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PubMed1990

Analyses of surface membrane carbohydrates in parasitic flagellates of the order kinetoplastida using lectins.

Crithidia fasciculata, Leishmania donovani, Leishmania major, Leishmania mexicana amazonensis, Leishmania tropica, Leishmania tarentolae, Trypanosoma sp. from Formosan bats (Tb), Trypanosoma lewisi, Trypanosoma musculi, and different strains of Trypanosoma cruzi (Tc) were cultivated at 27 degrees C in a liquid culture medium. Flagellates harvested from log phase culture were analyzed for their lectin agglutinating characteristics with concanavalin A (Con A), Peanut agglutinin, Ricinus communis agglutinin 120, soybean agglutinin (SBA), Ulex europeus agglutinin (UEA) and wheat germ agglutinin (WGA). Results indicated that all these flagellates might have D-galactose and methyl- alpha-D-manopyranoside on their surface. The presence of L-Fucose, which complexes specifically with UEA, could not be demonstrated on the surface of these flagellates. Results from quantitative comparison of surface molecules of Tb and the Tulahuen strain of Tc suggested that Tb may have more WGA-binding molecules while Tc may have more ConA-binding molecules. Pretreatment of the flagellates with 0.05% trypsin at 37 degrees C for 30 minutes caused some reduction of agglutination titers. Cell agglutination with lectins was completely inhibited or reversed in the presence of the specific lectin-binding monosaccharides.

Agglutination↗
PubMed1995

Examination of nonflagellate and flagellate round forms of Trichomonas vaginalis by transmission electron microscopy.

Plasmodium-like round cells without sections of flagella, round flagellar cells with dividing nucleus and binuclear flagellate round forms were represented from the log-phase of Trichomonas vaginalis cultures. The fine-structural characteristics of the round cells support the opinion that the cells without flagella as well as the round multinuclear flagellate cells represent developmental stages preceding the appearance of mononuclear flagellate cells. In the round cells, amitotic division was observed instead of the well-known cryptopleuromitosis, without formation of metaphasic chromosomes and desmosomes. Our investigations onto the fine structure of the parasite support the assumption that the non-flagellate forms are viable cells of the parasite and point to still unknown phases of its biology.

Animals↗
PubMed1998

Electron microscopical identification of the flagellate Spironucleus torosa (Hexamitidae) from burbot Lota lota (Gadidae) with comments upon its probable introduction to this freshwater host.

Hexamitid flagellates from the rectum of the freshwater gadid burbot, from the river Glomma in southeastern Norway, were studied by scanning and transmission electron microscopy. The surface morphology of the flagellates was consistent with that of Spironucleus torosa, previously only found in the cod, haddock, and saithe, all marine gadids. Posteriolateral depressions with central protrusions were present in the flagellates, a feature reported from S. torosa only. Further, the microtubular cytoskeleton of the present species had the same general arrangement as in S. torosa, clearly different from what is described for other Spironucleus spp. It is therefore concluded that the present flagellate from burbot is this species. Any recent exchange of parasites between the marine hosts and burbot is believed to be only theoretically possible. The burbot became established in Norwegian rivers and lakes after the last ice age, some 7,000-8,000 yr ago, by following water courses across Sweden from the Baltic Sea. In the Baltic Sea there were, and still are, sympatric populations of burbot and cod, and the burbot is believed to have been infected before migrating westward.

Animals↗
PubMed2003

Flagellate hyperpigmentation following intralesional bleomycin treatment of verruca plantaris.

BACKGROUND: Flagellate hyperpigmentation is a well-documented complication of systemic bleomycin sulfate therapy when using doses of 100 U or more as an antineoplastic agent. Two cases occurred after using systemic doses from 15 to 30 U injected intravenously or intrapleurally; however, it has not been described as a complication following intralesional treatment of verruca plantaris. OBSERVATIONS: We report a case of flagellate hyperpigmentation after intralesional injection of 14 U of bleomycin for verrucae plantaris and review the literature associated with this cutaneous complication. CONCLUSIONS: Flagellate hyperpigmentation from extremely low doses of intralesional bleomycin is a previously undescribed complication. Although the mechanisms of reaction are not clearly understood, the clinician should be mindful of this uncommon complication.

Abdomen↗
PubMed1994

Multiple origins of colonial green flagellates from unicells: evidence from molecular and organismal characters.

