Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| method for determination of chemoattraction in tetrahymena pyriformis. | earlier works presented a variety of techniques for detection of chemoattractants in ciliates. the present agar layer model and the used double-p cutter give an easy, reproducible way of quantitative evaluation of positive chemotaxis. beside the two-channel chamber, the multi-channel one seems to be also useful in characterization of different taxons or different chemoattractants. | 1995 | 7765899 |
| identification of an hsp70-related protein associated with the centrosome from dinoflagellates to human cells. | the monoclonal antibody ctr210 raised against isolated human centrosomes strongly decorates the centrosome and more weakly a domain congruent with the golgi apparatus in several animal cells (hela, 3t3, cho, ptk2). both decorations resist triton extraction in conditions which totally extract the golgi apparatus, as judged by galactosyltransferase decoration. a 67 kda centrosomal antigen can be demonstrated in human cells with this antibody. ctr210 also decorates the centrosome or associated stru ... | 1995 | 7769013 |
| cellular polarity in ciliates: persistence of global polarity in a disorganized mutant of tetrahymena thermophila that disrupts cytoskeletal organization. | much of the cell surface on the ciliate tetrahymena thermophila is covered by a polarized lattice of cytoskeletal structures that are associated with basal bodies of the ciliary rows. unique structural landmarks, including an oral apparatus and contractile vacuole pores, develop before cell division in localized domains located, respectively, posterior and anterior to the transverse fission zone. all of these structures can be visualized by specific monoclonal antibodies. a single-locus recessiv ... | 1995 | 7781905 |
| protein-dna interactions in soluble telosomes from saccharomyces cerevisiae. | telomeric dna in saccharomyces is organized into a non-nucleosomal chromatin structure called the telosome that can be released from chromosome ends in soluble form by nuclease digestion (wright, j. h., gottschling, d. e. and zakian, v. a. (1992) genes dev. 6, 197-210). the protein-dna interactions of soluble telosomes were investigated by monitoring isolated telomeric dna fragments for the retention of bound protein using both gel mobility shift and nitrocellulose filter-binding assays. telosom ... | 1995 | 7784196 |
| cortical memory in paramecium: a theoretical approach to the structural heredity. | structural heredity is frequently encountered in ciliates. in particular, during division of paramecium the cortical characteristics of the 2 daughter cells are inherited from those of the mother cell. genesis of new structures is therefore only possible if there are pre-existing older structures. we attempted to simulate this phenomenon with a model already used to describe the structure and morphogenesis of the cortex of paramecium. we show that to initiate spatial organization it is enough to ... | 1995 | 7788506 |
| quantitative structure-toxicity relationships and volume fraction analyses for selected esters. | the acute toxicity of aliphatic and aromatic mono and diesters in two eucaryotic organisms was compared. the test systems were the static 2-d tetrahymena pyriformis 50% population growth impairment (igc50(-1)) assay, and the flow-through 4-d pimephales promelas 50% mortality (lc50(-1)) assay. in ciliates, esters act via the nonpolar narcosis mechanism of toxic action. this was indicated by: the high quality 1-octanol/water partition coefficient (log kow) dependent quantitative structure-activity ... | 1995 | 7794017 |
| purification and primary structure of metallothioneins induced by cadmium in the protists tetrahymena pigmentosa and tetrahymena pyriformis. | tetrahymena pyriformis and tetrahymena pigmentosa grown in the presence of a non-toxic dose of cadmium, accumulate the metal in the cytosol. purification by gel-permeation, ion-exchange and reverse-phase high-performance liquid chromatography showed that the metal is bound principally to newly formed proteins with ultraviolet spectra and cysteine contents similar to those of cd(2+)-metallothioneins from multicellular organisms. the isolated proteins revealed that the two species of ciliates each ... | 1994 | 7813475 |
| [ambiphrya ameiuri (ciliophora: peritricha): its ultrastructure and distribution on the body of carp fry]. | the mass infection of larvae and youngsters of carp fishes with the peritrichoid ambiphrya ameiuri has been recorded in natural condition in the rybinsk water reservoir. the uneven localisation of ambiphyrans on the body surface has been observed on the hosts blicca bjorkna and abramis brama. most high density of parasites was on the breast, back and tail fins. the morphological variability of ambiphyrans in dependence upon their localisation on the fish body has been observed. details being sig ... | 1994 | 7824286 |
| free-living ciliates in csf of a patient with meningoencephalitis: a contaminant? | 1994 | 7825018 | |
| the fate of deleted dna produced during programmed genomic deletion events in tetrahymena thermophila. | 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 ... | 1994 | 7838724 |
| detection of circular excised dna deletion elements in tetrahymena thermophila during development. | extensive programmed dna deletion occurs in ciliates during development. in this study we examine the excised forms of two previously characterized deletion elements, the r- and m-element, in tetrahymena. using divergently oriented primers in polymerase chain reactions we have detected the junctions formed by joining the two ends of these elements, providing evidence for the presence of circular excised forms. these circular forms were detected in developing macronuclear dna from 12-24 h after m ... | 1994 | 7838725 |
| [tetrahymena pyriformis--a cell test system for environmental medicine. the effect of harmful substances on the cell morphology of tetrahymena pyriformis]. | in the region of middle germany phenols and their derivatives are important toxicological compounds for the environment and man. these compounds from wastes water of brown coal mining are source of danger, which can't estimate now. the influence of phenolic compounds on cells and organisms will be investigated with a species of ciliates-tetrahymena pyriformis as testing system. t. pyriformis is a single-celled eucaryotic organism, which is comparable in sensitiveness and responsiveness to human ... | 1994 | 7848498 |
| acute toxicity of lead, chromium, and other heavy metals to ciliates from activated sludge plants. | 1994 | 7919720 | |
| telomerase rnas of different ciliates have a common secondary structure and a permuted template. | telomerase is composed of protein and rna. the rna serves as a template for telomere dna synthesis and may also be important for enzyme structure or catalysis. we have used the presence of conserved sequence elements in the promoter and template regions to amplify by pcr the telomerase rna genes from six different hypotrichous ciliates: oxytricha nova, oxytricha trifallax, stylonychia mytilis, stylonychia lemnae, euplotes aediculatus, and euplotes eurystomus. rnaseh cleavage of the o. nova rna i ... | 1994 | 7958872 |
