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The Parkin co-regulated gene product, PACRG, is an evolutionarily conserved axonemal protein that functions in outer-doublet microtubule morphogenesis.

Eukaryotic cilia and flagella are highly conserved structures composed of a canonical 9+2 microtubule axoneme. Comparative genomics of flagellated and non-flagellated eukaryotes provides one way to identify new putative flagellar proteins. We identified the Parkin co-regulated gene, or PACRG, from such a screen. Male mice deficient in PACRG are sterile, but its function has been little explored. The flagellated protozoan parasite Trypanosoma brucei possesses two homologues of PACRG. We performed RNA interference knockdown experiments of the two genes independently and both together. Simultaneous ablation of both proteins produced slow growth and paralysis of the flagellum with consequent effects on organelle segregation. Moreover, using transmission electron microscopy, structural defects were seen in the axoneme, with microtubule doublets missing from the canonical 9+2 formation. The occurrence of missing doublets increased toward the distal end of the flagellum and sequential loss of doublets was observed along individual axonemes. GFP fusion proteins of both PACRG homologues localised along the full length of the axoneme. Our results provide the first evidence for PACRG function within the axoneme, where we suggest that PACRG acts to maintain functional stability of the axonemal outer doublets of both motile and sensory cilia and flagella.

Amino Acid Sequence↗

[The epidemiology of Chagas' disease in a rural area of the city of Teresina, Piauí, Brazil].

In the rural areas of Teresina, 129 triatomines were captured distributed in (a) artificial ecotopes; a house with one Triatoma brasiliensis, one Panstrongylus geniculatus, Rhodnius pictipes, and one Rhodnius prolixus and in a uninhabited chicken house (7 Rhodnius nasutus). (b) Natural ecotopes; Pahus Orbignya martiana (41 Rhodnius neglectus, 33 Rhodnius prolixus and 41 Rhodnius nasutus) and Copernicia cerifera (3 Rhodnius neglectus). The 22.6% of captured triatomines were infected by flagellates similar to Trypanosoma cruzi. Twenty-eight sylvatic mammals were captured and examined. Seven Didelphia albiventris, 2 Rattus rattus and a Tamandua tetradactyla were infected with flagellates. The flagellates found in both triatomines and mammals were morphologically indistinguishable from Trypanosoma cruzi. Serology by the indirect immunofluorescence test for Chagas disease revealed two positive seroreactions of positivity among 123 inhabitants examined.

Adolescent↗

Trypanosomatid protozoa in fruit of Solanaceae in southeastern Brazil.

Fruits of cultivated and indigenous Solanaceae from Southeastern Brazil have been examined for the presence of trypanosomatid flagellates. The 14 species found infected were: Capsicum annuum, C. praetermissum, Lycopersicon esculentum, Nicandra physaloides, Physalis angulata, Solanum sp., S. americanum, S. concinnum, S. diflorum, S. erianthum, S. gilo, S. robustum, S. variable and S. viarum. The pentatomid hemipteran Arvelius albopunctatus experimentally transmitted flagellates to fruits of some species. Cultures of flagellates were obtained from fruits of eight species of Solanaceae and from A. albopunctatus.

Animals↗

Development of trypanosomatids in the phytophagous insect Dysdercus peruvianus (Hemiptera: Pyrrochoridae). A light and eletron microscopic study.

Experimental infections of the phytophagous Hemiptera Dysdercus peruvianus with different trypanosomatids were studied for up to 55 days by light microscopy while the course of infection with Leptomonas seymouri and the Leptomonas isolate 49/553G.O. was analyzed by electron microscopy. Rates of infection of D. peruvianus varied according to the infecting flagellate. The lower part of the midgut was found to be the preferential site of colonization where most flagellates were found isolated or arranged in clumps or rosettes. Specialized junctional structures with host cells were never observed. Flagellates could also be seen inside midgut cells within a parasitophorous vacuole. Infection of haemocoele and salivary glands was also observed.