Phylogenetic hypotheses generated from cladistic analysis of organismal and molecular data are shown to be generally congruent and/or complementary for comparisons of unicellular and colonial green algae in the Chlorophyceae. Cladistic analysis of organismal character data corroborates the alliance of colonial Stephanosphaera with unicellular Haematococcus (Haematococcaceae sensu Smith), inferred from previous studies of nuclear-encoded rRNA sequence data. The organismal data also support monophyly of the colonial Volvocaceae (sensu Smith). Alliances of other unicellular taxa, including those ascribed to the "Euchlamydomonas" Hauptgruppe (sensu Ettl), are not resolved by organismal characters principally because the structure of the data is skewed to shared ancestral characters (symplesiomorphies) and unique characters (autapomorphies) which define individual taxa only. Reanalysis of rRNA sequence data, with additional sequence data for critical taxa, does not support monophyly of the colonial Volvocaceae (sensu Smith). However, these data are weak in the support of the alternate hypothesis of nonmonophyly. In contrast, relationships among most unicellular flagellates are unambiguously resolved by the molecular data. Although the failure of the sequence data to resolve relationships among colonial flagellates appears to be due to a sampling of conservative sequences, an ancient, rapid radiation event or taxon sampling bias may also be contributing to the ambiguity problem. Results from analysis of a combined data set (organismal and molecular) are generally consistent with the inferences of the organismal character data regarding the colonial flagellates and are also consistent with the inferences of the sequence data regarding the unicellular taxa.

Animals↗
PubMed1987

Ultrastructure of the amoebo-flagellate Protonaegleria westphali.

Investigation of the ultrastructure of Protonaegleria westphali has been carried out by means of scanning electron microscopy (SEM) and transmission electronmicroscopy (TEM). SEM investigation demonstrated much enlarged trophozoites, flagellates and cysts corresponding to those under light microscopical observation. In situ fixation of moving trophozoites revealed attachment to the substratum by many uroidal and lateral filopodia. The typical flagellate stage has four flagella inserted two by two at the anterior pole of the cell. The smooth wall of cysts had prominent pores sealed by a mucous plug. Apart from their greater size, trophozoites and cysts resemble those of the genus Naegleria. Mitochondria are not as elongated as in the case of Naegleria; rather, they are round. The cyst is surrounded by a thick, layered endocyst (0.2-0.5 micron) and a delicate ecotcyst loosely apposed to the endocyst. Both walls join at the region of the prominent pores, forming a characteristically thick collar. This, together with the pore structure (up to 1.0 micron in diameter) places the amoeba in group I of N. gruberi, according to Pussard and Pons (1979). The flagellate state usually has four flagella which are anchored firmly by a prominent flagellar apparatus or mastigont at the anterior pole of the cell, comparable to that of the genus Tetramitus. The flagella show a typical 9 + 2 arrangement of microtubules (MT) and are surrounded by a sheath which is continuous with the cell membrane. Main elements of the mastigont could be demonstrated as typical kinetosomes of 0.75 micron length. Each is closely associated with the cross-striated rhizoplast located perpendicular to it.(ABSTRACT TRUNCATED AT 250 WORDS)

Amoeba↗
PubMed2006

Prey food quality affects flagellate ingestion rates.

Flagellate feeding efficiency appears to depend on morphological characteristics of prey such as cell size and motility, as well as on other characteristics such as digestibility and cell surface characteristics. Bacteria of varying morphological characteristics (cell size) and mineral nutrient characteristics or food quality (as determined by the C:N:P ratio) were obtained by growing Pseudomonas fluorescens in chemostats at four dilution rates (0.03, 0.06, 0.10, and 0.13 h-1) and three temperatures (14 degrees C, 20 degrees C, and 28 degrees C). Cells of a given food quality were heat-killed and used to grow the flagellate Ochromonas danica. Ingestion and digestion rates were determined by using fluorescently labeled bacteria of the same food quality as the bacteria supporting growth. Ingestion rates were affected by both food quality and cell size. Cells of high food quality (low carbon:element ratio) were ingested at higher rates than cells of low food quality. Multiple regression analysis indicated that cell size also influenced ingestion rate but to a much lesser extent than did food quality. Digestion rates were not correlated with either food quality or cell size. Results suggest that flagellates may adjust feeding efficiency based on the quality of food items available.

Animals↗
PubMed2000

The Microbial Food Web in the Recently Flooded Sep Reservoir: Diel Fluctuations in Bacterial Biomass and Metabolic Activity in Relation to Phytoplankton and Flagellate Grazers.

