyright © 2012 Elsevier Inc. All rights reserved.

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

Science.gov (United States)

Soleymani, Ali; Pennekamp, Frank; Petchey, Owen L; Weibel, Robert

2015-01-01

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.

1+1 = 3: a fusion of 2 enzymes in the methionine salvage pathway of Tetrahymena thermophila creates a trifunctional enzyme that catalyzes 3 steps in the pathway.

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Hannah M W Salim

2009-10-01

Full Text Available The methionine salvage pathway is responsible for regenerating methionine from its derivative, methylthioadenosine. The complete set of enzymes of the methionine pathway has been previously described in bacteria. Despite its importance, the pathway has only been fully described in one eukaryotic organism, yeast. Here we use a computational approach to identify the enzymes of the methionine salvage pathway in another eukaryote, Tetrahymena thermophila. In this organism, the pathway has two fused genes, MTNAK and MTNBD. Each of these fusions involves two different genes whose products catalyze two different single steps of the pathway in other organisms. One of the fusion proteins, mtnBD, is formed by enzymes that catalyze non-consecutive steps in the pathway, mtnB and mtnD. Interestingly the gene that codes for the intervening enzyme in the pathway, mtnC, is missing from the genome of Tetrahymena. We used complementation tests in yeast to show that the fusion of mtnB and mtnD from Tetrahymena is able to do in one step what yeast does in three, since it can rescue yeast knockouts of mtnB, mtnC, or mtnD. Fusion genes have proved to be very useful in aiding phylogenetic reconstructions and in the functional characterization of genes. Our results highlight another characteristic of fusion proteins, namely that these proteins can serve as biochemical shortcuts, allowing organisms to completely bypass steps in biochemical pathways.

Prevalence of Intestinal Protozoans among Schoolchildren in Suburban Areas near Yangon, Myanmar.

Science.gov (United States)

Kim, Min-Jae; Jung, Bong-Kwang; Cho, Jaeeun; Kim, Deok-Gyu; Song, Hyemi; Lee, Keon-Hoon; Cho, Seon; Htoon, Thi Thi; Tin, Htay Htay; Chai, Jong-Yil

2016-06-01

Although intestinal protozoans are common etiologies of diarrhea, few studies have been conducted in Myanmar. This study planned to investigate the prevalence of Giardia lamblia, Entamoeba coli, Entamoeba histolytica, and Endolimax nana among schoolchildren and their guardians in suburban areas near Yangon, Myanmar. We performed a cross-sectional survey among schoolchildren and their guardians from 7 primary schools in South Dagon and Hlaing Thar Yar districts, Yangon, Myanmar. Stool samples were observed with a microscope after concentration technique and iodine staining. Total 821 stool samples, including 556 from schoolchildren and 265 from guardians, were examined. The median age was 6 years old for schoolchildren and 36 years old for guardians. A 53.1% of the school children and 14.6 % of the guardians were males. The overall prevalence of each intestinal protozoan species was as follows: 3.4% (28/821) for G. lamblia; 3.5% (29/821) for E. coli; 1.2% (10/821) for E. histoytica, and 3.0% for E. nana. This study showed that intestinal protozoans are common in primary schoolchildren and their guardians in suburban areas near Yangon, Myanmar. Health interventions, such as hand washing education, improvement of sanitation, and establishment of water purification systems are urgently needed in this area.

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

We have determined the nucleotide sequence of the 26S large subunit (LSU) rRNA genes for two Tetrahymena species, T. thermophila and T. pyriformis. The inferred rRNA sequences are presented in their most probable secondary structures based on compensatory mutations, energy, and conservation crite...

Zoonotic intestinal protozoan of the wild boars, Sus scrofa, in Persian Gulf's coastal area (Bushehr province), Southwestern Iran.

Science.gov (United States)

Yaghoobi, Kambiz; Sarkari, Bahador; Mansouri, Majid; Motazedian, Mohammad Hossein

2016-10-01

Wild boars, Sus scrofa , are potential reservoirs of many zoonotic diseases, and there are a possibility of transmission of the zoonotic diseases from these animals to humans and also domestic animals. This study aimed to evaluate the protozoan contamination of wild boars in the Persian Gulf's coastal area (Bushehr Province), southwestern Iran. A total of 25 crossbred boars were collected during a course of vertebrate pest control in Bushehr province, in 2013. Samples were collected from the gastrointestinal tracts of each boar in 5% formalin, Bouin's solution, sodium acetate-acetic acid-formalin, and polyvinyl alcohol fixatives. Fixed stool smears examined by trichrome and Ziehl-Neelsen staining. Each of the 25 wild boars was infected with at least one of the intestinal protozoans. The rate of contamination with intestinal protozoan was 64% for Balantidium coli , 76% for Iodamoeba sp., 52% for Entamoeba polecki , 44% for Blastocystis sp. and 8% for Chilomastix sp. No intestinal coccidian was detected in studied boars when the stool samples were evaluated by Ziehl-Neelsen staining method. Findings of this study demonstrated that wild boars in the Persian Gulf coastal area are contaminated by many protozoans, including zoonotic protozoan, which poses a potential risk to locals as well as the domestic animals of the area.

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.

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.

Evolutionary implications of genetic code deviations

International Nuclear Information System (INIS)

Chela Flores, J.

1986-07-01

By extending the standard genetic code into a temperature dependent regime, we propose a train of molecular events leading to alternative coding. The first few examples of these deviations have already been reported in some ciliated protozoans and Gram positive bacteria. A possible range of further alternative coding, still within the context of universality, is pointed out. (author)

A Comparative Study of the Common Protozoan Parasites of Clarias gariepinus from the Wild and Cultured Environments in Benue State, Nigeria

Science.gov (United States)

Omeji, S.; Solomon, S. G.; Idoga, E. S.

2011-01-01

A total of one hundred and twenty Clarias gariepinus comprising 30 dead and 30 live fishes were examined for protozoan parasites infestation, sixty each from the wild and a pond (cultured environment) over a period of six months. Ichthyophthirius multifiliis was the most common protozoan parasites found in C. gariepinus from the wild (River Benue) and cultured (pond) environments. These protozoan parasites constitute 37.08% of the total parasites encountered for fishes in the pond and 42.51% of fishes in the wild. Among the body parts of the sampled fishes from the pond, the gills had the highest parasite load (38.86%). Also, the gills had the highest parasite load (40.54%) among the body parts of the fishes sampled from the wild. Fishes not infested with any protozoan parasites from the pond constituted 36.70% of the total fish sampled. On the other hand, fishes not infested with any protozoan parasites from the wild constituted 31.65% of the total fish sampled. Female fishes had more protozoan parasites than the male fishes. Bigger fishes of total length (25–48 cm) had more parasite load than the smaller ones (19–24 cm). Also, fishes between 150–750 g had more parasite load than the smaller ones of less than 150 g. Protozoan parasite load of fish from the cultured environment (pond) did not differ significantly (P < 0.05) from those from River Benue (wild). PMID:22028952

A Comparative Study of the Common Protozoan Parasites of Clarias gariepinus from the Wild and Cultured Environments in Benue State, Nigeria

Directory of Open Access Journals (Sweden)

S. Omeji

2011-01-01

Full Text Available A total of one hundred and twenty Clarias gariepinus comprising 30 dead and 30 live fishes were examined for protozoan parasites infestation, sixty each from the wild and a pond (cultured environment over a period of six months. Ichthyophthirius multifiliis was the most common protozoan parasites found in C. gariepinus from the wild (River Benue and cultured (pond environments. These protozoan parasites constitute 37.08% of the total parasites encountered for fishes in the pond and 42.51% of fishes in the wild. Among the body parts of the sampled fishes from the pond, the gills had the highest parasite load (38.86%. Also, the gills had the highest parasite load (40.54% among the body parts of the fishes sampled from the wild. Fishes not infested with any protozoan parasites from the pond constituted 36.70% of the total fish sampled. On the other hand, fishes not infested with any protozoan parasites from the wild constituted 31.65% of the total fish sampled. Female fishes had more protozoan parasites than the male fishes. Bigger fishes of total length (25–48 cm had more parasite load than the smaller ones (19–24 cm. Also, fishes between 150–750 g had more parasite load than the smaller ones of less than 150 g. Protozoan parasite load of fish from the cultured environment (pond did not differ significantly (P<0.05 from those from River Benue (wild.

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

Effects of temporally persistent ant nests of soil protozoan communities and the abundance of morphological types of amoeba

Science.gov (United States)

We compared soil protozoan communities near ant nests with soil protozoans in reference soils 5m from the edge of any mounds. We sampled three species of Chihuahuan Desert ants that construct nests that persist for more than a decade: a seed harvester, Pogonomymex rugosus, a liquid feeding honey-po...

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

Czech Academy of Sciences Publication Activity Database

Peštová, D.; Macek, Miroslav; Pérez, M. E. M.

2008-01-01

Roč. 44, č. 1 (2008), s. 13-25 ISSN 0932-4739 Institutional research plan: CEZ:AV0Z60170517 Keywords : ciliates * autotrophic picoplankton * feeding rates Subject RIV: EH - Ecology, Behaviour Impact factor: 1.000, year: 2008

Blood protozoan parasites of rodents in Jos, Plateau State, Nigerai ...

African Journals Online (AJOL)

One hundred and thirty rodents, comprising nine different species caught from seven different locations in Jos, Nigeria, were examined for blood protozoan parasites, and 82(63.08%) were positive, with Plasmodium 63(48.46%), Trypanosoma 4(3.08%), Toxoplasma 6(4.62%), Babesia 7(5.38%) and Anaplasma 2(1.54%).

Transposon Invasion of the Paramecium Germline Genome Countered by a Domesticated PiggyBac Transposase and the NHEJ Pathway

Science.gov (United States)

Dubois, Emeline; Bischerour, Julien; Marmignon, Antoine; Mathy, Nathalie; Régnier, Vinciane; Bétermier, Mireille

2012-01-01

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. PMID:22888464

Ciliated Hepatic Foregut Cyst: Two Case Reports in Children and Review of the Literature

Directory of Open Access Journals (Sweden)

Maliheh Khoddami

2013-01-01

Full Text Available Ciliated hepatic foregut cyst (CHFC is a rare lesion which originates from detached hepatic diverticulum or from detachment and migration of buds from the esophageal and bronchial regions of the foregut which subsequently get entrapped by the liver during the early embryonic development of the foregut. CHFCs are mostly seen in adults and are rarely reported in children, with only about 10 cases reported in this age group. Hereby, we present two cases of CHFC in two 3.5-year-old boys; one of them had cystic lesion at medial segment of left lobe of liver (common site, and in the other one it was located at right lobe of liver (less common site. Histologically, both cysts had four layers composed of inner ciliated, pseudostratified, columnar epithelium; subepithelial connective tissue; smooth muscle layer; and an outer fibrous layer.

A serological study of removal of UV-induced photoproducts in the DNA of tetrahymena pyriformis GL: influence of caffeine, quinacrine and chloroquine

International Nuclear Information System (INIS)

Lakhanisky, Th.; Hendrickx, B.; Mouton, R.F.; Cornelis, J.J.

1979-01-01

Antisera that recognise specifically UV-photoproducts in DNA have been used to follow the elimination of photolesions in UV irradiated Tetrahymena pyriformis. The amount of bound tritium-labelled antibodies to nuclei has been estimated by autoradiography. Curves of dose-response of DNA photo-products, their elimination by dark repair, and effect of caffeine, quinacrine, and chloroquine on the disappearance of UV-lesions have been evaluated. (author)

How Far do Ciliate Flagships Sail? A Proposed Gondawanaland Endemic Species at Anchor in Idaho Soils.

Science.gov (United States)

Bourland, William

2017-07-01

In terms of protist biogeography, "flagship species" (Foissner 2005) have been defined as those so remarkable or "showy" that they are unlikely to be overlooked when present in a given habitat. On this basis, flagship species have been suggested as an ideal or ultimate test for the existence of protist endemism. One example of a flagship ciliate is the terrestrial lepidosome-bearing trachelophyllid, Luporinophrys micelae, previously thought to be a Gondwanan endemic. This report comprises a morphologic description of two populations of L. micelae from Laurentian soils (Idaho, Northwest USA). The flagship concept is briefly reviewed and ciliate biogeography is discussed in light of these findings. Copyright © 2017 Elsevier GmbH. All rights reserved.

The First Record for the Americas of Loxodes rex, a Flagship Ciliate with an Alleged Restricted Biogeography.

Science.gov (United States)

Hines, Hunter N; McCarthy, Peter J; Esteban, Genoveva F

2016-01-01

As the foundations of food webs, protozoa are essential to the success of an ecological system. These organisms are often overlooked, and research in the Americas is sparse. Recent samplings conducted in freshwater canals and ponds in Florida, USA, have revealed Loxodes rex, an alleged endemic ciliate species. Originally described as endemic to tropical Africa, L. rex has been considered a prime candidate for proof of microbial endemism. Our studies have shown this giant, non-encysting ciliate to be thriving in subtropical Florida. Our observations are novel and include both the first record of occurrence for the Americas and the first high-quality in vivo images for this charismatic species.

The past, present and future of fluorescent protein tags in anaerobic protozoan parasites.

Science.gov (United States)

Morin-Adeline, Victoria; Šlapeta, Jan

2016-03-01

The world health organization currently recognizes diarrhoeal diseases as a significant cause of death in children globally. Protozoan parasites such as Giardia and Entamoeba that thrive in the oxygen-deprived environment of the human gut are common etiological agents of diarrhoea. In the urogenital tract of humans, the anaerobic protozoan parasite Trichomonas vaginalis is notorious as the most common non-viral, sexually transmitted pathogen. Even with high medical impact, our understanding of anaerobic parasite physiology is scarce and as a result, treatment choices are limited. Fluorescent proteins (FPs) are invaluable tools as genetically encoded protein tags for advancing knowledge of cellular function. These FP tags emit fluorescent colours and once attached to a protein of interest, allow tracking of parasite proteins in the dynamic cellular space. Application of green FPs-like FPs in anaerobic protozoans is hindered by their oxygen dependency. In this review, we examine aspects of anaerobic parasite biology that clash with physio-chemical properties of FPs and limit their use as live-parasite protein tags. We expose novel FPs, such as miniSOG that do not require oxygen for signal production. The potential use of novel FPs has the opportunity to leverage the anaerobe parasitologist toolkit to that of aerobe parasitologist.

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.

Breast-feeding protects infantile diarrhea caused by intestinal protozoan infections.

Science.gov (United States)

Abdel-Hafeez, Ekhlas Hamed; Belal, Usama Salah; Abdellatif, Manal Zaki Mohamed; Naoi, Koji; Norose, Kazumi

2013-10-01

This study investigated the effect of breast-feeding in protection against protozoan infection in infants with persistent diarrhea. Infants were classified into 2 groups; 161 breast-fed infants and the same number of non-breast-fed infants. Microscopic examinations of stool were done for detection of parasites and measuring the intensity of infection. Moreover, serum levels of IgE and TNF-α were measured by ELISA. Cryptosporidium spp., Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Blastocystis sp. were demonstrated in infants with persistent diarrhea. The percentage of protozoan infections was significantly lower in breast-fed infants than that in the non-breast-fed infants. The levels of IgE and TNF-α were significantly lower in the breast-fed group than in the non-breast-fed group. There were significant positive associations between the serum levels of IgE and TNF-α and the intensity of parasite infection in the breast-fed group. It is suggested that breast-feeding has an attenuating effect on the rate and intensity of parasite infection.

Cancer in the parasitic protozoans Trypanosoma brucei and Toxoplasma gondii.

Science.gov (United States)

Lun, Zhao-Rong; Lai, De-Hua; Wen, Yan-Zi; Zheng, Ling-Ling; Shen, Ji-Long; Yang, Ting-Bo; Zhou, Wen-Liang; Qu, Liang-Hu; Hide, Geoff; Ayala, Francisco J

2015-07-21

Cancer is a general name for more than 100 malignant diseases. It is postulated that all cancers start from a single abnormal cell that grows out of control. Untreated cancers can cause serious consequences and deaths. Great progress has been made in cancer research that has significantly improved our knowledge and understanding of the nature and mechanisms of the disease, but the origins of cancer are far from being well understood due to the limitations of suitable model systems and to the complexities of the disease. In view of the fact that cancers are found in various species of vertebrates and other metazoa, here, we suggest that cancer also occurs in parasitic protozoans such as Trypanosoma brucei, a blood parasite, and Toxoplasma gondii, an obligate intracellular pathogen. Without treatment, these protozoan cancers may cause severe disease and death in mammals, including humans. The simpler genomes of these single-cell organisms, in combination with their complex life cycles and fascinating life cycle differentiation processes, may help us to better understand the origins of cancers and, in particular, leukemias.

First report on the colony-forming freshwater ciliate Ophrydium versatile in an African river

CSIR Research Space (South Africa)

Oberholster, Paul J

2010-04-01

Full Text Available Ophrydium versatile (Müller 1786) Ehrenberg 1830 – a symbiotic ciliate that forms gelatinous colonies – is widely distributed in temperate lakes in Europe and America, but has not previously been recorded from rivers. In this paper we report...

Zoonotic intestinal protozoan of the wild boars, Sus scrofa, in Persian Gulf’s coastal area (Bushehr province, Southwestern Iran

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Kambiz Yaghoobi

2016-10-01

Full Text Available Aim: Wild boars, Sus scrofa, are potential reservoirs of many zoonotic diseases, and there are a possibility of transmission of the zoonotic diseases from these animals to humans and also domestic animals. This study aimed to evaluate the protozoan contamination of wild boars in the Persian Gulf’s coastal area (Bushehr Province, southwestern Iran. Materials and Methods: A total of 25 crossbred boars were collected during a course of vertebrate pest control in Bushehr province, in 2013. Samples were collected from the gastrointestinal tracts of each boar in 5% formalin, Bouin’s solution, sodium acetate-acetic acid-formalin, and polyvinyl alcohol fixatives. Fixed stool smears examined by trichrome and Ziehl–Neelsen staining. Results: Each of the 25 wild boars was infected with at least one of the intestinal protozoans. The rate of contamination with intestinal protozoan was 64% for Balantidium coli, 76% for Iodamoeba sp., 52% for Entamoeba polecki, 44% for Blastocystis sp. and 8% for Chilomastix sp. No intestinal coccidian was detected in studied boars when the stool samples were evaluated by Ziehl–Neelsen staining method. Conclusion: Findings of this study demonstrated that wild boars in the Persian Gulf coastal area are contaminated by many protozoans, including zoonotic protozoan, which poses a potential risk to locals as well as the domestic animals of the area.

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

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Hansen, T S; Andreasen, P H; Dreisig, H; Højrup, P; Nielsen, H; Engberg, J; Kristiansen, K

1991-09-15

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.

Insights into bioassessment of marine pollution using body-size distinctness of planktonic ciliates based on a modified trait hierarchy.

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Xu, Henglong; Jiang, Yong; Xu, Guangjian

2016-06-15

Based on a modified trait hierarchy of body-size units, the feasibility for bioassessment of water pollution using body-size distinctness of planktonic ciliates was studied in a semi-enclosed bay, northern China. An annual dataset was collected at five sampling stations within a gradient of heavy metal contaminants. Results showed that: (1) in terms of probability density, the body-size spectra of the ciliates represented significant differences among the five stations; (2) bootstrap average analysis demonstrated a spatial variation in body-size rank patterns in response to pollution stress due to heavy metals; and (3) the average body-size distinctness (Δz(+)) and variation in body-size distinctness (Λz(+)), based on the modified trait hierarchy, revealed a clear departure pattern from the expected body-size spectra in areas with pollutants. These results suggest that the body-size diversity measures based on the modified trait hierarchy of the ciliates may be used as a potential indicator of marine pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prevalence and Risk Factors for Intestinal Protozoan Infections with Cryptosporidium, Giardia, Blastocystis and Dientamoeba among Schoolchildren in Tripoli, Lebanon.

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Osman, Marwan; El Safadi, Dima; Cian, Amandine; Benamrouz, Sadia; Nourrisson, Céline; Poirier, Philippe; Pereira, Bruno; Razakandrainibe, Romy; Pinon, Anthony; Lambert, Céline; Wawrzyniak, Ivan; Dabboussi, Fouad; Delbac, Frederic; Favennec, Loïc; Hamze, Monzer; Viscogliosi, Eric; Certad, Gabriela

2016-03-01

Intestinal protozoan infections are confirmed as major causes of diarrhea, particularly in children, and represent a significant, but often neglected, threat to public health. No recent data were available in Lebanon concerning the molecular epidemiology of protozoan infections in children, a vulnerable population at high risk of infection. In order to improve our understanding of the epidemiology of intestinal pathogenic protozoa, a cross-sectional study was conducted in a general pediatric population including both symptomatic and asymptomatic subjects. After obtaining informed consent from the parents or legal guardians, stool samples were collected in January 2013 from 249 children in 2 schools in Tripoli, Lebanon. Information obtained from a standard questionnaire included demographic characteristics, current symptoms, socioeconomic status, source of drinking water, and personal hygiene habits. After fecal examination by both microscopy and molecular tools, the overall prevalence of parasitic infections was recorded as 85%. Blastocystis spp. presented the highest infection rate (63%), followed by Dientamoeba fragilis (60.6%), Giardia duodenalis (28.5%) and Cryptosporidium spp. (10.4%). PCR was also performed to identify species and genotypes of Cryptosporidium, subtypes of Blastocystis, and assemblages of Giardia. Statistical analysis using a logistic regression model showed that contact with family members presenting gastrointestinal disorders was the primary risk factor for transmission of these protozoa. This is the first study performed in Lebanon reporting the prevalence and the clinical and molecular epidemiological data associated with intestinal protozoan infections among schoolchildren in Tripoli. A high prevalence of protozoan parasites was found, with Blastocystis spp. being the most predominant protozoans. Although only 50% of children reported digestive symptoms, asymptomatic infection was observed, and these children may act as unidentified

Protozoan and helminth infections in pregnancy. Short-term and long-term implications of transmission of infection from mother to foetus

DEFF Research Database (Denmark)

Petersen, Eskild

2007-01-01

This review of protozoan and helminth infections in pregnancy focuses on the impact on the immune response in the newborn infant to maternal infection. Studies of protozoan and helminth infections in pregnant women and in their offspring have shown that children exposed to antigens or microorgani...

Recurrent wheezing is associated with intestinal protozoan infections in Warao Amerindian children in Venezuela: a cross-sectional survey.

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Overeem, Marcella M A; Verhagen, Lilly M; Hermans, Peter W M; del Nogal, Berenice; Sánchez, Adriana Márquez; Acevedo, Natacha Martinez; Murga, Rosalicia Ramirez; Roelfsema, Jeroen; Pinelli, Elena; de Waard, Jacobus H

2014-05-29

While in developed countries the prevalence of allergic diseases is rising, inflammatory diseases are relatively uncommon in rural developing areas. High prevalence rates of helminth and protozoan infections are commonly found in children living in rural settings and several studies suggest an inverse association between helminth infections and allergies. No studies investigating the relationship between parasitic infections and atopic diseases in rural children of developing countries under the age of 2 years have been published so far. We performed a cross-sectional survey to investigate the association of helminth and protozoan infections and malnutrition with recurrent wheezing and atopic eczema in Warao Amerindian children in Venezuela. From August to November 2012, 229 children aged 0 to 2 years residing in the Orinoco Delta in Venezuela were enrolled. Data were collected through standardized questionnaires and physical examination, including inspection of the skin and anthropometric measurements. A stool sample was requested from all participants and detection of different parasites was performed using microscopy and real time polymerase chain reaction (PCR). We observed high prevalence rates of atopic eczema and recurrent wheezing, respectively 19% and 23%. The prevalence of helminth infections was 26% and the prevalence of protozoan infections was 59%. Atopic eczema and recurrent wheezing were more frequently observed in stunted compared with non-stunted children in multivariable analysis (OR 4.3, 95% CI 1.3 - 13.6, p = 0.015 and OR 4.5, 95% CI 0.97 - 21.2, p = 0.055). Furthermore, recurrent wheezing was significantly more often observed in children with protozoan infections than in children without protozoan infections (OR 6.7, 95% CI 1.5 - 30.5). High prevalence rates of atopic eczema and recurrent wheezing in Warao Amerindian children under 2 years of age were related to stunting and intestinal protozoan infections respectively. Helminth

Analysis of the secondary structure of ITS transcripts in peritrich ciliates (Ciliophora, Oligohymenophorea): implications for structural evolution and phylogenetic reconstruction.

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Sun, Ping; Clamp, John C; Xu, Dapeng

2010-07-01

Despite extensive previous morphological work, little agreement has been reached about phylogenetic relationships among peritrich ciliates, making it difficult to study the evolution of the group in a phylogenetic framework. In this study, the nucleotide characteristics and secondary structures of internal transcribed spacers 1 and 2 (ITS1 and ITS2) of 26 peritrich ciliates in 12 genera were analyzed. Information from secondary structures of ITS1 and ITS2 then was used to perform the first systematic study of ITS regions in peritrich ciliates, including one species of Rhabdostyla for which no sequence has been reported previously. Lengths of ITS1 and ITS2 sequences varied relatively little among taxa studied, but their G+C content was highly variable. General secondary structure models of ITS1 and ITS2 were proposed for peritrich ciliates and their reliability was assessed by compensatory base changes. The secondary structure of ITS1 contains three major helices in peritrich ciliates and deviations from this basic structure were found in all taxa examined. The core structure of peritrich ITS2 includes four helices, with helix III as the longest and containing a motif 5'-MAC versus GUK-3' at its apex as well as a YU-UY mismatch in helix II. In addition, the structural motifs of both ITS secondary structures were identified. Phylogenetic analyses using ITS data were performed by means of Bayesian inference, maximum likelihood and neighbor joining methods. Trees had a consistent branching pattern that included the following features: (1) Rhabdostyla always clustered with members of the family Vorticellidae, instead of members of the family Epistylididae, in which it is now classified on the basis of morphology. (2) The systematically questionable genus Ophrydium closely associated with Carchesium, forming a clearly defined, monophyletic group within the Vorticellidae. This supported the hypothesis derived from previous study based on small subunit rRNA gene sequences

Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

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Hu, Simin; Guo, Zhiling; Li, Tao; Carpenter, Edward J; Liu, Sheng; Lin, Senjie

2014-01-01

Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC) to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected, as copepod prey

H3-THYMIDINE DERIVATIVE POOLS IN RELATION TO MACRONUCLEAR DNA SYNTHESIS IN TETRAHYMENA PYRIFORMIS

Science.gov (United States)

Stone, G. E.; Miller, O. L.; Prescott, D. M.

1965-01-01

The formation of a soluble H3-thymidine derivative pool has been examined in Tetrahymena pyriformis as a function of macronuclear DNA synthesis during the cell life cycle. An autoradiographic technique which allows the detection of water-soluble materials within a cell has shown that these cells do not take up and retain exogenous H3-thymidine during G1 or G2. Uptake of H3-thymidine is restricted to the S period of the cell cycle. Additional autoradiographic experiments show, however, that a soluble pool of H3-thymidine derivatives persists from the end of one DNA synthesis period to the beginning of the next synthesis period in the subsequent cell cycle. Since this persisting pool cannot be labeled with H3-thymidine, the pool does not turn over during non-S periods. PMID:19866660

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

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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.

Molecular characterization of ABC transporters in marine ciliate, Euplotes crassus: Identification and response to cadmium and benzo[a]pyrene.

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Kim, Hokyun; Yim, Bora; Kim, Jisoo; Kim, Haeyeon; Lee, Young-Mi

2017-11-30

ATP-binding cassette (ABC) transporters participate in transporting various substances, including xenobiotics, in or out of cells. However, their genetic information and function in ciliates remain still unclear. In this study, we sequenced and characterized two ABC transporter genes (EcABCB and EcABCC), and investigated the effect of cadmium (Cd) and benzo[a]pyrene (B[a]P) on their function and gene expression, using efflux assay and real-time reverse transcription-polymerase chain reaction (qRT-PCR), respectively, in the marine ciliate, Euplotes crassus. Sequencing analysis and efflux assay showed that EcABCB and EcABCC are typical ABC transporters, possessing conserved function. Exposure to Cd (≥5mg/L) and B[a]P (≥50.5μg/L) enhanced accumulation of a substrate. A significant increase in the expression of EcABCB and EcABC mRNA was observed at lower concentration in response to Cd and B[a]P. Our findings indicate that Cd and B[a]P could inhibit the efflux function of ABC transporters, leading to cellular toxicity in the ciliate. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Czech Academy of Sciences Publication Activity Database

Sánchez Medina, X.; Macek, Miroslav; Bautista-Reyes, F.; Perz, A.; Bonilla Lemus, P.; Chávez Arteaga, M.

2016-01-01

Roč. 75, č. 1 (2016), s. 179-190 ISSN 1129-5767 Institutional support: RVO:60077344 Keywords : Oxycline * ciliates * scuticociliates * mixotrophy * biomass Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.451, year: 2016

The role of ciliates within the microbial food web in the eutrophicated part of Kaštela Bay (Middle Adriatic Sea

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Natalia Bojanic

2006-09-01

Full Text Available Interactions among phytoplankton, bacterioplankton, heterotrophic nanoflagellates (HNF, ciliated protozoa and copepod nauplii were studied in the eutrophicated part of Kas?tela Bay from May 1998 to November 1999. Special emphasis was placed on relationships between size categories of nonloricate ciliates (NLC and other microbial food web components. Biomasses of phytoplankton and bacteria were primarily influenced by abiotic parameters. Temperature indirectly controlled variation in HNF biomass through the changes in biomass of bacteria and the smaller phytoplankton fraction. Besides HNF, bacterial biomass was affected by the NLC

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

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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.

Gravitaxis of Bursaria truncatella: electrophysiological and behavioural analyses of a large ciliate cell.

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Krause, Martin; Bräucker, Richard

2009-05-01

Bursaria truncatella is a giant ciliate. Its volume of 3 x 10(7)microm(3) and a sedimentation rate of 923microm s(-1) would induce the cell to rapidly sink to the bottom of a pond unless compensating mechanisms exist. The upward swimming behaviour of a cell population (negative gravitaxis) may be either a result of reorientations of the cells (graviorientation) and/or direction-dependent changes in propulsion rate (gravikinesis). The special statocyst hypothesis assumes a stimulation of mechanosensitive ion channels by forces of the cytoplasmic mass acting on the lower membrane. Here, we present basic electrophysiological data on B. truncatella. Investigation of the mechanosensitivity reveals a polar distribution of depolarising and hyperpolarising mechanosensitive channels at least on the dorsal membrane of the cell. Analysis of swimming behaviour demonstrates that Bursaria orients against the gravity vector (r(Oc)=0.34) and performs a negative gravikinesis (-633microm s(-1)) compensating the sedimentation rate by 70%. Under hypergravity conditions gravitaxis in Bursaria is enhanced. Microgravity experiments indicate an incomplete relaxation of graviresponses during 4s of weightlessness. Experimental data are in accordance with the special statocyst hypothesis of graviperception, as was demonstrated in other ciliates.

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

International Nuclear Information System (INIS)

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

2012-01-01

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.

Protozoan parasites of four species of wild anurans from a local zoo in Malaysia.

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Mohammad, K N; Badrul, M M; Mohamad, N; Zainal-Abidin, A H

2013-12-01

The parasitic protozoan fauna in sixty-six anurans comprising of Duttaphrynus melanostictus, Phrynoidis juxtaspera, Hylarana erythraea and Polypedates leucomystax collected from Zoo Negara Malaysia was investigated. The distribution and prevalence rate of parasitic species in the digestive tract and blood were examined. Seven species of intestinal protozoa (Opalina ranarum, Cepedea dimidiata, Nycthetorus cordiformis, Entamoeba ranarum, Iodamoeba butschlii, Endamoeba blattae, and Tritrichomonas sp.) and two species of blood protozoa (Lankesterella sp. and Trypanosoma sp.) were recorded. Opalina ranarum was the most common protozoan found in the rectum and intestine (prevalence rate: 34.8%) infecting all host species, with P. juxtaspera heavily infected with the parasite, whereas Tritrichomonas sp. was the least prevalent intestinal species infecting only D. melanostictus. Both Lankesterella sp. and Trypanosoma sp. were found in the blood of H. erythraea.