| detection of ubiquinone in parasitic and free-living protozoa, including species devoid of mitochondria. | ubiquinone (coenzyme q, coq) was analyzed and individual homologues quantified in 11 species of parasitic and free-living protozoa by a combination of thin-layer chromatography and high performance liquid chromatography. fast atom bombardment ionization-mass spectrometry was used for the first time to confirm the identity of the fractionated coq homologues and proved to be a fast, gentle and convenient method for ubiquinone identification. ubiquinone was detected in all organisms including those ... | 1994 | 7969263 |
| architecture of telomerase rna. | telomerase, an essential ribonucleoprotein reverse transcriptase, adds telomeric dna to the ends of eukaryotic chromosomes. we examined the conformational properties of the naked rna moiety of telomerase from two related ciliates, tetrahymena thermophila and glaucoma chattoni. as well as finding evidence for features proposed previously on the basis of phylogenetic comparisons, novel conserved structural properties were revealed. specifically, although the region around helix iii was previously ... | 1994 | 7988568 |
| differential elimination of enteric bacteria by protists in a freshwater system. | the short-term (1 h) and long-term (3 d) elimination of low and high densities of five enteric bacteria, klebsiella pneumoniae, aeromonas hydrophila, escherichia coli, enterococcus faecalis and staphylococcus epidermidis, by flagellate and ciliate protists were measured in a freshwater system. in addition, the two processes, ingestion and digestion, which cause the disappearance of those enteric bacteria as time passes, were quantified. the results showed that the elimination of these enteric ba ... | 1994 | 8002473 |
| [proposition of a new classification of the phylum of the protozoa ciliophora doflein, 1901]. | it is proposed to use all the presently available molecular, ultrastructural, biological and ecological data on ciliates for the new classification of this group of protists. on the basis of the cortical organization and the mode of cilia anchoring as well as the degree of conservation of the cortical pattern during the process of morphogenesis, eleven classes (karyorelictea, heterotrichea, hypotrichea, oligotrichea, plagiopylea, colpodea, litostomatea, vestibuliferea, phyllopharyngea, nassophor ... | 1993 | 8044695 |
| redescription of trichodina kamchatika konovalov, shevlyakov et krasin, 1970 (ciliophora: peritrichida) from the brook trout (salvelinus fontinalis) of eastern canada. | trichodina kamchatika konovalov, shevlyakov et krasin, 1970 is redescribed based on specimens obtained from the gills and body surface of brook trout (salvelinus fontinalis) from nova scotia and quebec, canada and its taxonomic history briefly reviewed. this is the first report of t. kamchatika from north america. | 1994 | 8050753 |
| natural vectors of three bovine onchocerca species (nematoda: onchocercidae) and seasonal transmission by three blackfly species (diptera: simuliidae) in central kyushu, japan. | eleven blackfly species were examined in relation to the transmission of bovine onchocerciasis in central kyushu, japan. a total of 19,005 out of 47,746 females captured from june 1989 to june 1990 at two cattle sheds each in oita and kumamoto were dissected for their parities, infections with onchocerca larvae, and intakes of onchocerca microfilariae. overall results showed that simulium bidentatum (shiraki), the predominant species, is a natural vector of the two bovine onchocerca species, i.e ... | 1994 | 8057315 |
| the dna of ciliated protozoa. | ciliates contain two types of nuclei: a micronucleus and a macronucleus. the micronucleus serves as the germ line nucleus but does not express its genes. the macronucleus provides the nuclear rna for vegetative growth. mating cells exchange haploid micronuclei, and a new macronucleus develops from a new diploid micronucleus. the old macronucleus is destroyed. this conversion consists of amplification, elimination, fragmentation, and splicing of dna sequences on a massive scale. fragmentation pro ... | 1994 | 8078435 |
| systematic and morphological diversity of endosymbiotic methanogens in anaerobic ciliates. | the identities and taxonomic diversity of the endosymbiotic methanogens from the anaerobic protozoa metopus contortus, metopus striatus, metopus palaeformis, trimyema sp. and pelomyxa palustris were determined by comparative analysis of their 16s ribosomal rna sequences. fluorescent oligonucleotide probes were designed to bind to the symbiont rrna sequences and to provide direct visual evidence of their origins from methanogenic archaea contained within the host cells. confocal microscopy was us ... | 1993 | 8085789 |
| accumulation of selenium in a model freshwater microbial food web. | the transfer of selenium between bacteria and the ciliated protozoan, paramecium putrinum, was examined in laboratory cultures. the population growth of the ciliate was not inhibited in the presence of the highest concentrations of dissolved selenite or selenate tested (10(3) micrograms liter-1). experiments with radioactive 75selenite or 75selenate indicated that accumulation of selenium by ciliates through time was low when feeding and metabolism were reduced by incubating at 0 degrees c. howe ... | 1994 | 8085812 |
| identification of the tubulin gene family and sequence determination of one beta-tubulin gene in a cold-poikilotherm protozoan, the antarctic ciliate euplotes focardii. | four different tubulin genes were identified in the somatic nucleus (macronucleus) of euplotes focardii, a strictly cold-adapted, antarctic ciliate: one of 1,800 bp for alpha-tubulin and three of 2,150, 1,900, and 1,600 bp, respectively, for beta-tubulin. preliminarily analysed for restriction fragment length polymorphisms, these genes showed remarkable differences in organisation from tubulin genes of other ciliates which live in temperate areas and were analysed in parallel with e. focardii. t ... | 1994 | 8087111 |
| [molecular biology of ciliates]. | 1994 | 8108566 | |
| [molecular biology of the behavior in ciliates]. | 1994 | 8108569 | |
| tolerance of sewage treatment plant microorganisms to mosquitocides. | beneficial protozoa and rotifers collected from a wastewater treatment plant in panama city, fl, were tested for tolerance to 11 commonly used mosquito larvicides and adulticides in the laboratory. the acute effects were assessed using selected concentrations of the adulticides fenthion, malathion, naled, permethrin, and resmethrin; and the larvicides bacillus thuringiensis israelensis, bacillus sphaericus, diflubenzuron, larviciding oil, methoprene, and temephos for the following microorganism ... | 1993 | 8126488 |