Animals↗

Biochemical characterization of a trypanosomatid isolated from the plant Amaranthus retroflexus.

A protozoan flagelate has recently been isolated from Amaranthus retroflexus. This plant grows near economically important crops in southeastern Spain, which are known to be parasitized by Phytomonas spp. The present study focuses on the characterization of the energy metabolism of this new isolate. These flagellates utilize glucose efficiently as their primary energy source, although they are unable to completely degrade it. They excrete ethanol, acetate, glycine, and succinate in lower amount, as well as ammonium. The presence of glycosomes was indicated by the early enzymes of the glycolytic pathway, one enzyme of the glycerol pathway (glycerol kinase), and malate dehydrogenase. No evidence of a fully functional citric-acid cycle was found. In the absence of catalase activity, these flagellates showed significant superoxide dismutase activity located in the glycosomal and cytosolic fractions. These trypanosomes, despite being morphologically and metabolically similar to other Phytomonas isolated from the same area, showed significant differences, suggesting that they are phylogenetically different species.

Animals↗

Phlebotomines (Diptera: Psychodidae) in forested areas of the Serra da Bodoquena, state of Mato Grosso do Sul, Brazil.

Investigation was undertaken on the behaviour of the phlebotomine fauna in caves, forests, and anthropic environments of the Serra da Bodoquena, between January 1998 and January 2000. This paper reports on the phlebotomines captured in forested areas with automatic light traps (ALT), Shannon traps (ST), aspiration (AN), at natural resting sites and by human attractiveness (HA) during 24 h. The diversity and abundance of the species were investigated with ALT installed at 16 points (ground level) and 6 in the canopy. Natural infection by flagellates was investigated in females captured with ST AN, and HA. The sandfly fauna was represented by 23 species. Twenty-two of these were captured with ALT 15 of them on the western side, and 20 on the eastern. Lutzomyia longipalpis and Nyssomyia whitmani were the most abundant on the former and this species together with Lutzomyia almerioi on the latter side. On the eastern side the ecotopes located close to caves rendered a significantly greater number (P < or = 0.01) of specimens than did more distant sites. On this side Lu. almerioi contributed with 56% of the total number of specimens. Lu. almerioi females were predominantly attracted by humans (96.4%) and by ST (93.2%) and three of the 2173 dissected (0.138%) presented natural infection by flagellates. The attraction of Lu. almerioi to humans occurred during all seasons, predominantly in the summer, and in nocturnal and diurnal periods. Thus it is bothersome to inhabitants of and visitors to the Bodoquena ridge and a potential vector of flagellates.

Animals↗

Hexamita meleagridis (Spironucleus meleagridis) infection in chukar partridges associated with high mortality and intracellular trophozoites.

An outbreak of infectious catarrhal enteritis, associated with the flagellated protozoan Spironucleus meleagridis (syn. Hexamita meleagridis), is reported from a commercial flock of chukar partridges in California. The disease affected birds between the ages of 4 and 6 wk and resulted in diarrhea, listlessness, depression, and high mortality. Concurrent infection with other intestinal pathogens, including Cryptosporidia, group E Salmonella, long-segmented filamentous microorganisms (LSFMOs), and Rotavirus-like virus particles, was found in some but not all affected birds. Dermatitis of the face, shanks, and feet, suggestive of B-complex vitamin deficiency, was present in most affected birds as well. Flagellated protozoan parasites could be found in the lumen of the duodenum and jejunum and in the intestinal crypts. In some cases the flagellates were wedged between epithelial cells or were located intracellularly within cells of the mucosal epithelium and the intestinal lamina propria.

Animals↗

Structure of the microbial flora associated with periodontal health and disease in man. A light and electron microscopic study.