Social biases determine spatiotemporal sparseness of ciliate mating heuristics

Science.gov (United States)

2012-01-01

Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate’s initial subjective bias, responsiveness, or preparedness, as defined by Stevens’ Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The

Diversification dynamics of rhynchostomatian ciliates: the impact of seven intrinsic traits on speciation and extinction in a microbial group.

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Vďačný, Peter; Rajter, Ľubomír; Shazib, Shahed Uddin Ahmed; Jang, Seok Won; Shin, Mann Kyoon

2017-08-30

Ciliates are a suitable microbial model to investigate trait-dependent diversification because of their comparatively complex morphology and high diversity. We examined the impact of seven intrinsic traits on speciation, extinction, and net-diversification of rhynchostomatians, a group of comparatively large, predatory ciliates with proboscis carrying a dorsal brush (sensoric structure) and toxicysts (organelles used to kill the prey). Bayesian estimates under the binary-state speciation and extinction model indicate that two types of extrusomes and two-rowed dorsal brush raise diversification through decreasing extinction. On the other hand, the higher number of contractile vacuoles and their dorsal location likely increase diversification via elevating speciation rate. Particular nuclear characteristics, however, do not significantly differ in their diversification rates and hence lineages with various macronuclear patterns and number of micronuclei have similar probabilities to generate new species. Likelihood-based quantitative state diversification analyses suggest that rhynchostomatians conform to Cope's rule in that their diversity linearly grows with increasing body length and relative length of the proboscis. Comparison with other litostomatean ciliates indicates that rhynchostomatians are not among the cladogenically most successful lineages and their survival over several hundred million years could be associated with their comparatively large and complex bodies that reduce the risk of extinction.

Emerging infectious diseases with cutaneous manifestations: Fungal, helminthic, protozoan and ectoparasitic infections.

Science.gov (United States)

Kollipara, Ramya; Peranteau, Andrew J; Nawas, Zeena Y; Tong, Yun; Woc-Colburn, Laila; Yan, Albert C; Lupi, Omar; Tyring, Stephen K

2016-07-01

Given increased international travel, immigration, changing climate conditions, and the increased incidence of iatrogenic immunosuppression, fungal, protozoan, helminthic, and ectoparasitic infections that were once uncommon are being seeing more frequently in the Western hemisphere. However, the diagnosis and management of these infections is fraught with a lack of consistency because there is a dearth of dermatology literature on the cutaneous manifestations of these infections. In addition, delays in the diagnosis and treatment of these diseases can lead to significant patient morbidity and mortality. We review the epidemiology, cutaneous manifestations, diagnostic modalities, and treatment options for emerging fungal, protozoan, helminthic, and ectoparasitic infections. It should be noted, however, that throughout this review we cite statistics documenting their increased incidence to back-up these infections as emerging, and although some of the diagnoses are clinical, others rely on newer laboratory tests, and the possibility exists that the increased incidence could be caused by better detection methods. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Early detection of protozoan grazers in algal biofuel cultures.

Science.gov (United States)

Day, John G; Thomas, Naomi J; Achilles-Day, Undine E M; Leakey, Raymond J G

2012-06-01

Future micro-algal biofuels will most likely be derived from open-pond production systems. These are by definition open to "invasion" by grazers, which could devastate micro-algal mass-cultures. There is an urgent requirement for methodologies capable of early detection and control of grazers in dense algal cultures. In this study a model system employing the marine alga Nannochloropsis oculata was challenged by grazers including ciliates, amoebae and a heterotrophic dinoflagellate. A FlowCAM flow-cytometer was used to detect all grazers investigated (size range 80 μm in length) in the presence of algae. Detection limits were 1.4 × 10(8) cells ml(-1) (>0.5 g l(-1) dry wt.). Copyright © 2012 Elsevier Ltd. All rights reserved.

Spectral dependence of some UV-B and UV-C responses of Tetrahymena pyriformis irradiated with dye laser generated UV

International Nuclear Information System (INIS)

Calkins, John; Colley, Ed; Wheeler, John; Kentucky Univ., Lexington

1987-01-01

We have generated UV-B and UV-C radiations using a flashlamp driven tunable dye laser combined with frequency doubling crystals. Using this novel UV source, we have investigated lethality and its modification by growth phase, photoreactivation and caffeine in Tetrahymena pyriformis at 254 nm and from 260-315 nm in 5 nm steps. From the observed responses we have constructed action spectra for lethality, with or without caffeine (a repair inhibitor) and under conditions of photoreactivation. We have also estimated quantum efficiencies for these responses. Our observations suggest that complex changes in response occur at several wavelengths over the UV-C and UV-B regions. (author)

Visible-light-responsive ZnCuO nanoparticles: benign photodynamic killers of infectious protozoans.

Science.gov (United States)

Nadhman, Akhtar; Nazir, Samina; Khan, Malik Ihsanullah; Ayub, Attiya; Muhammad, Bakhtiar; Khan, Momin; Shams, Dilawar Farhan; Yasinzai, Masoom

2015-01-01

Human beings suffer from several infectious agents such as viruses, bacteria, and protozoans. Recently, there has been a great interest in developing biocompatible nanostructures to deal with infectious agents. This study investigated benign ZnCuO nanostructures that were visible-light-responsive due to the resident copper in the lattice. The nanostructures were synthesized through a size-controlled hot-injection process, which was adaptable to the surface ligation processes. The nanostructures were then characterized through transmission electron microscopy, X-ray diffraction, diffused reflectance spectroscopy, Rutherford backscattering, and photoluminescence analysis to measure crystallite nature, size, luminescence, composition, and band-gap analyses. Antiprotozoal efficiency of the current nanoparticles revealed the photodynamic killing of Leishmania protozoan, thus acting as efficient metal-based photosensitizers. The crystalline nanoparticles showed good biocompatibility when tested for macrophage toxicity and in hemolysis assays. The study opens a wide avenue for using toxic material in resident nontoxic forms as an effective antiprotozoal treatment.

Everybody needs sphingolipids, right! Mining for new drug targets in protozoan sphingolipid biosynthesis.

Science.gov (United States)

Mina, John G M; Denny, P W

2018-02-01

Sphingolipids (SLs) are an integral part of all eukaryotic cellular membranes. In addition, they have indispensable functions as signalling molecules controlling a myriad of cellular events. Disruption of either the de novo synthesis or the degradation pathways has been shown to have detrimental effects. The earlier identification of selective inhibitors of fungal SL biosynthesis promised potent broad-spectrum anti-fungal agents, which later encouraged testing some of those agents against protozoan parasites. In this review we focus on the key enzymes of the SL de novo biosynthetic pathway in protozoan parasites of the Apicomplexa and Kinetoplastidae, outlining the divergence and interconnection between host and pathogen metabolism. The druggability of the SL biosynthesis is considered, alongside recent technology advances that will enable the dissection and analyses of this pathway in the parasitic protozoa. The future impact of these advances for the development of new therapeutics for both globally threatening and neglected infectious diseases is potentially profound.

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......Shipboard experiments were performed to examine the qualitative importance of large marine microzooplankton for the reproduction of Acartia clausi in the North Sea. Feeding and egg production were compared in 2 treatments in which females were fed natural seston or natural seston selectively...

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

Ecological traits of the algae-bearing Tetrahymena utriculariae (Ciliophora) from traps of the aquatic carnivorous plant Utricularia reflexa

Czech Academy of Sciences Publication Activity Database

Šimek, Karel; Pitsch, G.; Salcher, Michaela M.; Sirová, Dagmara; Shabarova, Tatiana; Adamec, Lubomír; Posch, T.

2017-01-01

Roč. 64, č. 3 (2017), s. 336-348 ISSN 1066-5234 R&D Projects: GA ČR(CZ) GA13-00243S Institutional support: RVO:60077344 ; RVO:67985939 Keywords : aquatic Utricularia * bacterial turnover rate * ciliate bacterivory and mixotrophy * microbial interactions Subject RIV: EE - Microbiology, Virology OBOR OECD: Ecology; Microbiology (BU-J) Impact factor: 2.692, year: 2016

Species composition, abundance and distribution of zooplankton in a tropical eutrophic lake: Lake Catemaco, México

OpenAIRE

Roberto E. Torres-Orozco B.; Sandra A. Zanatta

1998-01-01

From April 1992 to May 1993, zooplankton samples were collected monthly by means of horizontal tows in nine sites of the lake. Prior to the towing, temperature of surface water, transparency (Secchi), pH and dissolved oxygen were evaluated. A total of 31 zooplankton forms, including 14 species of rotifers, three copepods, five cladocerans and one ostracod, as well as protozoans (mainly vorticellids and ciliates), were detected. Rotifers were the dominant organisms, mainly Brachionus havanaens...

Can fungal zoospores be the source of energy for the rumen protozoa Eudiplodinium maggii?

Science.gov (United States)

Miltko, Renata; Bełżecki, Grzegorz; Kowalik, Barbara; Michałowski, Tadeusz

2014-10-01

Results of our earlier studies showed the ability of ciliates Eudiplodinium maggii to digest and metabolize commercial chitin. The natural source of this polysaccharide in the rumen are fungi. The objectives of present research were to determine the effect of fungal zoospores on the survival and population density of E. maggii to quantify the concentration of chitin in the cells of protozoa and to examine the ability of E. maggii, to ferment chitin of fungal zoospores. The cultivation experiment showed that the survival of protozoa was shorter than 4 days when the culture medium was composed of buffer solution and lyophilized fungal spores. An enrichment of this medium with wheat gluten prolonged the survival of ciliates up to 8 days. The supplementation of the last medium with meadow hay enabled the protozoa to survive for 28 days but a positive effect was observed only during the last 8 days of experiment. The chitin content was 0.27 ng and 0.21-0.35 ng per single zoospore and ciliate, respectively. An increase in the concentration of volatile fatty acids (VFA) was found when protozoa were incubated with zoospores. The production rate of VFA was 46.3 pM/protozoan per h whereas the endogenous production did not exceed 31 pM/protozoan per h. The molar proportion of acetic acid was 77.7% and these of butyric and propionic acids-12.2 and 11.0%, respectively. The obtained results make it evident that carbohydrates present in fungal zoospores were utilized by protozoa in energy yielding processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

Subclass Exogenia Collin Order Metacinetida Jankowski Family Paracinetidae Jankowski Limnoricus ceter Jankowski, 1981 (Fig. 1–3) Diagnosis: Marine commensal, loricate, suctorian ciliate with stalk delimited from posterior margin of lorica. Both lorica...–11) =Thecacineta halacari Schulz, 1933 DOVGAL ET AL.62 · Zootaxa 1810 © 2008 Magnolia Press =Lissacineta allgeni Jankowski, 1981, syn. n. =Thecacineta allgeni (Jankowski, 1981), syn. n. Diagnosis: Marine suctorians with stylotheca. Cell body, slightly...

Zooplankton

Digital Repository Service at National Institute of Oceanography (India)

Jyothibabu, R.; Madhu, N.V.

, based on Gauns (2000), indicates the presence of a rich microzooplankton community in the Mandovi and Zuari estuaries. The community is qualitatively and quantitatively dominated by ciliated protozoans (e.g., tintinnids), with nearly 60 species recorded...; Oceanography and Marine Biology: An Annual Review 28 381?496. ?lvares Claude (2002) Fish, Curry and Rice (Revised 4th edn.). Goa Foundation. Alzieu C. (2000) Environmental impact of TBT: the French experience; Science of the Total Environment 258 99?102. Alzieu...

Use of metabolic inhibitors to estimate protozooplankton grazing and bacterial production in a monomictic eutrophic lake with an anaerobic hypolimnion

International Nuclear Information System (INIS)

Sanders, R.W.; Porter, K.G.

1986-01-01

Inhibitors of eucaryotes (cycloheximide and amphotericin B) and procaryotes (penicillin and chloramphenical) were used to estimate bacterivory and bacterial production in a eutrophic lake. Bacterial production appeared to be slightly greater than protozoan grazing in the aerobic waters of Lake Oglethorpe. Use of penicillin and cycloheximide yielded inconsistent results in anaerobic water and in aerobic water when bacterial production was low. Production measured by inhibiting eucaryotes with cycloheximide did not always agree with [ 3 H]thymidine estimates or differential filtration methods. Laboratory experiments showed that several common freshwater protozoans continued to swim and ingest bacterium-size latex beads in the presence of the eucaryote inhibitor. Penicillin also affected grazing rates of some ciliates. The authors recommended that caution and a corroborating method be used when estimating ecologically important parameters with specific inhibitors

ANTIOXIDANT ENZYMES, POTENTIAL VIRULENT FACTORS, IN DIFFERENT STRAINS OF THE OYSTER PROTOZOAN PARASITE, PERKINSUS MARINUS

Science.gov (United States)

The oyster protozoan parasite, Perkinsus marinus, is one of the two important parasites causing severe mortality in the eastern oysters (Crassostrea virginica) on the US east coast. Our recent study suggests that P. marinus cells and its extracellular products (ECP) could scaveng...

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

International Nuclear Information System (INIS)

Jumat, Muhammad Raihan; Yan, Yan; Ravi, Laxmi Iyer; Wong, Puisan; Huong, Tra Nguyen; Li, Chunwei; Tan, Boon Huan; Wang, De Yun; Sugrue, Richard J.

2015-01-01

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

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.

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.

Synergistic Interactions within a Multispecies Biofilm Enhance Individual Species Protection against Grazing by a Pelagic Protozoan

DEFF Research Database (Denmark)

Raghupathi, Prem Krishnan; Liu, Wenzheng; Sabbe, Koen

2018-01-01

of a multispecies bacterial biofilm subject to grazing by a pelagic protozoan predator were investigated. To this end, a mono and multispecies biofilms of four bacterial soil isolates, namely Xanthomonas retroflexus, Stenotrophomonas rhizophila, Microbacterium oxydans and Paenibacillus amylolyticus, were...

Trophic-functional patterns of biofilm-dwelling ciliates at different water depths in coastal waters of the Yellow Sea, northern China.

Science.gov (United States)

Abdullah Al, Mamun; Gao, Yangyang; Xu, Guangjian; Wang, Zheng; Warren, Alan; Xu, Henglong

2018-04-01

Vertical variations in trophic-functional patterns of biofilm-dwelling ciliates were studied in coastal waters of the Yellow Sea, northern China. A total of 50 species were identified and assigned to four trophic-functional groups (TFgrs): algivores (A), bacterivorous (B), non-selective (N) and raptors (R). The trophic-functional structures of the ciliate communities showed significant variability among different water depths: (1) with increasing water depth, relative species numbers and relative abundances of groups A and R decreased sharply whereas those of groups B and N increased gradually; (2) in terms of the frequency of occurrences, group A dominated at depths of 1-3.5 m whereas group B dominated at 5 m, while in terms of the probability density function of the trophic-functional spectrum, group A was the highest contributor at 1 m and group B was highest at the other three depths; (3) distance-based redundancy analyses revealed significant differences in trophic-functional patterns among the four depths, except between 2 and 3.5 m (P > 0.05); and (4) the trophic-functional trait diversity increased from 1 to 3.5 m and decreased sharply at 5 m. Our results suggest that the biofilm-dwelling ciliates maintain a stable trophic-functional pattern and high biodiversity at depths of 1-3.5 m. Copyright © 2018 Elsevier GmbH. All rights reserved.

The dynamics of neutrophils in zebrafish (Danio rerio) during infection with the parasite Ichthyophthirius multifiliis

DEFF Research Database (Denmark)

Jørgensen, Louise von Gersdorff

2016-01-01

Ichthyophthirius multifiliis is a ciliated protozoan parasite infecting the skin and gills of freshwater fish. Neutrophils are attracted to the infection sites, as a part of the innate immune response. In this study a transgenic line of zebrafish (Tg(MPO:GFP)i114) with GFP-tagged neutrophils was ...... the infection. Neutrophils interacted directly with the parasites with pseudopod formation projecting towards the pathogen. These results indicate a strong innate immune response immediately following infection and/or a subsequent immune evasion by the parasite....

Use of PFU protozoan community structural and functional characteristics in assessment of water quality in a large, highly polluted freshwater lake in China.

Science.gov (United States)

Xu, Muqi; Cao, Hong; Xie, Ping; Deng, Daogui; Feng, Weisong; Xu, Jian

2005-07-01

Structural and functional parameters of protozoan communities colonizing on PFU (polyurethane foam unit) artificial substrate were assessed as indicators of water quality in the Chaohu Lake, a large, shallow and highly polluted freshwater lake in China. Protozoan communities were sampled 1, 3, 6, 9 and 14 days after exposure of PFU artificial substrate in the lake during October 2003. Four study stations with the different water quality gradient changes along the lake were distinguishable in terms of differences in the community's structural (species richness, individual abundance, etc.) and functional parameters (protozoan colonization rates on PFU). The concentrations of TP, TN, COD and BOD as the main chemical indicators of pollution at the four sampling sites were also obtained each year during 2002-2003 for comparison with biological parameters. The results showed that the species richness and PFU colonization rate decreased as pollution intensity increased and that the Margalef diversity index values calculated at four sampling sites also related to water quality. The three functional parameters based on the PFU colonization process, that is, S(eq), G and T90%, were strongly related to the pollution status of the water. The number of protozoan species colonizing on PFU after exposure of 1 to 3 days was found to give a clear comparative indication of the water quality at the four sampling stations. The research provides further evidence that the protozoan community may be utilized effectively in the assessment of water quality and that the PFU method furnishes rapid, cost-effective and reliable information that may be useful for measuring responses to pollution stress in aquatic ecosystems.

Ciliados nas cavidades do estômago de bovinos Ciliates present in the stomach chambers of bovines

Directory of Open Access Journals (Sweden)

G.M.M. Salvio

2001-12-01

Full Text Available O presente trabalho teve como objetivo identificar e quantificar os gêneros de ciliados do rúmen, retículo, omaso e abomaso de bovinos abatidos em matadouro municipal. Foram coletados 45ml de conteúdo de cada cavidade de 30 animais. No momento da coleta foram medidos temperatura e pH e as amostras posteriormente analisadas em laboratório. Os resultados mostraram que o ambiente do rúmen e do retículo é bastante estável com temperatura média entre 36 e 37ºC e pH 6,5. Os gêneros mais encontrados no rúmen foram Entodinium (65,0%, Isotricha (7,0%, Diplodinium (5,7%, Ostracodinium (5,1%, Eremoplastron (4,5%, Dasytricha (3,8% e outros sete gêneros que totalizaram os 8,7% restantes. No retículo os resultados foram Entodinium (35,2%, Isotricha (23,4%, Dasytricha (15,4% Eodinium (7,2%, Eremoplastron (5,0%, Diplodinium (4,3%, Ostracodinium (3,8% e outros cinco gêneros totalizando os 5,6% restantes. No omaso foram encontrados os mesmos gêneros, porém em menor quantidade que no rúmen e retículo. No abomaso não foram encontrados ciliados. A análise do perfil populacional das amostras do rúmen mostrou predominância do tipo 0 (87%, seguido do tipo B (13%.The objective of this study was to collect and to quantify the ciliate genera present in the rumen, reticulum, omasum and abomasum in 30 slaughtered bovines. Rumen, reticulum, omasum and abomasum were sampled and their contents (45ml were collected and evaluated for temperature, pH and ciliates population. The results showed that the rumen and reticulum environments are quite stable with average temperature between 36 and 37ºC and pH 6.5. The ciliate population in the rumen was Entodinium (65.0%, Isotricha (7.0%, Diplodinium (5.7%, Ostracodinium (5.1%, Eremoplastron (4.5%, Dasytricha (3.8% and seven other genera which made 8.7%. In the reticulum, the population was Entodinium (35.2%, Isotricha (23.4%, Dasytricha (15.4% Eodinium (7.2%, Eremoplastron (5.0%, Diplodinium (4

Impacts of radiation exposure on the experimental microbial ecosystem: a particle-based model simulation approach

International Nuclear Information System (INIS)

Doi, M.; Tanaka, N.; Fuma, S.; Kawabata, Z.

2004-01-01

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

Genome and transcriptome studies of the protozoan parasites Trypanosoma cruzi and Giardia intestinalis

OpenAIRE

Franzén, Oscar

2012-01-01

Trypanosoma cruzi and Giardia intestinalis are two human pathogens and protozoan parasites responsible for the diseases Chagas disease and giardiasis, respectively. Both diseases cause su ering and illness in several million individuals. The former disease occurs primarily in South America and Central America, and the latter disease occurs worldwide. Current therapeutics are toxic and lack e cacy, and potential vaccines are far from the market. Increased knowledge about the bio...

Molecular and biochemical analysis of conjugation and adolescence in Tetrahymena thermophila

International Nuclear Information System (INIS)

Rogers, M.B.

1986-01-01

A previously unrecognized stage in the development of sexual maturity in Tetrahymena thermophila, adolescence, has been described. When the progeny of successfully mated cells are grown logarithmically, they are unable to form mating pairs for about 65 generations. This period is known as immaturity. During the next stage, adolescence, the progeny pair with mature cells but not with other adolescent cells despite the presence of complementary mating types. Adolescence persists for 20-25 generations before the cells attain maturity (the ability to mate with any cell of different mating type). Once paired with mature cells, adolescents successfully complete conjugation was shown genetically. Mating pairs formed between adolescent and mature cells are indistinguishable from those formed between mature cells by the criteria of cytology and two-dimensional gel electrophoresis of proteins extracted from mating pairs pulse-labelled with [ 35 S]methionine. An analysis of proteins induced during the first ten hours of conjugation was carried out using two-dimensional gel electrophoresis. The protein patterns obtained from all controls were similar. The synthesis of numerous large and basic proteins were induced during conjugation. The majority of the proteins were detected during meiosis and none were mating type specific. A library of micronuclear DNA was constructed in the plasmic PUC18. The library was screened by differential colony hybridization using cDNA complementary to polyA + RNA isolated from conjugating and control cells. Eight recombinant clones were isolated which contain sequences transcriptionally induced in conjugating cells

RNA precursor pool metabolism and RNA synthesis in X-irradiated Tetrahymena

International Nuclear Information System (INIS)

Stephens, R.E.; Paul, I.J.; Zimmerman, A.M.

1976-01-01

The incorporation of a radioactive RNA precursor ( 3 H-uridine) has been used in many studies as an index for measuring the synthesis of RNA, yet there is a distinct possibility that the results so obtained were significantly influenced by radiation-induced effects on the metabolism of this precursor into UTP (the primary immediate precursor of RNA) before its incorporation into RNA. A direct examination was therefore undertaken of the effects of X-irradiation on the metabolism of 3 H-uridine and its relationship to RNA synthesis as determined by incorporation. X-irradiation of logarithmically growing Tetrahymena pyriformis caused a dose-dependent depression of total cellular RNA synthesis. Ribosomal RNA (which comprises about 80 per cent of total cellular RNA) synthesis was also depressed by X-irradiation in a dose-dependent manner. Measurements of the levels of radioactivity present in the UTP precursor pool of both irradiated and unirradiated cells were obtained by means of DEAE-cellulose column chromatography of the extracted free nucleotides. Metabolism of 3 H-uridine into UMP, UDP and UTP was depressed by 40%, 26% and 27% respectively, whereas incorporation of 3 H-uridine into RNA was depressed by 77%. The results show that about one-third of the observed (apparent) depression in RNA synthesis was due to radiation-induced effects on the precursor pool, and the remaining two-thirds due to some definite effect of radiation at the transcription level leading to depressed synthesis of RNA. (U.K.)

Host-Parasite list updating of Ciliates and fermentation in the digestive tract of wild miscellaneous herbivores in South Africa (RSA).

Science.gov (United States)

Booyse, D G; Dehority, B A

2017-05-03

This article is dedicated to the Author, Burk Dehority, who became very ill with cancer. Fortunately he confirmed or corrected all identifications on ciliates in this article. This paper was 80% finished when he became ill. He unfortunately passed away in February 2016.

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.

Developmentally programmed DNA deletion in Tetrahymena thermophila by a transposition-like reaction pathway.

Science.gov (United States)

Saveliev, S V; Cox, M M

1996-01-01

We provide a molecular description of key intermediates in the deletion of two internal eliminated sequences (IES elements), the M and R regions, during macronuclear development in Tetrahymena thermophila. Using a variety of PCR-based methods in vivo, double-strand breaks are detected that are generated by hydrolytic cleavage and correspond closely to the observed chromosomal junctions left behind in the macronuclei. The breaks exhibit a temporal and structural relationship to the deletion reaction that provides strong evidence that they are intermediates in the deletion pathway. Breaks in the individual strands are staggered by 4 bp, producing a four nucleotide 5' extension. Evidence is presented that breaks do not occur simultaneously at both ends. The results are most consistent with a deletion mechanism featuring initiation by double-strand cleavage at one end of the deleted element, followed by transesterification to generate the macronuclear junction on one DNA strand. An adenosine residue is found at all the nucleophilic 3' ends used in the postulated transesterification step. Evidence for the transesterification step is provided by detection of a 3' hydroxyl that would be liberated by such a step at a deletion boundary where no other DNA strand ends are detected. Images PMID:8654384

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.

[Regeneration of the ciliary beat of human ciliated cells].

Science.gov (United States)

Wolf, G; Koidl, B; Pelzmann, B

1991-10-01

The influence of an isotonic, alkaline saline solution (diluted "Emser Sole" or brine from the spa of Bad Ems) on the ciliary beat of isolated cultured human ciliated cells of the upper respiratory tract was investigated. The ciliary beat was observed via an inverted phase contrast microscope (Zeiss Axiomat IDPC) and measured microphotometrically under physiological conditions and after the damaging influence of 1% propanal solution. Under physiological conditions the saline solution had a positive, although statistically not significant influence on the frequency of the ciliary beat. After damage of the cultivated cells by 1% propanal solution, the saline solution had a significant better influence on the regeneration of the cultured cells than a physiological sodium chloride solution. It is concluded that diluted brine from Bad Ems has a positive effect on the ciliary beat of the respiratory epithelium and accelerates its regeneration after damage by viral and bacterial infections, surgery or inhaled noxae.

Drug target identification in protozoan parasites.

Science.gov (United States)

Müller, Joachim; Hemphill, Andrew

2016-08-01

Despite the fact that diseases caused by protozoan parasites represent serious challenges for public health, animal production and welfare, only a limited panel of drugs has been marketed for clinical applications. Herein, the authors investigate two strategies, namely whole organism screening and target-based drug design. The present pharmacopoeia has resulted from whole organism screening, and the mode of action and targets of selected drugs are discussed. However, the more recent extensive genome sequencing efforts and the development of dry and wet lab genomics and proteomics that allow high-throughput screening of interactions between micromolecules and recombinant proteins has resulted in target-based drug design as the predominant focus in anti-parasitic drug development. Selected examples of target-based drug design studies are presented, and calcium-dependent protein kinases, important drug targets in apicomplexan parasites, are discussed in more detail. Despite the enormous efforts in target-based drug development, this approach has not yet generated market-ready antiprotozoal drugs. However, whole-organism screening approaches, comprising of both in vitro and in vivo investigations, should not be disregarded. The repurposing of already approved and marketed drugs could be a suitable strategy to avoid fastidious approval procedures, especially in the case of neglected or veterinary parasitoses.

Detection of protozoan hosts for Legionella pneumophila in engineered water systems by using a biofilm batch test

NARCIS (Netherlands)

Valster, R.M.; Wullings, B.A.; Kooij, van der D.

2010-01-01

Legionella pneumophila proliferates in aquatic habitats within free-living protozoa, 17 species of which have been identified as hosts by using in vitro experiments. The present study aimed at identifying protozoan hosts for L. pneumophila by using a biofilm batch test (BBT). Samples (600 ml)

Programmed Rearrangement in Ciliates: Paramecium.

Science.gov (United States)

Betermier, Mireille; Duharcourt, Sandra

2014-12-01

Programmed genome rearrangements in the ciliate Paramecium provide a nice illustration of the impact of transposons on genome evolution and plasticity. During the sexual cycle, development of the somatic macronucleus involves elimination of ∼30% of the germline genome, including repeated DNA (e.g., transposons) and ∼45,000 single-copy internal eliminated sequences (IES). IES excision is a precise cut-and-close process, in which double-stranded DNA cleavage at IES ends depends on PiggyMac, a domesticated piggyBac transposase. Genome-wide analysis has revealed that at least a fraction of IESs originate from Tc/mariner transposons unrelated to piggyBac. Moreover, genomic sequences with no transposon origin, such as gene promoters, can be excised reproducibly as IESs, indicating that genome rearrangements contribute to the control of gene expression. How the system has evolved to allow elimination of DNA sequences with no recognizable conserved motif has been the subject of extensive research during the past two decades. Increasing evidence has accumulated for the participation of noncoding RNAs in epigenetic control of elimination for a subset of IESs, and in trans-generational inheritance of alternative rearrangement patterns. This chapter summarizes our current knowledge of the structure of the germline and somatic genomes for the model species Paramecium tetraurelia, and describes the DNA cleavage and repair factors that constitute the IES excision machinery. We present an overview of the role of specialized RNA interference machineries and their associated noncoding RNAs in the control of DNA elimination. Finally, we discuss how RNA-dependent modification and/or remodeling of chromatin may guide PiggyMac to its cognate cleavage sites.

Faecal and protozoan parasite contamination of water spinach (Ipomoea aquatica) cultivated in urban wastewater in Phnom Penh, Cambodia

DEFF Research Database (Denmark)

Anh, Vuong Tuan; Tram, Nguyen Thuy; Klank, Lise Tønner

2007-01-01

Objective To identify the level of contamination with thermotolerant coliforms (ThC), intestinal helminth eggs and protozoan parasites in water spinach (Ipomoea aquatica) cultivated in a wastewater-fed lake in Phnom Penh, Cambodia. Methods The investigation was carried out from July 2004 to May...... into a stream. Water spinach samples were harvested at each of the three locations with and without wastewater contact according to the normal practices of farmers, and analysed for ThC, protozoan parasites (Giardia, Cryptosporidium and Cyclospora), and helminth eggs (Ascaris lumbricoides, Trichuris trichura...... and hookworm) using standard methods. Wastewater samples were also collected at each of the three locations and analysed for ThC and helminth eggs. Results High concentrations of ThC (approximately 10(5)-10(7)/g) were found in water spinach samples. ThC mean counts did not differ significantly, neither between...

Cloning and characterization of the major histone H2A genes completes the cloning and sequencing of known histone genes of Tetrahymena thermophila.

Science.gov (United States)

Liu, X; Gorovsky, M A

1996-01-01

A truncated cDNA clone encoding Tetrahymena thermophila histone H2A2 was isolated using synthetic degenerate oligonucleotide probes derived from H2A protein sequences of Tetrahymena pyriformis. The cDNA clone was used as a homologous probe to isolate a truncated genomic clone encoding H2A1. The remaining regions of the genes for H2A1 (HTA1) and H2A2 (HTA2) were then isolated using inverse PCR on circularized genomic DNA fragments. These partial clones were assembled into intact HTA1 and HTA2 clones. Nucleotide sequences of the two genes were highly homologous within the coding region but not in the noncoding regions. Comparison of the deduced amino acid sequences with protein sequences of T. pyriformis H2As showed only two and three differences respectively, in a total of 137 amino acids for H2A1, and 132 amino acids for H2A2, indicating the two genes arose before the divergence of these two species. The HTA2 gene contains a TAA triplet within the coding region, encoding a glutamine residue. In contrast with the T. thermophila HHO and HTA3 genes, no introns were identified within the two genes. The 5'- and 3'-ends of the histone H2A mRNAs; were determined by RNase protection and by PCR mapping using RACE and RLM-RACE methods. Both genes encode polyadenylated mRNAs and are highly expressed in vegetatively growing cells but only weakly expressed in starved cultures. With the inclusion of these two genes, T. thermophila is the first organism whose entire complement of known core and linker histones, including replication-dependent and basal variants, has been cloned and sequenced. PMID:8760889

Far beyond Phagocytosis: Phagocyte-Derived Extracellular Traps Act Efficiently against Protozoan Parasites In Vitro and In Vivo

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Liliana M. R. Silva

2016-01-01

Full Text Available Professional mononuclear phagocytes such as polymorphonuclear neutrophils (PMN, monocytes, and macrophages are considered as the first line of defence against invasive pathogens. The formation of extracellular traps (ETs by activated mononuclear phagocytes is meanwhile well accepted as an effector mechanism of the early host innate immune response acting against microbial infections. Recent investigations showed evidence that ETosis is a widely spread effector mechanism in vertebrates and invertebrates being utilized to entrap and kill bacteria, fungi, viruses, and protozoan parasites. ETs are released in response to intact protozoan parasites or to parasite-specific antigens in a controlled cell death process. Released ETs consist of nuclear DNA as backbone adorned with histones, antimicrobial peptides, and phagocyte-specific granular enzymes thereby producing a sticky extracellular matrix capable of entrapping and killing pathogens. This review summarizes recent data on protozoa-induced ETosis. Special attention will be given to molecular mechanisms of protozoa-induced ETosis and on its consequences for the parasites successful reproduction and life cycle accomplishment.