| developmentally excised sequences in micronuclear dna of paramecium. | dna processing occurs in ciliates at autogamy and conjugation when new macronuclei are formed from micronuclei and old macronuclei degrade. processing of micronuclear dna consists of removal of certain internal sequences, chromosomal fragmentation, addition of new telomeres, and amplification. aside from a recent brief report, internal eliminated sequences have not been described in paramecium. in this paper we characterize nine internal eliminated sequences found within and near the gene that c ... | 1994 | 8134383 |
| a standardized method for the in vivo maintenance of cryptocaryon irritans (ciliophora) using the grey mullet chelon labrosus as an experimental host. | experimental primary infections with cryptocaryon irritans were successfully established in mullet following exposure to theronts and maintained for up to 34 successive cycles in this host. fish were exposed to measured numbers of theronts collected within 4 hr of excystment. free-swimming trophonts and reproductive cysts were maintained in wells of tissue culture plates containing sterilized seawater and subjected to a photoperiod of 12 hr light:12 hr dark. excystment was found to be asynchrono ... | 1994 | 8158473 |
| tannins in treehole habitats and their effects on aedes sierrensis (diptera: culicidae) production and parasitism by lambornella clarki (ciliophora: tetrahymenidae). | tannin concentration, measured as total phenolics, varied widely in natural treehole water throughout the period of development for aedes sierrensis (ludlow), the western treehole mosquito. tannic acid induced a parasitic response in free-living populations of the protozoan lambornella clarki corliss & coats, an effect not entirely explained by acidity. tannic acid concentration influenced mosquito developmental rates, survival, size, and proportion females more than food level, l. clarki parasi ... | 1994 | 8158619 |
| the alpha- and beta-tubulin genes of euplotes octocarinatus. | the alpha- and the beta-tubulin genes of the hypotrichous ciliate euplotes octocarinatus were isolated from a size-selected macronuclear dna library. the alpha-tubulin gene is located on a 1,587 bp macronuclear dna molecule and the beta-tubulin gene on a 1,524 bp macronuclear dna molecule. sequencing revealed that all the cysteine residues of the two genes are encoded by the common cysteine codons ugu and ugc and none by an uga codon. this is in contrast to the genes of e. octocarinatus sequence ... | 1994 | 8167618 |
| the use of small subunit rrna sequences to unravel the relationships between anaerobic ciliates and their methanogen endosymbionts. | 1994 | 8180687 | |
| some rumen ciliates have endosymbiotic methanogens. | most of the small ciliate protozoa, including dasytricha ruminantium and entodinium spp. living in the rumen of sheep, were found to have intracellular bacteria. these bacteria were not present in digestive vacuoles. they showed characteristic coenzyme f420 autofluorescence and they were detected with a rhodamine-labelled archaea-specific oligonucleotide probe. the measured volume percent of autofluorescing bacteria (1%) was close to the total volume of intracellular bacteria estimated from tem ... | 1994 | 8181718 |
| polypeptides of hydrogenosome-enriched fractions from rumen ciliate protozoa and trichomonads: immunological studies. | the evolution of hydrogenosomes, energy-generating organelles of rumen ciliate protozoa and the flagellate trichomonads has been the subject of much speculation. polypeptides of the hydrogenosome-enriched fractions from the rumen ciliates, dasytricha ruminantium, isostricha spp., polyplastron multivesiculatum and eudiplodinium maggii were separated by sds-page and compared to analogous polypeptide preparations from tritrichomonas foetus. immunoblotting with antisera specific to the hydrogenosome ... | 1994 | 8181726 |
| signalling in cell growth and death: adequate nutrition alone may not be sufficient for ciliates. a minireview. | the initial inoculum level of tetrahymena in a chemically defined medium determines whether the cells are capable of exponential growth. below 750 cells ml-1, the cells fail to go into exponential growth and will die within about 20 hours. by adding certain growth stimulants, death can be postponed and the cells begin to grow after a delay which depends on the intensity of the signal. the implication is that autocrine growth factor expression might be required for cells to grow, and that these s ... | 1993 | 8220307 |
| a distant 10-bp sequence specifies the boundaries of a programmed dna deletion in tetrahymena. | programmed dna deletion occurs at thousands of specific sites in most ciliates studied. to understand the mechanism of this prominent dna rearranging process, we analyzed one of the deletion elements (the m-element) in tetrahymena by making specific mutations in cloned dnas and testing their effects on rearrangement in vivo. we found that a 10-bp polypurine sequence (5'-aaaaaggggg) plays a crucial role. this sequence is located at a short distance (approximately 45 bp) outside of the element on ... | 1993 | 8253382 |
| restructuring of dna sequences in the germline genome of oxytricha. | most genes in the germline genome of hypotrichous ciliates are crippled by the presence of interrupting sequences. some genes are additionally impaired because their sequences are in disorder. these gene defects are corrected when germline chromosomal dna sequences are amplified, cut, spliced, reordered, and eliminated to produce somatic dna. | 1993 | 8274854 |
| photosensory transduction in ciliates. role of intracellular ph and comparison between stentor coeruleus and blepharisma japonicum. | to test the hypothesis that light signal transduction in the unicellular ciliates stentor coeruleus and blepharisma japonicum involves a change in intracellular ph as an initial signal following photoexcitation, we studied the dependence of the photophobic responses of the cells to changes in extracellular ph and to reagents that specifically affect intracellular ph. the extracellular ph can modify not only the intracellular ph, but can even reverse the sign of the ph gradient across the cell me ... | 1993 | 8289111 |
| the processing of macronuclear dna sequences during macronuclear development of the hypotrichous ciliate stylonychia lemnae. | the organization of two macronuclear dna sequences in the polytene chromosomes of the hypotrichous ciliate stylonychia lemnae and their processing from the micronucleus via the polytene chromosome stage up to the macronucleus was analyzed. the overall organization of these sequences in the polytene chromosomes resembles that described for the micronucleus of other hypotrichous ciliates, i.e. they are interrupted by internal eliminated sequences and not associated with telomeric sequences. the sp ... | 1993 | 8292542 |