The spatial distribution of the bacterial biomass and production and of potential heterotrophic activity (PHA) were measured every 4 h between 23 July (10:00 h) and 25 July (10:00 h) 1997 in a recently flooded oligo-mesotrophic reservoir (the Sep Reservoir, Puy-de-Dôme, France), in relation to temperature, the phytoplankton biomass and production, and the abundance of heterotrophic flagellates. The temperature varied slightly with time during the study, but the well-established thermal stratification agreed well with vertical distribution of the biological variables that were measured. Only the bacterial production and the PHA showed significant diel changes (t-test, p <0.05), with maxima at 18:00 h and minima at 02:00 h. A significant positive relation was found between bacterial abundance and that of heterotrophic flagellates, which, rather than being an association related to the thermal stratification of the water column, was considered to reflect a trophic relation between these two communities. A carbon balance analysis suggested that at least 30% of the C from primary production measured during the sampling period was used by bacteria, and that 42% of this secondary production, or 6% of the primary production, would be used for the development of the heterotrophic flagellates present. We conclude that the bacterioplankton forms, at least occasionally, an important source of carbon for higher trophic levels, and reject the hypothesis that bacterial production in the Sep Reservoir depends exclusively on organic matter of allochthonous origin.

Journal Article↗
PubMed2003

Electron microscopic identification of the intestinal protozoan flagellates of the xylophagous cockroach Parasphaeria boleiriana from Brazil.

Flagellate protozoa of the hindgut of the xylophagous blattid Parasphaeria boleiriana were examined by light and electron microscopy. This species harbours two oxymonad species of the genera Monocercomonoides and Polymastix, the latter bearing Fusiformis bacteria on its surface. A diplomonad was present and has features of the genus Hexamita rather than Spironucleus. In addition, two trichomonads of the genera Monocercomonas and Tetratrichomastix were identified. A precise comparison with species of blattids and other insects was difficult because most of these flagellates have been described only by light microscopy after cell staining and there are few electron microscope studies and no molecular studies. None of the flagellates contained wood fragments in their food vacuoles and so evidently do not participate in the digestion of wood or cellulose.

Animals↗
PubMed2002

Localization of p210-related proteins in green flagellates and analysis of flagellar assembly in the green alga Dunaliella bioculatawith monoclonal anti-p210.

Recently, p210 was identified as a component of the flagellar basal apparatus in the green flagellate Spermatozopsis similis. In a search for potential homologues to p210, isolated cytoskeletons of several green flagellates were probed with a monoclonal antibody, BAS4.13, against p210. In Western blots, cross-reacting bands in the molecular-mass range of 210 kDa were detected only in the quadriflagellate Spermatozopsis exsultans. As described earlier for S. similis, the flagellar transition region was decorated in Chlamydomonas reinhardtii and several other green flagellates, whereas in the marine alga Dunaliella bioculata the antigen was present in the proximal part of the axoneme. Double immunofluorescence of D. bioculata with an antitubulin antibody further revealed dotlike signals at sites where the probasal bodies are located. Since most of the antigen in D. bioculata was located in the axoneme, deflagellation offered a possibility to study the kinetics of its incorporation during flagellar regeneration. The antigen was only detected after a flagellum reached a length of 3-4 microm and its integration into the growing flagellar proceeded from proximal to distal. A similar delay in the incorporation of the antigen was also observed during flagellar assembly on new basal bodies during cell division. Thus, the antigen of BAS4.13 was incorporated late and from proximal to distal into the growing flagellum. We conclude that the pace and site by which individual proteins are integrated into the flagellum differ greatly.

Algal Proteins↗
PubMed1989

A temporary flagellate (mastigote) stage in the vahlkampfiid amoeba Willaertia magna and its possible evolutionary significance.

A temporary flagellate (mastigote) stage has been observed in several isolates of the vahlkampfiid amoeba Willaertia magna. In an Australian isolate studied in detail, flagellates appeared synchronously, although later than in Naegleria fowleri or N. lovaniensis under similar conditions (half-maximal time, t50 = 168 min at 37 degrees C). The flagellates initially have four flagella and lack a cytostome, but undergo several successive divisions, the first of them synchronous, resulting in progressive reduction in cell volume. New flagella appear during and after division, and the number of flagella in daughter cells of later divisions is rather variable. Comparison of these observations with descriptions of other amoeboflagellates confirms that Willaertia is a valid genus. A likely sequence of morphological changes in the evolution of Willaertia and Naegleria from a hypothetical ancestral vahlkampfiid is proposed.

Amoeba↗
PubMed1999

Ethidium bromide: a fast fluorescent staining procedure for the detection of symbiotic partnership of flagellates and prokaryotes.