Calmyonemin: a 23 kDa analogue of algal centrin occurring in contractile myonemes of Eudiplodinium maggii (ciliate).

Science.gov (United States)

David, C; Viguès, B

1994-01-01

Myonemes are bundles of thin filaments (3-6 nm in diameter) which mediate calcium-induced contraction of the whole or only parts of the cell body in a number of protists. In Eudiplodinium maggii, a rumen ciliate which lacks a uniform ciliation of the cell body, myonemes converge toward the bases of apical ciliary zones that can be retracted under stress conditions, entailing immobilization of the cell. An mAB (A69) has been produced that identifies a calcium-binding protein by immunoblot, immunoprecipitation experiments and specifically labels the myonemes in immunoelectron microscopy. Solubility properties, apparent molecular weight (23 kDa) and isoelectric point (4.9) of the myonemal protein, are similar to the values reported for the calcium-modulated contractile protein centrin. Western-blot analysis indicates that the 23 kDa protein cross-reacts antigenically with anti-centrin antibodies. In addition, the 23 kDa protein displays calcium-induced changes in both electrophoretic and chromatographic behaviour, and contains calcium-binding domains that conform to the EF-hand structure, as known for centrin. Based on these observations, we conclude that a calcium-binding protein with major similarities to centrin occurs in the myonemes of E. maggii. We postulate that this protein plays an essential role in myoneme-mediated retraction of the ciliature.

Swimming of Paramecium in confined channels

Science.gov (United States)

Jung, Sunghwan

2012-02-01

Many living organisms in nature have developed a few different swimming modes, presumably derived from hydrodynamic advantage. Paramecium is a ciliated protozoan covered by thousands of cilia with a few nanometers in diameter and tens of micro-meters in length and is able to exhibit both ballistic and meandering motions. First, we characterize ballistic swimming behaviors of ciliated microorganisms in glass capillaries of different diameters and explain the trajectories they trace out. We develop a theoretical model of an undulating sheet with a pressure gradient and discuss how it affects the swimming speed. Secondly, investigation into meandering swimmings within rectangular PDMS channels of dimension smaller than Paramecium length. We find that Paramecium executes a body-bend (an elastic buckling) using the cilia while it meanders. By considering an elastic beam model, we estimate and show the universal profile of forces it exerts on the walls. Finally, we discuss a few other locomotion of Paramecium in other extreme environments like gel.

Two Gonostomatid Ciliates from the Soil of Lombardia, Italy; including Note on the Soil Mapping Project.

Science.gov (United States)

Bharti, Daizy; Kumar, Santosh; La Terza, Antonietta

2015-01-01

Two gonostomatid ciliates, Gonostomum paronense n. sp. and G. strenuum, isolated from the soil sample of paddy field, Lombardia, Italy, were investigated using live observation and protargol impregnation. Gonostomum paronense n. sp. is mainly characterized by a tailed body, frontoventral cirri arranged in pairs, and presence of pretransverse and transverse cirri. Morphologically and morphometrically, the new species is similar to Gonostomum namibiense in having a tailed body and frontoventral cirral pairs; however, it differs mainly in the number of frontoventral cirral pairs (seven vs. three). Phylogenetic analyses based on the SSU rDNA sequences show that the new species is more closely related to G. namibiense than to G. strenuum, supporting the morphological classification based on the cirral pattern and the tailed body. However, due to the poor nodal support and absence of gene sequence of the type species Gonostomum, a more robust phylogeny of this group still remains unresolved. The biometric data of the Italian population of Gonostomum strenuum overlap with those from other known populations. Both species were collected from the industrial area of Parona, in the framework of the "Soil Mapping, Lombardia" project in which, for the first time in Italy, soil ciliates were used as bioindicators of soil quality. © 2015 The Author(s) Journal of Eukaryotic Microbiology © 2015 International Society of Protistologists.

The ciliate Paramecium shows higher motility in non-uniform chemical landscapes.

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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.

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

2011-01-01

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. PMID:21494596

The effect of low- and high-fiber diets on the population of entodiniomorphid ciliates Troglodytella abrassarti in captive chimpanzees (Pan troglodytes)

Czech Academy of Sciences Publication Activity Database

Petrželková, Klára Judita; Schovancová, Kateřina; Profousová, Ilona; Kišidayová, S.; Váradyová, Z.; Pekár, S.; Kamler, Jiří; Modrý, David

2012-01-01

Roč. 74, č. 7 (2012), s. 669-675 ISSN 0275-2565 R&D Projects: GA ČR GA524/06/0264; GA ČR GA206/09/0927 Institutional support: RVO:68081766 ; RVO:60077344 Keywords : entodiniomorphid ciliate * chimpanzee * fiber * starch Subject RIV: EG - Zoology Impact factor: 2.459, year: 2012

The Anti-Oxidant Defense System of the Marine Polar Ciliate Euplotes nobilii: Characterization of the MsrB Gene Family

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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.

Kupffer's vesicle is a ciliated organ of asymmetry in the zebrafish embryo that initiates left-right development of the brain, heart and gut.

Science.gov (United States)

Essner, Jeffrey J; Amack, Jeffrey D; Nyholm, Molly K; Harris, Erin B; Yost, H Joseph

2005-03-01

Monocilia have been proposed to establish the left-right (LR) body axis in vertebrate embryos by creating a directional fluid flow that triggers asymmetric gene expression. In zebrafish, dorsal forerunner cells (DFCs) express a conserved ciliary dynein gene (left-right dynein-related1, lrdr1) and form a ciliated epithelium inside a fluid-filled organ called Kupffer's vesicle (KV). Here, videomicroscopy demonstrates that cilia inside KV are motile and create a directional fluid flow just prior to the onset of asymmetric gene expression in lateral cells. Laser ablation of DFCs and surgical disruption of KV provide direct evidence that ciliated KV cells are required during early somitogenesis for subsequent LR patterning in the brain, heart and gut. Antisense morpholinos against lrdr1 disrupt KV fluid flow and perturb LR development. Furthermore, lrdr1 morpholinos targeted to DFC/KV cells demonstrate that Lrdr1 functions in these ciliated cells to control LR patterning. This provides the first direct evidence, in any vertebrate, that impairing cilia function in derivatives of the dorsal organizer, and not in other cells that express ciliogenic genes, alters LR development. Finally, genetic analysis reveals novel roles for the T-box transcription factor no tail and the Nodal signaling pathway as upstream regulators of lrdr1 expression and KV morphogenesis. We propose that KV is a transient embryonic 'organ of asymmetry' that directs LR development by establishing a directional fluid flow. These results suggest that cilia are an essential component of a conserved mechanism that controls the transition from bilateral symmetry to LR asymmetry in vertebrates.

Tintinnid ciliates of Amundsen Sea (Antarctica plankton communities

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John R. Dolan

2013-05-01

Full Text Available The Amundsen Sea has been described as one of the most productive and dynamic pelagic systems in Antarctica and is one of the least studied. Based on samples from 15 stations in the Amundsen Sea, we describe for the first time the composition of the tintinnid ciliate assemblage of the microzooplankton. We compared the species compositions of coastal polynya sites, where the phytoplankton communities are dominated by Phaeocystis, to those of the offshore deep water sites, which are dominated by diatoms. We found a total of 15 species. Polynya sites were dominated by a few species of tintinnids, mostly those endemic to the Southern Ocean. In contrast, the deep-water sites contained many widespread tintinnid species, which are known from a wide variety of systems as well as other areas of the Southern Ocean. We examined polymorphism known to characterize the Antarctic tintinnid species Cymatocylis affinis/convallaria and Codonellopsis gaussi. We found that the types or forms found appeared unrelated to the type of microplankton community, defined by the identity of the dominant phytoplankton taxa. However, the number of different morphotypes found at a site appeared related to the overall concentration of the species, suggesting that different morphologies, previously considered distinct species, may simply be developmental stages.

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

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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.

Visible-light-responsive ZnCuO nanoparticles: benign photodynamic killers of infectious protozoans

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Nadhman A

2015-11-01

Full Text Available Akhtar Nadhman,1,2 Samina Nazir,2 Malik Ihsanullah Khan,1 Attiya Ayub,2,3 Bakhtiar Muhammad,3 Momin Khan,1 Dilawar Farhan Shams,4 Masoom Yasinzai1,5 1Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan; 2Nanosciences and Catalysis Division, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad, Pakistan; 3Department of Chemistry, Hazara University, Dhodial, Pakistan; 4Department of Environmental Sciences, Abdul Wali Khan University Mardan, Mardan, Pakistan; 5Center of Interdisciplinary Research, International Islamic University, Islamabad, Pakistan Abstract: Human beings suffer from several infectious agents such as viruses, bacteria, and protozoans. Recently, there has been a great interest in developing biocompatible nanostructures to deal with infectious agents. This study investigated benign ZnCuO nanostructures that were visible-light-responsive due to the resident copper in the lattice. The nanostructures were synthesized through a size-controlled hot-injection process, which was adaptable to the surface ligation processes. The nanostructures were then characterized through transmission electron microscopy, X-ray diffraction, diffused reflectance spectroscopy, Rutherford backscattering, and photoluminescence analysis to measure crystallite nature, size, luminescence, composition, and band-gap analyses. Antiprotozoal efficiency of the current nanoparticles revealed the photodynamic killing of Leishmania protozoan, thus acting as efficient metal-based photosensitizers. The crystalline nanoparticles showed good biocompatibility when tested for macrophage toxicity and in hemolysis assays. The study opens a wide avenue for using toxic material in resident nontoxic forms as an effective antiprotozoal treatment. Keywords: zinc oxide, nanoparticles, doping, photodynamic therapy, Leishmania

Seasonal variation of the protozooplanktonic community in a tropical oligotrophic environment (Ilha Solteira reservoir, Brazil).

Science.gov (United States)

Mansano, A S; Hisatugo, K F; Leite, M A; Luzia, A P; Regali-Seleghim, M H

2013-05-01

The seasonal variation of the protozooplanktonic community (ciliates and testate amoebae) was studied in a tropical oligotrophic reservoir in Brazil, which was under the influence of two contrasting climatic seasons (rainy/warm and dry/cold). The aim of this study was to evaluate the effect of these climatic changes on physical, chemical and biological variables in the dynamic of this community. The highest mean density of total protozoans occurred in the rainy/warm season (5683.2 ind L-1), while the lowest was in the dry/cold (2016.0 ind L-1). Considering the seasonal variations, the protozoan groups that are truly planktonic, such as the oligotrichs (Spirotrichea), predominated in the dry season, whereas during the rainy season, due to the material input and resuspension of sediment, sessile protozoans of the Peritrichia group were the most important ones. The dominant protozoans were Urotricha globosa, Cothurnia annulata, Pseudodifflugia sp. and Halteria grandinella. The highest densities of H. grandinella were associated with more oxygenated and transparent water conditions, while the highest densities of C. annulata occurred in sites with high turbidity, pH and trophic state index (TSI). The study demonstrated that density and composition of protozooplanktonic species and groups of the reservoir suffered seasonal variation due to the environmental variables (mainly temperature, turbidity, water transparency, dissolved oxygen and TSI) and the biological variables (e.g. morphological characteristics, eating habits and escape strategies from predation of the species).

Microfaunal primary succession on the volcanic island Surtsey

DEFF Research Database (Denmark)

Frederiksen, Helle B.; Kraglund, H. O.; Ekelund, F.

2001-01-01

and nematodes were absent and only amoebae and heterotrophic flagellates were found. Most of the protozoan populations we examined were unable to survive salinity levels corresponding to seawater. We therefore conclude that many of soil protozoa populations on Surtsey arrived to the island as airborne cysts...... with different vegetation types (unvegetated soil, soil with one or two plant species, and bird colony soil with a diverse vegetation). We recorded at least 16 nematode taxa and 13 flagellate taxa. Most of these were not reported in previous surveys from Surtsey. On the location with unvegetated soil, ciliates...

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.

Nuclear Architecture and Patterns of Molecular Evolution Are Correlated in the Ciliate Chilodonella uncinata.

Science.gov (United States)

Maurer-Alcalá, Xyrus X; Katz, Laura A

2016-06-08

The relationship between nuclear architecture and patterns of molecular evolution in lineages across the eukaryotic tree of life is not well understood, partly because molecular evolution is traditionally explored as changes in base pairs along a linear sequence without considering the context of nuclear position of chromosomes. The ciliate Chilodonella uncinata is an ideal system to address the relationship between nuclear architecture and patterns of molecular evolution as the somatic macronucleus of this ciliate is composed of a peripheral DNA-rich area (orthomere) and a DNA-poor central region (paramere) to form a "heteromeric" macronucleus. Moreover, because the somatic chromosomes of C. uncinata are highly processed into "gene-sized" chromosomes (i.e., nanochromosomes), we can assess fine-scale relationships between location and sequence evolution. By combining fluorescence microscopy and analyses of transcriptome data from C. uncinata, we find that highly expressed genes have the greatest codon usage bias and are enriched in DNA-poor regions. In contrast, genes with less biased sequences tend to be concentrated in DNA abundant areas, at least during vegetative growth. Our analyses are consistent with recent work in plants and animals where nuclear architecture plays a role in gene expression. At the same time, the unusual localization of nanochromosomes suggests that the highly structured nucleus in C. uncinata may create a "gene bank" that facilitates rapid changes in expression of genes required only in specific life history stages. By using "nonmodel" organisms like C. uncinata, we can explore the universality of eukaryotic features while also providing examples of novel properties (i.e., the presence of a gene bank) that build from these features. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Studies evaluating the applicability of utilizing the same concentration techniques for the detection of protozoan parasites and viruses in water

CSIR Research Space (South Africa)

Kfir, R

1995-01-01

Full Text Available sample volume to about 101. This study shows that concentration techniques utilised for the isolation of enteric viruses can also be applied for the detection of protozoan parasites from water. This procedure allows for co-analysis of both viruses...

Sulfide assimilation by ectosymbionts of the sessile ciliate, Zoothamnium niveum

DEFF Research Database (Denmark)

Røy, Hans; Vopel, Kay; Huettel, Marcus

2009-01-01

with flow adjusted to in situ velocity. The water motion around the colonies was then characterized by particle tracking velocimetry. This shows that the feather-shaped colony of Z. niveum generates a unidirectional flow of seawater through the colony with no recirculation. The source of the feeding current......We investigated the constraints on sulfide uptake by bacterial ectosymbionts on the marine peritrich ciliate Zoothamnium niveum by a combination of experimental and numerical methods. Protists with symbionts were collected on large blocks of mangrove-peat. The blocks were placed in a flow cell...... bacteria due to Z. niveum's habitat preference and due to the feeding current. Z. niveum is capable of exploiting low concentrations of sulfide in near norm-oxic seawater. This links its otherwise dissimilar habitats and makes it functionally similar to invertebrates with thiotrophic symbionts in filtering...

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. Copyright © 2016 Elsevier B.V. All rights reserved.

Parasitic fauna of eight species of ornamental freshwater fish species from the middle Negro River in the Brazilian Amazon Region Fauna parasitária de oito espécies de peixes ornamentais de água doce do médio Rio Negro na Amazônia brasileira

Directory of Open Access Journals (Sweden)

Marcos Tavares-Dias

2010-06-01

Full Text Available Twenty-seven specimens of cardinal tetra Paracheirodon axelrodi, 33 rosy tetra Hyphessobrycon copelandi (Characidae, 28 marbled hatchetfish Carnegiella strigata, 26 blackwing hatchetfish Carnegiella martae (Gasteropelecidae, 27 bodó Ancistrus hoplogenys (Loricariidae, 31 brown pencilfish Nannostomus eques, 38 oneline pencilfish Nannostomus unifasciatus (Lebiasinidae and 13 angelfish Pterophyllum scalare (Cichlidae were collected from the middle Negro River, State of Amazonas, Brazil, for parasitological studies. Out of the total of 223 fish examined, 143 (64.1% were parasitized by at least one parasite species. The highest prevalence rate was for Monogenea (36.7%, followed by Ichthyophthirius multifiliis (Ciliophora (20.6%, Trichodina spp. (Ciliophora (4.0%, Piscinoodinium pillulare (Dinoflagellida (1.3%, Tetrahymena sp. (Ciliophora (0.89%, and Procamallanus sp. (Nematoda (0.4%. All eight fish species had Monogenea (Gyrodactylidae and Dactylogyridae in the gills, but the highest prevalence occurred in P. scalare and the lowest in P. axelrodi and C. strigata. However, the highest mean intensity of Monogenea was found in P. scalare and A. hoplogenys. The protozoan I. multifiliis occurred in the six ornamental fish species examined, but C. strigata and C. martae had higher prevalence and mean intensity. Trichodina spp. were found only in the gills of C. strigata, C. martae and N. eques, and with higher mean intensity in C. strigata. On the other hand, the protozoan P. pilullare was found only in the gills of C. martae. This is the first report of Tetrahymena sp. in Brazil, and it occurred in the gills of C. strigata.Para estudos parasitológicos, 27 espécimes de cardinal Paracheirodon axelrodi, 33 rosa-céu Hyphessobrycon copelandi (Characidae, 28 peixes borboleta Carnegiella strigata e 26 Carnegiella martae (Gasteropelecidae, 27 bodó ou cascudo Ancistrus hoplogenys (Loricariidae, 31 peixes-lápis Nannostomus eques e 38 Nannostomus unifasciatus

Ciliates (Protozoa from dried sediments of a temporary pond from Argentina Ciliados (Protozoa de sedimentos secos de una charca temporaria de la Argentina

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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

Ciliate protists from Cabiúnas Lagoon (Restinga de Jurubatiba, Macaé, Rio de Janeiro) with emphasis on water quality indicator Species and description of Oxytricha marcili sp. n.

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Paiva, T S; Silva-Neto, I D

2004-08-01

We found 34 species of ciliate protists in the samples collected by the margins of Cabiúnas Lagoon during 2001. The ciliates were cultivated in the laboratory, where they were examined in vivo and identified through silver impregnation techniques. A new species, Oxytricha marcili (Ciliophora, Oxytrichidae), was found and characterized as follows: in vivo length about 60-80 microm x 30-40 microm wide; on average 22 adoral membranelles; 18 left marginal cirri; 18 right marginal cirri; and 3 small caudal cirri. All specimens analyzed presented 7 frontal cirri (3 anterior + 4 posterior), 1 buccal cirrus, 4 ventral cirri (3 postoral + 1 pre-transverse), and 5 transverse cirri. Among the species found, some are considered as water quality indicators ranging from alpha-mesosaprobity to polysaprobity and isosaprobity.

Marked seasonality and high spatial variation in estuarine ciliates are driven by exchanges between the ?abundant? and ?intermediate? biospheres

OpenAIRE

Sun, Ping; Huang, Liying; Xu, Dapeng; Huang, Bangqin; Chen, Nengwang; Warren, Alan

2017-01-01

We examined the spatial and temporal variability of ciliate community in a subtropical estuary by rRNA and rDNA-based high throughput sequencing of 97 samples collected along the entire salinity gradient at two-month intervals in 2014. Community divided statistically into three groups: freshwater (salinity??1%) OTUs. Further analyses demonstrated that the intermediate group not only encompassed comparable OTU richness to that of the total community and maintained high metabolic activity but a...

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

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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

Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater

Energy Technology Data Exchange (ETDEWEB)

Holmes, Dawn; Giloteaux, L.; Williams, Kenneth H.; Wrighton, Kelly C.; Wilkins, Michael J.; Thompson, Courtney A.; Roper, Thomas J.; Long, Philip E.; Lovley, Derek

2013-07-28

The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well-recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, acetate amendments initially promoted the growth of metal-reducing Geobacter species followed by the growth of sulfate-reducers, as previously observed. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater prior to the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the amoeboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey-predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity, and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies.

[The staphylococcal enterotoxin burden determines the ultrastructure of ciliated epithelia and inflammatory changes in maxillary sinus mucosa of rabbits].

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Wei, Hongqi; Zhu, Zhengwen; Cao, Zhongsheng; Liu, Zhiyong; Wu, Xiaofan; Yuan, Hui

2014-12-01

To investigate the ultrastructure of ciliated epithelia and inflammatory changes upon repeated exposure to staphylococcal enterotoxin A (SEA) of different concentrations in the maxillary sinus mucosa of rabbits. The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEA group and high-dose SEA group. The low-dose SEA group and high-dose SEA group received daily injections of 0.6 ng of SEA (2 ml) and 60 ng of SEA (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as control. Six rabbits chosen randomly in two groups were examined by computed tomography (CT) scans and then sacrificed to obtain the sinus mucosa from the two-side of maxillary sinuses for histological assessment on days 3, 7, 14 and 28. To characterize the inflammatory changes of the sinus mucosa examined using light microscope, hematoxylin and eosin (HE) and toluidine blue staining was performed. Scanning and transmission electron microscopy were performed to observe ultrastructure of ciliated epithelia in the maxillary sinus mucosa. SPSS 13.0 software was used to analyze the data. On days 14 and 28, CT images showed opacification of the left maxillary sinus in the high-dose SEA group. The percentage of epithelial disruption was (22.73 ± 5.72) % and (30.79 ± 4.30)% in the high-dose SEA group respectively, and were significantly greater than those in the low-dose SEA group (5.12% ± 1.98% and 5.38% ± 1.64%, q value was 10.079 and 19.132) and control group (4.08% ± 1.29% and 4.81% ± 1.62%, q value was 11.016 and 19.592, respectively, all P microscope, loss of cilia was observed, a few compound cilia and cytoplasmic protrusion were found, an obvious stretching of the endoplasmic reticulum and an obvious turgescence of the mitochondria was also observed. However, in the low-dose SEA group on days 14 and 28, CT scan of the left maxillary sinus showed transparency; light

A novel soluble immune-type receptor (SITR in teleost fish: carp SITR is involved in the nitric oxide-mediated response to a protozoan parasite.

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Carla M S Ribeiro

2011-01-01

Full Text Available The innate immune system relies upon a wide range of germ-line encoded receptors including a large number of immunoglobulin superfamily (IgSF receptors. Different Ig-like immune receptor families have been reported in mammals, birds, amphibians and fish. Most innate immune receptors of the IgSF are type I transmembrane proteins containing one or more extracellular Ig-like domains and their regulation of effector functions is mediated intracellularly by distinct stimulatory or inhibitory pathways.Carp SITR was found in a substracted cDNA repertoire from carp macrophages, enriched for genes up-regulated in response to the protozoan parasite Trypanoplasma borreli. Carp SITR is a type I protein with two extracellular Ig domains in a unique organisation of a N-proximal V/C2 (or I- type and a C-proximal V-type Ig domain, devoid of a transmembrane domain or any intracytoplasmic signalling motif. The carp SITR C-proximal V-type Ig domain, in particular, has a close sequence similarity and conserved structural characteristics to the mammalian CD300 molecules. By generating an anti-SITR antibody we could show that SITR protein expression was restricted to cells of the myeloid lineage. Carp SITR is abundantly expressed in macrophages and is secreted upon in vitro stimulation with the protozoan parasite T. borreli. Secretion of SITR protein during in vivo T. borreli infection suggests a role for this IgSF receptor in the host response to this protozoan parasite. Overexpression of carp SITR in mouse macrophages and knock-down of SITR protein expression in carp macrophages, using morpholino antisense technology, provided evidence for the involvement of carp SITR in the parasite-induced NO production.We report the structural and functional characterization of a novel soluble immune-type receptor (SITR in a teleost fish and propose a role for carp SITR in the NO-mediated response to a protozoan parasite.

Environmental drivers of heterogeneity in the trophic-functional structure of protozoan communities during an annual cycle in a coastal ecosystem.

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Xu, Guangjian; Yang, Eun Jin; Xu, Henglong

2017-08-15

Trophic-functional groupings are an important biological trait to summarize community structure in functional space. The heterogeneity of the tropic-functional pattern of protozoan communities and its environmental drivers were studied in coastal waters of the Yellow Sea during a 1-year cycle. Samples were collected using the glass slide method at four stations within a water pollution gradient. A second-stage matrix-based analysis was used to summarize spatial variation in the annual pattern of the functional structure. A clustering analysis revealed significant variability in the trophic-functional pattern among the four stations during the 1-year cycle. The heterogeneity in the trophic-functional pattern of the communities was significantly related to changes in environmental variables, particularly ammonium-nitrogen and nitrates, alone or in combination with dissolved oxygen. These results suggest that the heterogeneity in annual patterns of protozoan trophic-functional structure may reflect water quality status in coastal ecosystems. Copyright © 2017. Published by Elsevier Ltd.

First record of two ectoparasitic ciliates of the genus Trichodina (Ciliophora: Trichodinidae) parasitizing gills of an invasive freshwater fish, Micropercops swinhonis, in Tibet.

Science.gov (United States)

Wang, Zhe; Deng, Qiong; Zhou, Tong; Yang, Hao; Gu, Zemao

2018-07-01

Although high diversity of parasitic ciliates has been reported in China, little is known about the species from high altitude areas, especially in Tibet. To investigate the species of parasitic ciliates in Tibet, a project was initiated in the Chabalang wetland in 2013. Two Trichodina species, namely, Trichodina sp. and T. reticulata Hirschmann & Partsch, 1955, were isolated from gills of an invasive fish, Micropercops swinhonis for the first time. In the present study, we provided the morphological, morphometrical, and molecular characterizations of the two species and conducted the phylogenetic analyses of mobilids based on the small subunit ribosomal RNA gene (SSU rDNA) sequences. Both morphological characters and morphometric data of the T. reticulata agreed well with previous studies. Although two partial SSU rDNA sequences were obtained in the present study, only the sequence of T. reticulata population in the present study was thought to be reliable. The other sequence may not belong to the other species. Thus, we regarded the other species isolated in the present study as Trichodina sp. to avoid the wrong or confused species identification. Morphologically, Trichodina sp. is distinguished mainly by its large body shape with a broad adhesive disk, robust and obliquely quadrilateral blades, and well-developed rays. T. reticulata is mainly characterized with the 8-12 spherical or elliptical granules in the central zone of adhesive disk. Phylogenetic analyses consistently showed the two ectoparasites clustered with freshwater species of the genus Trichodina within the order Mobilida. Our study extended the host range of T. reticulata and supplemented the molecular data. Also, results reveal that invasion of exotic fish may cause a potential threat to native fish by introducing or dispersing parasitic ciliates.

Separation and Identification of Odd Chain Triacylglycerols of the Protozoan Khawkinea quartana and the Mold Mortierella alpina Using LC-MS

Czech Academy of Sciences Publication Activity Database

Řezanka, Tomáš; Vítová, Milada; Nováková, Alena; Sigler, Karel

2015-01-01

Roč. 50, č. 8 (2015), s. 811-820 ISSN 0024-4201 R&D Projects: GA ČR(CZ) GAP503/11/0215; GA ČR GA14-00227S Institutional support: RVO:61388971 Keywords : Protozoan * Khawkinea quartana * Mold Subject RIV: CE - Biochemistry Impact factor: 1.892, year: 2015

Ciliate protists from Cabiúnas Lagoon (Restinga de Jurubatiba, Macaé, Rio de Janeiro with emphasis on water quality indicator species and description of Oxytricha marcili sp. n.

Directory of Open Access Journals (Sweden)

T. S. Paiva

Full Text Available We found 34 species of ciliate protists in the samples collected by the margins of Cabiúnas Lagoon during 2001. The ciliates were cultivated in the laboratory, where they were examined in vivo and identified through silver impregnation techniques. A new species, Oxytricha marcili (Ciliophora, Oxytrichidae, was found and characterized as follows: in vivo length about 60-80 mum x 30-40 mum wide; on average 22 adoral membranelles; 18 left marginal cirri; 18 right marginal cirri; and 3 small caudal cirri. All specimens analyzed presented 7 frontal cirri (3 anterior + 4 posterior, 1 buccal cirrus, 4 ventral cirri (3 postoral + 1 pre-transverse, and 5 transverse cirri. Among the species found, some are considered as water quality indicators ranging from alpha-mesosaprobity to polysaprobity and isosaprobity.

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

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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.

Combinatorial QSAR modeling of chemical toxicants tested against Tetrahymena pyriformis.

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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

Surface interactions affect the toxicity of engineered metal oxide nanoparticles toward Paramecium.

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Li, Kungang; Chen, Ying; Zhang, Wen; Pu, Zhichao; Jiang, Lin; Chen, Yongsheng

2012-08-20

To better understand the potential impacts of engineered metal oxide nanoparticles (NPs) in the ecosystem, we investigated the acute toxicity of seven different types of engineered metal oxide NPs against Paramecium multimicronucleatum, a ciliated protozoan, using the 48 h LC(50) (lethal concentration, 50%) test. Our results showed that the 48 h LC(50) values of these NPs to Paramecium ranged from 0.81 (Fe(2)O(3) NPs) to 9269 mg/L (Al(2)O(3) NPs); their toxicity to Paramecium increased as follows: Al(2)O(3) Paramecium; this implies that metal oxide NPs with strong association with the cell surface might induce more severe cytotoxicity in unicellular organisms.

Ultrastructure observation on the cells at different life history stages of Cryptocaryon irritans (Ciliophora: Prostomatea), a parasitic ciliate of marine fishes.

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Ma, Rui; Ni, Bing; Fan, Xinpeng; Warren, Alan; Yin, Fei; Gu, Fukang

2016-09-01

Cells of Cryptocaryon irritans at different life history stages were studied using both light and electron microscopy. The characteristics of several organelles were revealed for the first time at the ultrastructural level. It was confirmed that the cytostome of trophonts, protomonts and theronts was surrounded by cilium-palp triplets rather than ciliary triplets. The nematodesmata underlying the circumoral dikinetids were single bundles, whereas these were always paired in Prorodontids. Toxicysts were present in late-stage tomonts and theronts, but were absent in trophonts and protomonts. We posited that toxicysts might play a role in infection and invasion of host-fish tissue by theronts. The adoral brosse was unlike that of any other family of the class Prostomatea based on its location and morphology. Membranous folds were present in trophonts, protomonts and theronts. These folds were longer and more highly developed in C. irritans than in exclusively free-living prostome ciliates suggesting that they might be linked to parasitism in C. irritans. Trophonts, protomonts and theronts had multiple contractile vacuoles. The basic ultrastructure of the contractile vacuole of C. irritans was similar to that of other kinetofragminophoran ciliates. They might play different roles in different stages of the life cycle since their ultrastructure varied among trophonts, protomonts and theronts.

Simple and rapid staining for detection of Entamoeba cysts and other protozoans with fluorochromes.

Science.gov (United States)

Kawamoto, F; Mizuno, S; Fujioka, H; Kumada, N; Sugiyama, E; Takeuchi, T; Kobayashi, S; Iseki, M; Yamada, M; Matsumoto, Y

1987-02-01

Three fluorochromes were applied to stain various parasitic protozoans. By double staining with 4',6-diamidino-2-phenylindole and propidium iodide, differentiation of the nuclei from the cytoplasm can easily be achieved within several seconds. The chromatoid bodies in Entamoeba cysts were stained bright red. Plasmodium yoelii at all stages except late trophozoites and young gametocytes was easily identified. In the oocysts of Cryptosporidium sp., the nuclei and cytoplasm of the sporozoites fluoresced bluish white and red, respectively, whereas the residual body appeared blue or green. The third fluorochrome, Calcofluor white M2R, was suitable for detecting the cysts of Entamoeba spp. and Chilomastix mesnili.