| kingdom protozoa and its 18 phyla. | the demarcation of protist kingdoms is reviewed, a complete revised classification down to the level of subclass is provided for the kingdoms protozoa, archezoa, and chromista, and the phylogenetic basis of the revised classification is outlined. removal of archezoa because of their ancestral absence of mitochondria, peroxisomes, and golgi dictyosomes makes the kingdom protozoa much more homogeneous: they all either have mitochondria and peroxisomes or have secondarily lost them. predominantly p ... | 1993 | 8302218 |
| structure of the large ribosomal subunit rna of phytophthora megasperma, and phylogeny of the oomycetes. | the 5.8s and 28s rrna sequences of the oomycete phytophthora megasperma were determined in order to study the secondary structure of these molecules and to assess the phylogenetic position of the oomycetes among the eukaryotes. preliminary results point to an affiliation between the oomycetes, dinoflagellates and ciliates, a cluster which seems related to the fungi. in the course of this work, we developed a set of primers which allow sequencing and pcr amplification of eukaryotic large ribosoma ... | 1994 | 8307170 |
| processing of food vacuoles in the parasitic ciliate ichthyophthirius multifiliis after exit from the host. | the digestive cycle of the fish parasite ichthyophthirius multifiliis (ciliophora) can be divided into three main stages. during stage a the vacuoles are not yet condensed. this stage can be subdivided into an early phase in which food vacuoles contain almost intact fish cells and a later phase in which dense material accumulates at the periphery of the vacuoles. at stage b, food vacuoles attain a very high density, and at stage c the vacuole expands when the membrane pulls away from a condensed ... | 1993 | 8327449 |
| [the basic types and forms of the fine structure of mitochondrial cristae: the degree of their evolutionary stability (capacity for morphological transformations)]. | the organellological analysis being made of the fine structure of mitochondria in different species of the kingdom protista, and in different cells of representatives of the kingdoms plantae and animalia (metazoa). on the base of this analysis the following classification of types and forms of the fine structure of mitochondrial cristae is proposed. the ist type, with lamellar (flat) cristae includes four morphological forms: ribbon, sheet, bundle-like and rounded ones (discoidal and plate-like) ... | 1993 | 8328023 |
| new host record for the entodiniomorphid ciliate, troglodytella abrassarti, from siamangs (hylobates syndactylus). | examination of faecal samples from several diarrhoeic siamangs hylobates syndactylus (anthropoidea: hylobatidae) revealed the presence of numerous entodiniomorphid ciliates whose morphological and ultrastructural characteristics were consistent with those of troglodytella abrassarti previously recorded from chimpanzees, orangutans and gorillas (anthropoidea: pongidae). | 1993 | 8359993 |
| phylogenetic position of the genus perkinsus (protista, apicomplexa) based on small subunit ribosomal rna. | parasites of the genus perkinsus destroy marine molluscs worldwide. their phylogenetic position within the kingdom protista is controversial. nucleotide sequence data (1792 bp) from the small subunit rrna gene of perkinsus sp. from anadara trapezia (mollusca: bivalvia) from moreton bay, queensland, was used to examine the phylogenetic affinities of this enigmatic genus. these data were aligned with nucleotide sequences from 6 apicomplexans, 3 ciliates, 3 flagellates, a dinoflagellate, 3 fungi, m ... | 1993 | 8366895 |
| photosensory transduction in ciliates. ii. possible role of g-protein and cgmp in stentor coeruleus. | the heterotrichous ciliate, stentor coeruleus, exhibits a well-defined photophobic response to a sudden increase in the intensity of visible light. the phobic reactions usually appear with a latency period (i.e. a time delay between the onset of the stimulus and the stop response). this latency of phobic response was significantly increased when the cells were incubated with 8-bromo-guanosine 3',5'-cyclic monophosphate. in the presence of this nucleotide, a reduction of cell responsiveness (i.e. ... | 1993 | 8389485 |
| phospholipid biosynthesis in protozoa. | because of the diverse nature of the organisms which are all classed as 'protozoa' (and because of the lack of detailed information on phospholipid metabolism about most of them), it will probably never be possible to generalize phospholipid metabolism to the degree that it has been possible to characterize a mammalian metabolism. nonetheless, patterns have begun to emerge (i.e. the similarities among the ciliates entodinium, paramecium and tetrahymena) and will not doubt be expanded upon in the ... | 1993 | 8415798 |
| rumen ciliates of ezo deer (cervus nippon yesoensis) with the morphological comparison with those of cattle. | the composition of rumen ciliate protozoa was surveyed in 13 ezo deer, cervus nippon yesoensis, inhabiting hokkaido, japan. as a result, two species of the genus entodinium, e. simplex and e. dubardi, were detected. each ezo deer had only a single species of protozoa, e. simplex or e. dubardi. since e. simplex in ezo deer had a wide variation in body size and shape, its measurements were compared with those of e. simplex, e. nanellum and e. exiguum obtained from holstein-friesian cattle feeding ... | 1993 | 8461433 |
| effect of various organic nutrients on the reproductive rates of bacterivorous hymnostomes in a freshwater canal, shibin el-koum, menoufia, egypt. | the effect of adding two different organic materials; wheat extract and bactopeptone was studied on some of the most abundant bacterivorous hymnostomes collected from freshwater canal in shibin el-koum, menoufia. it was found that some of these ciliates prefer plant protein as wheat, others prefer animal protein as bactopeptone, someone have the ability to accommodate with both organic materials. a significant positive relationship between log doubling times and log cell volumes of these hymnost ... | 1993 | 8482857 |
| photosensory transduction in ciliates. i. an analysis of light-induced electrical and motile responses in stentor coeruleus. | light-induced membrane potential changes and motile responses have been studied in stentor cells with intracellular microelectrodes and video microscopy, respectively. intracellular microelectrode recordings showed that step-up increase in light intensity induced an electrical membrane response which consisted of an initial membrane depolarization (photoreceptor potential) followed by an action potential and maintaining phase of depolarization (afterdepolarization). the amplitude of the receptor ... | 1993 | 8506399 |
| spinal and facial innervation of the skin in the gadid fish ciliata mustela (teleostei). | the pattern of innervation of the skin of the rockling ciliata mustela was investigated to sort out spinal from facial nerve innervation of cutaneous chemosensory and mechanosensory systems. this fish has a variety of appendages with different functional sensory specializations, i.e., the chin barbel, pelvic fin, anterior dorsal fin, and dorsal trunk skin. the carbocyanine dye, dii, was applied to nerve stumps in dissected aldehyde-fixed tissue. in the case of the chin barbel, the dye was applie ... | 1993 | 8514918 |