Teeth slated for extraction were evaluated with respect to their periodontal status and classified accordingly into five categories; namely normal, gingivitis, periodontitis, periodontosis and postperiodontosis. After processing, one approximal surface of each tooth was sampled at various levels in an apico-occlusal direction for light and electron microscopic study of the associated bacterial flora. In normal samples, the flora consisted of a relatively thin, adherent bacterial layer confined to the enamel surface. The cells were predominantly coccoid in shape with cell wall features compatible with those of Gram-positive organisms. Isolated filamentous or branching forms and some Gram-negative bacteria were noted on the surface of the more apical portion of the bacterial layer. No flagellated cells or spirochetes were present. Gingivitis samples yielded a relatively more voluminous and complex supragingival flora with relatively more filamentous bacteria and more cells with a Gram-negative cell wall ultrastructure. These samples also contained corncob formations on the surface of supragingival deposits, and flagellated cells with spirochetes within the predominantly Gram-negative flora of the sulcus bottom. Supragingival bacterial deposits of periodontitis samples were similar to those observed in gingivitis. The subgingival flora consisted of relatively fewer cells adherent to the root surface with a concomitant increase in the population of Gram-negative and flagellated cells, as well as spirochetes. The tissue side of the subgingival flora generally exhibited a distinctive concentration of "test-tube brush" formations, spirochetes of predominantly medium size, and assorted cell types peculiar to this region. A transitional flora generally separated the supra- from the subgingival microbial population. Periodontosis samples had a relatively sparse, predominantly Gram-negative flora. A unique electron-dense, lobulated cuticular deposit covered the majority of the samples studied. Postperiodontosis samples were much more similar in their microbial flora to the periodontitis group. The results suggest that (1) a certain microbial flora may be compatible with a state of periodontal health; (2) a different flora is associated with varying degrees of periodontal disease; (3) the structure and composition of the supragingival flora differs markedly from that of the subgingival flora; (4) with the exception of periodontis, the alterations of the microbial flora as periodontal disease increases inseverity parallel the changes described previously in the microbial population collected on artificial crowns during experimentally induced gingivitis. The use of the expressions "microbial flora" or "microbial population" is considered preferable to the terms "plaque", "materia alba", or "debris" in reference to the microbiota of the gingival sulcus region.

Adolescent↗

[Fine Structures Of Trichomonas Tenax And Trichomonas Hominis]

Trichomonas tenax(T. tenax) and Trichomonas hominis (T. hominis) were collected, cultured and sampled for comparative microscopical studies using electron microscope. 1. Both flagellates were oval in shape and surrounded by a distinct outer membrane. Five recurrent flagella and one anterior flagellum had, each, 9 paris of peripheral and 1 pair of central fibrils, Undulating membrane was curved over the recurrent flagella, and bended in the middle at right angles with cell surface. Cytostome, engulfing bacteria, was observed in T. hominis. 2. In the cytoplasm, there were fine dense glycogen particles, and vacuoles containing ingested materials. Dense pigment rods were also observed in both flagellates, but the rods were not distributed around the vacuoles in T. hominis. 3. In T. tenax axostyle appeared as a cup-shaped structure comprising a single row of 41 fibrils, each about 120 a in diameter. It enclosed glycogen particles, and the open side was faced to the nucleus. 4. Endoplasmic reticulum was observed around the nucleus, but it was less developed in T. hominis. 5. Nucleus was ovoid having double nuclear membrane, which was clearly defined in T. hominis. 6. Blepharoplast, parabasal body, Golgi appartus and mitochondrion was not observed in both flagellates.

Journal Article↗

Systemic spironucleosis in sea-farmed Atlantic salmon Salmo salar, caused by Spironucleus barkhanus transmitted from feral Arctic char Salvelinus alpinus?

A hexamitid flagellate was found in the gall bladder and intestine of Arctic char Salvelinus alpinus in northern Norway. Scanning and transmission electron microscopy showed this flagellate to be identical to Spironucleus barkhanus from grayling Thymallus thymallus and farmed Atlantic salmon Salmo salar. It is hypothesized that systemic spironucleosis in sea-caged Atlantic salmon was due to transmission of flagellates from feral char to the salmon.