Incidence of adult brain cancers is higher in countries where the protozoan parasite Toxoplasma gondii is common

OpenAIRE

Thomas, Frédéric; Lafferty, Kevin D.; Brodeur, Jacques; Elguero, Eric; Gauthier-Clerc, Michel; Missé, Dorothée

2011-01-01

We explored associations between the common protozoan parasite Toxoplasma gondii and brain cancers in human populations. We predicted that T. gondii could increase the risk of brain cancer because it is a long-lived parasite that encysts in the brain, where it provokes inflammation and inhibits apoptosis. We used a medical geography approach based on the national incidence of brain cancers and seroprevalence of T. gondii. We corrected reports of incidence for national gross domestic product b...

Foodborne intestinal protozoan infection and associated factors among patients with watery diarrhea in Northern Ethiopia; a cross-sectional study.

Science.gov (United States)

Berhe, Birhane; Bugssa, Gessessew; Bayisa, Sena; Alemu, Megbaru

2018-03-02

Intestinal protozoa are parasites transmitted by consumption of contaminated water and food and mainly affect children and elder people and cause considerable health problems. They are the leading causes of outpatient morbidity due to diarrhea in the developing countries. So, assessing water and food source of diarrheal patients and identifying the main associated factors for transmission of protozoan parasitic infections help for effective control measures of protozoan infections. Hence, the current study was aimed at determining the prevalence of foodborne intestinal protozoa infections and associated factors among diarrheic patients in North Ethiopia. A health facility based cross-sectional study was conducted among 223 patients with watery diarrhea in four selected government health facilities in North Ethiopia from November 2016-June 2017. A structured questionnaire was used to collect data on socio-demography of study participants and factors associated with foodborne protozoa infections. The diarrheic stool samples were collected, transported, and processed using direct wet mount, formal-ether concentration and modified ZiehlNeelson staining methods. The data were analyzed using SPSS version 21 and descriptive statistics, bi-variate, and multivariate logistic regressions were computed. P-value parasite infection .

Selective Inhibitors of Protozoan Protein N-myristoyltransferases as Starting Points for Tropical Disease Medicinal Chemistry Programs

Science.gov (United States)

Bell, Andrew S.; Mills, James E.; Williams, Gareth P.; Brannigan, James A.; Wilkinson, Anthony J.; Parkinson, Tanya; Leatherbarrow, Robin J.; Tate, Edward W.; Holder, Anthony A.; Smith, Deborah F.

2012-01-01

Inhibition of N-myristoyltransferase has been validated pre-clinically as a target for the treatment of fungal and trypanosome infections, using species-specific inhibitors. In order to identify inhibitors of protozoan NMTs, we chose to screen a diverse subset of the Pfizer corporate collection against Plasmodium falciparum and Leishmania donovani NMTs. Primary screening hits against either enzyme were tested for selectivity over both human NMT isoforms (Hs1 and Hs2) and for broad-spectrum anti-protozoan activity against the NMT from Trypanosoma brucei. Analysis of the screening results has shown that structure-activity relationships (SAR) for Leishmania NMT are divergent from all other NMTs tested, a finding not predicted by sequence similarity calculations, resulting in the identification of four novel series of Leishmania-selective NMT inhibitors. We found a strong overlap between the SARs for Plasmodium NMT and both human NMTs, suggesting that achieving an appropriate selectivity profile will be more challenging. However, we did discover two novel series with selectivity for Plasmodium NMT over the other NMT orthologues in this study, and an additional two structurally distinct series with selectivity over Leishmania NMT. We believe that release of results from this study into the public domain will accelerate the discovery of NMT inhibitors to treat malaria and leishmaniasis. Our screening initiative is another example of how a tripartite partnership involving pharmaceutical industries, academic institutions and governmental/non-governmental organisations such as Medical Research Council and Wellcome Trust can stimulate research for neglected diseases. PMID:22545171

In silico prediction of Tetrahymena pyriformis toxicity for diverse industrial chemicals with substructure pattern recognition and machine learning methods.

Science.gov (United States)

Cheng, Feixiong; Shen, Jie; Yu, Yue; Li, Weihua; Liu, Guixia; Lee, Philip W; Tang, Yun

2011-03-01

There is an increasing need for the rapid safety assessment of chemicals by both industries and regulatory agencies throughout the world. In silico techniques are practical alternatives in the environmental hazard assessment. It is especially true to address the persistence, bioaccumulative and toxicity potentials of organic chemicals. Tetrahymena pyriformis toxicity is often used as a toxic endpoint. In this study, 1571 diverse unique chemicals were collected from the literature and composed of the largest diverse data set for T. pyriformis toxicity. Classification predictive models of T. pyriformis toxicity were developed by substructure pattern recognition and different machine learning methods, including support vector machine (SVM), C4.5 decision tree, k-nearest neighbors and random forest. The results of a 5-fold cross-validation showed that the SVM method performed better than other algorithms. The overall predictive accuracies of the SVM classification model with radial basis functions kernel was 92.2% for the 5-fold cross-validation and 92.6% for the external validation set, respectively. Furthermore, several representative substructure patterns for characterizing T. pyriformis toxicity were also identified via the information gain analysis methods. Copyright © 2010 Elsevier Ltd. All rights reserved.

Metal concentrations in stream biofilm and sediments and their potential to explain biofilm microbial community structure

International Nuclear Information System (INIS)

Ancion, Pierre-Yves; Lear, Gavin; Dopheide, Andrew; Lewis, Gillian D.

2013-01-01

Concentrations of metals associated with sediments have traditionally been analysed to assess the extent of heavy metal contamination in freshwater environments. Stream biofilms present an alternative medium for this assessment which may be more relevant to the risk incurred by stream ecosystems as they are intensively grazed by aquatic organisms at a higher trophic level. Therefore, we investigated zinc, copper and lead concentrations in biofilms and sediments of 23 stream sites variously impacted by urbanisation. Simultaneously, biofilm bacterial and ciliate protozoan community structure was analysed by Automated Ribosomal Intergenic Spacer Analysis and Terminal Restriction Fragment Length Polymorphism, respectively. Statistical analysis revealed that biofilm associated metals explained a greater proportion of the variations observed in bacterial and ciliate communities than did sediment associated-metals. This study suggests that the analysis of metal concentrations in biofilms provide a good assessment of detrimental effects of metal contaminants on aquatic biota. - Highlights: ► Zn, Cu and Pb concentrations in biofilm and sediments from 23 streams were assessed. ► Bacteria and ciliate protozoa were simultaneously used as biological indicators. ► Zn and Cu were generally enriched in biofilm compared to sediments. ► Metals in biofilm provide a useful assessment of freshwater ecosystem contamination. ► Results highlight the likely ecological importance of biofilm associated metals. - Metal concentrations in stream biofilms provide a good assessment of the effects of trace metal contaminants on freshwater ecosystems.

13C-NMR reveals glycerol as an unexpected major metabolite of the protozoan parasite Trichomonas vaginalis

International Nuclear Information System (INIS)

Chapman, A.; Lloyd, D.; Linstead, D.J.; Williams, J.

1985-01-01

13 C-NMR has been used to study the kinetics of the formation of metabolites from [l- 13 C]glucose in intact cells of Trichomonas vaginalis during anaerobic incubation. As well as the expected metabolites lactate and acetate, this technique revealed glycerol as an additional major product, present in amounts equimolar with acetate. The formation of glycerol is readily explained in terms of the need to maintain redox balance. This protozoan now joins the small group of organisms which are known to produce glycerol as a result of normal metabolic activities. (Auth.)

Distribution and Evolution of Peroxisomes in Alveolates (Apicomplexa, Dinoflagellates, Ciliates)

Science.gov (United States)

Ludewig-Klingner, Ann-Kathrin; Michael, Victoria; Jarek, Michael; Brinkmann, Henner

2018-01-01

Abstract The peroxisome was the last organelle to be discovered and five decades later it is still the Cinderella of eukaryotic compartments. Peroxisomes have a crucial role in the detoxification of reactive oxygen species, the beta-oxidation of fatty acids, and the biosynthesis of etherphospholipids, and they are assumed to be present in virtually all aerobic eukaryotes. Apicomplexan parasites including the malaria and toxoplasmosis agents were described as the first group of mitochondriate protists devoid of peroxisomes. This study was initiated to reassess the distribution and evolution of peroxisomes in the superensemble Alveolata (apicomplexans, dinoflagellates, ciliates). We established transcriptome data from two chromerid algae (Chromera velia, Vitrella brassicaformis), and two dinoflagellates (Prorocentrum minimum, Perkinsus olseni) and identified the complete set of essential peroxins in all four reference species. Our comparative genome analysis provides unequivocal evidence for the presence of peroxisomes in Toxoplasma gondii and related genera. Our working hypothesis of a common peroxisomal origin of all alveolates is supported by phylogenetic analyses of essential markers such as the import receptor Pex5. Vitrella harbors the most comprehensive set of peroxisomal proteins including the catalase and the glyoxylate cycle and it is thus a promising model organism to investigate the functional role of this organelle in Apicomplexa. PMID:29202176

Effects of decreased resource availability, protozoan grazing and viral impact on a structure of bacterioplankton assemblage in a canyon-shaped reservoir

Czech Academy of Sciences Publication Activity Database

Horňák, Karel; Mašín, Michal; Jezbera, Jan; Bettarel, Y.; Nedoma, Jiří; Sime-Ngando, T.; Šimek, Karel

2005-01-01

Roč. 52, č. 3 (2005), s. 315-327 ISSN 0168-6496 R&D Projects: GA ČR(CZ) GA206/02/0003 Grant - others:PICS(FR) project 1111 Institutional research plan: CEZ:AV0Z60170517 Keywords : bacterioplankton * protozoan grazing * viral lysis Subject RIV: EH - Ecology, Behaviour Impact factor: 2.787, year: 2005

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

2017-05-01

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. © 2016 John Wiley & Sons Ltd.

A morphogenetic survey on ciliate plankton from a mountain lake pinpoints the necessity of lineage-specific barcode markers in microbial ecology.

Science.gov (United States)

Stoeck, Thorsten; Breiner, Hans-Werner; Filker, Sabine; Ostermaier, Veronika; Kammerlander, Barbara; Sonntag, Bettina

2014-02-01

Analyses of high-throughput environmental sequencing data have become the 'gold-standard' to address fundamental questions of microbial diversity, ecology and biogeography. Findings that emerged from sequencing are, e.g. the discovery of the extensive 'rare microbial biosphere' and its potential function as a seed-bank. Even though applied since several years, results from high-throughput environmental sequencing have hardly been validated. We assessed how well pyrosequenced amplicons [the hypervariable eukaryotic V4 region of the small subunit ribosomal RNA (SSU rRNA) gene] reflected morphotype ciliate plankton. Moreover, we assessed if amplicon sequencing had the potential to detect the annual ciliate plankton stock. In both cases, we identified significant quantitative and qualitative differences. Our study makes evident that taxon abundance distributions inferred from amplicon data are highly biased and do not mirror actual morphotype abundances at all. Potential reasons included cell losses after fixation, cryptic morphotypes, resting stages, insufficient sequence data availability of morphologically described species and the unsatisfying resolution of the V4 SSU rRNA fragment for accurate taxonomic assignments. The latter two underline the necessity of barcoding initiatives for eukaryotic microbes to better and fully exploit environmental amplicon data sets, which then will also allow studying the potential of seed-bank taxa as a buffer for environmental changes. © 2013 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

A Comparative Study of Four Methods for the Detection of Nematode Eggs and Large Protozoan Cysts in Mandrill Faecal Material.

Science.gov (United States)

Pouillevet, Hanae; Dibakou, Serge-Ely; Ngoubangoye, Barthélémy; Poirotte, Clémence; Charpentier, Marie J E

2017-01-01

Coproscopical methods like sedimentation and flotation techniques are widely used in the field for studying simian gastrointestinal parasites. Four parasites of known zoonotic potential were studied in a free-ranging, non-provisioned population of mandrills (Mandrillus sphinx): 2 nematodes (Necatoramericanus/Oesophagostomum sp. complex and Strongyloides sp.) and 2 protozoan species (Balantidium coli and Entamoeba coli). Different coproscopical techniques are available but they are rarely compared to evaluate their efficiency to retrieve parasites. In this study 4 different field-friendly methods were compared. A sedimentation method and 3 different McMaster methods (using sugar, salt, and zinc sulphate solutions) were performed on 47 faecal samples collected from different individuals of both sexes and all ages. First, we show that McMaster flotation methods are appropriate to detect and thus quantify large protozoan cysts. Second, zinc sulphate McMaster flotation allows the retrieval of a higher number of parasite taxa compared to the other 3 methods. This method further shows the highest probability to detect each of the studied parasite taxa. Altogether our results show that zinc sulphate McMaster flotation appears to be the best technique to use when studying nematodes and large protozoa. © 2017 S. Karger AG, Basel.

Phylloseptins: a novel class of anti-bacterial and anti-protozoan peptides from the Phyllomedusa genus.

Science.gov (United States)

Leite, José Roberto S A; Silva, Luciano P; Rodrigues, Maria Izabel S; Prates, Maura V; Brand, Guilherme D; Lacava, Bruno M; Azevedo, Ricardo B; Bocca, Anamélia L; Albuquerque, Sergio; Bloch, Carlos

2005-04-01

Six novel peptides called phylloseptins (PS-1, -2, -3, -4, -5, and -6) showing anti-bacterial (PS-1) and anti-protozoan (PS-4 and -5) activities were isolated from the skin secretion of the Brazilian tree-frogs, Phyllomedusa hypochondrialis and Phyllomedusa oreades. Phylloseptins have a primary structure consisting of 19-21 amino acid residues (1.7-2.1 kDa). They have common structural features, such as a highly conserved N-terminal region and C-terminal amidation. Phylloseptin-1 (FLSLIPHAINAVSAIAKHN-NH2) demonstrated a strong effect against gram-positive and gram-negative bacteria (MICs ranging from 3 to 7.9 microM), without showing significant hemolytic activity (Trypanosoma cruzi.

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.

Evidence for the bacterial origin of genes encoding fermentation enzymes of the amitochondriate protozoan parasite Entamoeba histolytica.

Science.gov (United States)

Rosenthal, B; Mai, Z; Caplivski, D; Ghosh, S; de la Vega, H; Graf, T; Samuelson, J

1997-06-01

Entamoeba histolytica is an amitochondriate protozoan parasite with numerous bacterium-like fermentation enzymes including the pyruvate:ferredoxin oxidoreductase (POR), ferredoxin (FD), and alcohol dehydrogenase E (ADHE). The goal of this study was to determine whether the genes encoding these cytosolic E. histolytica fermentation enzymes might derive from a bacterium by horizontal transfer, as has previously been suggested for E. histolytica genes encoding heat shock protein 60, nicotinamide nucleotide transhydrogenase, and superoxide dismutase. In this study, the E. histolytica por gene and the adhE gene of a second amitochondriate protozoan parasite, Giardia lamblia, were sequenced, and their phylogenetic positions were estimated in relation to POR, ADHE, and FD cloned from eukaryotic and eubacterial organisms. The E. histolytica por gene encodes a 1,620-amino-acid peptide that contained conserved iron-sulfur- and thiamine pyrophosphate-binding sites. The predicted E. histolytica POR showed fewer positional identities to the POR of G. lamblia (34%) than to the POR of the enterobacterium Klebsiella pneumoniae (49%), the cyanobacterium Anabaena sp. (44%), and the protozoan Trichomonas vaginalis (46%), which targets its POR to anaerobic organelles called hydrogenosomes. Maximum-likelihood, neighbor-joining, and parsimony analyses also suggested as less likely E. histolytica POR sharing more recent common ancestry with G. lamblia POR than with POR of bacteria and the T. vaginalis hydrogenosome. The G. lamblia adhE encodes an 888-amino-acid fusion peptide with an aldehyde dehydrogenase at its amino half and an iron-dependent (class 3) ADH at its carboxy half. The predicted G. lamblia ADHE showed extensive positional identities to ADHE of Escherichia coli (49%), Clostridium acetobutylicum (44%), and E. histolytica (43%) and lesser identities to the class 3 ADH of eubacteria and yeast (19 to 36%). Phylogenetic analyses inferred a closer relationship of the E

Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater

Directory of Open Access Journals (Sweden)

Kamika Ilunga

2013-02-01

Full Text Available Abstract Background Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen and the growth/die-off-rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates. Results The results revealed that the industrial-wastewater samples were highly polluted with heavy-metal concentrations exceeding by far the maximum limits (in mg/l of 0.05-Co, 0.2-Ni, 0.1-Mn, 0.1-V, 0.01-Pb, 0.01-Cu, 0.1-Zn and 0.005-Cd, prescribed by the UN-FAO. Industrial-wastewater had no major effects on Pseudomonas putida, Bacillus licheniformis and Peranema sp. (growth rates up to 1.81, 1.45 and 1.43 d-1, respectively compared to other test isolates. This was also revealed with significant COD increases (p Pseudomonas putida demonstrated the highest removal rates of heavy metals (Co-71%, Ni-51%, Mn-45%, V-83%, Pb-96%, Ti-100% and Cu-49% followed by Bacillus licheniformis (Al-23% and Zn-53% and Peranema sp. (Cd-42%. None of the dead cells were able to remove more than 25% of the heavy metals. Bacterial isolates contained the genes copC, chrB, cnrA3 and nccA encoding the resistance to Cu, Cr, Co-Ni and Cd-Ni-Co, respectively. Protozoan isolates contained only the genes encoding Cu and Cr resistance (copC and chrB genes. Peranema sp. was the only protozoan isolate which had an additional resistant gene cnrA3 encoding Co-Ni resistance. Conclusion Significant differences (p Peranema sp. as a potential candidate for the bioremediation of heavy-metals in wastewater treatment, in addition to Pseudomonas

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

OpenAIRE

Alfonso Esquivel; Aude Barani; Miroslav Macek; Ruth Ruth Soto-Castor; Celia Bulit

2016-01-01

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 leve...

AON-mediated Exon Skipping Restores Ciliation in Fibroblasts Harboring the Common Leber Congenital Amaurosis CEP290 Mutation

Directory of Open Access Journals (Sweden)

Xavier Gerard

2012-01-01

Full Text Available Leber congenital amaurosis (LCA is a severe hereditary retinal dystrophy responsible for congenital or early-onset blindness. The most common disease-causing mutation (>10% is located deep in intron 26 of the CEP290 gene (c.2991+1655A>G. It creates a strong splice donor site that leads to insertion of a cryptic exon encoding a premature stop codon. In the present study, we show that the use of antisense oligonucleotides (AONs allow an efficient skipping of the mutant cryptic exon and the restoration of ciliation in fibroblasts of affected patients. These data support the feasibility of an AON-mediated exon skipping strategy to correct the aberrant splicing.

Phylogenetic analysis of the Neks reveals early diversification of ciliary-cell cycle kinases.

Directory of Open Access Journals (Sweden)

Jeremy D K Parker

2007-10-01

Full Text Available NIMA-related kinases (Neks have been studied in diverse eukaryotes, including the fungus Aspergillus and the ciliate Tetrahymena. In the former, a single Nek plays an essential role in cell cycle regulation; in the latter, which has more than 30 Neks in its genome, multiple Neks regulate ciliary length. Mammalian genomes encode an intermediate number of Neks, several of which are reported to play roles in cell cycle regulation and/or localize to centrosomes. Previously, we reported that organisms with cilia typically have more Neks than organisms without cilia, but were unable to establish the evolutionary history of the gene family.We have performed a large-scale analysis of the Nek family using Bayesian techniques, including tests of alternate topologies. We find that the Nek family had already expanded in the last common ancestor of eukaryotes, a ciliated cell which likely expressed at least five Neks. We suggest that Neks played an important role in the common ancestor in regulating cilia, centrioles, and centrosomes with respect to mitotic entry, and that this role continues today in organisms with cilia. Organisms that lack cilia generally show a reduction in the number of Nek clades represented, sometimes associated with lineage specific expansion of a single clade, as has occurred in the plants.This is the first rigorous phylogenetic analysis of a kinase family across a broad array of phyla. Our findings provide a coherent framework for the study of Neks and their roles in coordinating cilia and cell cycle progression.

Biomonitoring of coastal pollution status using protozoan communities with a modified PFU method.

Science.gov (United States)

Xu, Kuidong; Choi, Joong Ki; Yang, Eun Jin; Lee, Kyu Chul; Lei, Yanli

2002-09-01

Structural and functional parameters of protozoan communities were assessed as indicators of water quality in Korean coastal waters in the summer of 2000. A modified polyurethane foam unit (PFU) method, named the bottled PFU (BPFU) system, was used in order to carry out the bioassessment. Both parameters suggested that biomonitoring using the BPFU system was more effective than the conventional PFU method in offshore areas. The species number collected by the BPFU system generally decreased as pollution intensity increased at three main stations and was greater than that collected using the PFU method (paired t-test, t = 4.83, p PFU method (paired t-test, t = 5.37, p < 0.0001). Furthermore, the functional parameters, i.e. S(eq),G and T90%, correlated with the pollution status and could thus clearly discriminate the different classes of water quality.

Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum

Science.gov (United States)

Teixeira, Luzia; Moreira, João; Melo, Joana; Bezerra, Filipa; Marques, Raquel M; Ferreirinha, Pedro; Correia, Alexandra; Monteiro, Mariana P; Ferreira, Paula G; Vilanova, Manuel

2015-01-01

The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet+ cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-γ was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue. PMID:25581844

Heteroagglomeration of zinc oxide nanoparticles with clay mineral modulates the bioavailability and toxicity of nanoparticle in Tetrahymena pyriformis.

Science.gov (United States)

Gupta, Govind Sharan; Senapati, Violet Aileen; Dhawan, Alok; Shanker, Rishi

2017-06-01

The extensive use of zinc oxide nanoparticles (ZnO NPs) in cosmetics, sunscreens and healthcare products increases their release in the aquatic environment. The present study explored the possible interaction of ZnO NPs with montmorillonite clay minerals in aqueous conditions. An addition of ZnO NPs on clay suspension significantly (pclay particles from 1652±90nm to 2158±13nm due to heteroagglomeration. The electrokinetic measurements showed a significant (pclay association (-1.37±0.03μmcm/Vs) that results to the electrostatic interaction between ZnO NPs and clay particles. The attenuated total reflectance Fourier transform infrared spectroscopy analysis of ZnO NPs-clay association demonstrated the binding of ZnO NPs with the Si-O-Al region on the edges of clay particles. The increase in size of ZnO NPs-clay heteroagglomerates further leads to their sedimentation at 24h. Although, the stability of ZnO NPs in the clay suspension was decreased due to heteroagglomeration, but the bioavailability and toxicity of ZnO NPs-clay heteroagglomerates in Tetrahymena pyriformis was enhanced. These observations provide an evidence on possible mechanisms available in natural environment that can facilitate nanoparticles entry into the organisms present in lower trophic levels of the food web. Copyright © 2017 Elsevier Inc. All rights reserved.

A microfluidic-enabled mechanical microcompressor for the immobilization of live single- and multi-cellular specimens.

Science.gov (United States)

Yan, Yingjun; Jiang, Liwei; Aufderheide, Karl J; Wright, Gus A; Terekhov, Alexander; Costa, Lino; Qin, Kevin; McCleery, W Tyler; Fellenstein, John J; Ustione, Alessandro; Robertson, J Brian; Johnson, Carl Hirschie; Piston, David W; Hutson, M Shane; Wikswo, John P; Hofmeister, William; Janetopoulos, Chris

2014-02-01

A microcompressor is a precision mechanical device that flattens and immobilizes living cells and small organisms for optical microscopy, allowing enhanced visualization of sub-cellular structures and organelles. We have developed an easily fabricated device, which can be equipped with microfluidics, permitting the addition of media or chemicals during observation. This device can be used on both upright and inverted microscopes. The apparatus permits micrometer precision flattening for nondestructive immobilization of specimens as small as a bacterium, while also accommodating larger specimens, such as Caenorhabditis elegans, for long-term observations. The compressor mount is removable and allows easy specimen addition and recovery for later observation. Several customized specimen beds can be incorporated into the base. To demonstrate the capabilities of the device, we have imaged numerous cellular events in several protozoan species, in yeast cells, and in Drosophila melanogaster embryos. We have been able to document previously unreported events, and also perform photobleaching experiments, in conjugating Tetrahymena thermophila.

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. Copyright © 2014 Elsevier GmbH. All rights reserved.

Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater.

Science.gov (United States)

Kamika, Ilunga; Momba, Maggy N B

2013-02-06

Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/die-off-rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates. The results revealed that the industrial-wastewater samples were highly polluted with heavy-metal concentrations exceeding by far the maximum limits (in mg/l) of 0.05-Co, 0.2-Ni, 0.1-Mn, 0.1-V, 0.01-Pb, 0.01-Cu, 0.1-Zn and 0.005-Cd, prescribed by the UN-FAO. Industrial-wastewater had no major effects on Pseudomonas putida, Bacillus licheniformis and Peranema sp. (growth rates up to 1.81, 1.45 and 1.43 d-1, respectively) compared to other test isolates. This was also revealed with significant COD increases (p heavy metals (Co-71%, Ni-51%, Mn-45%, V-83%, Pb-96%, Ti-100% and Cu-49%) followed by Bacillus licheniformis (Al-23% and Zn-53%) and Peranema sp. (Cd-42%). None of the dead cells were able to remove more than 25% of the heavy metals. Bacterial isolates contained the genes copC, chrB, cnrA3 and nccA encoding the resistance to Cu, Cr, Co-Ni and Cd-Ni-Co, respectively. Protozoan isolates contained only the genes encoding Cu and Cr resistance (copC and chrB genes). Peranema sp. was the only protozoan isolate which had an additional resistant gene cnrA3 encoding Co-Ni resistance. Significant differences (p metal-removal and the presence of certain metal-resistant genes indicated that the selected microbial isolates used both passive (biosorptive) and active (bioaccumulation) mechanisms to remove heavy metals from industrial wastewater. This study

Regulation of galactokinase gene expression in Tetrahymena thermophila. II. Identification of 3,4-dihydroxyphenylalanine as a primary effector of adrenergic control of galactokinase expression.

Science.gov (United States)

Ness, J C; Morse, D E

1985-08-25

Intracellular concentrations of catecholamines were determined in wild-type and mutant Tetrahymena thermophila, using the highly sensitive techniques of high-performance liquid chromatography and electro-chemical detection. Catecholamines were determined in these cell strains grown under various steady-state conditions, including those which initiate and maintain repression of galactokinase gene expression. Wild-type cells grown in defined minimal medium supplemented with 1% glycerol, exhibiting derepressed galactokinase synthesis, were found to contain considerable quantities of dopa (3,4-dihydroxyphenylalanine) and dopamine, but no detectable levels of either norepinephrine or epinephrine. Analyses of wild-type cells revealed a strong positive correlation between the internal concentration of dopa and expression of the galactokinase gene, both of which are regulated by exogenous carbohydrates, catecholamine agonists, or dibutyryl-cAMP; an analogous relationship between intracellular dopamine concentrations and galactokinase activity was not found. In addition, a correlation between intracellular dopa content and the phenotypic expression of galactokinase in various mutants deficient in the catecholamine biosynthetic pathway or in glucokinase further confirms the role of dopa as a primary effector in the regulation of galactokinase gene expression.

Marked seasonality and high spatial variation in estuarine ciliates are driven by exchanges between the 'abundant' and 'intermediate' biospheres.

Science.gov (United States)

Sun, Ping; Huang, Liying; Xu, Dapeng; Huang, Bangqin; Chen, Nengwang; Warren, Alan

2017-08-25

We examined the spatial and temporal variability of ciliate community in a subtropical estuary by rRNA and rDNA-based high throughput sequencing of 97 samples collected along the entire salinity gradient at two-month intervals in 2014. Community divided statistically into three groups: freshwater (salinity  1%) OTUs. Further analyses demonstrated that the intermediate group not only encompassed comparable OTU richness to that of the total community and maintained high metabolic activity but also had the highest proportion in transition, either to abundance or rarity, thus offering a first view on how it varies across space and time and revealing the essential role it played in maintaining stability and functionality within the community.

Dicty_cDB: SLK195 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 0.003 4 AF312772 |AF312772.1 Tetrahymena thermophila macronuclear immobilization antigen LC (SerLC) mRNA, pa...rtial cds. 30 0.044 3 AF312771 |AF312771.1 Tetrahymena thermophila macronuclear immobilization antigen LB (S...survey sequence. 44 1.2 1 AF312774 |AF312774.1 Tetrahymena thermophila macronuclear immobilization...hermophila macronuclear immobilization antigen LD (SerLD) mRNA, complete cds. 30 ...erLB) mRNA, complete cds. 30 0.060 3 AF312770 |AF312770.1 Tetrahymena thermophila macronuclear immobilizat

Factors related to occurrence and distribution of selected bacterial and protozoan pathogens in Pennsylvania streams

Science.gov (United States)

Duris, Joseph W.; Reif, Andrew G.; Donna A. Crouse,; Isaacs, Natasha M.

2013-01-01

The occurrence and distribution of fecal indicator bacteria (FIB) and bacterial and protozoan pathogens are controlled by diverse factors. To investigate these factors in Pennsylvania streams, 217 samples were collected quarterly from a 27-station water-quality monitoring network from July 2007 through August 2009. Samples were analyzed for concentrations of Escherichia coli (EC) and enterococci (ENT) indicator bacteria, concentrations of Cryptosporidium oocysts and Giardia cysts, and the presence of four genes related to pathogenic types of EC (eaeA, stx2, stx1, rfbO157) plus three microbial source tracking (MST) gene markers that are also associated with pathogenic ENT and EC (esp, LTIIa, STII). Water samples were concurrently analyzed for basic water chemistry, physical measures of water quality, nutrients, metals, and a suite of 79 organic compounds that included hormones, pharmaceuticals, and antibiotics. For each sample location, stream discharge was measured by using standardized methods at the time of sample collection, and ancillary sample site information, such as land use and geological characteristics, was compiled. Samples exceeding recreational water quality criteria were more likely to contain all measured pathogen genes but notCryptosporidium or Giardia (oo)cysts. FIB and Giardia density and frequency of eaeA gene occurrence were significantly related to season. When discharge at a sampling location was high (>75th percentile of daily mean discharge), there were greater densities of FIB and Giardia, and the stx2, rfbO157, STII, and esp genes were found more frequently than at other discharge conditions. Giardia occurrence was likely related to nonpoint sources, which are highly influential during seasonal overland transport resulting from snowmelt and elevated precipitation in late winter and spring in Pennsylvania. When MST markers of human, swine, or bovine origin were present, samples more frequently carried the eaeA, stx2

C. elegans ciliated sensory neurons release extracellular vesicles that function in animal communication.

Science.gov (United States)

Wang, Juan; Silva, Malan; Haas, Leonard A; Morsci, Natalia S; Nguyen, Ken C Q; Hall, David H; Barr, Maureen M

2014-03-03

Cells release extracellular vesicles (ECVs) that play important roles in intercellular communication and may mediate a broad range of physiological and pathological processes. Many fundamental aspects of ECV biogenesis and signaling have yet to be determined, with ECV detection being a challenge and obstacle due to the small size (100 nm) of the ECVs. We developed an in vivo system to visualize the dynamic release of GFP-labeled ECVs. We show here that specific Caenorhabdidits elegans ciliated sensory neurons shed and release ECVs containing GFP-tagged polycystins LOV-1 and PKD-2. These ECVs are also abundant in the lumen surrounding the cilium. Electron tomography and genetic analysis indicate that ECV biogenesis occurs via budding from the plasma membrane at the ciliary base and not via fusion of multivesicular bodies. Intraflagellar transport and kinesin-3 KLP-6 are required for environmental release of PKD-2::GFP-containing ECVs. ECVs isolated from wild-type animals induce male tail-chasing behavior, while ECVs isolated from klp-6 animals and lacking PKD-2::GFP do not. We conclude that environmentally released ECVs play a role in animal communication and mating-related behaviors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Soil ciliate bioassay for the pore water habitat. A missing link between microflora and earthworm testing in soil toxicity assessment

Energy Technology Data Exchange (ETDEWEB)

Berthold, A. [Lab. for Ecotoxicology, Univ. of Veterinary Medicine, Vienna (Austria); Jakl, T. [Chemicals Policy Unit, Federal Ministry of Agriculture, Forestry, Environment and Water Management, Vienna (Austria)

2002-07-01

Background, Scope and Goal. The chemical, pesticide and biocide legislation of the European Union assembles a variety of bioassays. Among the ecotoxicological tests involved, the testing strategy for the aquatic compartment builds up on three tests reflecting the main trophic levels (algae, Daphnia, fish). For the soil compartment at least one trophic level for a basic food chain is missing, namely between microflora and earthworms. Protozoa are an ideal missing link as they were shown to be the most prominent faunal contributors to nutrient cycling in soil ecosystems and as they represent the lacking first level consumers as well as the highly diverse microfauna. As protozoa inhabit the soil pore water, they can serve as direct indicators for the solved and thus bioavailable portion of xenobiotics. In order to widen the spectrum of available toxicity tests for a meaningful effect assessment for the soil compartment, a test with the soil ciliate Colpoda inflata (Ciliophora, Protozoa), introduced by Pratt et al. (1997), was improved. Methods. The novel improvements comprise a substantially refined inoculation and counting procedure, as well as the adaptation to yeast as a nutritional source. The test was designed to be rapid and easy to perform, in order to have both a higher degree of standardisation and reproducibility, as well as to be in compliance with international test guidelines. Results and Discussion. Five test substances, cadmium chloride, potassium dichromate, acetone, atrazine, and metolachlor, were used in single-compound, static, short-term exposure (24 h, 48 h) tests to examine the effect on the population growth of C. inflata. The median effective concentrations (EC50) were 0.17 to 0.26 mg/l for Cd, 34 to 63 mg/l for Cr, >3000 mg/l for acetone, 91-112 mg/l for atrazine and 83-119 mg/l for metolachlor. The equilibrium partitioning approach was used to extrapolate the results to total soil exposure and thus enable a sensitivity comparison to

Tetrahymena telomerase protein p65 induces conformational changes throughout telomerase RNA (TER) and rescues telomerase reverse transcriptase and TER assembly mutants.