| transcription rates and transcript stabilities of macronuclear genes in vegetative euplotes crassus cells. | in hypotrichous ciliates such as euplotes crassus genes in the transcriptionally active macronucleus are present on individual minichromosomes which occur in gene-specific copy numbers. this different degree of gene amplification can be understood as a means to preset the expression potential of the respective genetic information. in addition, the actual steady state transcript amounts are governed by the transcription rates and transcript stabilities. to establish the relative effects of these ... | 1995 | 8520583 |
| [host preference of culicidae (diptera) collected in central argentina]. | in order to study the host preference of female mosquitoes, samples were taken fortnightly in cordoba and cosquin (argentina), during october-april of two consecutive years. four different vertebrates were used in baited-can traps: frogs, chickens, rabbits and turtles. the genus culex accounted for 92.9% of the specimens collected. aedes for 7.0% and psorophora ciliata 0.02%. the highest proportion of females were collected in chicken traps (68.7%), followed by rabbit traps (29.9%), turtles (0.8 ... | 1995 | 8525319 |
| notes on the use of invertebrates, especially ciliates, in studies on pollution and toxicity. | after treatment of the paramecia with 0.0005% cartap solution a high mortality of the paramecia in the postautogamic experimental group was observed. in the studied postautogamic experimental daily isolation line some defective paramecia were found. the abnormality was manifested by a defective separation of animals during binary fission resulting in the formation of chain forms. | 1995 | 8529755 |
| differential amplification of pheromone genes of the ciliate euplotes raikovi. | in hypotrich ciliates, the entire silent chromosomal genome of the germinal nucleus (micronucleus) undergoes extensive dna rearrangements that, during the development of the somatic nucleus (macronucleus) at the beginning a new cell life cycle, eventually result in the production of linear dna molecules. these molecules represent functional genes, each one consisting of a central coding region flanked by two shorter regions, which apparently lack canonical elements for regulation of replication ... | 1995 | 8565333 |
| infection of aedes albopictus (diptera: culicidae) and ae. aegypti with lambornella stegomyiae (ciliophora: tetrahymenidae). | the transformation of lambornella stegomyiae trophonts to theronts, the distribution of invasion cysts on larval aedes albopictus cuticle, and the virulence of l. stegomyiae to ae. albopictus and aedes aegypti were studied in the laboratory. transformation of trophonts into theronts was induced by a morphogenic agent released from larval ae. albopictus homogenate. the first transformation was observed 4 hr after exposure to larval mosquito homogenate, but most transformations occurred between 12 ... | 1995 | 8568285 |
| epinigericin toxicity towards tetrahymena pyriformis gl; changes in cell volume and intracellular ph. | a study of the toxicity of epinigericin, an antibiotic ionophor, towards the ciliate tetrahymena pyriformis showed that this molecule stopped cell division, increased cell volume and led to a more basic intracellular ph. the action of epinigericin was probably linked to its function as an ionophor. the ionic selectivity of this molecule is still not known. the raising of the intracellular ph of ciliates by this antibiotic may be linked to its toxic action and its iontransport mechanism in tetrah ... | 1995 | 8579832 |
| globins in nonvertebrate species: dispersal by horizontal gene transfer and evolution of the structure-function relationships. | using a new template based on an alignment of 145 nonvertebrate globins we examined several recently determined sequences of putative globins and globin-like hemeproteins. we propose that all globins have evolved from a family of ancestral, approx. 17-kda hemeproteins, which displayed the globin fold and functioned as redox proteins. once atmospheric o2 became available the acquisition of oxygen-binding properties was initiated, culminating in the various highly specialized functions known as pr ... | 1996 | 8587498 |
| the ethograms of tetrahymena pyriformis gl and t. malaccensis. | the behaviour of tetrahymena, one of the most intensively investigated laboratory organisms, was analysed, and ethograms of t. pyriformis and t. malaccensis were studied. the basic ethogram, which previously described the behaviour of ciliates was appropriate for t. pyriformis and t. malaccensis. although quite similar to each other, the two new ethograms differed significantly in some aspects of ciliate behaviour. four new behavioural patterns were recognized and described quantitatively and qu ... | 1995 | 8620687 |
| two different macronuclear ef-1 alpha-encoding genes of the ciliate euplotes crassus are very dissimilar in their sequences, copy numbers and transcriptional activities. | genes (efa) encoding the translation elongation factor ef-1 alpha (efa) or the prokaryotic homolog eftu frequently occur in multiple copies in the same organism. this has been interpreted either in terms of a potential of differential gene expression during different phases of development, or as gene dosage adaptation to the need of high-level production of the gene products. since ciliates can differentially amplify their genes, the latter argument would lead to the expectation of only one efa ... | 1996 | 8626055 |
| insights into the evolution of nuclear dualism in the ciliates revealed by phylogenetic analysis of rrna sequences. | the small subunit rrna gene sequences of the karyorelictean ciliates, loxodes striatus and protocruzia sp., and the heterotrichian ciliates, climacostomum virens and eufolliculina uhligi, were used to test the evolution of nuclear dualism in the phylum ciliophora. phylogenies derived using a least squares distance method, neighbour joining, and maximum parsimony demonstrate that the karyorelictean ciliates sensu small and lynn, 1985 do not form a monophyletic group. however, loxodes and the hete ... | 1996 | 8640192 |
| a single telomerase rna is sufficient for the synthesis of variable telomeric dna repeats in ciliates of the genus paramecium. | paramecium telomeric dna consists largely of a random distribution of ttgggg and tttggg repeats. given the precise nature of other ciliate telomerases, it has been postulated that there are two distinct types of the paramecium enzyme, each synthesizing perfect telomeric repeats: one with a template rna that specifies the addition of tttggg and the second dictating the synthesis of ttgggg repeats. we have cloned and sequenced telomerase rna genes from paramecium tetraurelia, p. primaurelia, p. mu ... | 1996 | 8657163 |
