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Zdenek Zizka - One of the best experts on this subject based on the ideXlab platform.
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Unikaryon montanum sp. n. (Protista: Microspora), a new pathogen of the spruce bark beetle, Ips typographus (Coleoptera: Scolytidae)
Folia Parasitologica, 2013Co-Authors: Jaroslav Weiser, Rudolf Wegensteiner, Zdenek ZizkaAbstract:Unikaryon montanum sp. n. infects the fat body, muscle, Malpighian tubules and ovaries of adult Ips typographus L. The development is haplokaryotic, with separate nuclei during the schizogony and sporogony. Sporonts have the cellular envelope with added layer of electron dense material. Two types of spores are formed: small broad-oval primary spores, 1.5 × 1.0 µm, with warty surface of spore wall, uninucleate, with isofilar Polar Filament in 5/6 coils and elongated-oval environmental spores, 0.8-1 × 2 µm, with warty spore wall attenuated at the anterior end, uninucleate, with spore Polar Filament in 8 coils. Both types have a dual Polaroplast with the anterior part of a layer of confluent fine lamellae ending posteriorly in bulbous processes, and posterior part composed of coil of tubules.
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Ultrastructure of the Microsporidium, Duboscqia legeri, the Type Species of the Genus Duboscqia Perez, 1908
Acta Protozoologica, 2010Co-Authors: J. Weiser, Zdenek Zizka, Peter Belton, Jaroslav HolušaAbstract:The type species of the genus Duboscqia Perez, 1908 (Opisthokonta, Microspora), D. legeri is a pathogen of termites. It was found again in Zootermopsis angusticollis in British Columbia and the material is used for emendation of data on ultrastructures of this old genus. The sporogony of this microsporidian ends with 16 oval spores closed in sporophorous vesicles. The isofilar Polar Filament coiled in 13 coils, the arched anchoring disc and the Polaroplast with tightly packed lamellae are typical for the ultrastructures of uninucleate spores. The sporophorous vesicle is persistent. The microsporidian infects cyst-like lobes of the fat body hanging free in the body cavity. Relations to other related genera are discussed.
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Larssoniella duplicati n.sp. (Microsporidia, Unikaryonidae), a newly described pathogen infecting the double-spined spruce bark beetle, Ips duplicatus (Coleoptera, Scolytidae) in the Czech Republic
Journal of Pest Science, 2006Co-Authors: J. Weiser, Jaroslav Holuša, Zdenek ZizkaAbstract:Larssoniella duplicati n.sp . infects the midgut muscularis, the Malpighian tubules, and the ovaries of adult Ips duplicatus (Sahlb.) in the Czech Republic. The microsporidian attacks up to 50% of the population. Oval spores of two sizes, 3–3.5×1.5–2 and 2–2.5×1.5 μm have the Polar Filament coiled in 6/7 coils, representing primary and environmental spores, respectively. In early sporogony the young spores produce long electron dense threads and tubules of secretions, which remain fixed around the spore and avoid their free release during dissection of infected hosts. The microsporidian was not found in associated bark beetles such as Ips typographus (L.), or I. amitinus (Eichh.) and others.
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Infection of Tomicus piniperda (Col., Scolytidae) with Canningia tomici sp. n. (Microsporidia, Unikaryonidae)
Anzeiger Fur Schadlingskunde-journal of Pest Science, 2003Co-Authors: B. Kohlmayr, Uschi Handel, Jaroslav Weiser, Rudolf Wegensteiner, Zdenek ZizkaAbstract:Canningia tomici sp. n. (Microsporidia, Unikaryonidae) infects the midgut epithelium, the gut muscules, Malpighian tubules, connective tissues, adipose tissues and the gonads of the pine shoot beetle, Tomicus piniperda (L.) (Coleoptera, Scolytidae). The infection is present in populations of Tomicus piniperda in Europe and in the United States. Uninucleate oval single spores occur in two sizes: 2.8 ± 0.4 × 1.4 ± 0.4 μm and 3.8 ± 0.3 × 2.0 ± 0.2 μm. The Polar Filament of this microsporidium is fixed subapically in a flat anchoring disc. The thick posterior lamellae of the binary Polaroplast are asymmetric due to the lateral fixation of the Polar Filament.
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Unikaryon polygraphi sp.n. (Protista, Microspora): a new pathogen of the four‐eyed spruce bark beetle Polygraphus poligraphus (Col., Scolytidae)
Journal of Applied Entomology, 2002Co-Authors: Jaroslav Weiser, Rudolf Wegensteiner, U. Händel, Zdenek ZizkaAbstract:The microsporidium Unikaryon polygraphi sp.n., a pathogen of Polygraphus poligraphus in Austria is described based on light microscopic and ultrastructural characteristics. All life stages have isolated nuclei. Sporogony ends with uninucleate single sporoblasts and spores. Mature oval spores measure 2.5–3.0 μm × 1.0–1.5 μm. The larger spores (3 × 1.5 μm) belong to the `early spore type' with a Polar Filament coiled in five turns and the smaller spores (2.5 × 1 μm) with Polar Filament coiled in 6/7 turns belong to the `environmental spore type'. Columnar cells of the midgut, longitudinal and circular muscles and the secretory part of Malpighian tubules of adult beetles are infected. Mature spores are excreted together with the faeces.
Carlos Azevedo - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructural and molecular characterization of Glugea serranus n. sp., a microsporidian infecting the blacktail comber, Serranus atricauda (Teleostei: Serranidae), in the Madeira Archipelago (Portugal).