Science.gov (United States)

Berman, Andrea J; Gooding, Anne R; Cech, Thomas R

2010-10-01

The biogenesis of the Tetrahymena telomerase ribonucleoprotein particle (RNP) is enhanced by p65, a La family protein. Single-molecule and biochemical studies have uncovered a hierarchical assembly of the RNP, wherein the binding of p65 to stems I and IV of telomerase RNA (TER) causes a conformational change that facilitates the subsequent binding of telomerase reverse transcriptase (TERT) to TER. We used purified p65 and variants of TERT and TER to investigate the conformational rearrangements that occur during RNP assembly. Nuclease protection assays and mutational analysis revealed that p65 interacts with and stimulates conformational changes in regions of TER beyond stem IV. Several TER mutants exhibited telomerase activity only in the presence of p65, revealing the importance of p65 in promoting the correct RNP assembly pathway. In addition, p65 rescued TERT assembly mutants but not TERT activity mutants. Taken together, these results suggest that p65 stimulates telomerase assembly and activity in two ways. First, by sequestering stems I and IV, p65 limits the ensemble of structural conformations of TER, thereby presenting TERT with the active conformation of TER. Second, p65 acts as a molecular buttress within the assembled RNP, mutually stabilizing TER and TERT in catalytically active conformations.

The effect of rumen ciliates on chitinolytic activity, chitin content and the number of fungal zoospores in the rumen fluid of sheep.

Science.gov (United States)

Miltko, Renata; Bełżecki, Grzegorz; Herman, Andrzej; Kowalik, Barbara; Skomiał, Jacek

2016-12-01

The objective of this study was to investigate the effect of selected protozoa on the degradation and concentration of chitin and the numbers of fungal zoospores in the rumen fluid of sheep. Three adult ewes were fed a hay-concentrate diet, defaunated, then monofaunated with Entodinium caudatum or Diploplastron affine alone and refaunated with natural rumen fauna. The average density of the protozoa population varied from 6.1 · 10(4) (D. affine) to 42.2 · 10(4) cells/ml rumen fluid (natural rumen fauna). The inoculation of protozoa in the rumen of defaunated sheep increased the total activity of chitinolytic enzymes from 2.9 to 3.6 μmol N-acetylglucosamine/g dry matter (DM) of rumen fluid per min, the chitin concentration from 6.3 to 7.2 mg/g DM of rumen fluid and the number of fungal zoospores from 8.1 to 10.9 · 10(5) cells/ml rumen fluid. All examined indices showed diurnal variations. Ciliate population density was highest immediately prior to feeding and lowest at 4 h thereafter. The opposite effects were observed for the numbers of fungal zoospores, the chitin concentration and chitinolytic activity. Furthermore, it was found that chitin from zoospores may account for up to 95% of total microbial chitin in the rumen fluid of sheep. In summary, the examined ciliate species showed the ability of chitin degradation as well as a positive influence on the development of the ruminal fungal population.

Distribution of the Entodiniomorphid ciliate Troglocorys cava Tokiwa, Modrý, Ito, Pomajbíková, Petrželková, & Imai, 2010, (Entodiniomorphida: Blepharocorythidae) in wild and captive chimpanzees

Czech Academy of Sciences Publication Activity Database

Pomajbíková, K.; Petrželková, Klára Judita; Petrášová, J.; Profousová, Ilona; Kalousová, Barbora; Jirků, Miloslav; Sá, R. M.; Modrý, David

2012-01-01

Roč. 59, č. 1 (2012), s. 97-99 ISSN 1066-5234 R&D Projects: GA ČR GA524/06/0264; GA ČR GA206/09/0927; GA AV ČR KJB600930615 Institutional research plan: CEZ:AV0Z60930519; CEZ:AV0Z60220518 Keywords : chimpanzees * Entodiniomorphida * intestinal ciliates * prevalence * Troglocorys cava Subject RIV: EG - Zoology Impact factor: 2.162, year: 2012

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.

Drug resistance in the sexually transmitted protozoan Trichomonas vaginalis

Institute of Scientific and Technical Information of China (English)

REBECCA L DUNNE; LINDA A DUNN; PETER UPCROFT; PETER J O'DONOGHUE; JACQUELINE A UPCROFT

2003-01-01

Trichomoniasis is the most common, sexually transmitted infection. It is caused by the flagellated protozoan parasite Trichomonas vaginalis. Symptoms include vaginitis and infections have been associated with preterm delivery, low birth weight and increased infant mortality, as well as predisposing to HIV/AIDS and cervical cancer. Trichomoniasis has the highest prevalence and incidence of any sexually transmitted infection. The 5-nitroimidazole drugs, of which metronidazole is the most prescribed, are the only approved,effective drugs to treat trichomoniasis. Resistance against metronidazole is frequently reported and crossresistance among the family of 5-nitroimidazole drugs is common, leaving no alternative for treatment, with some cases remaining unresolved. The mechanism of metronidazole resistance in T. vaginalis from treatment failures is not well understood, unlike resistance which is developed in the laboratory under increasing metronidazole pressure. In the latter situation, hydrogenosomal function which is involved in activation of the prodrug, metronidazole, is down-regulated. Reversion to sensitivity is incomplete after removal of drug pressure in the highly resistant parasites while clinically resistant strains, so far analysed, maintain their resistance levels in the absence of drug pressure. Although anaerobic resistance has been regarded as a laboratory induced phenomenon, it clearly has been demonstrated in clinical isolates. Pursuit of both approaches will allow dissection of the underlying mechanisms. Many alternative drugs and treatments have been tested in vivo in cases of refractory trichomoniasis, as well as in vitro with some successes including the broad spectrum anti-parasitic drug nitazoxanide. Drug resistance incidence in T. vaginalis appears to be on the increase and improved surveillance of treatment failures is urged.

De novo arachidonic acid synthesis in Perkinsus marinus, a protozoan parasite of the eastern oyster Crassostrea virginica.

Science.gov (United States)

Chu, Fu-Lin E; Lund, Eric; Soudant, Philippe; Harvey, Ellen

2002-02-01

The capability of synthesizing fatty acids de novo in the meront stage of the oyster protozoan parasite, Perkinsus marinus, was investigated employing stable-isotope-labeled precursors (1,2 13C-acetate and palmitic-d(31) acid). Fatty acid methyl esters derived from 1,2 13C-acetate and palmitic-d(31) acid were analyzed using gas chromatography/mass spectrometry and gas chromatography/flame ionization detection. Results revealed that in vitro cultured P. marinus meronts utilized 13C-acetate to synthesize a range of saturated and unsaturated fatty acids. The saturated fatty acids 14:0, 16:0, 18:0, 20:0, 22:0, 24:0 and the unsaturated fatty acids, 18:1(n-9), 18:2(n-6), 20:1(n-9), 20:2(n-6), 20:2(n-9), 20:3(n-6), 20:4(n-6) were found to contain 13C, after 7, 14, and 21 days incubation with the precursor. This indicates that meronts can synthesize fatty acid de novo using acetate as a substrate. Meronts efficiently elongated 16:0-d(31) to 18:0, 20:0, 22:0, 24:0, but desaturation activity was limited, after 7 and 14 days cultivation. Only a small quantity of 18:1-d(29) was detected. This suggests that meronts cannot directly convert exogenous palmitic acid or its products of elongation to unsaturated counterparts. The ability to synthesize 20:4(n-6) from acetate is particularly interesting. No parasitic protozoan has been reported to be capable of synthesizing long chain essential fatty acids, such as 20:4(n-6) de novo. Future study will be directed to determine whether the observed in vitro activities indeed reflect the in vivo activities, when meronts are associated with the host.

Identification, Localization, and Functional Implications of the Microdomain-Forming Stomatin Family in the Ciliated Protozoan Paramecium tetraurelia

Science.gov (United States)

Stuermer, Claudia A. O.; Plattner, Helmut

2013-01-01

The SPFH protein superfamily is assumed to occur universally in eukaryotes, but information from protozoa is scarce. In the Paramecium genome, we found only Stomatins, 20 paralogs grouped in 8 families, STO1 to STO8. According to cDNA analysis, all are expressed, and molecular modeling shows the typical SPFH domain structure for all subgroups. For further analysis we used family-specific sequences for fluorescence and immunogold labeling, gene silencing, and functional tests. With all family members tested, we found a patchy localization at/near the cell surface and on vesicles. The Sto1p and Sto4p families are also associated with the contractile vacuole complex. Sto4p also makes puncta on some food vacuoles and is abundant on vesicles recycling from the release site of spent food vacuoles to the site of nascent food vacuole formation. Silencing of the STO1 family reduces mechanosensitivity (ciliary reversal upon touching an obstacle), thus suggesting relevance for positioning of mechanosensitive channels in the plasmalemma. Silencing of STO4 members increases pulsation frequency of the contractile vacuole complex and reduces phagocytotic activity of Paramecium cells. In summary, Sto1p and Sto4p members seem to be involved in positioning specific superficial and intracellular microdomain-based membrane components whose functions may depend on mechanosensation (extracellular stimuli and internal osmotic pressure). PMID:23376944

Effect of far-UV and near-UV radiation on the cell surface charge of the protozoan Tritrichomonas foetus

Energy Technology Data Exchange (ETDEWEB)

Silva Filho, F C; Elias, C A; Souza, W de

1986-05-01

Cell electrophoresis was used to detect the effect of far-UV or near-UV radiation on the cell surface charge of the pathogenic protozoan Tritrichomonas foetus. Either far-UV or near-UV radiation interfered with the surface charge of T. foetus at fluences which inhibited cell growth by 50%. Both UV-radiations induced a significant decrease on surface charge of T. foetus, as evaluated by measurement of its electrophoretic mobility (EPM). Determinations of EPM of protozoa in solution of low ionic strength indicated that the decrease in the EPM induced by far-UV is much less pronounced that that observed for near-UV or control cells.

Effect of far-UV and near-UV radiation on the cell surface charge of the protozoan Tritrichomonas foetus

International Nuclear Information System (INIS)

Silva Filho, F.C.; Elias, C.A.; Souza, W. de

1986-01-01

Cell electrophoresis was used to detect the effect of far-UV or near-UV radiation on the cell surface charge of the pathogenic protozoan Tritrichomonas foetus. Either far-UV or near-UV radiation interfered with the surface charge of T. foetus at fluences which inhibited cell growth by 50%. Both UV-radiations induced a significant decrease on surface charge of T. foetus, as evaluated by measurement of its electrophoretic mobility (EPM). Determinations of EPM of protozoa in solution of low ionic strength indicated that the decrease in the EPM induced by far-UV is much less pronounced that that observed for near-UV or control cells. (author)

Global Distribution, Public Health and Clinical Impact of the Protozoan Pathogen Cryptosporidium

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Lorenza Putignani

2010-01-01

Full Text Available Cryptosporidium spp. are coccidians, oocysts-forming apicomplexan protozoa, which complete their life cycle both in humans and animals, through zoonotic and anthroponotic transmission, causing cryptosporidiosis. The global burden of this disease is still underascertained, due to a conundrum transmission modality, only partially unveiled, and on a plethora of detection systems still inadequate or only partially applied for worldwide surveillance. In children, cryptosporidiosis encumber is even less recorded and often misidentified due to physiological reasons such as early-age unpaired immunological response. Furthermore, malnutrition in underdeveloped countries or clinical underestimation of protozoan etiology in developed countries contribute to the underestimation of the worldwide burden. Principal key indicators of the parasite distribution were associated to environmental (e.g., geographic and temporal clusters, etc. and host determinants of the infection (e.g., age, immunological status, travels, community behaviours. The distribution was geographically mapped to provide an updated picture of the global parasite ecosystems. The present paper aims to provide, by a critical analysis of existing literature, a link between observational epidemiological records and new insights on public health, and diagnostic and clinical impact of cryptosporidiosis.

Temporal variability of the microbial food web (viruses to ciliates under the influence of the Black Sea Water inflow (N. Aegean, E. Mediterranean

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A. GIANNAKOUROU

2014-12-01

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.

Prediction of acute toxicity of phenol derivatives using multiple linear regression approach for Tetrahymena pyriformis contaminant identification in a median-size database.

Science.gov (United States)

Dieguez-Santana, Karel; Pham-The, Hai; Villegas-Aguilar, Pedro J; Le-Thi-Thu, Huong; Castillo-Garit, Juan A; Casañola-Martin, Gerardo M

2016-12-01

In this article, the modeling of inhibitory grown activity against Tetrahymena pyriformis is described. The 0-2D Dragon descriptors based on structural aspects to gain some knowledge of factors influencing aquatic toxicity are mainly used. Besides, it is done by some enlarged data of phenol derivatives described for the first time and composed of 358 chemicals. It overcomes the previous datasets with about one hundred compounds. Moreover, the results of the model evaluation by the parameters in the training, prediction and validation give adequate results comparable with those of the previous works. The more influential descriptors included in the model are: X3A, MWC02, MWC10 and piPC03 with positive contributions to the dependent variable; and MWC09, piPC02 and TPC with negative contributions. In a next step, a median-size database of nearly 8000 phenolic compounds extracted from ChEMBL was evaluated with the quantitative-structure toxicity relationship (QSTR) model developed providing some clues (SARs) for identification of ecotoxicological compounds. The outcome of this report is very useful to screen chemical databases for finding the compounds responsible of aquatic contamination in the biomarker used in the current work. Copyright © 2016 Elsevier Ltd. All rights reserved.

An overview of diseases in fish hatcheries and nurseries

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Md. Ali Reza Faruk

2017-12-01

Full Text Available Quality and healthy fish seed is the prerequisite for sustainable aquaculture. A major challenge to the expansion of aquaculture production is the outbreak of diseases. Disease induced mortality is a serious issue for the fish seed industry. The immature immune system in fish makes the early developmental stages more susceptible to infectious diseases. Common fish diseases in hatcheries and in early rearing systems are caused by protozoan, ciliates, myxosporodians, worms, opportunistic bacteria and fungi. Production of healthy fish seed and survivality depends on the proper health management, maintenance of good water quality, proper nutrition and application of biosecurity measures. The paper highlighted the different types of diseases, causative agents and their prevention and control measures in fish hatcheries and nurseries. [Fundam Appl Agric 2017; 2(3.000: 311-316

Diversity and distribution of parasites from potentially cultured freshwater fish in Nakhon Si Thammarat

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Supamattaya, K.

2005-02-01

Full Text Available Twenty-one species from 16 genera of potentially cultured freshwater fish were examined for external and internal parasites. Ten individuals of each fish species were sampled from various places in Nakhon Si Thammarat. Eight groups, 72 species were identified and the majority was external (52 spp.. The parasites found were ciliated protozoan (2 spp., myxozoan (2 spp., monogenean (44 spp., digenean (7 spp., cestode (6 spp., nematode (6 spp., acanthocephalan (2 spp. and crustacean (3 spp.. Monogenean was regarded as a major group of parasites with 44 species. Dactylogyrus (Monogenea had the highest number of species (12 spp., whereas Trichodina pediculus (Ciliophora was the most widely distributed species observed from at least 7 fish species (7 families. Most of the parasites (72 % found in this study were specific to their host species.

Discovery of a new hypotrich ciliate from petroleum contaminated soil.

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Santosh Kumar

Full Text Available Pollution after oil spill represents extreme habitat for survival and is a major concern for loss of species diversity in the affected area. In this study, we investigated soil samples collected from a petrochemical industry, Ulsan, South Korea. The soil was in the phase of recovery from the contamination of crude oil spill. Detailed investigation, based on morphology, ontogenesis, and molecular phylogenetic methods, resulted in discovery of a novel hypotrich ciliate, i.e., Metasterkiella koreana n. gen., n. sp., which is morphologically characterized by a semirigid body, undulating membranes in Oxytricha pattern, 18 frontal-ventral-transverse cirri with cirrus V/3 placed posteriorly, one right and one left row of marginal cirri, four dorsal kineties, two dorsomarginal rows, and caudal cirri at the end of dorsal kineties 1, 2, and 4. Interestingly, during ontogenesis, formation of three common anlagen for the proter and the opisthe and involvement of cirrus V/3 in anlagen formation was observed. The dorsal ontogenesis was typical of oxytrichids, i.e., simple fragmentation of dorsal kinety 3 and formation of dorsomarginal rows close to the right marginal row. The new species was found to be similar with Sterkiella subtropica, except for some minor differences in morphometry, and at gene level with only one base pair difference. In phylogenetic analyses, based on SSU rRNA gene sequence, M. koreana cluster in a clade away from Sterkiella species, which could be explained by the differences in the morphogenetic pattern between these two genera. It is proposed that S. subtropica probably belongs to Metasterkiella; however, we do not perform changes and wait for the reinvestigation of its morphogenetic pattern.

IMPORTANT PROTOZOAN PARASITES IN INDONESIA

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Srisasi Gandahusada

2012-09-01

Full Text Available The most important protozoan parasites in Indonesia are the malaria parasites, Toxoplasma gondii and Entamoeba histolytica. After the second world war the residual insecticides and effective antimalarial drugs were used in the control of malaria. After development of resistance among mosquitoes to insecticides, the Malaria Control Programme was switched over to the Malaria Eradication Programme. Malaria incidence dropped heavily. However, due to the quick development of vector resistance and financial limitations, malaria came back and so did the Malaria Control Programme. P. falciparum and P.vivax are the most common species in Indonesia. Important vectors are An. sundaicus, An. aconitus, An. maculatus, An. hyrcanus group, An. balabacensis, An. farauti etc. An. sundaicus and An. aconitus have developed resistance to DDT and Dieldrin in Java. In 1959 the Malaria Eradication Programme was started in Java, Bali and Lampung. In 1965 the API dropped to 0,15 per thousand. From 1966 onwards malaria transmission was on the increase, because spraying activities were slowed down, but dropped again from 1974 onwards by occasional residual house spraying with DDT or Fenitrothion, malaria surveillance and treatment of malaria cases, resulting in an API of 0.18 per thousand in 1987. At present malaria is not transmitted in Jakarta and in capitals of the provinces and kabupatens, except in Irian Jaya, Nusa Tenggara Timur and one or two other provinces, but it still exists in rural areas. The distribution of chloroquine resistant P.falciparum is patchy. Resistance is at the RI, RII and RUT levels. The main problems of malaria control are : the increasing development of resistance of the vector to insecticides, the change of An.aconitus from zoophili to anthropophili and from indoor to outdoor biting, the increasing resistance of P.falciparum to chloroquine, the shortage of skilled manpower and limitation of budget. In Indonesia many newborns with congenital

Global analysis of gene expression in response to L-Cysteine deprivation in the anaerobic protozoan parasite Entamoeba histolytica

Science.gov (United States)

2011-01-01

Background Entamoeba histolytica, an enteric protozoan parasite, causes amebic colitis and extra intestinal abscesses in millions of inhabitants of endemic areas. E. histolytica completely lacks glutathione metabolism but possesses L-cysteine as the principle low molecular weight thiol. L-Cysteine is essential for the structure, stability, and various protein functions, including catalysis, electron transfer, redox regulation, nitrogen fixation, and sensing for regulatory processes. Recently, we demonstrated that in E. histolytica, L-cysteine regulates various metabolic pathways including energy, amino acid, and phospholipid metabolism. Results In this study, employing custom-made Affymetrix microarrays, we performed time course (3, 6, 12, 24, and 48 h) gene expression analysis upon L-cysteine deprivation. We identified that out of 9,327 genes represented on the array, 290 genes encoding proteins with functions in metabolism, signalling, DNA/RNA regulation, electron transport, stress response, membrane transport, vesicular trafficking/secretion, and cytoskeleton were differentially expressed (≥3 fold) at one or more time points upon L-cysteine deprivation. Approximately 60% of these modulated genes encoded proteins of no known function and annotated as hypothetical proteins. We also attempted further functional analysis of some of the most highly modulated genes by L-cysteine depletion. Conclusions To our surprise, L-cysteine depletion caused only limited changes in the expression of genes involved in sulfur-containing amino acid metabolism and oxidative stress defense. In contrast, we observed significant changes in the expression of several genes encoding iron sulfur flavoproteins, a major facilitator super-family transporter, regulator of nonsense transcripts, NADPH-dependent oxido-reductase, short chain dehydrogenase, acetyltransferases, and various other genes involved in diverse cellular functions. This study represents the first genome-wide analysis of

Global analysis of gene expression in response to L-Cysteine deprivation in the anaerobic protozoan parasite Entamoeba histolytica

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Jeelani Ghulam

2011-05-01

Full Text Available Abstract Background Entamoeba histolytica, an enteric protozoan parasite, causes amebic colitis and extra intestinal abscesses in millions of inhabitants of endemic areas. E. histolytica completely lacks glutathione metabolism but possesses L-cysteine as the principle low molecular weight thiol. L-Cysteine is essential for the structure, stability, and various protein functions, including catalysis, electron transfer, redox regulation, nitrogen fixation, and sensing for regulatory processes. Recently, we demonstrated that in E. histolytica, L-cysteine regulates various metabolic pathways including energy, amino acid, and phospholipid metabolism. Results In this study, employing custom-made Affymetrix microarrays, we performed time course (3, 6, 12, 24, and 48 h gene expression analysis upon L-cysteine deprivation. We identified that out of 9,327 genes represented on the array, 290 genes encoding proteins with functions in metabolism, signalling, DNA/RNA regulation, electron transport, stress response, membrane transport, vesicular trafficking/secretion, and cytoskeleton were differentially expressed (≥3 fold at one or more time points upon L-cysteine deprivation. Approximately 60% of these modulated genes encoded proteins of no known function and annotated as hypothetical proteins. We also attempted further functional analysis of some of the most highly modulated genes by L-cysteine depletion. Conclusions To our surprise, L-cysteine depletion caused only limited changes in the expression of genes involved in sulfur-containing amino acid metabolism and oxidative stress defense. In contrast, we observed significant changes in the expression of several genes encoding iron sulfur flavoproteins, a major facilitator super-family transporter, regulator of nonsense transcripts, NADPH-dependent oxido-reductase, short chain dehydrogenase, acetyltransferases, and various other genes involved in diverse cellular functions. This study represents the first

Dysfunctions at human intestinal barrier by water-borne protozoan parasites: lessons from cultured human fully differentiated colon cancer cell lines.

Science.gov (United States)

Liévin-Le Moal, Vanessa

2013-06-01

Some water-borne protozoan parasites induce diseases through their membrane-associated functional structures and virulence factors that hijack the host cellular molecules and signalling pathways leading to structural and functional lesions in the intestinal barrier. In this Microreview we analyse the insights on the mechanisms of pathogenesis of Entamoeba intestinalis, Giardia and Cryptosporidium observed in the human colon carcinoma fully differentiated colon cancer cell lines, cell subpopulations and clones expressing the structural and functional characteristics of highly specialized fully differentiated epithelial cells lining the intestinal epithelium and mimicking structurally and functionally an intestinal barrier. © 2013 John Wiley & Sons Ltd.

Preliminary report on the development of some indices of relative nutritive value (RNV) of cereal and legume samples, applicable in the early generations of selection

International Nuclear Information System (INIS)

Kaul, A.K.; Niemann, E.G.

1975-01-01

Rapid screening methods for biuret nitrogen determination and fluorometric lysine estimation are described. While the biuret method has been found to be suitable for early generation screening for peptide nitrogen determination, fluorescence estimation of dansylated grain meal could be taken as a good index of available lysine in cereal and legume samples. The necessity of rapid and inexpensive tests for the determination of Relative Nutritive Value (RNV) in the advance generations of screening, is discussed. Preliminary data available on two such tests, utilizing protozoan Tetrahymena pyriformis W. and flour beetle Tribolium confusum Duval, indicated promise. Both techniques were tried on different cereal and legume samples. The relative lethality of beetle larvae and their nitrogen retention were taken as indices of RNV in legumes. Larval Nitrogen Retention Index (LNRI) of cereal samples was found to be dependent both on nitrogen content and on protein quality. It was concluded that both these organisms need to be further investigated for their potential as test animals for RNV determination in the advance segregating populations. (author)

The novel measuring method for screening and assessing chromium content in clothes and shoes materials

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Salerno-Kochan, R.

2017-10-01

The aim of this paper is to propose the bioindicative measuring method for screening and assessing the safety of textile and leather materials in relation to chemical threats. This method is based on toxicological assay in which Tetrahymena pyriformis, unicellular organism belonging to protozoans, is used as a test organism. For the realization of the research goal the sensitivity threshold of test organisms to chromium(VI) solutions was identified. The changes in cell development of test organisms in chromium solutions were registered by colorimetric measurements in the presence of alamarBlue® cell viability reagent. Empirical data enabled to fit logistic curves on the base of which the level of chromium toxicity was estimated. In the second step, harmfulness of aqueous extracts obtained from textile and leather samples containing chromium in relation to test organisms was evaluated. The performed research confirmed the high efficiency of the proposed method in screening and assessing chromium content in clothes and shoes materials and showed possibilities of using it in safety assessment of products with regard to chemical risks.

Purification and crystallization of human Cu/Zn superoxide dismutase recombinantly produced in the protozoan Leishmania tarentolae

International Nuclear Information System (INIS)

Gazdag, Emerich Mihai; Cirstea, Ion Cristian; Breitling, Reinhard; Lukeš, Julius; Blankenfeldt, Wulf; Alexandrov, Kirill

2010-01-01

The structures of two new crystal forms of human Cu/Zn superoxide dismutase produced in the eukaryotic expression host L. tarentolae are reported. The rapid and inexpensive production of high-quality eukaryotic proteins in recombinant form still remains a challenge in structural biology. Here, a protein-expression system based on the protozoan Leishmania tarentolae was used to produce human Cu/Zn superoxide dismutase (SOD1) in recombinant form. Sequential integration of the SOD1 expression cassettes was demonstrated to lead to a linear increase in expression levels to up to 30 mg per litre. Chromatographic purification resulted in 90% pure recombinant protein, with a final yield of 6.5 mg per litre of culture. The protein was crystallized and the structures of two new crystal forms were determined. These results demonstrate the suitability of the L. tarentolae expression system for structural research

Assembly-history dynamics of a pitcher-plant protozoan community in experimental microcosms.

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Kohmei Kadowaki

Full Text Available History drives community assembly through differences both in density (density effects and in the sequence in which species arrive (sequence effects. Density effects arise from predictable population dynamics, which are free of history, but sequence effects are due to a density-free mechanism, arising solely from the order and timing of immigration events. Few studies have determined how components of immigration history (timing, number of individuals, frequency alter local dynamics to determine community assembly, beyond addressing when immigration history produces historically contingent assembly.We varied density and sequence effects independently in a two-way factorial design to follow community assembly in a three-species aquatic protozoan community. A superior competitor, Colpoda steinii, mediated alternative community states; early arrival or high introduction density allowed this species to outcompete or suppress the other competitors (Poterioochromonas malhamensis and Eimeriidae gen. sp.. Multivariate analysis showed that density effects caused greater variation in community states, whereas sequence effects altered the mean community composition.A significant interaction between density and sequence effects suggests that we should refine our understanding of priority effects. These results highlight a practical need to understand not only the "ingredients" (species in ecological communities but their "recipes" as well.

Cell chirality: its origin and roles in left-right asymmetric development.

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Inaki, Mikiko; Liu, Jingyang; Matsuno, Kenji

2016-12-19

An item is chiral if it cannot be superimposed on its mirror image. Most biological molecules are chiral. The homochirality of amino acids ensures that proteins are chiral, which is essential for their functions. Chirality also occurs at the whole-cell level, which was first studied mostly in ciliates, single-celled protozoans. Ciliates show chirality in their cortical structures, which is not determined by genetics, but by 'cortical inheritance'. These studies suggested that molecular chirality directs whole-cell chirality. Intriguingly, chirality in cellular structures and functions is also found in metazoans. In Drosophila, intrinsic cell chirality is observed in various left-right (LR) asymmetric tissues, and appears to be responsible for their LR asymmetric morphogenesis. In other invertebrates, such as snails and Caenorhabditis elegans, blastomere chirality is responsible for subsequent LR asymmetric development. Various cultured cells of vertebrates also show intrinsic chirality in their cellular behaviours and intracellular structural dynamics. Thus, cell chirality may be a general property of eukaryotic cells. In Drosophila, cell chirality drives the LR asymmetric development of individual organs, without establishing the LR axis of the whole embryo. Considering that organ-intrinsic LR asymmetry is also reported in vertebrates, this mechanism may contribute to LR asymmetric development across phyla.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Authors.