| protistan bacterivory in an oligomesotrophic lake: importance of attached ciliates and flagellates | 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 grea ... | 1996 | 8661531 |
| [effects of altered gravity on the culture of unicellular eucaryotic organisms, bursaria truncatella (ciliophora)]. | the paper reports the results of experiments with centrifugation and clinostating. growth rate, cellular division and several morphofunctional characteristics of unicellular organisms of infusoria bursaria truncatella in culture were studied under normal (1 g), elevated (hypergravity at 2 and 5 g), and compensated gravity. the data point to certain changes in the functional activity and morphology of cells consequent to long-time cultivation under these conditions. the observed regularities in t ... | 1995 | 8664872 |
| intestinal ciliates found in the feces of japanese native tokara pony, with the description of a new genus and a new species. | the composition of intestinal ciliates excreted in the feces of 20 tokara native ponies kept in iriki farm of kagoshima university was surveyed. eleven genera consisting of 18 species were identified based on the description of strelkow. one new genus including a new species, wolskana tokarensis n. gen., n. sp., of the family buetschliidae was recognized and described. the average ciliate density of all horses was 13.8 x 10(3)/ml. those of stallions (n = 5), mares (n = 11) and foals (n = 4) were ... | 1996 | 8672578 |
| phylogeny of the haplosporidia (eukaryota: alveolata) based on small subunit ribosomal rna gene sequence. | the phylogenetic position of the phylum haplosporidia was investigated with the complete small subunit rrna gene sequences from 5 species in the phylum: haplosporidium nelsoni and haplosporidium costale, parasites of the eastern oyster crassostrea virginica; haplosporidium louisiana, a parasite of the mudcrab panopeus herbstii; minchinia teredinis, a parasite of shipworms (teredo spp.) and urosporidium crescens, a hyperparasite found in metacercariae of the trematode megalophallus sp. in the blu ... | 1996 | 8691370 |
| surface antigen cross-linking triggers forced exit of a protozoan parasite from its host. | we used the common fish pathogen ichthyophthirius multifiliis as a model for studying interactions between parasitic ciliates and their vertebrate hosts. although highly pathogenic, ichthyophthirius can elicit a strong protective immune response in fish after exposure to controlled infections. to investigate the mechanisms underlying host resistance, a series of passive immunization experiments were carried out using mouse monoclonal antibodies against a class of surface membrane proteins, known ... | 1996 | 8692903 |
| [chemical components of lindernia ciliata (colsm) pennell]. | three known compounds were isolated from the petroleum ether extract of the whole plant of lindernia ciliata. they are beta-sitosterol, stigmasterol and lup-20(29)-en-3 beta-ol. their structures were established by ir, ms, 1hnmr and 13cnmr spectroscopy. | 1996 | 8703351 |
| models of initiation of replicative senescence by loss of telomeric dna. | situated at the ends of all eukaryotic chromosomes are telomeres, genetic elements that are essential for genomic stability. it has recently been established that telomere length shortens during replicative aging of normal human somatic cells. although the cause of replicative senescence of somatic cells is still debated, we believe that telomere shortening plays a causal role in this process. in support of this hypothesis, mutant strains of yeast and ciliates that are incapable of maintaining t ... | 1996 | 8706793 |
| do cyanobacteria swim using traveling surface waves? | bacteria that swim without the benefit of flagella might do so by generating longitudinal or transverse surface waves. for example, swimming speeds of order 25 microns/s are expected for a spherical cell propagating longitudinal waves of 0.2 micron length, 0.02 micron amplitude, and 160 microns/s speed. this problem was solved earlier by mathematicians who were interested in the locomotion of ciliates and who considered the undulations of the envelope swept out by ciliary tips. a new solution is ... | 1996 | 8710872 |
| a community model of ciliate tetrahymena and bacteria e. coli: part i. individual-based models of tetrahymena and e. coli populations. | the dynamics of a microbial community consisting of a eucaryotic ciliate tetrahymena pyriformis and procaryotic escherichia coli in a batch culture is explored by employing an individual-based approach. in this portion of the article, part i, population models are presented. because both models are individual-based, models of individual organisms are developed prior to construction of the population models. the individual models use an energy budget method in which growth depends on energy gain ... | 1996 | 8713659 |
| commitment to division in ciliate cell cycles. | near the end of the cell cycle, ciliates commit irreversibly to cell division. the point of commitment occurs at the time of oral polykinetid assembly and micronuclear anaphase. the commitment is a checkpoint which requisites a threshold cell mass/dna ratio and stomatogenesis. it is also a physiological transition point, involving cdk protein kinases similar to those of other eukaryotes. both p34 kd and p36 kd kinases, similar to the s. pombe cdc2 kinases, have been described to have activity as ... | 1996 | 8720937 |
| lipid and fatty acid contents in red tides from tropical fish ponds of the coastal water of south china sea. | microplanktonic red tide blooms (dominated by dinoflagellates) were observed in brackish water fish ponds of terengganu between march 1992 to january 1993. the first short-lived bloom (2-3 days) occurred in october 1992 while the second long-lived bloom (6-7 days) occurred in january 1993. the dominant dinoflagellate species comprised of peridinium quinquecorne (> 90% total cell count) with considerable proportion of protoperidinium excentricum. ciliophora consisting of tintinopsis sp. and favel ... | 1996 | 8724878 |
| dynamic analysis of the evolution of a novel genetic system: the evolution of ciliate meiosis. | many ciliates undergo a peculiar form of meiosis in which four haploid nuclei are produced, three are digested, and the single remaining nucleus undergoes mitosis. it is paradoxical that such a meiotic process occurs, since one could imagine several other less costly ways of producing two nuclei. here we investigate a possible resolution of this paradox. it is shown that the spread of a selfish gene that kills the mate not containing it, provides the conditions for the spread of a costly modifie ... | 1996 | 8733474 |