Animals↗

In vitro cultivation of Trypanoplasma borreli (protozoa: kinetoplastida), a parasite from the blood of common carp Cyprinus carpio.

An in vitro culture system was developed for Trypanoplasma borreli, a pathogenic flagellate from the blood of European cyprinids. Trypanoplasms multiplied rapidly in a mixture of Hanks' balanced salt solution (HBSS, 45%), L15 (22.5%), Earle's minimum essential medium (MEM, 22.5%) and 10% distilled water, which was supplemented with 5 to 10% heat-inactivated pooled carp serum. In medium supplemented with fetal bovine serum, multiplication of T. borreli seemed to be inhibited. Cultures initiated with less than 100 000 T. borreli per ml culture medium did not survive, and a substantial multiplication of trypanoplasms was found at inocula beginning with 630 000 flagellates ml(-1). Trypanoplasms multiplied at 15, 20 and 25 degrees C. In cultures incubated at 4 degrees C the trypanoplasms remained viable but the number of flagellates did not increase. Trypanoplasms from in vitro cultures retained their infectivity for carp for at least 90 d (5 passages). The trypanoplasms survived in culture over a period of up to 5 mo (10 passages). The established culture system allows the propagation of high numbers of fish-infective trypanoplasms, which are required to study parasite-host relationships in carp.

Animals↗

Ichthyobodo necator (Kinetoplastida)--a complex of sibling species.

Ichthyobodo necator is a parasitic flagellate that attacks fishes, causing disease problems in freshwater worldwide. Findings of similar flagellates in strictly marine fishes have indicated that ichthyobodiosis may be caused by more than 1 flagellate species. We obtained partial small subunit rDNA (ssu rDNA) sequences of 14 Ichthyobodo isolates originating from fishes in Norway, Japan, Singapore, South Africa and Brazil, and identified 8 strains or species, including 2 species infecting cultured salmon in Norway. An Ichthyobodo species isolated from the skin of Atlantic salmon parr in freshwater is suggested to represent L. necator sensu stricto, while another species, showing particular affinity for the gills, infects salmon in both fresh- and seawater. Atlantic cod is infected with a marine Ichthyobodo species unrelated to those infecting salmonids; 2 cyprinids originating from different parts of the world had related Ichthyobodo strains/species, and 2 isolates from unrelated North and South American fishes were also closely related. The phylogenetic relationships of the Ichthyobodo isolates is described, and the implications of the molecular findings on past and future morphological studies of Ichthyobodo spp. are discussed.

Animals↗

Flagella on Legionnaires' disease bacteria: ultastructural observations.

Scanning and transmission electron microscopic studies were done on five strains of flagellated Legionella pneumophila cultured for 1 to 3 days on charcoal yeast extract agar or yeast extract broth. Ultrastructurally, each strain consisted of pleomorphic, flagellated bacilli, many of which showed the typical pinching type of division as seen with other gram-negative bacteria. Most of the flagellated organisms, regardless of the strain, had a single, relatively straight or undulant polar flagellum, about 25 nm in diameter. In some instances, retraction of the bacterial cell membranes made the flagellar basal bodies (bulbs) visible when observed by transmission electron microscopy. The bulbous nature of these bodies appears to be different from the basal structures described for Escherichia coli and other gram-negative bacteria. Long "streamers," previously observed with the light microscope, appear to be fimbriae (or pili) that have a diameter approximatley half that of the flagella and are somewhat coiled and bent at irregular intervals.

Cell Membrane↗

[Diversity and function of symbiotic microbes in the gut of lower termites].

