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PubMed1976

A localized region of basal body proliferation in growing cells of Dileptus visscheri (ciliata, gymnostomate).

In the ciliate Dileptus organisms are completely organized at the time of excystation. They grow intensively, increasing in volume several times, before they reach the trophic cell size. The growth includes both the somatic part of the body as well as the oral parts, consisting of the cytostomal field and the ventral band of the proboscis. From the time of excystation, during the growth of the cell, the oral apparatus is able to capture and ingest food. Growth of an oral apparatus while functioning has not previously been reported in cilates. The proliferation of new oral kinetosomes in the growing oral apparatus occurs only in the cytostomal field. There is no proliferation of ciliature in the oral kineties of the growing proboscis. In those regions of the somatic kineties bordering the cytostomal field an extensive proliferation of somatic ciliature takes place. The zone of proliferation common to the oral and somatic ciliature supplies new kinetosomes for the elongating proboscis, the growing oral apparatus and the growth of the rest of the body. The mode of proliferation of the oral kinetosomes differs from that of the somatic kinetosomes. The oral kinetosomes form randomly in large numbers, appearing similar to an anarchic field such as is found in other ciliates. The somatic kinetosomes always arise singly and in a defined position in relation to the mature kinetosome. The proliferation of basal bodies in a defined area in Dileptus suggests the existence of a growth zone localized around the cytostomal field.

Ciliophora↗
PubMed1983

Regulation of ciliary pattern in dileptus (Ciliata). II. Formation of a cortical domain of sensory cilia from a domain of locomotor cilia.

The surface of the ciliate Dileptus contains locomotor and sensory domains. Each domain contains cilia of its own kind, arranged in a characteristic pattern. Transformation of a portion of the locomotor area into the sensory domain has been studied. Locomotor ciliary units in the transforming area undergo resorption of ciliary shafts, which are subsequently replaced by shafts of a sensory type. Anterior to each transforming ciliary unit a new one is formed, and both acquire sensory rootlets. As a result, a double-kinetosomal sensory unit emerges. A regulatory change in structure occurs over a definite area that is determined to become the sensory cortical domain.

Animals↗
PubMed1976

Ciliary propulsion of objects in tubes: wall drag on swimming Tetrahymena (Ciliata) in the presence of mucin and other long-chain polymers.

The lubrication effect of three long-chain polymers - mucin, methylcellulose and Ficoll - on ciliary propulsion in tubes is measured by plotting the relative velocities of swimming cilitates as a function of the tube bore diameter. Mucin shows the most unequivocal lubrication, which is found at concentrations between 0% and 9.1% (w/v). This observation, coupled with viscometric measurements which show that ciliary tip shear rates are sufficient to solate mucin, serve as the groundwork for a model of mucin lubrication which explains the optimized lubrication behaviour of thixotropic gelating polymers as an expression of the response to shear by the various stages of polymer clustering during the gelatin process. In addition to the lubricative effect, another wall drag reduction effect by mucin was measured in the clearance region beyond the lubrication layer. This apparent viscosity reduction is optimized in the concentration range between I.7% and 4.I% mucin and may also be explained in terms of the properties of gel clustering.

Animals↗
PubMed2000

Photooxidation of cedrelone, a tetranortriterpenoid from Toona ciliata.

Cedrelone, a tetranortriterpenoid on photolysis by UV light yields a true photooxidation product 3 [14 beta,15beta,22beta,23beta-diepoxy-6-hydroxy-1,5, 20(22)-meliatriene-2,7,21-trione] whose structure is well established by NMR studies and confirmed by X-ray crystallography, along with product 4 [14 beta,15beta-epoxy-6,23-dihydroxy-1,5,20(22)-meliatriene-2,7, 21-trione]. Addition of rose bengal increases the rate of photooxidation whereas DABCO decreases rate of photolysis proving the involvement of singlet oxygen in the photooxygenation. Both the photoproducts exhibited antifeedant activity.

Crystallography, X-Ray↗
PubMed2004

Defense function of pigment granules in the ciliate Blepharisma japonicum against two predatory protists, Amoeba proteus (Rhizopodea) and Climacostomum virens (Ciliata).

The defense function of pigment granules in the red ciliate Blepharisma japonicum against two predatory protists, Amoeba proteus and Climacostomum virens, was investigated by (1) comparing normally-pigmented and albino mutant cells of B. japonicum as the prey of these predators and (2) comparing resistance of the predators to blepharismin, the toxic pigment contained in the pigment granules of B. japonicum. Normally pigmented cells which contained more blepharismin than albino cells were less vulnerable to A. proteus than albino cells, but not to C. virens. C. virens was more resistant than A. proteus to the lethal effect of blepharismin. The results indicate that pigment granules of B. japonicum function as defense organelles against A. proteus but not against C. virens and suggest that successful defense against a predator depends on the susceptibility of the predator to blepharismin.