Cell chirality: its origin and roles in left–right asymmetric development

Science.gov (United States)

Inaki, Mikiko; Liu, Jingyang

2016-01-01

An item is chiral if it cannot be superimposed on its mirror image. Most biological molecules are chiral. The homochirality of amino acids ensures that proteins are chiral, which is essential for their functions. Chirality also occurs at the whole-cell level, which was first studied mostly in ciliates, single-celled protozoans. Ciliates show chirality in their cortical structures, which is not determined by genetics, but by ‘cortical inheritance’. These studies suggested that molecular chirality directs whole-cell chirality. Intriguingly, chirality in cellular structures and functions is also found in metazoans. In Drosophila, intrinsic cell chirality is observed in various left–right (LR) asymmetric tissues, and appears to be responsible for their LR asymmetric morphogenesis. In other invertebrates, such as snails and Caenorhabditis elegans, blastomere chirality is responsible for subsequent LR asymmetric development. Various cultured cells of vertebrates also show intrinsic chirality in their cellular behaviours and intracellular structural dynamics. Thus, cell chirality may be a general property of eukaryotic cells. In Drosophila, cell chirality drives the LR asymmetric development of individual organs, without establishing the LR axis of the whole embryo. Considering that organ-intrinsic LR asymmetry is also reported in vertebrates, this mechanism may contribute to LR asymmetric development across phyla. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’. PMID:27821533

Influence of water chemistry on the distribution of an acidophilic protozoan in an acid mine drainage system at the abandoned Green Valley coal mine, Indiana, USA

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Brake, S.S.; Dannelly, H.K.; Connors, K.A.; Hasiotis, S.T. [Indiana State University, Terre Haute, IN (United States). Dept. of Geography Geology & Anthropology

2001-07-01

Euglena mutabilis, a benthic photosynthetic protozoan that intracellularly sequesters Fe, is variably abundant in the main effluent channel that contains acid mine drainage (AMD) discharging from the Green Valley coal mine site in western Indiana. Samples of effluent (pH 3.0-4.6) taken from the main channel and samples of contaminated stream water (pH 3.3 to 8.0) collected from an adjacent stream were analyzed to evaluate the influence of water chemistry on E. mutabilis distribution. E. mutabilis communities were restricted to areas containing unmixed effluent with the thickest (up to 3 mm) benthic communities residing in effluent containing high concentrations of total Fe (up to 12110 mg/l), SO{sub 4}(up to 2940 mg/l), Al (up to 1846 mg/l), and Cl (up to 629 mg/l). Communities were also present, but much less abundant, in areas with effluent containing lower concentrations of these same constituents. In effluent where SO{sub 4} was most highly concentrated, E. mutabilis was largely absent, suggesting that extremely high concentrations of SO{sub 4} may have an adverse effect on this potentially beneficial Fe-mediating, acidophilic protozoan.

A description of Apocarchesium rosettum n. gen., n. sp. and a redescription of Ophrydium eichornii Ehrenberg, 1838, two freshwater peritrichous ciliates from Japan.

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Ji, Daode; Kusuoka, Yasushi

2009-01-01

This paper includes the proposal of a new genus for a new species of peritrichous ciliate, Apocarchesium rosettum n. gen., n. sp., as well as the first description by modern techniques of another peritrich, Ophrydium eichornii Ehrenberg, 1838. The genus Apocarchesium is separated from the related genus Carchesium by the appearance of the stalk and the arrangement of zooids, and diagnosed as follows: colonial vorticellid, with all zooids attached in rosette fashion to the tip of their common stalk, which is unbranched and contracts spirally; pellicle with parallel silverlines. The morphology, infraciliature, and silverline system of both species were investigated by observation in vivo and silver-staining methods.

Characteristics of the digestive vacuole membrane of the alga-bearing ciliate Paramecium bursaria.

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Kodama, Yuuki; Fujishima, Masahiro

2012-07-01

Cells of the ciliate Paramecium bursaria harbor symbiotic Chlorella spp. in their cytoplasm. To establish endosymbiosis with alga-free P. bursaria, symbiotic algae must leave the digestive vacuole (DV) to appear in the cytoplasm by budding of the DV membrane. This budding was induced not only by intact algae but also by boiled or fixed algae. However, this budding was not induced when food bacteria or India ink were ingested into the DVs. These results raise the possibility that P. bursaria can recognize sizes of the contents in the DVs. To elucidate this possibility, microbeads with various diameters were mixed with alga-free P. bursaria and traced their fate. Microbeads with 0.20μm diameter did not induce budding of the DVs. Microbeads with 0.80μm diameter produced DVs of 5-10μm diameter at 3min after mixing; then the DVs fragmented and became vacuoles of 2-5μm diameter until 3h after mixing. Each microbead with a diameter larger than 3.00μm induced budding similarly to symbiotic Chlorella. These observations reveal that induction of DV budding depends on the size of the contents in the DVs. Dynasore, a dynamin inhibitor, greatly inhibited DV budding, suggesting that dynamin might be involved in DV budding. Copyright © 2011 Elsevier GmbH. All rights reserved.

Epidemiology and geographical distribution of enteric protozoan infections in Sydney, Australia

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Stephanie Fletcher

2014-07-01

Full Text Available Background. Enteric protozoa are associated with diarrhoeal illnesses in humans; however there are no recent studies on their epidemiology and geographical distribution in Australia. This study describes the epidemiology of enteric protozoa in the state of New South Wales and incorporates spatial analysis to describe their distribution. Design and methods. Laboratory and clinical records from four public hospitals in Sydney for 910 patients, who tested positive for enteric protozoa over the period January 2007-December 2010, were identified, examined and analysed. We selected 580 cases which had residence post code data available, enabling us to examine the geographic distribution of patients, and reviewed the clinical data of 252 patients to examine possible links between protozoa, demographic and clinical features. Results. Frequently detected protozoa were Blastocystis spp. (57%, Giardia intestinalis (27% and Dientamoeba fragilis (12%. The age distribution showed that the prevalence of protozoa decreased with age up to 24 years but increasing with age from 25 years onwards. The geographic provenance of the patients indicates that the majority of cases of Blastocystis (53.1% are clustered in and around the Sydney City Business District, while pockets of giardiasis were identified in regional/rural areas. The distribution of cases suggests higher risk of protozoan infection may exist for some communities. Conclusions. These findings provide useful information for policy makers to design and tailor interventions to target high risk communities. Follow-up investigation into the risk factors for giardiasis in regional/rural area is needed.

First report of scuticociliatosis caused by Uronema sp. in ornamental reef fish imported into Brazil

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Pedro Henrique Magalhães Cardoso

Full Text Available Abstract Scuticociliatosis, which is caused by an opportunistic ciliate protozoan, is responsible for significant economic losses in marine ornamental fish. This study reports the occurrence of Uronema sp., which was found to be parasitizing three species of marine reef fish imported into Brazil and maintained in quarantine: Vanderbilt’s Chromis (Chromis vanderbilti, blue-green damselfish (Chromis viridis, and sea goldie (Pseudanthias squamipinnis. During the quarantine period, some fish presented with behavioral disorders and hemorrhages and ulcerative lesions on the body surface. Histopathological analysis showed hemorrhages, inflammation comprising mononuclear and granular cells in the skeletal muscle, and necrosis of the skin and the secondary lamellae of the gills, and parasites were also observed in the renal capsule. The absence of transboundary measures available to prevent the occurrence of ornamental fish diseases is also discussed.

The first suicides: a legacy inherited by parasitic protozoans from prokaryote ancestors.

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Taylor-Brown, Emilie; Hurd, Hilary

2013-04-18

It is more than 25 years since the first report that a protozoan parasite could die by a process resulting in a morphological phenotype akin to apoptosis. Since then these phenotypes have been observed in many unicellular parasites, including trypanosomatids and apicomplexans, and experimental evidence concerning the molecular pathways that are involved is growing. These observations support the view that this form of programmed cell death is an ancient one that predates the evolution of multicellularity. Here we review various hypotheses that attempt to explain the origin of apoptosis, and look for support for these hypotheses amongst the parasitic protists as, with the exception of yeast, most of the work on death mechanisms in unicellular organisms has focussed on them. We examine the role that addiction modules may have played in the original eukaryote cell and the part played by mitochondria in the execution of present day cells, looking for examples from Leishmania spp. Trypanosoma spp. and Plasmodium spp. In addition, the expanding knowledge of proteases, nucleases and other molecules acting in protist execution pathways has enabled comparisons to be made with extant Archaea and bacteria and with biochemical pathways that evolved in metazoans. These comparisons lend support to the original sin hypothesis but also suggest that present-day death pathways may have had multifaceted beginnings.

Protozoan and metazoan parasites of Nile tilapia Oreochromis niloticus cultured in Brazil

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Wanderson Pantoja MF

2012-04-01

Full Text Available Objective. This study describes the parasitic fauna and relative condition factor (Kn in Nile tilapia Oreochromis niloticus L. (Cichlidae from fish farms in the State of Amapá. Material and methods. 123 fish from four fish farms in the state of Amapá, Brazil were necropsied for parasitological and Kn analysis. Results. 64.2% of the examined fish, had the gills infected with Cichlidogyrus tilapiae Paperna, 1960 (Monogenoidea: Dactylogyridae; Ichthyophthirius multifiliis Fouquet, 1876 (Protozoa: Ciliophora, Trichodina Ehrenberg, 1830 and Paratrichodina africana Kazubski & El-Tantawy, 1986 (Protozoa: Trichodinidae. The highest prevalence found corresponded to Monogenoidea C. tilapiae while the lowest corresponded to Trichodinidae. However, I. multifiliis was the parasite that presented the greatest intensity and abundance. The differences found in the infection rates of the different fish farms due to causes further discussed. The parasitism did not influence the relative condition factor (Kn of fish. This was the first record of P. africana in Brazil and occurred in the Eastern Amazon. Conclusions. In Brazil, Lamproglena sp. is an emerging parasite in the Southern and Southeastern regions, but this crustacean was not found in the Nile tilapia in the State of Amapá. The parasitic infections in Nile tilapia farmed in Brazil are caused by protozoan, monogenoidea, crustacea and digenea species, and the regional differences on their prevalence and intensity rates are discussed in this study.

Dicty_cDB: SLJ818 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available its) Value N AF312775 |AF312775.1 Tetrahymena thermophila macronuclear immobilization antigen LD (SerLD) mRN...Y9928, primer: M13 forward, sequence 1. 30 0.014 4 AF312772 |AF312772.1 Tetrahymena thermophila macronuclear immobilization...r RE70748 full insert cDNA. 42 0.096 2 AF312771 |AF312771.1 Tetrahymena thermophila macronuclear immobilization...mena thermophila macronuclear immobilization antigen LA (SerLA) mRNA, complete cds. 30 0.12 3 AC116673 |AC11

NCBI nr-aa BLAST: CBRC-BTAU-01-2897 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-BTAU-01-2897 ref|YP_740836.1| NADH dehydrogenase subunit 5 [Tetrahymena pigmento...sa] gb|ABI51745.1| NADH dehydrogenase subunit 5 [Tetrahymena pigmentosa] YP_740836.1 0.019 21% ...

Community of protozoans and metazoans parasitizing Auchenipterus nuchalis (Auchenipteridae, a catfish from the Brazilian Amazon

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Marcos Tavares Dias

2017-05-01

Full Text Available This paper describes the first study on parasite diversity in Auchenipterus nuchalis Spix & Agassiz, 1829 (Auchenipteridae. In 31 fish caught in a tributary of the Amazon River, 10,708 parasites were collected, such as Ichthyophthirius multifiliis, Piscinoodinium pilullare, Cosmetocleithrum striatuli, metacercariae of Posthodiplostomum sp, and larvae and adults of Procamallanus (Spirocamallanus inopinatus. These parasite species showed aggregated dispersion, except for C. striatuli, which had a uniform dispersion. The component community of parasites showed a low Brillouin diversity (0.67 ± 0.27, low species richness (3.5 ± 0.8 and low evenness (0.43 ± 0.17, and it was characterized by the presence of species with high prevalence and abundance. Protozoan species were the prevalent parasites, which may be a consequence of the host’s mode of life, while the low presence of endoparasites in A. nuchalis suggests that this fish may occupy an intermediate trophic level in the food web. These data represent the first record of such parasite species for this host.

Metazoan-protozoan parasite co-infections and host body weight in St Kilda Soay sheep.

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Craig, B H; Tempest, L J; Pilkington, J G; Pemberton, J M

2008-04-01

For hundreds of years, the unmanaged Soay sheep population on St Kilda has survived despite enduring presumably deleterious co-infections of helminth, protozoan and arthropod parasites and intermittent periods of starvation. Important parasite taxa in young Soay sheep are strongyles (Trichostrongylus axei, Trichostrongylus vitrinus and Teladorsagia circumcincta), coccidia (11 Eimeria species) and keds (Melophagus ovinus) and in older animals, Teladorsagia circumcincta. In this research, associations between the intensity of different parasite taxa were investigated. Secondly, the intensities of different parasite taxa were tested for associations with variation in host weight, which is itself a determinant of over-winter survival in the host population. In lambs, the intensity of strongyle eggs was positively correlated with that of Nematodirus spp. eggs, while in yearlings and adults strongyle eggs and coccidia oocysts were positively correlated. In lambs and yearlings, of the parasite taxa tested, only strongyle eggs were significantly and negatively associated with host weight. However, in adult hosts, strongyles and coccidia were independently and negatively associated with host weight. These results are consistent with the idea that strongyles and coccidia are exerting independent selection on Soay sheep.

Effects of a radiosensitizer and radiation on the ciliated mucous membrane

International Nuclear Information System (INIS)

Albertsson, M.

1985-01-01

Fractionated irradiation (2 Gy/F, TD:2-20 Gy) in vivo on the ciliated epithelium of the rabbit's trachea, caused measurable physiological alternations ten consecutive days after completion of irradiation with an initial heightening of the ciliary activity after 2 and 4 Gy, followed by a dose-dependent decrease. On scanning electron microscopy-pictures, knobs were observed on the cilia with the number being related to the dose. The addition of misonidazole potentiated the effects described above, with an enhancement ratio ( physiologically) of 1.2 and an enhancement ratio (morphologically) of 1.6. Furthermore, administration of misonidazole to the rabbits caused an increased vascularity in the subepithelial layer of the trachea, directly correlated to an oedema in the same region. Single doses (2,2.5,5,10,15,20,25, and 30 Gy) were given to the trachea in vivo and daily investigation of the ciliary beating and morphologic examinations of the tissue were made for ten days. The ciliary activity showed a dose-dependent reduction of about 50% after 30 Gy. A development of damage, in relation to the dose, was observed in the cilia. The changes were blebs, swollen tips, bent and curved tips, and broken cilia clustered together. During in vitro irradiation with 10 Gy Single Dose, an increase of the ciliary activity to about 25 % of its original value was observed without any morphological changes, while in vivo irradiation and examinations during 10 days thereafter, showed three different phases, day 1-3: Stimulation phase, day 4-8: Damage-phase, day 9-10: Repair-phase. The ciliary epithelium offers an exceptional system for the study of early radiobiological effects, since mutual comparisons can be made between physiology and morphology. (Author)

GPSit: An automated method for evolutionary analysis of nonculturable ciliated microeukaryotes.

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Chen, Xiao; Wang, Yurui; Sheng, Yalan; Warren, Alan; Gao, Shan

2018-05-01

Microeukaryotes are among the most important components of the microbial food web in almost all aquatic and terrestrial ecosystems worldwide. In order to gain a better understanding their roles and functions in ecosystems, sequencing coupled with phylogenomic analyses of entire genomes or transcriptomes is increasingly used to reconstruct the evolutionary history and classification of these microeukaryotes and thus provide a more robust framework for determining their systematics and diversity. More importantly, phylogenomic research usually requires high levels of hands-on bioinformatics experience. Here, we propose an efficient automated method, "Guided Phylogenomic Search in trees" (GPSit), which starts from predicted protein sequences of newly sequenced species and a well-defined customized orthologous database. Compared with previous protocols, our method streamlines the entire workflow by integrating all essential and other optional operations. In so doing, the manual operation time for reconstructing phylogenetic relationships is reduced from days to several hours, compared to other methods. Furthermore, GPSit supports user-defined parameters in most steps and thus allows users to adapt it to their studies. The effectiveness of GPSit is demonstrated by incorporating available online data and new single-cell data of three nonculturable marine ciliates (Anteholosticha monilata, Deviata sp. and Diophrys scutum) under moderate sequencing coverage (~5×). Our results indicate that the former could reconstruct robust "deep" phylogenetic relationships while the latter reveals the presence of intermediate taxa in shallow relationships. Based on empirical phylogenomic data, we also used GPSit to evaluate the impact of different levels of missing data on two commonly used methods of phylogenetic analyses, maximum likelihood (ML) and Bayesian inference (BI) methods. We found that BI is less sensitive to missing data when fast-evolving sites are removed. © 2018 John

Propulsion of swimming microrobots inspired by metachronal waves in ciliates: from biology to material specifications

International Nuclear Information System (INIS)

Palagi, Stefano; Mazzolai, Barbara; Beccai, Lucia; Jager, Edwin WH

2013-01-01

The quest for swimming microrobots originates from possible applications in medicine, especially involving navigation in bodily fluids. Swimming microorganisms have become a source of inspiration because their propulsion mechanisms are effective in the low-Reynolds number regime. In this study, we address a propulsion mechanism inspired by metachronal waves, i.e. the spontaneous coordination of cilia leading to the fast swimming of ciliates. We analyse the biological mechanism (referring to its particular embodiment in Paramecium caudatum), and we investigate the contribution of its main features to the swimming performance, through a three-dimensional finite-elements model, in order to develop a simplified, yet effective artificial design. We propose a bioinspired propulsion mechanism for a swimming microrobot based on a continuous cylindrical electroactive surface exhibiting perpendicular wave deformations travelling longitudinally along its main axis. The simplified propulsion mechanism is conceived specifically for microrobots that embed a micro-actuation system capable of executing the bioinspired propulsion (self-propelled microrobots). Among the available electroactive polymers, we select polypyrrole as the possible actuation material and we assess it for this particular embodiment. The results are used to appoint target performance specifications for the development of improved or new electroactive materials to attain metachronal-waves-like propulsion. (paper)

Propulsion of swimming microrobots inspired by metachronal waves in ciliates: from biology to material specifications.

Science.gov (United States)

Palagi, Stefano; Jager, Edwin W H; Mazzolai, Barbara; Beccai, Lucia

2013-12-01

The quest for swimming microrobots originates from possible applications in medicine, especially involving navigation in bodily fluids. Swimming microorganisms have become a source of inspiration because their propulsion mechanisms are effective in the low-Reynolds number regime. In this study, we address a propulsion mechanism inspired by metachronal waves, i.e. the spontaneous coordination of cilia leading to the fast swimming of ciliates. We analyse the biological mechanism (referring to its particular embodiment in Paramecium caudatum), and we investigate the contribution of its main features to the swimming performance, through a three-dimensional finite-elements model, in order to develop a simplified, yet effective artificial design. We propose a bioinspired propulsion mechanism for a swimming microrobot based on a continuous cylindrical electroactive surface exhibiting perpendicular wave deformations travelling longitudinally along its main axis. The simplified propulsion mechanism is conceived specifically for microrobots that embed a micro-actuation system capable of executing the bioinspired propulsion (self-propelled microrobots). Among the available electroactive polymers, we select polypyrrole as the possible actuation material and we assess it for this particular embodiment. The results are used to appoint target performance specifications for the development of improved or new electroactive materials to attain metachronal-waves-like propulsion.

Mass spectrometric analysis of L-cysteine metabolism: physiological role and fate of L-cysteine in the enteric protozoan parasite Entamoeba histolytica.

Science.gov (United States)

Jeelani, Ghulam; Sato, Dan; Soga, Tomoyoshi; Watanabe, Haruo; Nozaki, Tomoyoshi

2014-11-04

L-cysteine is essential for virtually all living organisms, from bacteria to higher eukaryotes. Besides having a role in the synthesis of virtually all proteins and of taurine, cysteamine, glutathione, and other redox-regulating proteins, L-cysteine has important functions under anaerobic/microaerophilic conditions. In anaerobic or microaerophilic protozoan parasites, such as Entamoeba histolytica, L-cysteine has been implicated in growth, attachment, survival, and protection from oxidative stress. However, a specific role of this amino acid or related metabolic intermediates is not well understood. In this study, using stable-isotope-labeled L-cysteine and capillary electrophoresis-time of flight mass spectrometry, we investigated the metabolism of L-cysteine in E. histolytica. [U-(13)C3, (15)N]L-cysteine was rapidly metabolized into three unknown metabolites, besides L-cystine and L-alanine. These metabolites were identified as thiazolidine-4-carboxylic acid (T4C), 2-methyl thiazolidine-4-carboxylic acid (MT4C), and 2-ethyl-thiazolidine-4-carboxylic acid (ET4C), the condensation products of L-cysteine with aldehydes. We demonstrated that these 2-(R)-thiazolidine-4-carboxylic acids serve for storage of L-cysteine. Liberation of L-cysteine occurred when T4C was incubated with amebic lysates, suggesting enzymatic degradation of these L-cysteine derivatives. Furthermore, T4C and MT4C significantly enhanced trophozoite growth and reduced intracellular reactive oxygen species (ROS) levels when it was added to cultures, suggesting that 2-(R)-thiazolidine-4-carboxylic acids are involved in the defense against oxidative stress. Amebiasis is a human parasitic disease caused by the protozoan parasite Entamoeba histolytica. In this parasite, L-cysteine is the principal low-molecular-weight thiol and is assumed to play a significant role in supplying the amino acid during trophozoite invasion, particularly when the parasites move from the anaerobic intestinal lumen to highly

Evolutionary Cell Biology of Proteins from Protists to Humans and Plants.

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Plattner, Helmut

2018-03-01

During evolution, the cell as a fine-tuned machine had to undergo permanent adjustments to match changes in its environment, while "closed for repair work" was not possible. Evolution from protists (protozoa and unicellular algae) to multicellular organisms may have occurred in basically two lineages, Unikonta and Bikonta, culminating in mammals and angiosperms (flowering plants), respectively. Unicellular models for unikont evolution are myxamoebae (Dictyostelium) and increasingly also choanoflagellates, whereas for bikonts, ciliates are preferred models. Information accumulating from combined molecular database search and experimental verification allows new insights into evolutionary diversification and maintenance of genes/proteins from protozoa on, eventually with orthologs in bacteria. However, proteins have rarely been followed up systematically for maintenance or change of function or intracellular localization, acquirement of new domains, partial deletion (e.g. of subunits), and refunctionalization, etc. These aspects are discussed in this review, envisaging "evolutionary cell biology." Protozoan heritage is found for most important cellular structures and functions up to humans and flowering plants. Examples discussed include refunctionalization of voltage-dependent Ca 2+ channels in cilia and replacement by other types during evolution. Altogether components serving Ca 2+ signaling are very flexible throughout evolution, calmodulin being a most conservative example, in contrast to calcineurin whose catalytic subunit is lost in plants, whereas both subunits are maintained up to mammals for complex functions (immune defense and learning). Domain structure of R-type SNAREs differs in mono- and bikonta, as do Ca 2+ -dependent protein kinases. Unprecedented selective expansion of the subunit a which connects multimeric base piece and head parts (V0, V1) of H + -ATPase/pump may well reflect the intriguing vesicle trafficking system in ciliates, specifically in

Ecological impacts of umbrella effects of radiation on the individual members

International Nuclear Information System (INIS)

Doi, Masahiro; Kawaguchi, Isao

2007-01-01

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

Molecular evidence of the protozoan parasite Marteilia refringens in Crassostrea gigas and Crassostrea corteziensis from the Gulf of California

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José Manuel Grijalva-Chon

2015-09-01

Full Text Available The search for exotic pathogens related to the outbreaks and in surveillance samplings of the Mexican oyster farms, is a recent activity achieved by academic institutions and state committees for Aquatic Animal Health, with remarkable results. In samples of Crassostrea gigas collected through December 2009, January 2010 and November 2010, and of C. corteziensis in September 2011, the protozoan Marteilia refringens was detected for the first time in the Gulf of California. The carrier oysters were from cultures without abnormal mortality rates, whereby, the use of histology, in situ hybridization and transmission electron microscopy studies are necessary to determine if M. refringens has become established in the Gulf of California oyster cultures. Detection of M. refringens is of great concern to the global oyster farming industry.

NCBI nr-aa BLAST: CBRC-XTRO-01-2527 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-XTRO-01-2527 ref|XP_001008699.1| H1 immobilization antigen, putative [Tetrahym...ena thermophila SB210] gb|EAR88454.1| H1 immobilization antigen, putative [Tetrahymena thermophila SB210] XP_001008699.1 4.2 29% ...

NCBI nr-aa BLAST: CBRC-XTRO-01-0480 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-XTRO-01-0480 ref|XP_001008699.1| H1 immobilization antigen, putative [Tetrahym...ena thermophila SB210] gb|EAR88454.1| H1 immobilization antigen, putative [Tetrahymena thermophila SB210] XP_001008699.1 4.2 29% ...

NCBI nr-aa BLAST: CBRC-XTRO-01-0562 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-XTRO-01-0562 ref|XP_001008699.1| H1 immobilization antigen, putative [Tetrahym...ena thermophila SB210] gb|EAR88454.1| H1 immobilization antigen, putative [Tetrahymena thermophila SB210] XP_001008699.1 4.2 29% ...

NCBI nr-aa BLAST: CBRC-XTRO-01-0714 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-XTRO-01-0714 ref|XP_001008699.1| H1 immobilization antigen, putative [Tetrahym...ena thermophila SB210] gb|EAR88454.1| H1 immobilization antigen, putative [Tetrahymena thermophila SB210] XP_001008699.1 4.2 28% ...

Bax function in the absence of mitochondria in the primitive protozoan Giardia lamblia.

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Adrian B Hehl

Full Text Available Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant organelles (mitosomes that lack a genome. Here we tested whether human Bax expressed in Giardia can be used to ablate mitosomes. We demonstrate that these organelles are neither targeted, nor compromised, by Bax. However, specialized compartments of the regulated secretory pathway are completely ablated by Bax. As a consequence, maturing cyst wall proteins that are sorted into these organelles are released into the cytoplasm, causing a developmental arrest and cell death. Interestingly, this ectopic cargo release is dependent on the carboxy-terminal 22 amino acids of Bax, and can be prevented by the Bax-inhibiting peptide Ku70. A C-terminally truncated Bax variant still localizes to secretory organelles, but is unable to permeabilize these membranes, uncoupling membrane targeting and cargo release. Even though mitosomes are too diverged to be recognized by Bax, off-target membrane permeabilization appears to be conserved and leads to cell death completely independently of mitochondria.

Neurochemical characterization of sea lamprey taste buds and afferent gustatory fibers: presence of serotonin, calretinin, and CGRP immunoreactivity in taste bud bi-ciliated cells of the earliest vertebrates.

Science.gov (United States)

Barreiro-Iglesias, Antón; Villar-Cerviño, Verona; Villar-Cheda, Begoña; Anadón, Ramón; Rodicio, María Celina

2008-12-01

Neuroactive substances such as serotonin and other monoamines have been suggested to be involved in the transmission of gustatory signals from taste bud cells to afferent fibers. Lampreys are the earliest vertebrates that possess taste buds, although these differ in structure from taste buds in jawed vertebrates, and their neurochemistry remains unknown. We used immunofluorescence methods with antibodies raised against serotonin, tyrosine hydroxylase (TH), gamma-aminobutyric acid (GABA), glutamate, calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), calretinin, and acetylated alpha-tubulin to characterize the neurochemistry and innervation of taste buds in the sea lamprey, Petromyzon marinus L. For localization of proliferative cells in taste buds we used bromodeoxyuridine labeling and proliferating cell nuclear antigen immunohistochemistry. Results with both markers indicate that proliferating cells are restricted to a few basal cells and that almost all cells in taste buds are nonproliferating. A large number of serotonin-, calretinin-, and CGRP-immunoreactive bi-ciliated cells were revealed in lamprey taste buds. This suggests that serotonin participates in the transmission of gustatory signals and indicates that this substance appeared early on in vertebrate evolution. The basal surface of the bi-ciliated taste bud cells was contacted by tubulin-immunoreactive fibers. Some of the fibers surrounding the taste bud were calretinin immunoreactive. Lamprey taste bud cells or afferent fibers did not exhibit TH, GABA, glutamate, or NPY immunoreactivity, which suggests that expression of these substances evolved in taste buds of some gnathostomes lines after the separation of gnathostomes and lampreys. (c) 2008 Wiley-Liss, Inc.

Phototactic orientation mechanism in the ciliate Fabrea salina, as inferred from numerical simulations.

Science.gov (United States)

Marangoni, R; Preosti, G; Colombetti, G

2000-02-01

The marine ciliate Fabrea salina shows a clear positive phototaxis, but the mechanism by which a single cell is able to detect the direction of light and orient its swimming accordingly is still unknown. A simple model of phototaxis is that of a biased random walk, where the bias due to light can affect one or more of the parameters that characterize a random walk, i.e., the mean speed, the frequency distribution of the angles of directional changes and the frequency of directional changes. Since experimental evidence has shown no effect of light on the mean speed of Fabrea salina, we have excluded models depending on this parameter. We have, therefore, investigated the phototactic orientation of Fabrea salina by computer simulation of two simple models, the first where light affects the frequency distribution of the angles of directional changes (model M1) and the second where the light bias modifies the frequency of directional changes (model M2). Simulated M1 cells directly orient their swimming towards the direction of light, regardless of their current swimming orientation; simulated M2 cells, on the contrary, are unable to actively orient their motion, but remain locked along the light direction once they find it by chance. The simulations show that these two orientation models lead to different macroscopic behaviours of the simulated cell populations. By comparing the results of the simulations with the experimental ones, we have found that the phototactic behaviour of real cells is more similar to that of the M2 model.

Alginic Acid-Aided Dispersion of Carbon Nanotubes, Graphene, and Boron Nitride Nanomaterials for Microbial Toxicity Testing.

Science.gov (United States)

Wang, Ying; Mortimer, Monika; Chang, Chong Hyun; Holden, Patricia A

2018-01-30

Robust evaluation of potential environmental and health risks of carbonaceous and boron nitride nanomaterials (NMs) is imperative. However, significant agglomeration of pristine carbonaceous and boron nitride NMs due to strong van der Waals forces renders them not suitable for direct toxicity testing in aqueous media. Here, the natural polysaccharide alginic acid (AA) was used as a nontoxic, environmentally relevant dispersant with defined composition to disperse seven types of carbonaceous and boron nitride NMs, including multiwall carbon nanotubes, graphene, boron nitride nanotubes, and hexagonal boron nitride flakes, with various physicochemical characteristics. AA's biocompatibility was confirmed by examining AA effects on viability and growth of two model microorganisms (the protozoan Tetrahymena thermophila and the bacterium Pseudomonas aeruginosa ). Using 400 mg·L -1 AA, comparably stable NM (200 mg·L -1 ) stock dispersions were obtained by 30-min probe ultrasonication. AA non-covalently interacted with NM surfaces and improved the dispersibility of NMs in water. The dispersion stability varied with NM morphology and size rather than chemistry. The optimized dispersion protocol established here can facilitate preparing homogeneous NM dispersions for reliable exposures during microbial toxicity testing, contributing to improved reproducibility of toxicity results.

Alginic Acid-Aided Dispersion of Carbon Nanotubes, Graphene, and Boron Nitride Nanomaterials for Microbial Toxicity Testing

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Ying Wang

2018-01-01

Full Text Available Robust evaluation of potential environmental and health risks of carbonaceous and boron nitride nanomaterials (NMs is imperative. However, significant agglomeration of pristine carbonaceous and boron nitride NMs due to strong van der Waals forces renders them not suitable for direct toxicity testing in aqueous media. Here, the natural polysaccharide alginic acid (AA was used as a nontoxic, environmentally relevant dispersant with defined composition to disperse seven types of carbonaceous and boron nitride NMs, including multiwall carbon nanotubes, graphene, boron nitride nanotubes, and hexagonal boron nitride flakes, with various physicochemical characteristics. AA’s biocompatibility was confirmed by examining AA effects on viability and growth of two model microorganisms (the protozoan Tetrahymena thermophila and the bacterium Pseudomonas aeruginosa. Using 400 mg·L−1 AA, comparably stable NM (200 mg·L−1 stock dispersions were obtained by 30-min probe ultrasonication. AA non-covalently interacted with NM surfaces and improved the dispersibility of NMs in water. The dispersion stability varied with NM morphology and size rather than chemistry. The optimized dispersion protocol established here can facilitate preparing homogeneous NM dispersions for reliable exposures during microbial toxicity testing, contributing to improved reproducibility of toxicity results.