The hindgut of 'lower' termites harbors a dense population of flagellates and bacteria. The flagellates possess ecto- and endosymbiotic prokaryotes. Most of them are hardly visible in the phase contrast microscope. Staining with the DNA-intercalating agent ethidium bromide visualizes the nuclei of the flagellates as well as the ecto- and endosymbiotic bacteria as red objects. Furthermore, it is possible to distinguish between endosymbiotic methanogens and other bacteria. Following UV excitation, the blue-green autofluorescence of the methanogenic bacteria eclipses the red fluorescence light of the intercalated ethidium bromide. The dye facilitates the observation of symbiotic bacteria and helps identify the number, shape, localization, and dividing status of the nuclei. Thus, it is a powerful tool for the examination of microorganisms in complex habitats, which are rich in strongly autofluorescent material, like wood.

Animals↗
PubMed2003

Gravitaxis and graviperception in flagellates.

There is strong evidence that gravitactic orientation in flagellates and ciliates is mediated by an active physiological gravireceptor rather than by passive alignment of the cells in the water column. In flagellates the threshold for graviorientation was found to be at 0.12 x g on a slow rotating centrifuge during the IML-2 mission on the Shuttle Columbia and a subsequent parabolic rocket flight (TEXUS). During the IML-2 mission no adaptation to microgravity was observed over the duration of the space flight, while gravitaxis was lost in a terrestrial closed environmental system over the period of almost two years. Sedimenting statoliths are not likely to be involved in graviperception because of the small size of the cells and their rotation around the longitudinal axis during forward locomotion. Instead the whole cytoplasmic content of the cell, being heavier than the surrounding aqueous medium (1.05 g/ml), exerts a pressure on the lower membrane. This force activates stretch-sensitive calcium specific ion channels which can be inhibited by the addition of gadolinium which therefore abolishes gravitaxis. The channels seem to mainly allow calcium ions to pass since gravitaxis is blocked by the addition of the calcium ionophore A23187 and by vanadate which blocks the Ca-ATPase in the cytoplasmic membrane. Recently, a gene for a mechanosensitive channel, originally sequenced for Saccharomyces, was identified in Euglena by PCR. The increase in intracellular free calcium during reorientation can be visualized by the fluorophore Calcium Crimson using laser excitation and image intensification. This result was confirmed during recent parabolic flights. The gated calcium changes the membrane potential across the membrane which may be the trigger for the reorientation of the flagellum. cAMP plays a role as a secondary messenger. Photosynthetic flagellates are suitable candidates for life support systems since they absorb CO2 and produce oxygen. Preliminary experiments are discussed.

Acceleration↗
PubMed2004

Complex flagellar motions and swimming patterns of the flagellates Paraphysomonas vestita and Pteridomonas danica.

Most flagellates with hispid flagella, that is, flagella with rigid filamentous hairs (mastigonemes), swim in the direction of the flagellar wave propagation with an anterior position of the flagellum. Previous analysis was based on planar wave propagation showing that the mastigonemes pull fluid along the flagellar axis. In the present study, we investigate the flagellar motions and swimming patterns for two flagellates with hispid flagella: Paraphysomonas vestita and Pteridomonas danica. Studies were carried out using normal and high-speed video recording, and particles were added to visualize flow around cells generating feeding currents. When swimming or generating flow, P. vestita was able to pull fluid normal to, and not just along, the flagellum, implying the use of the mastigonemes in an as yet un-described way. When the flagellum made contact with food particles, it changed the flagellar waveform so that the particle was fanned towards the ingestion area, suggesting mechano-sensitivity of the mastigonemes. Pteridomonas danica was capable of more complex swimming than previously described for flagellated protists. This was associated with control of the flagellar beat as well as an ability to bend the plane of the flagellar waveform.

Animals↗
PubMed1967

The ameba-to-flagellate transformation in Tetramitus rostratus. II. Microtubular morphogenesis.

Tetramitus exhibits independent ameboid and flagellate stages of remarkable morphological dichotomy. Transformation of the ameba involves the formation of four kinetosomes and their flagella. The arrangement of these kinetosomes and associated whorls of microtubules extending under the pellicle establishes the asymmetric flagellate form. While no recognizable kinetosomal precursors have been seen in amebae, and there is no suggestion of self-replication in dividing flagellates, developmental stages of kinetosomes have been identified. These are occasionally seen in association with the nucleus or with dense bodies which lie either inside of or close to the proximal end of the prokinetosome. Outgrowth of flagella involves formation of an axoneme and a membrane. From the distal tip of the kinetosome microtubules grow into a short bud, which soon forms an expanded balloon containing a reticulum of finely beaded filaments. The free ends of the microtubules appear unraveled; they are seen first as single elements, then as doublets, and finally are arranged into a cylinder. Growth in length is accompanied by a reduction in the diameter of the balloon. The concept that the formation of the kinetic apparatus might involve a nuclear contribution, followed by a spontaneous assembly of microtubules, is suggested.