| classification of immature stage habitats of culicidae (diptera) collected in córdoba, argentina. | in order to classify mosquito immature stage habitats, samples were taken in 42 localities of córdoba province, argentina, representing the phytogeographic regions of chaco, espinal and pampa. immature stage habitats were described and classified according to the following criteria: natural or artificial; size; location related to light and neighboring houses; vegetation; water; permanence, movement, turbidity and ph. four groups of species were associated based on the habitat similarity by mean ... | 1996 | 8734943 |
| macronucleus structure and macronucleus development in hypotrichous ciliates. | in the course of macronuclear development of the hypotrichous ciliates all genetic information not required for normal growth of the cell is removed from the new macronucleus. this differentiation process involves dna-splicing, excision of transposons, dna-fragmentation, selective gene amplification and telomere addition. since many of the processes observed during macronuclear development, such as dna-transposition, dna-rearrangement or selective dna-amplification, may occur in differentiating ... | 1996 | 8735923 |
| fluorometric measurement of the intracellular free ca(2+)-concentration in the ciliate didinium nasutum using fura-2. | we developed an experimental approach to measure somatic and ciliary ca(2+)-signals in the ciliate didinium under voltage clamp conditions using the dye fura-2. intracellular pressure injection of fura-2 molecules did not alter electrophysiological membrane properties besides an expected buffering effect. the intracellular free ca(2+)-concentration was determined at 2 x 10(-7) m. during membrane excitation, this resting value increased in the cilia; a quantification was not feasible. within the ... | 1995 | 8746947 |
| the lobster parasite anophryoides haemophila (scuticociliatida: orchitophryidae): nuclear 18s rdna sequence, phylogeny and detection using oligonucleotide primers. | we have determined the nucleotide sequence of the nuclear gene encoding small-subunit ribosomal ribonucleic acid of the ciliate anophryoides haemophila, a parasite of the american lobster homarus americanus. the gene is 1763 bp in length, and has a guanosine-plus-cytosine content of 43.9%. inferred phylogenetic frameworks strongly support the monophyly of the scuticociliates, and suggest that order scuticociliatida should be elevated to at least subclass rank. oligonucleotide probes based on a. ... | 1996 | 8768439 |
| why does the genetic code deviate so easily in ciliates? | 1995 | 8785511 | |
| eosinophilic colitis and hepatitis in a horse with colonic intramucosal ciliated protozoa. | tissues from a 9-year-old american standardbred gelding with a history of anorexia, mild colic, and unexpected death were submitted to the laboratories of veterinary diagnostic medicine at the university of illinois for histopathologic examination. microscopic diagnoses were severe subacute, diffuse eosinophilic colitis with intralesional protozoa and a subacute to chronic eosinophilic portal hepatitis with granuloma formation. two tissue-invading, ciliated protozoa were identified in large numb ... | 1996 | 8801719 |
| secondary connections of the dorsal and ventral facial lobes in a teleost fish, the rockling (ciliata mustela). | in the rockling, ciliata mustela (teleostei), a portion of the dorsal fin is a specialized chemosensory organ possessing solitary chemoreceptor cells innervated by a recurrent branch of the facial nerve. previous studies have demonstrated that the specialized solitary chemoreceptor cell system is represented in the dorsal segment of the medullary facial lobe (dfl), whereas the taste buds in the remainder of the facial-nerve-innervated skin are represented in the ventral division of the lobe (vfl ... | 1996 | 8807445 |
| ciliates in rapid gravity filters of waterworks exploiting deep groundwaters. | potable water is increasingly produced from deep (>100 m) tertiary groundwaters which often are completely reduced and contain high amounts of ammonium, methane, and hydrogen sulphide. they thus require special treatment which includes oxygenation and removal of the reduced contaminants by the biofilm developing in rapid gravity filters. the biofilm is heavily colonized with ciliates and microinvertebrates. a total of 38 species of ciliates was found in 42 samples taken from 4 waterworks in germ ... | 1996 | 8820661 |
| signal peptide-induced sensory behavior in free ciliates: bioassays and cellular mechanisms. | 1996 | 8822800 | |
| cortical structure and function in euglenoids with reference to trypanosomes, ciliates, and dinoflagellates. | the membrane skeletal complex (cortex) of euglenoids generates and maintains cell form. in this review we summarize structural, biochemical, physiological, and molecular studies on the euglenoid membrane skeleton, focusing specifically on four principal components: the plasma membrane, a submembrane layer (epiplasm), cisternae of the endoplasmic reticulum, and microtubules. the data from euglenoids are compared with findings from representative organisms of three other protist groups: the trypan ... | 1996 | 8843656 |
| epigenetic programming of developmental genome rearrangements in ciliates. | 1996 | 8858143 | |
| gamma-tubulin is permanently associated with basal bodies in ciliates. | ciliates are of special interest owing to the multiplicity and diversity of their microtubule organizing centers (mtocs). the subcellular localization of gamma-tubulin in these protozoa has not been extensively studied. the cloning of a gamma-tubulin gene in euplotes (liang, a., k. heckmann, gene 136, 319-322 (1993) led us to examine the localization of this protein. we used three polyclonal antibodies, jh46, r58 and r70. they had been raised against peptides common to mammalian and aspergillus ... | 1996 | 8864661 |
| comparative study of rumen ciliates in buffalo, cattle and sheep in egypt. | rumen ciliates species and composition of the sheep, friesian-cattle and water buffaloes in egypt were surveyed. as a result, 7 genera with 18 species and 6 formae in sheep, 10 genera with 28 species and 11 formae in cattle and 12 genera with 29 species and 7 formae in water buffaloes were detected. twenty-two species were common in both cattle and buffaloes, while 12 species in sheep were common with the other ruminants. entodinium spp., such as e. simplex, e. nanellum and e. exigum, appeared m ... | 1996 | 8877984 |
| developmentally programmed dna rearrangement in tetrahymena thermophila: isolation and sequence characterization of three new alternative deletion systems. | extensive developmentally programmed dna rearrangements, including thousands of internal deletions, occur in the differentiating somatic macronucleus in tetrahymena thermophila. some deletion systems involve the use of multiple alternative deletion sites. we report here the cloning and the sequences of three new alternative deletion systems (rr, rp and b) obtained using genomic subtraction. the rp and rr deletion systems are 2 kb apart on chromosome 1r, and both involve the removal of < 2 kb of ... | 1996 | 8893500 |