Role of the Ubiquitin-Proteasome Systems in the Biology and Virulence of Protozoan Parasites

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Christian Muñoz

2015-01-01

Full Text Available In eukaryotic cells, proteasomes perform crucial roles in many cellular pathways by degrading proteins to enforce quality control and regulate many cellular processes such as cell cycle progression, signal transduction, cell death, immune responses, metabolism, protein-quality control, and development. The catalytic heart of these complexes, the 20S proteasome, is highly conserved in bacteria, yeast, and humans. However, until a few years ago, the role of proteasomes in parasite biology was completely unknown. Here, we summarize findings about the role of proteasomes in protozoan parasites biology and virulence. Several reports have confirmed the role of proteasomes in parasite biological processes such as cell differentiation, cell cycle, proliferation, and encystation. Proliferation and cell differentiation are key steps in host colonization. Considering the importance of proteasomes in both processes in many different parasites such as Trypanosoma, Leishmania, Toxoplasma, and Entamoeba, parasite proteasomes might serve as virulence factors. Several pieces of evidence strongly suggest that the ubiquitin-proteasome pathway is also a viable parasitic therapeutic target. Research in recent years has shown that the proteasome is a valid drug target for sleeping sickness and malaria. Then, proteasomes are a key organelle in parasite biology and virulence and appear to be an attractive new chemotherapeutic target.

Scanning electron microscopy and recording of the physiological activity of tracheal ciliated cells treated by fractionated irradiation

International Nuclear Information System (INIS)

Albertsson, M.; Hakansson, C.H.; Mecklenburg, C. von

1983-01-01

The ciliated epithelium of the rabbit's trachea was irradiated with daily fractions of 2 Gy to an accumulated dose of 20 Gy. The beat frequency of the cilia was recorded and specimens were taken for SEM-, TEM- and LM-investigations. Examination was made 1-10 days after each fractionation schedule. An increased ciliary beat frequency was recorded at 2 Gy and 4 Gy. With increasing dose, there was an inverted relationship to the frequency. Light-microscopy showed edema and an increased amount of goblet cells in relation to the increasing dose. With SEM an increased number of ciliary blebs could be seen. These could be classified according to size and number, and showed a positive correlation to the dose. TEM-investigations showed signs of increased intracellular activity at higher doses in the form of multilobulated nuclei and an increasing number of nuclear pores. At lower doses, an increased amount of mitochondria appeared in the apical part of the cell. It is at present difficult to evaluate any correlation between the physiological activity and the morphology. More biological data are needed to explain the early irradiation effects

A role for Sar1 and ARF1 GTPases during Golgi biogenesis in the protozoan parasite Trypanosoma brucei

Science.gov (United States)

Yavuz, Sevil; Warren, Graham

2017-01-01

A single Golgi stack is duplicated and partitioned into two daughter cells during the cell cycle of the protozoan parasite Trypanosoma brucei. The source of components required to generate the new Golgi and the mechanism by which it forms are poorly understood. Using photoactivatable GFP, we show that the existing Golgi supplies components directly to the newly forming Golgi in both intact and semipermeabilized cells. The movement of a putative glycosyltransferase, GntB, requires the Sar1 and ARF1 GTPases in intact cells. In addition, we show that transfer of GntB from the existing Golgi to the new Golgi can be recapitulated in semipermeabilized cells and is sensitive to the GTP analogue GTPγS. We suggest that the existing Golgi is a key source of components required to form the new Golgi and that this process is regulated by small GTPases. PMID:28495798

Survey on the Ability of Wolbachia to Control Human Viral, Protozoan, and Filarial Disease Pathogens

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Garedaghi Yagoob

2014-04-01

Full Text Available Objective: Most human filarial nematode parasites and arthropods are hosts for a bacterial endosymbiont, Wolbachia. In filariasis, Wolbachia are required for normal development, fertility, and survival. However, in arthropods, Wolbachia are largely parasitic and can influence development and reproduction, but are generally not required for host survival. Materials and Methods: Due to their obligate nature in filarial parasites, Wolbachia have been a target for drug discovery initiatives using several approaches including diversity and focused library screening and genomic sequence analysis. Results: In vitro and in vivo anti-Wolbachia antibiotic treatments have been shown to have adulticidal activity, a long sought goal of filarial parasite drug discovery. In mosquitoes, it has been shown that the presence of Wolbachia can inhibit the transmission of certain viruses, such as dengue, chikungunya, yellow fever, West Nile, as well as the infectivity of the malaria-causing protozoan, Plasmodium and filarial nematodes. Conclusion: Wolbachia can cause a form of conditional sterility that can be used to suppress populations of mosquitoes and additional medically important insects. Thus, Wolbachia, a pandemic endosymbiont, offers great potential for elimination of a wide-variety of devastating human diseases.

Purification and characterization of factors produced by Aspergillus fumigatus which affect human ciliated respiratory epithelium.

Science.gov (United States)

Amitani, R; Taylor, G; Elezis, E N; Llewellyn-Jones, C; Mitchell, J; Kuze, F; Cole, P J; Wilson, R

1995-09-01

The mechanisms by which Aspergillus fumigatus colonizes the respiratory mucosa are unknown. Culture filtrates of eight of nine clinical isolates of A. fumigatus slowed ciliary beat frequency and damaged human respiratory epithelium in vitro. These changes appeared to occur concurrently. Culture filtrates of two clinical isolates of Candida albicans had no effect on ciliated epithelium. We have purified and characterized cilioinhibitory factors of a clinical isolate of A. fumigatus. The cilioinhibitory activity was heat labile, reduced by dialysis, and partially extractable into chloroform. The activity was associated with both high- and low-molecular-weight factors, as determined by gel filtration on Sephadex G-50. A low-molecular-weight cilioinhibitory factor was further purified by reverse-phase high-performance liquid chromatography and shown by mass spectrometry to be gliotoxin, a known metabolite of A. fumigatus. Gliotoxin significantly slowed ciliary beat frequency in association with epithelial damage at concentrations above 0.2 microgram/ml; other Aspergillus toxins, i.e., fumagillin and helvolic acid, were also cilioinhibitory but at much higher concentrations. High-molecular-weight (> or = 35,000 and 25,000) cilioinhibitory materials had neither elastolytic nor proteolytic activity and remain to be identified. Thus, A. fumigatus produces a number of biologically active substances which slow ciliary beating and damage epithelium and which may influence colonization of the airways.

Sampling strategies for improving tree accuracy and phylogenetic analyses: a case study in ciliate protists, with notes on the genus Paramecium.

Science.gov (United States)

Yi, Zhenzhen; Strüder-Kypke, Michaela; Hu, Xiaozhong; Lin, Xiaofeng; Song, Weibo

2014-02-01

In order to assess how dataset-selection for multi-gene analyses affects the accuracy of inferred phylogenetic trees in ciliates, we chose five genes and the genus Paramecium, one of the most widely used model protist genera, and compared tree topologies of the single- and multi-gene analyses. Our empirical study shows that: (1) Using multiple genes improves phylogenetic accuracy, even when their one-gene topologies are in conflict with each other. (2) The impact of missing data on phylogenetic accuracy is ambiguous: resolution power and topological similarity, but not number of represented taxa, are the most important criteria of a dataset for inclusion in concatenated analyses. (3) As an example, we tested the three classification models of the genus Paramecium with a multi-gene based approach, and only the monophyly of the subgenus Paramecium is supported. Copyright © 2013 Elsevier Inc. All rights reserved.

Molecular evidence for bacterial and protozoan pathogens in hard ticks from Romania.

Science.gov (United States)

Ionita, Mariana; Mitrea, Ioan Liviu; Pfister, Kurt; Hamel, Dietmar; Silaghi, Cornelia

2013-09-01

The aim of the present study was to provide a preliminary insight into the diversity of tick-borne pathogens circulating at the domestic host-tick interface in Romania. For this, feeding and questing ticks were analyzed by real-time polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, Borrelia burgdorferi sensu latu, and by PCR and subsequent sequencing for Rickettsia spp., Babesia spp. and Theileria spp. A total of 382 ticks, encompassing 5 species from 4 genera, were collected in April-July 2010 from different areas of Romania; of them, 40 were questing ticks and the remainder was collected from naturally infested cattle, sheep, goats, horses or dogs. Tick species analyzed included Ixodes ricinus, Dermacentor marginatus, Hyalomma marginatum, Rhipicephalus bursa, and Rhipicephalus sanguineus. Four rickettsiae of the spotted fever group of zoonotic concern were identified for the first time in Romania: Rickettsia monacensis and Rickettsia helvetica in I. ricinus, and Rickettsia slovaca and Rickettsia raoultii in D. marginatus. Other zoonotic pathogens such as A. phagocytophilum, Borrelia afzelii, and Babesia microti were found in I. ricinus. Pathogens of veterinary importance were also identified, including Theileria equi in H. marginatum, Babesia occultans in D. marginatus and H. marginatum, Theileria orientalis/sergenti/buffeli-group in I. ricinus and in H. marginatum and E. canis in R. sanguineus. These findings show a wide distribution of very diverse bacterial and protozoan pathogens at the domestic host-tick interface in Romania, with the potential of causing both animal and human diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

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 R training 2 and R test 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 R training 2 and R test 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 (R training 2 and R test 2 were 0.91 and 0.93, respectively). The mean absolute error for the test set was computed as 0.1615. Copyright © 2016 Elsevier Ltd. All rights reserved.

An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

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Emma R Cold

Full Text Available The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1 Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2 Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3 Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications.

Taxonomic descriptions of three marine colepid ciliates, Nolandia sinica spec. nov., Apocoleps caoi spec. nov. and Tiarina fusa (Claparede & Lachmann, 1858) Bergh, 1881 (Ciliophora, Prorodontida).

Science.gov (United States)

Chen, Xiangrui; Gao, Shan; Liu, Weiwei; Song, Weibo; Al-Rasheid, Khaled A S; Warren, Alan

2012-03-01

The morphology of three marine colepid ciliates, Nolandia sinica spec. nov., Apocoleps caoi spec. nov. and Tiarina fusa (Claparède & Lachmann, 1858) Bergh, 1881, isolated from Chinese coastal waters, was investigated. N. sinica spec. nov. may be separated from its congeners by the structure of its armour plates, each of which may have up to five reniform windows. A. caoi spec. nov. is characterized by its large body with broad anterior end and by having 10-12 long, sharp posterior spines. New data and an improved diagnosis are supplied for Tiarina fusa (Claparède & Lachmann, 1858) Bergh, 1881, which has a spindle-shaped body, about 16 ciliary rows and a single adoral organelle. Sequence similarities with other available colepid species were determined.

Incidence of adult brain cancers is higher in countries where the protozoan parasite Toxoplasma gondii is common

Science.gov (United States)

Thomas, Frédéric; Lafferty, Kevin D.; Brodeur, Jacques; Elguero, Eric; Gauthier-Clerc, Michel; Missé, Dorothée

2012-01-01

We explored associations between the common protozoan parasite Toxoplasma gondii and brain cancers in human populations. We predicted that T. gondii could increase the risk of brain cancer because it is a long-lived parasite that encysts in the brain, where it provokes inflammation and inhibits apoptosis. We used a medical geography approach based on the national incidence of brain cancers and seroprevalence of T. gondii. We corrected reports of incidence for national gross domestic product because wealth probably increases the ability to detect cancer. We also included gender, cell phone use and latitude as variables in our initial models. Prevalence of T. gondii explained 19 per cent of the residual variance in brain cancer incidence after controlling for the positive effects of gross domestic product and latitude among nations. Infection with T. gondii was associated with a 1.8-fold increase in the risk of brain cancers across the range of T. gondii prevalence in our dataset (4–67%). These results, though correlational, suggest that T. gondii should be investigated further as a possible oncogenic pathogen of humans.

In situ examination of microbial populations in a model drinking water distribution system

DEFF Research Database (Denmark)

Martiny, Adam Camillo; Nielsen, Alex Toftgaard; Arvin, Erik

2002-01-01

A flow cell set-up was used as a model drinking water distribution system to analyze the in situ microbial population. Biofilm growth was followed by transmission light microscopy for 81 days and showed a biofilm consisting of microcolonies separated by a monolayer of cells. Protozoans (ciliates...... of a mixed population of α- and β-Proteobacteria. 65 strains from the inlet water and 20 from the biofilm were isolated on R2A agar plates and sorted into groups with amplified rDNA restriction analysis. The 16S rDNA gene was sequenced for representatives of the abundant groups. A phylogenetic analysis...... revealed that the majority of the isolated strains from the bulk water and biofilm were affiliated to the family of Comamonadaceae in the β-lineage of Proteobacteria. The majority of the strains from the α-lineage were affiliated to the family of Sphingomonadaceae. We were unable to detect any strains from...

The Selective Use of Hypochlorite to Prevent Pond Crashes for Algae-Biofuel Production.

Science.gov (United States)

2015-09-21

Although algae-biofuels have many advantages including high areal productivity, algae can be preyed upon by amoebas, protozoans, ciliates, and rotifers, particularly in open pond systems. Thus, these higher organisms need to be controlled. In this study, Chlorella kessleri was used as the algal culture and Brachionus calyciflorus as the source of predation. The effect of sodium hypochlorite (bleach) was tested with the goal of totally inhibiting the rotifer while causing minor inhibition to the alga. The 24-hr LC50 for B. calyciflorus in spring water was 0.198 mg Cl/L while the 24-hr LC50 for C. kessleri was 0.321 mg Cl/L. However, chlorine dissipates rapidly as the algae serves as reductant. Results showed a chlorine dosage between 0.45 to 0.6 mg Cl/L and a dosing interval of two hours created the necessary chlorine concentrations to inhibit predation while letting the algae grow; thus giving algae farmers a tool to prevent pond crashes. Water Environ. Res., 87 (2015).

Effects of acute gamma-irradiation on the aquatic microbial microcosm in comparison with chemicals

Energy Technology Data Exchange (ETDEWEB)

Fuma, Shoichi, E-mail: fuma@nirs.go.j [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ishii, Nobuyoshi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Doi, Kazutaka; Kawaguchi, Isao [Regulatory Sciences Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Tanaka, Nobuyuki [Environmental Chemistry Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Inamori, Yuhei [Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Polikarpov, Gennady G. [The A.O. Kovalevsky Institute of Biology of Southern Seas, Sevastopol 99011 (Ukraine)

2009-12-15

Effects of acute gamma-irradiation were investigated in the aquatic microcosm consisting of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producers; an oligochaete (Aeolosoma hemprichi), rotifers (Lecane sp. and Philodina sp.) and a ciliate protozoan (Cyclidium glaucoma) as consumers; and more than four species of bacteria as decomposers. At 100 Gy, populations were not affected in any taxa. At 500-5000 Gy, one or three taxa died out and populations of two or three taxa decreased over time, while that of Tolypothrix sp. increased. This Tolypothrix sp. increase was likely an indirect effect due to interspecies interactions. The principal response curve analysis revealed that the main trend of the effects was a dose-dependent population decrease. For a better understanding of radiation risks in aquatic microbial communities, effect doses of gamma-rays compared with copper, herbicides and detergents were evaluated using the radiochemoecological conceptual model and the effect index for microcosm.

Effects of acute γ-irradiation on the aquatic microbial microcosm in comparison with chemicals

International Nuclear Information System (INIS)

Fuma, Shoichi; Ishii, Nobuyoshi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei; Doi, Kazutaka; Kawaguchi, Isao; Tanaka, Nobuyuki; Inamori, Yuhei; Polikarpov, Gennady G.

2009-01-01

Effects of acute γ-irradiation were investigated in the aquatic microcosm consisting of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producers; an oligochaete (Aeolosoma hemprichi), rotifers (Lecane sp. and Philodina sp.) and a ciliate protozoan (Cyclidium glaucoma) as consumers; and more than four species of bacteria as decomposers. At 100 Gy, populations were not affected in any taxa. At 500-5000 Gy, one or three taxa died out and populations of two or three taxa decreased over time, while that of Tolypothrix sp. increased. This Tolypothrix sp. increase was likely an indirect effect due to interspecies interactions. The principal response curve analysis revealed that the main trend of the effects was a dose-dependent population decrease. For a better understanding of radiation risks in aquatic microbial communities, effect doses of γ-rays compared with copper, herbicides and detergents were evaluated using the radiochemoecological conceptual model and the effect index for microcosm.

Some aspects of interrelations between fungi and other biota in forest soil.

Science.gov (United States)

Krivtsov, Vladimir; Griffiths, Bryan S; Salmond, Ross; Liddell, Keith; Garside, Adam; Bezginova, Tanya; Thompson, Jacqueline A; Staines, Harry J; Watling, Roy; Palfreyman, John W

2004-08-01

Interrelations of fungal mycelium with other soil biota are of paramount importance in forestry and soil ecology. Here we present the results of statistical analysis of a comprehensive data set collected in the first (and the only) British fungus sanctuary over a period of four months. The variables studied included a number of soil properties, bacteria, protozoan flagellates, ciliates and amoebae, microbial and plant feeding nematodes, various microarthropods, and two fungal biomarkers--glomalin and ergosterol. One way ANOVA showed that the dynamics of the microbiota studied was influenced by seasonal changes. Superimposed on these changes, however, was variability due to biological interactions and habitat characteristics. Two fungal biomarkers, ergosterol and glomalin, were differently influenced by other biota and abiotic variables. The results indicate that the dynamics of soil fungi is influenced not only by soil microarthropods, but also by those found in forest litter. The overall outcome, therefore, is likely to be very complex and will depend upon specific conditions of any particular ecosystem.

Seroprevalence rates of antibodies againstLeishmania infantum and other protozoan and rickettsial parasites in dogs

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Silvana de Cássia Paulan

Full Text Available Canine visceral leishmaniasis (CVL is caused by the protozoan Leishmania infantum, which infects dogs and humans in many regions of Brazil. The present study involved an indirect fluorescent antibody test (IFAT to analyze L. infantum,Ehrlichia spp., Babesia canis,Toxoplasma gondii and Neospora caninuminfection rates in serum samples from 93 dogs in a rural settlement in Ilha Solteira, SP, Brazil. The seroprevalence rates of anti-L. infantum, anti-Ehrlichia, anti-B. canis, anti-T. gondii and anti-N. caninum antibodies were 37.6%, 75.3%, 72%, 47.3% and 6.4%, respectively. In addition to IFAT, direct microscopic examination of popliteal lymph node aspirates revealed 26.9% of CVL positive dogs. Serological tests revealed that 17.2% of the dogs were seropositive for a single parasite, 29% for two parasites, 33% for three, 16.1% for four, and 1.1% for five parasites, while 3.2% were seronegative for five parasites. The presence of antibodies against these parasites in serum samples from dogs confirmed their exposure to these parasites in this rural area. Because of the potential zoonotic risk of these diseases, mainly leishmaniasis, ehrlichiosis and toxoplasmosis, special attention should focus on programs for the improvement of diagnostic assays and control measures against these parasites.

Molecular characterization of 5S ribosomal RNA genes and transcripts in the protozoan parasite Leishmania major.

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Moreno-Campos, Rodrigo; Florencio-Martínez, Luis E; Nepomuceno-Mejía, Tomás; Rojas-Sánchez, Saúl; Vélez-Ramírez, Daniel E; Padilla-Mejía, Norma E; Figueroa-Angulo, Elisa; Manning-Cela, Rebeca; Martínez-Calvillo, Santiago

2016-12-01

Eukaryotic 5S rRNA, synthesized by RNA polymerase III (Pol III), is an essential component of the large ribosomal subunit. Most organisms contain hundreds of 5S rRNA genes organized into tandem arrays. However, the genome of the protozoan parasite Leishmania major contains only 11 copies of the 5S rRNA gene, which are interspersed and associated with other Pol III-transcribed genes. Here we report that, in general, the number and order of the 5S rRNA genes is conserved between different species of Leishmania. While in most organisms 5S rRNA genes are normally associated with the nucleolus, combined fluorescent in situ hybridization and indirect immunofluorescence experiments showed that 5S rRNA genes are mainly located at the nuclear periphery in L. major. Similarly, the tandemly repeated 5S rRNA genes in Trypanosoma cruzi are dispersed throughout the nucleus. In contrast, 5S rRNA transcripts in L. major were localized within the nucleolus, and scattered throughout the cytoplasm, where mature ribosomes are located. Unlike other rRNA species, stable antisense RNA complementary to 5S rRNA is not detected in L. major.

Cloning and bacterial expression of adenosine-5'-triphosphate sulfurylase from the enteric protozoan parasite Entamoeba histolytica.

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Nozaki, T; Arase, T; Shigeta, Y; Asai, T; Leustek, T; Takeuchi, T

1998-12-08

A gene encoding adenosine-5'-triphosphate sulfurylase (AS) was cloned from the enteric protozoan parasite Entamoeba histolytica by polymerase chain reaction using degenerate oligonucleotide primers corresponding to conserved regions of the protein from a variety of organisms. The deduced amino acid sequence of E. histolytica AS revealed a calculated molecular mass of 47925 Da and an unusual basic pI of 9.38. The amebic protein sequence showed 23-48% identities with AS from bacteria, yeasts, fungi, plants, and animals with the highest identities being to Synechocystis sp. and Bacillus subtilis (48 and 44%, respectively). Four conserved blocks including putative sulfate-binding and phosphate-binding regions were highly conserved in the E. histolytica AS. The upstream region of the AS gene contained three conserved elements reported for other E. histolytica genes. A recombinant E. histolytica AS revealed enzymatic activity, measured in both the forward and reverse directions. Expression of the E. histolytica AS complemented cysteine auxotrophy of the AS-deficient Escherichia coli strains. Genomic hybridization revealed that the AS gene exists as a single copy gene. In the literature, this is the first description of an AS gene in Protozoa.

Tissue mortality by Caribbean ciliate infection and white band disease in three reef-building coral species

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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.

Effects of crude extracts of Mucuna pruriens (Fabaceae) and Carica papaya (Caricaceae) against the protozoan fish parasite Ichthyophthirius multifiliis.

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Ekanem, A P; Obiekezie, A; Kloas, W; Knopf, K

2004-03-01

The ciliate Ichthyophthirius multifiliis is among the most pathogenic parasites of fish maintained in captivity. In the present study, the effects of the crude methanolic extract of leaves of Mucuna pruriens and the petroleum-ether extract of seeds of Carica papaya against I. multifiliis were investigated under in vivo and in vitro conditions. Goldfish (Carassius auratus auratus) infected with the parasites were immersed for 72 h in baths with M. pruriens extract, and for 96 h in baths with C. papaya extract. There was a 90% reduction in numbers of I. multifiliis on fish after treatment in baths of each plant extract at 200 mg l(-1 )compared to untreated controls. Consequently, parasite-induced fish mortality was reduced significantly. A complete interruption of trophont recruitment was achieved by immersion in the M. pruriens extract. In vitro tests led to a 100% mortality of I. multifiliis in 150 mg/l M. pruriens extract, and in 200 mg/l of C. papaya extract after 6 h. Although the active constituents of the medicinal plant extracts are still unknown, we have demonstrated that they have potential for effective control of I. multifiliis.

A synthetic cadmium metallothionein gene (PMCd1syn) of Paramecium species: expression, purification and characteristics of metallothionein protein.

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Dar, Saira; Shuja, Rukhsana N; Shakoori, Abdul Rauf

2013-02-01

Metallothioneins (MTs) are metal binding proteins that are rich in cysteine residues constituting 10-30 % of the total protein, and in which the thiol groups bind to the metal ions. The increasing amount of metal ions in the medium have shown increased production of MTs by different organisms such as bacteria, protozoa and mammals like humans. PMCd1 is the first gene ever discovered in Paramecium, a ciliated protozoan, that could produce this MT in response to cadmium. In this study the PMCd1syn gene has been cloned in pET41a expression vector and expressed in an Escherichia coli BL21-codonplus strain for the first time. Since the gene PMCd1 amplified from Paramecium contained 10 codons, which could act as stop codons during expression in E. coli, this gene of 612 bps was synthesized to substitute these (stop) codons for the Paramecium sp. specific amino acids. For stability of the expressed protein, glutathione-S-transferase gene was fused with PMCd1syn gene and coexpressed. The cells expressing PMCd1syn demonstrated increased accumulation of cadmium. This is the first report of cadmium MT protein expressed from Paramecium species, particularly from synthetic MT gene (PMCd1syn). This fusion protein, the molecular weight of which has been confirmed to be 53.03 kDa with MALDI analysis, is rich in cysteine residues, and has been shown for the first time in this ciliate to bind to and sequester Cd(2+)-ions.

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

Development and evaluation of specific PCR primers targeting the ribosomal DNA-internal transcribed spacer (ITS) region of peritrich ciliates in environmental samples

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Su, Lei; Zhang, Qianqian; Gong, Jun

2017-07-01

Peritrich ciliates are highly diverse and can be important bacterial grazers in aquatic ecosystems. Morphological identifications of peritrich species and assemblages in the environment are time-consuming and expertise-demanding. In this study, two peritrich-specific PCR primers were newly designed to amplify a fragment including the internal transcribed spacer (ITS) region of ribosomal rDNA from environmental samples. The primers showed high specificity in silico, and in tests with peritrich isolates and environmental DNA. Application of these primers in clone library construction and sequencing yielded exclusively sequences of peritrichs for water and sediment samples. We also found the ITS1, ITS2, ITS, D1 region of 28S rDNA, and ITS+D1 region co-varied with, and generally more variable than, the V9 region of 18S rDNA in peritrichs. The newly designed specific primers thus provide additional tools to study the molecular diversity, community composition, and phylogeography of these ecologically important protists in different systems.

Morphology and Phylogeny of the Soil Ciliate Metopus yantaiensis n. sp. (Ciliophora, Metopida), with Identification of the Intracellular Bacteria.

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Omar, Atef; Zhang, Qianqian; Zou, Songbao; Gong, Jun

2017-11-01

The morphology and infraciliature of a new ciliate, Metopus yantaiensis n. sp., discovered in coastal soil of northern China, were investigated. It is distinguished from its congeners by a combination of the following features: nuclear apparatus situated in the preoral dome; 18-21 somatic ciliary rows, of which three extend onto the preoral dome (dome kineties); three to five distinctly elongated caudal cilia, and 21-29 adoral polykinetids. The 18S rRNA genes of this new species and two congeners, Metopus contortus and Metopus hasei, were sequenced and phylogenetically analyzed. The new species is more closely related to M. hasei and the clevelandellids than to other congeners; both the genus Metopus and the order Metopida are not monophyletic. In addition, the digestion-resistant bacteria in the cytoplasm of M. yantaiensis were identified, using a 16S rRNA gene clone library, sequencing, and fluorescence in situ hybridization. The detected intracellular bacteria are affiliated with Sphingomonadales, Rhizobiales, Rickettsiales (Alphaproteobacteria), Pseudomonas (Gammaproteobacteria), Rhodocyclales (Betaproteobacteria), Clostridiales (Firmicutes), and Flavobacteriales (Bacteroidetes). © 2017 The Author(s) Journal of Eukaryotic Microbiology © 2017 International Society of Protistologists.

Involvement of the actin cytoskeleton and p21rho-family GTPases in the pathogenesis of the human protozoan parasite Entamoeba histolytica

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G.D. Godbold

1998-08-01

Full Text Available It has been estimated that infection with the enteric protozoan parasite Entamoeba histolytica kills more than 50,000 people a year. Central to the pathogenesis of this organism is its ability to directly lyse host cells and cause tissue destruction. Amebic lesions show evidence of cell lysis, tissue necrosis, and damage to the extracellular matrix. The specific molecular mechanisms by which these events are initiated, transmitted, and effected are just beginning to be uncovered. In this article we review what is known about host cell adherence and contact-dependent cytolysis. We cover the involvement of the actin cytoskeleton and small GTP-binding proteins of the p21rho-family in the process of cell killing and phagocytosis, and also look at how amebic interactions with molecules of the extracellular matrix contribute to its cytopathic effects.

Unicellular eukaryotes as models in cell and molecular biology: critical appraisal of their past and future value.

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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. © 2014 Elsevier Inc. All rights reserved.

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

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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.

Marine-Derived 2-Aminoimidazolone Alkaloids. Leucettamine B-Related Polyandrocarpamines Inhibit Mammalian and Protozoan DYRK & CLK Kinases

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Nadège Loaëc

2017-10-01

Full Text Available A large diversity of 2-aminoimidazolone alkaloids is produced by various marine invertebrates, especially by the marine Calcareous sponges Leucetta and Clathrina. The phylogeny of these sponges and the wide scope of 2-aminoimidazolone alkaloids they produce are reviewed in this article. The origin (invertebrate cells, associated microorganisms, or filtered plankton, physiological functions, and natural molecular targets of these alkaloids are largely unknown. Following the identification of leucettamine B as an inhibitor of selected protein kinases, we synthesized a family of analogues, collectively named leucettines, as potent inhibitors of DYRKs (dual-specificity, tyrosine phosphorylation regulated kinases and CLKs (cdc2-like kinases and potential pharmacological leads for the treatment of several diseases, including Alzheimer’s disease and Down syndrome. We assembled a small library of marine sponge- and ascidian-derived 2-aminoimidazolone alkaloids, along with several synthetic analogues, and tested them on a panel of mammalian and protozoan kinases. Polyandrocarpamines A and B were found to be potent and selective inhibitors of DYRKs and CLKs. They inhibited cyclin D1 phosphorylation on a DYRK1A phosphosite in cultured cells. 2-Aminoimidazolones thus represent a promising chemical scaffold for the design of potential therapeutic drug candidates acting as specific inhibitors of disease-relevant kinases, and possibly other disease-relevant targets.

Characterization of four arginine kinases in the ciliate Paramecium tetraurelia: Investigation on the substrate inhibition mechanism.

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Yano, Daichi; Suzuki, Takaya; Hirokawa, Saki; Fuke, Kyoko; Suzuki, Tomohiko

2017-08-01

The ciliate Paramecium tetraurelia contains four arginine kinase genes (AK1-4). We detected cDNA for only three of the AKs (AK1-3) via PCR. Recombinant AK1-4 were expressed in Escherichia coli and their kinetics parameters determined. AK3 showed typical substrate inhibition toward arginine, and enzymatic activity markedly decreased when arginine concentration increased. This is the first example of substrate inhibition in wild-type phosphagen kinases. To explore the substrate inhibition mechanism, site-directed mutations were generated, targeting the amino acid sequence D-D-S-Q-V at positions 77-81 in P. tetraurelia AK3. Among the mutants, substrate inhibition was lost remarkably in the S79A mutant. In spite of high amino acid sequence identity (91%) between P. tetraurelia AK3 and AK4, the enzymatic activity of AK4 was less by 3% than that of AK3. We noticed that the conservative G298 was unusually replaced by R in P. tetraurelia AK4, and we constructed two mutants, R298G/AK4 and G298R/AK3. Enzymatic activity of the former mutant was comparable with that of the wild-type AK3, whereas that of the latter mutant was dramatically reduced. Thus, we concluded that the significantly low activity of P. tetraurelia AK4 is due to the residue R298. Copyright © 2017 Elsevier B.V. All rights reserved.

Ectocommensal and ectoparasites in goldfish Carassius auratus (Linnaeus, 1758 in farmed in the State of São Paulo

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Carla Renata Serantoni Moyses

Full Text Available Concomitant infections by several parasitic genera are rare, very debilitating and often lethal to fish reared under commercial breeding conditions. Were describe a multiple and concurrent parasite infestation in cultured goldfish Carassius auratus with skin damage (nodules and/or ulceration. Fish with skin lesions underwent necropsy, and the skin and gills were scraped and examined. Histopathological examination with Hematoxylin-Eosin and Giemsa stain, and an ultrastructure study using transmission and scanning electron microscopy were conducted. In the skin, we identified multiple-parasite infestations by Gyrodactylidae, Epistylis sp., Trichodina sp., Ichthyophthirius multifiliis, Tetrahymena sp. and Ichthyobodo necator,associated with epithelial cell hyperplasia and epidermal sloughing. Although no gross lesions were observed, were identified a large number of parasites in the gills (Epistylis sp., Piscinoodinium sp., Ichthyophthirius multifiliis, Trichodina sp., Apiosoma sp., Hexamitasp. and cysts of a trematode digenean. The observed trematodes were not identified. The associated microscopic lesions were epithelial hypertrophic and hyperplasic and exhibited fusion of secondary lamellae and epithelial cell detachment. This is the first description of a protozoan Vorticella sp. parasitizing goldfish in Brazil. Multiple ectoparasitism by protozoa and Platyhelminthes, with or without apparent tissue damage, can be fatal for goldfish raised on farms with poor management.