Animals↗
PubMed1972

Free kinetosomes in Austrialian flagellates. I. Types and spatial arrangement.

An electron microscope study was made of Deltotrichonympha and Koruga, two closely-related hypermastigote flagellates that live in the hindgut of the Australian termite, Mastotermes darwiniensis These symbiotic protozoans have a typical flagellated rostrum and long body flagella. Their "giant centrioles" (centriolar apparatus) are large, fibrillar, and granular bodies which do not resemble typical centrioles in structure. The unique feature of interphase cells is the presence of more than half a million free kinetosomes in the anterior cytoplasm. Two classes of free kinetosomes, differing in length and spatial arrangement, were found. 500,000-750,000 short free kinetosomes are concentrated in a dense column which extends from the centriolar apparatus in the rostrum to the anterior side of the nucleus Most of the short free kinetosomes in the column are arranged end-to-end in chains of varying lengths. Within a kinetosomal chain, all of the individual kinetosomes face in the same direction with respect to their cartwheel ends In most flagellates, the short free kinetosomes are 0 07-0.13 micro long, and are remarkably similar in length within any cell Occasionally, cells with uniformly "longer" short free kinetosomes are found. 70,000-120,000 long free kinetosomes are scattered singly throughout the cytoplasm between the column of short free kinetosomes and the cell surface These long free kinetosomes are 0 4-0 7 micro long, similar in length to the kinetosomes of the body flagella, and are oriented parallel to the anterior-posterior axis of the cell. The significance of this remarkable accumulation of free kinetosomes is discussed.

Animals↗
PubMed1984

Helical flagellation in Centipeda periodontii, a gram-negative, anaerobic bacillus from periodontitis lesions.

The insertion pattern of flagellation of Centipeda periodontii was determined from electron micrographs of negatively stained cells treated with various detergents to remove their outer cell wall layer(s) selectively. The best results were obtained with 0.2% sodium dodecyl sulphate and a treatment time of 1-2 min. Detergent-treated cells displayed a unique helical pattern of flagellation which we designate as helicotrichous (Gk n. helix, helix + Gk n. thrix, hair). Flagella originated from an electron-dense region approximately 180 nm wide, which spiraled around the cell body. The length of the insertion path averaged 2.6 micron per 360 degrees turn; its periodicity was 2.5 micron. An average of 19 flagella were inserted per 1 micron length of the electron-dense region. The effects of cell division and branching on flagellation were also examined.

Bacteria, Anaerobic↗
PubMed2004

Symbionts of the gut flagellate Staurojoenina sp. from Neotermes cubanus represent a novel, termite-associated lineage of Bacteroidales: description of 'Candidatus Vestibaculum illigatum'.

The symbioses between cellulose-degrading flagellates and bacteria are one of the most fascinating phenomena in the complex micro-ecosystem found in the hindgut of lower termites. However, little is known about the identity of the symbionts. One example is the epibiotic bacteria colonizing the surface of hypermastigote protists of the genus Staurojoenina. By using scanning electron microscopy, it was shown that the whole surface of Staurojoenina sp. from the termite Neotermes cubanus is densely covered with long rod-shaped bacteria of uniform size and morphology. PCR amplification of 16S rRNA genes from isolated protozoa and subsequent cloning yielded a uniform collection of clones with virtually identical sequences. Phylogenetic analysis placed them as a new lineage among the Bacteroidales, only distantly related to other uncultivated bacteria in the hindgut of other termites, including an epibiont of the flagellate Mixotricha paradoxa. The closest cultivated relative was Tannerella forsythensis (<85 % sequence identity). Fluorescence in situ hybridization with a newly designed clone-specific oligonucleotide probe confirmed that these sequences belong to the rod-shaped epibionts of Staurojoenina sp. Transmission electron microscopy confirmed the presence of a Gram-negative cell wall and revealed special attachment sites for the symbionts on the cell envelope of the flagellate host. Based on the isolated phylogenetic position and the specific association with the surface of Staurojoenina sp., we propose to classify this new taxon of Bacteroidales under the provisional name 'Candidatus Vestibaculum illigatum'.

Animals↗