Amoeba↗
PubMed2003

Measurement of protease activity of live Uronema marinun (Ciliata: Scuticociliatida) by fluorescence polarization.

The proteolytic activity of live Uronema marinum was analyzed by a fluorescence polarization (FP) technique. Protease activity was measured as a decrease in the FP value using fluorescein isothiocynate (FITC)-casein as a protein substrate. A time-dependent decrease in FP occurred in plate wells containing live U. marinum. Supplementation with the cysteine protease inhibitor E-64 had no significant inhibitory effect on the decrease in FP at any of the concentrations used. In contrast, supplementation with 1,10-phenanthroline resulted in complete inhibition of proteolysis for 30 min at 1 mM and for 1 h at 2 and 5 mM. Effective inhibition of the proteolytic activity of live U. marinum by 1,10-phenanthroline indicated that metalloproteases are the main proteases excreted by U. marinum. As U. marinum has a high potential for systemically invading and destroying fish tissues, the metalloproteases excreted by live U. marinum are likely to be involved in the invasion of host tissues and the pathogenicity of the parasite.

Animals↗
PubMed2004

Comparison of toxic effects of nitric oxide and peroxynitrite on Uronema marinum (Ciliata: Scuticociliatida).

To discover the effects of nitric oxide (NO) and peroxynitrite on Uronema marinum (a ciliate responsible for systemic scuticociliatosis in cultured olive flounder Paralichthys olivaceus), the dose-dependent inhibitory effect of NO donors, S-nitroso-N-acetylpenicillamine (SNAP) and 3-morpholinosydnonimine (SIN-1) on the proliferation and survival of U. marinum was investigated. The inhibitory effects of exogenous superoxide dismutase (SOD) and catalase on the toxicity of SIN-1 were also investigated. After 24 h of incubation in the presence of 0.2 mM SNAP, the number of ciliates was not statistically different from that of the controls, whereas incubation in the presence of 0.5 mM SNAP reduced the number of parasites significantly to 59.1% of controls. Concentrations of SNAP higher than 0.5 mM resulted in greater reductions in the number of ciliates, but levels of generated NO far exceeded physiological ranges. The number of viable ciliates incubated for 24 h with 0.2 mM SIN-1 was reduced significantly to 25.0%, and all ciliates were killed by incubation in concentrations above 0.5 mM SIN-1. Although SOD decreased the toxic effect of SIN-1 on U. marinum, protection was not complete and did not improve after increasing the SOD concentration from 50 to 400 U ml(-1). Addition of catalase ranging from 500 to 10000 U ml(-1) completely protected U. marinum from SIN-1 toxicity. Ciliates exposed to catalase alone or catalase plus SIN-1 showed significantly higher and dose-dependent proliferation rates compared to controls. Addition of haemoglobin, ranging from 0.5 to 2.0 mg ml(-1), also protected U. marinum from SIN-1 toxicity, and increased the proliferation rate dose-dependently. In conclusion, resistance of U. marinum to oxidative and nitrative stress may allow this pathogen to withstand the NO- and oxygen-radical-dependent killing mechanisms of phagocytic cells.

Animals↗
PubMed1999

The formation of primary and secondary lysosomes in Balantidium coli, Ciliata.

Trophozoites, vegetative forms of Balantidum coli isolated from pigs affected by acute and asymptomatic balantidiasis were studied. Lysosomes and food vacuoles were revealed by cytochemical detection of lysosomal marker, acid phosphatase. The cytoplasm of all the B. coli trophozoites examined was found to contain numerous structures which differed widely in shape, size and location in the cells. One of them was located among the rough endoplasmic reticulum membranes and another one in the vicinity of endosomes. Those structures were regarded as the primary lysosomes. The two types of vesicular structures most probably represent two stages of the primary lysosome formation. Trophozoites were also found to contain secondary lysosomes which are formed by fusion of several primary lysosomes with phagosomes. The ultrathin sections of B. coli trohozoites showed the presence of two types of phagosomes. They were divided, based on their contents, into auto- and heterophagosomes.

Acid Phosphatase↗
PubMedDate not supplied

[A new genus of parasitic ciliata from tropical fishes].

Ichthyophthirius schlotfeldti Yunchis, 1997 (Ophryoglenidae) was described by the junior author from aquarium fishes from South-East Asia. In the present paper this species is separated into a new genus Neoichthyophthirius gen. n. The reproduction of this species takes place within the epithelium of fishes and not in water as in Ichthyophthirius multifilius. Neoichthyophthirius schlotfeldti has a ring-shaped macronucleus with ends overlapping. Maximum temperature, when the reproduction is possible, is about +34 degrees. The parasite is pathogenous and causes a mortality of aquarium fishes.

Animals↗