Application of magnetically induced hyperthermia in the model protozoan Crithidia fasciculata as a potential therapy against parasitic infections

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Grazú V

2012-10-01

Full Text Available V Grazú,1 AM Silber,2 M Moros,1 L Asín,1 TE Torres,1,3,5 C Marquina,3,4 MR Ibarra,1,3 GF Goya1,31Instituto de Nanociencia de Aragón (INA, Universidad de Zaragoza, Zaragoza, Spain; 2Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil; 3Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza, Spain; 4Instituto de Ciencia de Materiales de Aragón (ICMA, CSIC, Universidad de Zaragoza, Zaragoza, Spain; 5Laboratorio de Microscopías Avanzadas (LMA, Universidad de Zaragoza, Zaragoza, SpainBackground: Magnetic hyperthermia is currently a clinical therapy approved in the European Union for treatment of tumor cells, and uses magnetic nanoparticles (MNPs under time-varying magnetic fields (TVMFs. The same basic principle seems promising against trypanosomatids causing Chagas disease and sleeping sickness, given that the therapeutic drugs available have severe side effects and that there are drug-resistant strains. However, no applications of this strategy against protozoan-induced diseases have been reported so far. In the present study, Crithidia fasciculata, a widely used model for therapeutic strategies against pathogenic trypanosomatids, was targeted with Fe3O4 MNPs in order to provoke cell death remotely using TVMFs.Methods: Iron oxide MNPs with average diameters of approximately 30 nm were synthesized by precipitation of FeSO4 in basic medium. The MNPs were added to C. fasciculata choanomastigotes in the exponential phase and incubated overnight, removing excess MNPs using a DEAE-cellulose resin column. The amount of MNPs uploaded per cell was determined by magnetic measurement. The cells bearing MNPs were submitted to TVMFs using a homemade AC field applicator (f = 249 kHz, H = 13 kA/m, and the temperature variation during the experiments was measured. Scanning electron microscopy was used to assess morphological changes after the TVMF

Rumen ciliated protozoa of crossbred sheep kept in natural pasture of caatinga Protozoários ciliados do rúmen de ovinos mestiços mantidos em pastagem natural de caatinga

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Ângela Maria Vieira Batista

2008-06-01

Full Text Available Effects of the sampling time and ruminal pH on the concentration of ciliate protozoa in the rumen of five fistulated Santa Inez crossbred sheep, reared in natural caatinga (scrubland pasture were evaluated. Ruminal content samples were obtained at zero hour (before the animals were released to the pasture, at 7:00h and 2, 4, 6, 8 and 10 hours thereafter. Samples were fixed in formalin at 18.5% (v/v. It was identified and quantified organisms of the genera Dasytricha, Diplodinium, Diploplastron, Entodinium, Eodinium, Elytroplastron, Enoploplastron, Epidinium, Eremoplastron, Eudiplodinium, Isotricha, Metadinium and Ophryoscolex. Among them, only Diploplastron and Entodinium presented variations at their population concentrations in function of the sampling time. The number of ciliates undergoing division was not correlated with the sampling times. Stable division rate seemed to contribute the maintenance of ciliates concentrations in the rumen. Ruminal pH was negatively correlated with sampling time, and was not correlated with the number of protozoa, probably because the variations observed included parameters considered ideal for establishment and maintenance protozoa populations of rumen.Foram avaliados os efeitos do tempo de amostragem e do pH ruminal sobre a concentração de protozoários ciliados no rúmen de cinco ovinos mestiços Santa Inês, fistulados no rúmen, mantidos extensivamente em pastagem natural de caatinga no município de Sertânia, PE. As amostras de conteúdo ruminal foram obtidas nos seguintes horários: zero hora (antes dos animais serem soltos na pastagem, às 7:00h e 2, 4, 6, 8 e 10 horas depois de iniciado o pastejo. As amostras obtidas foram fixadas em formalina 18,5% (v/v. Foram identificados e quantificados organismos dos gêneros Dasytricha, Diplodinium, Diploplastron, Entodinium, Eodinium, Elytroplastron, Enoploplastron, Epidinium, Eremoplastron, Eudiplodinium, Isotricha, Metadinium e Ophryoscolex, sendo que

Comparative study on acute toxicity of tetracycline and tetracycline hydrochloride to three ciliates%四环素和盐酸四环素对3种纤毛虫急性毒性效应的比较研究

Institute of Scientific and Technical Information of China (English)

赵也; 张辰笈; 丁霜; 蔡兴隆; 潘旭明; 陈瑛

2017-01-01

In this paper,three ciliates were selected as experimental subjects,and a wide range of tetracycline and tetracycline hydrochloride were employed to carry out a comparative study of acute toxicity effects.It was showed that the 24 h medial lethal concentrations (24 h-LC50) of tetracycline to Stylonyciia lemnae, Paramecium caudatum and Stentor coeruleus were 171.025 16,52.361 25,199.356 32 mg/L,respectively;the 24 h lowest observed effect concentrations (24 h-LOEC) of tetracycline were 65.168 84,15.199 17,139.370 22 mg/L,respectively.On the other hand,the 24 h-LC50 of tetracycline hydrochloride to Stylonyciia lemnae, Paramecium caudatum and Stentor coeruleus were 44.485 66,50.245 83,33.777 69 mg/L,respectively;the 24 h-LOEC were 20.031 34,24.671 75,13.444 98 mg/L,respectively.The results showed that the tolerance of three ciliates to tetracycline was in the following order: Stentor coeruleus > Stylonyciia lemnae > Paramecium caudatum.The tolerance difference of the three ciliates to tetracycline hydrochloride was not significant.The acute toxicity of Paramecium caudatum to tetracycline antibiotics was low,so it was suitable to use ciliates for early monitoring and early warning of tetracycline antibiotic contamination in water environments.%以3种纤毛虫为受试原生动物,比较了四环素和盐酸四环素对3种纤毛虫的急性毒性效应.结果表明:四环素对浮萍棘尾虫(Stylonyciia lemnae)、尾草履虫(Paramecium caudatum)和天蓝喇叭虫(Stentor coeruleus)的24 h半致死质量浓度(24 h-LC50)分别为171.025 16、52.361 25、199.356 32 mg/L,24 h最低有影响质量浓度(24 h-LOEC)分别为65.168 84、15.199 17、139.370 22 mg/L;盐酸四环素对浮萍棘尾虫、尾草履虫和天蓝喇叭虫的24 h-LC50分别为44.485 66、50.245 83、33.777 69 mg/L,24 h-LOEC分别为20.031 34、24.671 75、13.444 98 mg/L.3种纤毛虫对四环素的耐受性强度为天蓝喇叭虫>浮萍棘尾虫>尾草履虫;3�

An evolutionarily conserved phosphatidate phosphatase maintains lipid droplet number and endoplasmic reticulum morphology but not nuclear morphology

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Anoop Narayana Pillai

2017-11-01

Full Text Available Phosphatidic acid phosphatases are involved in the biosynthesis of phospholipids and triacylglycerol, and also act as transcriptional regulators. Studies to ascertain their role in lipid metabolism and membrane biogenesis are restricted to Opisthokonta and Archaeplastida. Here, we report the role of phosphatidate phosphatase (PAH in Tetrahymena thermophila, belonging to the Alveolata clade. We identified two PAH homologs in Tetrahymena, TtPAH1 and TtPAH2. Loss of function of TtPAH1 results in reduced lipid droplet number and an increase in endoplasmic reticulum (ER content. It also results in more ER sheet structure as compared to wild-type Tetrahymena. Surprisingly, we did not observe a visible defect in the nuclear morphology of the ΔTtpah1 mutant. TtPAH1 rescued all known defects in the yeast pah1Δ strain and is conserved functionally between Tetrahymena and yeast. The homologous gene derived from Trypanosoma also rescued the defects of the yeast pah1Δ strain. Our results indicate that PAH, previously known to be conserved among Opisthokonts, is also present in a set of distant lineages. Thus, a phosphatase cascade is evolutionarily conserved and is functionally interchangeable across eukaryotic lineages.

Arrest in ciliated cell expansion on the bronchial lining of adult rats caused by chronic exposure to industrial noise

International Nuclear Information System (INIS)

Oliveira, Maria Joao R.; Pereira, Antonio S.; Ferreira, Paula G.; Guimara-tilde es, Laura; Freitas, Diamantino; Carvalho, Antonio P.O.; Grande, Nuno R.; Aguas, Artur P.

2005-01-01

Workers chronically exposed to high-intensity/low-frequency noise at textile plants show increased frequency of respiratory infections. This phenomenon prompted the herein investigation on the cytology of the bronchial epithelium of Wistar rats submitted to textile noise. Workplace noise from a cotton-mill room of a textile factory was recorded and reproduced in a sound-insulated animal room. The Wistar rats were submitted to a weekly schedule of noise treatment that was similar to that of the textile workers (8h/day, 5 days/week). Scanning electron microscopy (SEM) was used to compare the fine morphology of the inner surface of the bronchi in noise-exposed and control rats. SEM quantitative cytology revealed that exposure to noise for 5-7 months caused inhibition in the natural expansion of the area occupied by ciliated cells on the bronchial epithelium as adult rats grow older. This difference between noise-exposed and age-matched control rats was statistically significant (P0.05) and documents that the cytology of the rat bronchial epithelium is mildly altered by noise exposure. The decrease in the area of bronchial cilia may impair the mucociliar clearance of the respiratory airways and, thus, increase vulnerability to respiratory infection

The response of the ciliated epithelium during and after exposure to ionizing radiation

International Nuclear Information System (INIS)

Baldetorp, B.

1984-10-01

Irradiation of the ciliated tissues of the body gives undesirable sideefects. In vitro irradiation (10 Gy) of the rabbit's trachea shows that 1.5 Gy of indirectly ionizing radiation (50 kV and 6 MV X-ray 60 Co-gamma 1.25 MeV) causes a 20 per cent increase of the ciliary beat frequency lasting 5-10 seconds, followed by a decline to normal ciliary activity during the ensuing course of irradiation. Electron radiation (4 MeV) proved to be three times more effective than photon radiation in regard to the physiological response of the cilia to ionizing radiation. This finding led to introduction of the concept Relative Physiological Efficiency (RPE) in this study, complementing the Relative Biological Efficiency (RBE) concept. This momentary increase in frequency can be caused by a radiation-induced increased hydrolysis of the ATP available in the cilia. The ciliary activity was 20 per cent lower than normal at 45 min following irradiation (10 Gy, 50 kV X-ray), whereupon it increased to 12 per cent above normal activity at two hours after initial irradiation. At re-irradiation (10 Gy, 50 kV X-ray) administered two hours after initial irradiation, the cilia showed a constant rate of activity. In vivo irradiation (10 Gy, 160 kV X-ray) of the trachea of the rabbit caused a heightened activity (10%) during the first three days after irradiation, indicating a stimulation of the ATP-synthesis. During days 4 to 8 after irradiation, the ciliary epithelium's morphology was damaged resulting in reduced transport ability. Repair took place during days 9 and 10 after irradiation, i.e. the function of the ciliary epithelium appeared to be restored. The membrane potential of the ciliary cell, registered during irradiation (10 Gy, 50 kV X-ray) showed no changes, which supports the assumption that the increased ciliary beat frequency recorded during irradiation can be due to rapid radiation-induced biochemical changes that are connected to the motility of the cilia. (author)

Ultrastructural features of the uterus in the sexually immature ostrich (Struthio camelus during periods of ovarian inactivity and activity

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M-C. Madekurozwa

2007-09-01

Full Text Available The ultrastructure of the surface epithelium and tubular glands of the uterus in the immature ostrich is described. In ostriches with inactive ovaries the uterus is lined by a non-ciliated simple columnar epithelium, with basally located heterochromatic nuclei. Scanning electron microscopy revealed that these non-ciliated cells have a dense microvillous cover. A simple columnar to pseudostratified columnar epithelium, comprised of non-ciliated and ciliated cells, lines the uterus in birds with active ovaries. The ciliated cells possess a wide luminal region, which contains a nucleus and various organelles. An accumulation of secretory granules was observed in the apical regions of the non-ciliated cells, as well as in a few ciliated cells. In addition to non-ciliated and ciliated cells, a cell type with rarefied cytoplasm was also identified. These cells appear to correspond to calcium secreting cells identified in other avian species. The results of this study indicate that, although uterine differentiation is present in immature ostriches with active ovaries, the production of secretory product appears to occur mainly in non-ciliated epithelial cells.

Rational Engineering of a Cold-Adapted α-Amylase from the Antarctic Ciliate Euplotes focardii for Simultaneous Improvement of Thermostability and Catalytic Activity.

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Yang, Guang; Yao, Hua; Mozzicafreddo, Matteo; Ballarini, Patrizia; Pucciarelli, Sandra; Miceli, Cristina

2017-07-01

The α-amylases are endo-acting enzymes that hydrolyze starch by randomly cleaving the 1,4-α-d-glucosidic linkages between the adjacent glucose units in a linear amylose chain. They have significant advantages in a wide range of applications, particularly in the food industry. The eukaryotic α-amylase isolated from the Antarctic ciliated protozoon Euplotes focardii ( Ef Amy) is an alkaline enzyme, different from most of the α-amylases characterized so far. Furthermore, Ef Amy has the characteristics of a psychrophilic α-amylase, such as the highest hydrolytic activity at a low temperature and high thermolability, which is the major drawback of cold-active enzymes in industrial applications. In this work, we applied site-directed mutagenesis combined with rational design to generate a cold-active Ef Amy with improved thermostability and catalytic efficiency at low temperatures. We engineered two Ef Amy mutants. In one mutant, we introduced Pro residues on the A and B domains in surface loops. In the second mutant, we changed Val residues to Thr close to the catalytic site. The aim of these substitutions was to rigidify the molecular structure of the enzyme. Furthermore, we also analyzed mutants containing these combined substitutions. Biochemical enzymatic assays of engineered versions of Ef Amy revealed that the combination of mutations at the surface loops increased the thermostability and catalytic efficiency of the enzyme. The possible mechanisms responsible for the changes in the biochemical properties are discussed by analyzing the three-dimensional structural model. IMPORTANCE Cold-adapted enzymes have high specific activity at low and moderate temperatures, a property that can be extremely useful in various applications as it implies a reduction in energy consumption during the catalyzed reaction. However, the concurrent high thermolability of cold-adapted enzymes often limits their applications in industrial processes. The α-amylase from the

Prototapirella ciliates from wild habituated Virunga mountain gorillas (Gorilla beringei beringei) in Rwanda with the descriptions of two new species.

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Ito, Akira; Eckardt, Winnie; Stoinski, Tara S; Gillespie, Thomas R; Tokiwa, Toshihiro

2016-06-01

The morphology of Prototapirella fosseyi n. sp., P. rwanda n. sp. and P. gorillaeImai, Ikeda, Collet, and Bonhomme, 1991 in the Entodiniomorphida were described from the mountain gorillas, Gorilla beringei beringei, in Rwanda. The ciliates have a retractable adoral ciliary zone, four non-retractable ciliary tufts in four caudalia, and one broad skeletal plate beneath the body surface. P. rwanda has a dorsal lobe and ventral lobes in two rows whereas P. fosseyi has no lobes. These two new species have an elongated body, a flat tail flap leaning to the ventral, a macronucleus with a tapering anterior end, a round posterior end and a shallow depression on the dorsal side, a micronucleus lying near the anterior end of macronucleus, a thin left region of the skeletal plate, a distinct skeletal rod plate, and four contractile vacuoles. P. gorillae has some variations in the nuclei and the skeletal plate. The infraciliary bands of three Prototapirella species were the same as some Triplumaria species; a C-shaped adoral polybrachykinety, a slender perivestibular polybrachykinety, and paralabial kineties in their retractable adoral ciliary zone and short lateral polybrachykineties in their four caudalia. The perivestibular polybrachykinety is joined only to the right end of adoral polybrachykinety. Copyright © 2016 Elsevier GmbH. All rights reserved.

Functional and phylogenetic evidence of a bacterial origin for the first enzyme in sphingolipid biosynthesis in a phylum of eukaryotic protozoan parasites.

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Mina, John G; Thye, Julie K; Alqaisi, Amjed Q I; Bird, Louise E; Dods, Robert H; Grøftehauge, Morten K; Mosely, Jackie A; Pratt, Steven; Shams-Eldin, Hosam; Schwarz, Ralph T; Pohl, Ehmke; Denny, Paul W

2017-07-21

Toxoplasma gondii is an obligate, intracellular eukaryotic apicomplexan protozoan parasite that can cause fetal damage and abortion in both animals and humans. Sphingolipids are essential and ubiquitous components of eukaryotic membranes that are both synthesized and scavenged by the Apicomplexa. Here we report the identification, isolation, and analyses of the Toxoplasma serine palmitoyltransferase, an enzyme catalyzing the first and rate-limiting step in sphingolipid biosynthesis: the condensation of serine and palmitoyl-CoA. In all eukaryotes analyzed to date, serine palmitoyltransferase is a highly conserved heterodimeric enzyme complex. However, biochemical and structural analyses demonstrated the apicomplexan orthologue to be a functional, homodimeric serine palmitoyltransferase localized to the endoplasmic reticulum. Furthermore, phylogenetic studies indicated that it was evolutionarily related to the prokaryotic serine palmitoyltransferase, identified in the Sphingomonadaceae as a soluble homodimeric enzyme. Therefore this enzyme, conserved throughout the Apicomplexa, is likely to have been obtained via lateral gene transfer from a prokaryote. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Prevalence of Trichomonas vaginalis infection and protozoan load in South African women: a cross-sectional study

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de Waaij, Dewi J

2017-01-01

Objectives Trichomonas vaginalis is thought to be the most common non-viral sexually transmitted infection worldwide. We investigated the prevalence, risk factors and protozoan load of T. vaginalis infection in South African women. Methods A cross-sectional study of 604 women was conducted at 25 primary healthcare facilities in rural South Africa (Mopani district). T. vaginalis DNA was detected in vaginal and rectal swabs. In univariate and multivariate analyses, the T. vaginalis infection was investigated in relation to demographic characteristics, medical history and behavioural factors. The T. vaginalis load was determined as the logarithm of DNA copies per microlitre sample solution. Results Collected vaginal and rectal swabs were tested for T. vaginalis DNA. Prevalence of vaginal T. vaginalis was 20% (95% CI 17.0% to 23.4%) and rectal 1.2% (95% CI 0.6% to 2.4%). Most women (66%) with a vaginal infection were asymptomatic. Factors associated with T. vaginalis infection were a relationship status of single (OR 2.4; 95% CI 1.5 to 4.0; pvaginalis infection were more likely to have concurrent Chlamydia trachomatis rectal infection than those without vaginal infection (12%vs3%; pvaginalis load was observed among women with observed vaginal discharge compared with those without vaginal discharge (p=0.025). Conclusions Vaginal trichomoniasis is highly prevalent in rural South Africa, especially among single women and those with HIV infection, and often presents without symptoms. PMID:28993385

A Diverse Family of Host-Defense Peptides (Piscidins Exhibit Specialized Anti-Bacterial and Anti-Protozoal Activities in Fishes.

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Scott A Salger

Full Text Available Conventional antibiotics and other chemical-based drugs are currently one of the most common methods used to control disease-related mortality in animal agriculture. Use of the innate immune system to decrease disease related mortalities is a novel alternative to conventional drugs. One component of the innate immune system is the host-defense peptides, also known as antimicrobial peptides. Host-defense peptides are typically small, amphipathic, α-helical peptides with a broad-spectrum of action against viral, bacterial, fungal, and/or protozoal pathogens. Piscidins are host-defense peptides first discovered in the hybrid striped bass (white bass, Morone chrysops, x striped bass, M. saxatilis. In this paper we identify four new piscidin isoforms in the hybrid striped bass and describe their tissue distributions. We also determine the progenitor species of origin of each piscidin (orthology and propose a revised nomenclature for this newly described piscidin family based on a three class system. The Class I piscidins (22 amino acids in length; striped bass and white bass piscidin 1 and piscidin 3 show broad-spectrum activity against bacteria and ciliated protozoans, while the Class III piscidins (55 amino acids in length; striped bass and white bass piscidin 6 and striped bass piscidin 7 primarily show anti-protozoal activity. The Class II piscidins (44-46 amino acids in length; striped bass and white bass piscidin 4 and white bass piscidin 5 have a level of activity against bacteria and protozoans intermediate to Classes I and III. Knowledge of piscidin function and activity may help in the future development of disease-resistant lines of striped bass and white bass that could be used to produce superior hybrids for aquaculture.

A Diverse Family of Host-Defense Peptides (Piscidins) Exhibit Specialized Anti-Bacterial and Anti-Protozoal Activities in Fishes.

Science.gov (United States)

Salger, Scott A; Cassady, Katherine R; Reading, Benjamin J; Noga, Edward J

2016-01-01

Conventional antibiotics and other chemical-based drugs are currently one of the most common methods used to control disease-related mortality in animal agriculture. Use of the innate immune system to decrease disease related mortalities is a novel alternative to conventional drugs. One component of the innate immune system is the host-defense peptides, also known as antimicrobial peptides. Host-defense peptides are typically small, amphipathic, α-helical peptides with a broad-spectrum of action against viral, bacterial, fungal, and/or protozoal pathogens. Piscidins are host-defense peptides first discovered in the hybrid striped bass (white bass, Morone chrysops, x striped bass, M. saxatilis). In this paper we identify four new piscidin isoforms in the hybrid striped bass and describe their tissue distributions. We also determine the progenitor species of origin of each piscidin (orthology) and propose a revised nomenclature for this newly described piscidin family based on a three class system. The Class I piscidins (22 amino acids in length; striped bass and white bass piscidin 1 and piscidin 3) show broad-spectrum activity against bacteria and ciliated protozoans, while the Class III piscidins (55 amino acids in length; striped bass and white bass piscidin 6 and striped bass piscidin 7) primarily show anti-protozoal activity. The Class II piscidins (44-46 amino acids in length; striped bass and white bass piscidin 4 and white bass piscidin 5) have a level of activity against bacteria and protozoans intermediate to Classes I and III. Knowledge of piscidin function and activity may help in the future development of disease-resistant lines of striped bass and white bass that could be used to produce superior hybrids for aquaculture.

Mutagenicity of fly ash samples in a test with the protozoan Paramecium tetraurelia. Onderzoek naar de mutageniteit van een aantal vliegasmonsters in een toets met het pantoffeldiertje Paramecium tetraurelia

Energy Technology Data Exchange (ETDEWEB)

Hooftman, R.N.

1983-08-01

The mutagenicity of fly ash derived from combustion of coal was investigated in a test with the protozoan Paramecium tetraurelia. This unicellular organism is able to ingest particles of the size of these that are ingested and removed by the alveolar macrophages in the lung of man and other animals: in Paramecium, as in the macrophage, ingestion is followed by intracellular extraction. Both ash from the electrostatic filter and stack-ash were mutagenic in Paramecium. The results showed similarities with and some differences from those obtained in the Ames test. There are indications that the test with Paramecium is a sensitive test for the mutagenicity of complex wastes.

Mutagenicity of fly ash samples in a test with the protozoan Paramecium tetraurelia. Onderzoek naar de mutageniteit van een aantal vliegasmonsters in een toets met het pantoffeldiertje Paramecium tetraurelia

Energy Technology Data Exchange (ETDEWEB)

Hooftman, R.N.

1983-08-01

The mutagenicity of fly ash derived from combustion of coal was investigated in a test with the protozoan Paramecium tetraurelia. This unicellular organism is able to ingest particles of the size of those that are ingested and removed by the alveolar macrophages in the lung of man and other animals: in Paramecium, as in the macrophage, ingestion is followed by intracellular extraction. Both ash from the electrostatic filter and stack-ash were mutagenic in Paramecium. The results showed similarities with and some differences from those obtained in the Ames test. There are indications that the test with Paramecium is a sensitive test for the mutagenicity of complex wastes.

Polymeric immunoglobulin receptor in intestinal immune defense against the lumen-dwelling protozoan parasite Giardia.

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Davids, Barbara J; Palm, J E Daniel; Housley, Michael P; Smith, Jennifer R; Andersen, Yolanda S; Martin, Martin G; Hendrickson, Barbara A; Johansen, Finn-Eirik; Svärd, Staffan G; Gillin, Frances D; Eckmann, Lars

2006-11-01

The polymeric Ig receptor (pIgR) is conserved in mammals and has an avian homologue, suggesting evolutionarily important functions in vertebrates. It transports multimeric IgA and IgM across polarized epithelia and is highly expressed in the intestine, yet little direct evidence exists for its importance in defense against common enteric pathogens. In this study, we demonstrate that pIgR can play a critical role in intestinal defense against the lumen-dwelling protozoan parasite Giardia, a leading cause of diarrheal disease. The receptor was essential for the eradication of Giardia when high luminal IgA levels were required. Clearance of Giardia muris, in which IgA plays a dominant role, was severely compromised in pIgR-deficient mice despite significant fecal IgA output at 10% of normal levels. In contrast, eradication of the human strain Giardia lamblia GS/M, for which adaptive immunity is less IgA dependent in mice, was unaffected by pIgR deficiency, indicating that pIgR had no physiologic role when lower luminal IgA levels were sufficient for parasite elimination. Immune IgA was greatly increased in the serum of pIgR-deficient mice, conferred passive protection against Giardia, and recognized several conserved giardial Ags, including ornithine carbamoyltransferase, arginine deiminase, alpha-enolase, and alpha- and beta-giardins, that are also detected in human giardiasis. Corroborative observations were made in mice lacking the J chain, which is required for pIgR-dependent transepithelial IgA transport. These results, together with prior data on pIgR-mediated immune neutralization of luminal cholera toxin, suggest that pIgR is essential in intestinal defense against pathogenic microbes with high-level and persistent luminal presence.

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.

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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. Copyright © 2016 Elsevier B.V. All rights reserved.

Ecological effects of ionizing radiation on population and ecosystem: a computational model ecosystem study

International Nuclear Information System (INIS)

Doi, Masahiro; Fuma, Shoichi; Ishii, Nobuyuki; Sakashita, Tetsuya; Miyamoto, Kiriko; Takeda, Hiroshi; Kawabata, Zenichiro

2003-01-01

Ecosystem is a self-sustaining system of complexity, and their responses to the impacts are synergistic and subjected to the demographic stochasticity of the species, environmental stochasticity and randomness. Environmental fate and effects of radiation has ranged from observable DNA damage of the cell to the fare on tissues, individual, population, community and ecosystems. The quantitative, systematic individual-based model, SIM-COSM was developed to simulate impacts of radiation exposure and other toxicants on an aquatic microbial ecosystem (microcosm). The microcosm consists of heterotroph ciliate protozoa (Tetrahymena thermophila B) as a consumer, autotroph flagellate algae (Euglena gracilis Z) as a producer and saprotroph bacteria (Escherichia coli DH5) as a decomposer. The symbiosis among microbes is self-organized by realizing material cycle and sustained for more than 2 years after inoculation. The system can not afford to lose any one of the microbes to maintain its sustainability. Experimental ecotoxicological tests for (a) gamma radiation, (b) Manganese ions and (c) Gadolinium are summarized. Population dynamics of microbes in Microcosm and its computer simulations by SIM-COSM are shown together in a figure. Population dynamics in Microcosm and SIM-COSM exposed to 500 Gy of gamma-radiation at 50 days after inoculation are shown also in a figure. To take the effects on the interactions between species and environment into account, one option is to put the ecotoxicity tests as experimental micro ecosystem study and theoretical model ecosystem analysis. (M. Suetake)

Molecular phylogeny and species separation of five morphologically similar Holosticha-complex ciliates (Protozoa, Ciliophora) using ARDRA riboprinting and multigene sequence data

Science.gov (United States)

Gao, Feng; Yi, Zhenzhen; Gong, Jun; Al-Rasheid Khaled, A. S.; Song, Weibo

2010-05-01

To separate and redefine the ambiguous Holosticha-complex, a confusing group of hypotrichous ciliates, six strains belonging to five morphospecies of three genera, Holosticha heterofoissneri, Anteholosticha sp. pop1, Anteholosticha sp. pop2, A. manca, A. gracilis and Nothoholosticha fasciola, were analyzed using 12 restriction enzymes on the basis of amplified ribosomal DNA restriction analysis. Nine of the 12 enzymes could digest the DNA products, four ( Hinf I, Hind III, Msp I, Taq I) yielded species-specific restriction patterns, and Hind III and Taq I produced different patterns for two Anteholosticha sp. populations. Distinctly different restriction digestion haplotypes and similarity indices can be used to separate the species. The secondary structures of the five species were predicted based on the ITS2 transcripts and there were several minor differences among species, while two Anteholosticha sp. populations were identical. In addition, phylogenies based on the SSrRNA gene sequences were reconstructed using multiple algorithms, which grouped them generally into four clades, and exhibited that the genus Anteholosticha should be a convergent assemblage. The fact that Holosticha species clustered with the oligotrichs and choreotrichs, though with very low support values, indicated that the topology may be very divergent and unreliable when the number of sequence data used in the analyses is too low.

Cotterillia bromelicola nov. gen., nov. spec., a gonostomatid ciliate (Ciliophora, Hypotricha) from tank bromeliads (Bromeliaceae) with de novo originating dorsal kineties.

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Foissner, Wilhelm; Stoeck, Thorsten

2011-01-01

Cotterillia bromelicola nov. gen., nov. spec. was discovered in the tanks of the Mexican bromeliad Tillandsia heterophylla. Its morphology, ontogenesis, and 18S rDNA were studied with standard methods. Cotterillia has many cirral rows on both sides of the body. Uniquely, and thus used to diagnose the new genus Cotterillia, it has dorsal kineties originating de novo, producing neokinetal waves where the parental dorsal kineties reorganize to "combined rows", consisting of dorsal bristles anteriorly and of cirri posteriorly. Thus, up to four generations of bristles and cirri occur on the dorsal body surface. Cotterillia bromelicola has a gonostomatid body and adoral zone of membranelles, while the dense ciliature and the neokinetal waves resemble kahliellid hypotrichs. However, the de novo origin of anlage 1 and the molecular analyses show convincingly that Cotterillia belongs to the GonostomatidaeSmall and Lynn, 1985, for which an improved diagnosis is provided. Thus, neokinetal waves originated several times independently. The molecular differences between Trachelostyla, Gonostomum, and Cotterillia are small (≤ 5%) compared to their distinct morphologies and ontogeneses, suggesting that the 18S rDNA underestimates generic diversity. Our study emphasizes the need of combined morphological, ontogenetic, and molecular investigations to unravel the complex phylogeny and evolution of hypotrich ciliates. Published by Elsevier GmbH.

Developing a quick and inexpensive in vitro (non-animal) bioassay for mascara irritation.

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Thomason, H; Montagnes, D J S

2014-04-01

Mascara is a mild irritant that causes a range of medical problems. Animal models to predict ocular irritation have, however, been questioned at a number of levels, and there is a continued need to develop in vitro testing methods. We assess changes in an easily quantifiable attribute, ciliated protozoan growth rate, as a sensitive, sublethal measure. Specifically, we test six, randomly chosen, commercial mascara products against a control (as treatments) and reveal through ANOVA (n = 6, α = 0.05) significant differences in the specific growth rate to treatments (for both protozoa). We provide evidence that two easily cultured protozoa (Paramecium caudatum, Blepharisma japonicum) should be considered as models to assess ocular irritancy (and possibly cosmetics in general) and establish the groundwork for such studies to be applied at a more commercial level. We do this by developing a bioassay for mascara toxicity and indicate the low cost (after equipment is purchased, on the order of $100s) and the ease of performing such tests (able to be conducted by undergraduate students), as a consideration for their future commercial application. We first examined dose dependence of responses, revealing that there was a need to conduct preliminary work to determine appropriate levels for sublethal responses. We then show that some products resulted in mortality at high concentrations, others decreased growth rate by >50% (compared with the control), whereas others had no significant effect, compared with the control. We have provided a novel, quick and inexpensive means to assess mascara; the next step is to validate these ciliate bioassays by comparison with animal testing and epidemiological studies, which is beyond the scope of this fundamental 'proof-of-concept' study. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

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.