| ciliate protozoa in the forestomach of the dromedary camel, (camelus dromedarius), in egypt, with description of a new species. | the composition of ciliates obtained from the forestomachs of eleven dromedary (one-humped) camels in egypt was examined. as a result, eight genera containing 24 species with 11 forms were identified. of them, one species was concluded to be new, then described as dasytricha kabanii n. sp. this new species was clearly distinguished from d. ruminantium, the other species of the genus, by its lack of somatic cilia on the posterior one-fifth of the body surface. entodinium nanellum and epidinium ec ... | 1996 | 8898279 |
| [comparison of ciliate diversity in biodisc reactors which purify industrial wastewater]. | 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 ... | 1995 | 8900568 |
| [presence of red tides along the eastern coast of the gulf of california]. | records of the occurrence of red tides during the last 24 years in guaymas and for the last 16 years in mazatlán, on the coast of the gulf of california, mexico are presented here. the results indicate the presence of 4 dominant species in 34 red tides in guaymas and 9 dominant species in 60 red tides in mazatlán. the most common species is mesodinium rubrum, while the toxic one is gymnodinium catenatum. noctiluca scintillans and gonyaulax sp. were also present in guaymas. in mazatlán scrippsiel ... | 1995 | 8900569 |
| reconstitution of human telomerase activity and identification of a minimal functional region of the human telomerase rna. | telomerase is a ribonucleoprotein that catalyzes telomere elongation through the addition of ttaggg repeats in humans. activation of telomerase is often associated with immortalization of human cells and cancer. to dissect the human telomerase enzyme mechanism, we developed a functional in vitro reconstitution assay. after removal of the essential 445 nucleotide human telomerase rna (htr) by micrococcal nuclease digestion of partially purified human telomerase, the addition of in vitro transcrib ... | 1996 | 8918470 |
| the evolution of stramenopiles and alveolates as derived by "substitution rate calibration" of small ribosomal subunit rna. | the substitution rate of the individual positions in an alignment of 750 eukaryotic small ribosomal subunit rna sequences was estimated. from the resulting rate distribution, an equation was derived that gives a more precise relationship between sequence dissimilarity and evolutionary distance than hitherto available. trees constructed on the basis of evolutionary distances computed by this new equation for small ribosomal subunit rna sequences from ciliates, apicomplexans, dinoflagellates, oomy ... | 1996 | 8919872 |
| the roles of telomeres and telomerase in cell life span. | telomeres cap and protect the ends of chromosomes from degradation and illegitimate recombination. the termini of a linear template cannot, however, be completely replicated by conventional dna-dependent dna polymerases, and thus in the absence of a mechanisms to counter this effect, telomeres of eukaryotic cells shorten every round of dna replication. in humans and possibly other higher eukaryotes, telomere shortening may have been adopted to limit the life span of somatic cells. human somatic ... | 1996 | 8921986 |
| a study on macronuclear chromatin structure in colpoda inflata (protozoa, ciliophora) by means of image analysis. | resting encystment is a reversible cytodifferentiation phenomenon regularly taking place during the life cycle of colpodidae. the encystment involves regulation of the macronuclear dna content, accomplished via chromatin extrusion and dna synthesis mechanisms. an analysis of macronuclear chromatin texture was carried out in colpoda inflata logarithmically growing cells, pre-cystic cells, and increasingly aging resting cysts after feulgen staining. morphometric and densitometric parameters as wel ... | 1996 | 8922946 |
| doublet cells in tetrahymena as indicators of culture media composition. | stomatogenesis in ciliates is a complex and carefully orchestrated event. the exo- mutant sb255 of tetrahymena thermophila has defects in mucocyst formation and docking and can also have one or two mouths. three common culture media (proteose peptone, medium 357, and yeast extract) were analyzed for total c, n, and inorganic elements and then tested for their effect on the number of mouths present in sb255. cultures of sb255 grown in medium 357 consisted of a mixed population of cells with eithe ... | 1995 | 8962790 |
| secondary structures and features of the 18s, 5.8s and 26s ribosomal rnas from the apicomplexan parasite toxoplasma gondii. | the two major subunits of the ribosomal rna (rrna) of toxoplasma gondii, 18s and 26s, as well as 5.8s, have been sequenced and folded according to known consensus and established secondary structures. conserved and variable nucleotide (nt) regions were identified using multiple alignments with rrna sequences of selected organisms. the 18s rrna showed a well conserved core structure of 48 stems and a hypervariable v4 region identified four additional stems including a pseudoknot. the 18s rrna con ... | 1996 | 8964489 |
| volatility of internal eliminated segments in germ line genes of hypotrichous ciliates. | germ line micronuclear genes in ciliated protozoa contain two types of interrupting sequences. some genes contain introns, but internal eliminated segments (iess) are much more prevalent. iess are at-rich dna segments that separate macronucleus-destined segments (mdss) in micronuclear genes. all iess are excised and destroyed when a micronucleus develops into a macronucleus after each cell mating. iess have no discernible function. therefore, an investigation of the behavior of iess in evolution ... | 1997 | 8972213 |
| epigenetic regulation of programmed genomic rearrangements in paramecium aurelia. | in ciliates, development of the polyploid somatic macronucleus after sexual events involves extensive and reproducible rearrangements of the germ-line genome, including chromosome fragmentation and precise excision of numerous internal sequence elements. in paramecium aurelia, alternative macronuclear versions of the same germ-line genome can be maternally inherited across sexual generations, showing that rearrangement patterns are not strictly determined by the germ-line sequence. homology-depe ... | 1996 | 8976603 |
| identifying and distinguishing sibling species in the tetrahymena pyriformis complex (ciliophora, oligohymenophorea) using pcr/rflp analysis of nuclear ribosomal dna. | we describe a riboprinting strategy for identifying and distinguishing among sibling species in the tetrahymena pyriformis complex. it involves use of the polymerase chain reaction to amplify a large segment of the nuclear ribosomal dna and internal transcribed spacers, and digestion of this dna with restriction enzymes. unique restriction fragment length patterns or haplotypes were then used to distinguish species into: (1) six taxa that were identifiable to the species level, (2) eight taxa th ... | 1996 | 8976607 |