The gut of lower termites harbor a complex microbial community, including eukaryotic flagellates and prokaryotic bacteria and archaea, which play important roles in the wood-cellulose digestion of these termites. The hindguts of lower termites are characterized with an enlarged paunch with steep oxygen and hydrogen gradient and not randomly distributed abundant microorganisms. The symbiotic flagellates in the gut of lower termites, which are normally associated with epibionts or endobionts, are phylogenetically affiliated with Trichomonadida, Hypermastigida and Oxymonadida. They endocytose wood particles and ferment the polysaccharide components to acetate, CO2 and H2, which are further metabolized by symbiotic prokaryotes as energy and nutrition sources in the termites. Cellulose genes such as glycosyl hydrolase family 45 have been identified in gut protists with molecular approach. Phylogenetic analysis have revealed that in the gut of lower termites, such as several Reticulitermites species, most of the dominant bacteria belong to phyla like "Termite group 1", Spirochaetes, Firmicutes, Bacteroidetes, and Proteobacteria. These bacteria clones normally form distinct termite clusters in phylogenetic trees, which show the existence of specific microbial diversity in the termite guts. Most of the symbiotic archaea in the gut of lower termites are methanogens and affiliated with the genus Methanobrevibacter by phylogenetic analysis and pure culture. The symbiotic bacteria and archaea may involve in the reduction of CO2 and the metabolism of N2 in these termite guts. However, the functions and metabolic mechanisms of the symbiotic flagellates and prokaryotes in the gut of lower termites are still remaining to be further elucidated.

Animals↗

Chemotaxis in Listeria monocytogenes.

Listeria monocytogenes is a flagellated bacterium with a characteristic tumbling motion. It is intriguing to speculate that directional motility might facilitate penetration of the intestinal epithelium or selective colonization of the central nervous system or gravid uterus. There are conflicting reports on the extent of flagellation and degree of motility at temperatures corresponding to the internal environment of the mammalian host. No studies of chemotaxis in Listeria have been reported. We examined Listeria for flagella, motility, and chemotaxis after growth at 10 degrees, 24 degrees, 30 degrees, 37 degrees and 40 degrees C. Listeria grown at all temperatures possessed flagella and were motile to at least some degree. Those grown at 24 degrees or 30 degrees C were the most abundantly flagellated and the most vigorously motile. The bacteria were able to swim towards tryptose at all temperatures and toward glucose at all temperatures except 40 degrees C.

Cell Movement↗

[Trichomonadida and their hosts].

Relations of particular genera of Monocercomonadidae and Trichomonadidae with groups of hosts are discussed. Main hosts of these flagellates are insects (mainly termites) and cold-blooded vertebrates (amphibians and reptiles); the proper location within the host body is the intestine. Some representatives of these flagellates have changed their host and location and occur now in warm-blooded vertebrates (birds and mammals) and in man, usually in organs other than the intestine. Change of localization within the host body is probably responsible for growing pathogenicity of these flagellates.

Amphibians↗

DNA synthesis during growth and synchronous differentiation of Naegleria.

Naegleria gruberi amoebae were stimulated to differentiate synchronously into flagellates under growth conditions by lowering the temperature from 32 degrees C to 20.5 degrees C. In the presence of nutrient medium, flagellates will eventually revert to amoebae and resume growth. The time course of nuclear DNA synthesis, using a double thymidine isotope procedure, was determined for: (1) logarithmically growing amoebae, (2) differentiating cells, and (3) flagellates that were reverting to amoebae. DNA replication ceased 10 min. after the stimulation of differentiation, and began again during reversion. Neither de novo transcription nor translation appear to be required for the cessation of DNA replication during differentiation.

Amoeba↗

[A rapid staining method for the study of the flagellar and round forms of Trichomonas vaginalis from culture].

This method has been developed for the routine observation of the different forms of Trichomonas vaginalis in axenic culture with a low rate of cell loss. This rapid dyeing process is especially suitable for the examination of the ratio between the flagellated and round forms of the parasite. As a result of this staining one can not see fine cell details but can firmly distinguish between flagellated forms and multi-nucleated, multi-flagellated forms (i.e. dividing cells forms).

Animals↗