Parasitology research, 2016Co-Authors: Graca Casal, Sonia Rocha, Graça Costa, Saleh Al-quraishy, Carlos AzevedoAbstract:A new microsporidian infecting the connective tissue of the coelomic cavity of the blacktail comber Serranus atricauda, in the Madeira Archipelago (Portugal), is described on the basis of morphological, ultrastructural, and molecular features. The microsporidian formed large whitish xenomas adhering to the peritoneal visceral organs of the host. Each xenoma consisted of a single hypertrophic cell, in the cytoplasm of which mature spores proliferated within parasitophorous vacuoles surrounded by numerous collagen fibers. Mature spores were ellipsoidal and uninucleated, measuring an average of 6.5 ± 0.5 μm in length and 3.4 ± 0.6 μm in width. The anchoring disk of the Polar Filament was subterminal, laterally shifted from the anterior pole of the spore. The isofilar Polar Filament coiled in 18–19 turns, forming two rows that surrounded the posterior vacuole. The latter occupied about one third of the spore length. The Polaroplast surrounding the apical and uncoiled portion of the Polar Filament displayed two distinct regions: a lamellar region and an electron-dense globule. Molecular analysis of the rRNA genes, including the internal transcribed spacer region, and phylogenetic analysis using maximum likelihood and neighbor joining demonstrated that this microsporidian parasite clustered with some Glugea species. Based on the differences found both at the morphological and molecular levels, to other members of the genus Glugea, the microsporidian infecting the blacktail comber is considered a new species, thus named Glugea serranus n. sp.
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morphological and molecular characterization of a new myxozoan species myxosporea infecting the gall bladder of raja clavata chondrichthyes from the portuguese atlantic coast
Journal of Parasitology, 2013Co-Authors: Sonia Rocha, Graca Casal, Saleh Alquraishy, Carlos AzevedoAbstract:Abstract: Microscopic and molecular procedures are used to describe a new myxosporean species, Chloromyxum clavatum n. sp., infecting the cartilaginous fish Raja clavata Linnaeus, 1758 (Chondrichthyes: Rajidae), collected from the northwest Atlantic coast of Portugal. Young plasmodia and mature spores were found floating free in the gall bladder of R. clavata. Spores were spherical to subspherical with a pointed anterior end, measuring14.4 ± 0.5 μm (n = 25) in length, 11.9 ± 0.5 μm (n = 25) in width, and 9.4 ± 0.5 μm (n = 15) in thickness. The spore's wall was composed of 2 equally sized valves, each displaying 6–8 elevated surface ridges and a bundle of several tapering caudal Filaments attached to the basal portion. Spores contained 4 pyriform equally sized Polar capsules (5.5 ± 0.4 μm × 2.9 ± 0.5 μm) (n = 25), each possessing an obliquely arranged isofilar Polar Filament coiled in 7–8 coils. Morphological data, host specificity, tissue tropism, and molecular analysis of the SSU rDNA gene identify this ...
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a new myxozoan parasite from the amazonian fish metynnis argenteus teleostei characidae light and electron microscope observations
Journal of Parasitology, 2006Co-Authors: Graca Casal, Edilson Matos, Carlos AzevedoAbstract:Myxobolus metynnis n. sp. (Phylum Myxozoa) is described in the connective subcutaneous tissues of the orbicular region of the fish, Metynnis argenteus (Characidae), collected in the lower Amazon River, near the city of Peixe Boi, Para State, Brazil. Polysporic, histozoic plasmodia were delimited by a double membrane with numerous microvilli on the peripheral cytoplasm. Several life-cycle stages, including mature spores, were observed. An envelope formed by numerous fine and anastomosed microfibrils was observed at the spore surface. The spore body presented an ellipsoidal shape and was about 13.1 μm long, 7.8 μm wide, and 3.9 μm thick. Elongated-pyriform Polar capsules were of equal size, measuring 5.2 μm in length, 3.2 μm in width, and possessing a Polar Filament with 8–9 turns around the longitudinal axis. The binucleated sporoplasm contained a vacuole and numerous sporoplasmosomes. These were circular in cross-section, showing an adherent eccentric, dense structure, with a half-crescent section. Based ...
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Myxobolus desaequalis n. sp. (Myxozoa, Myxosporea), parasite of the Amazonian freshwater fish, Apteronotus albifrons (Teleostei, Apteronotidae).
The Journal of eukaryotic microbiology, 2002Co-Authors: Carlos Azevedo, Laura Corral, Edilson MatosAbstract:Myxobolus desaequalis n. sp. is described from the gill lamellae of the freshwater fish Apteronotus albifrons, collected in the Amazon River, near the city of Salvaterra, Brazil. Large spherical plasmodia filled with disporic pansporoblasts and spores were observed. Ellipsoidal to pyriform spores are 18.3 microm length x 11.2 microm width x 4.4 microm thickness. The anterior end of the spores contain two extremely unequal pyriform Polar capsules measuring: (larger): 11.2 microm length, 4.9 microm width, and an isofilar Polar Filament with 11 to 12 turns obliquely to the longitudinal axis; (smaller): 4.6 microm length, 2.8 microm width, and an isofilar Polar Filament with 4 to 5 turns, obliquely to the longitudinal axis.
Y-n Young - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of a semiflexible Polar Filament in Stokes flow.
Physical review. E Statistical nonlinear and soft matter physics, 2010Co-Authors: Y-n YoungAbstract:In this work, the dynamics and transport of a Polarly driven Filament is examined using a continuum slender-body model. Immersed in a viscous fluid, the Filament gains Polar propulsion from the motor proteins (anchored on the motility assay) while experiencing a viscous drag from the bottom wall. Results from the linear analysis on a straight Polar Filament illustrate the necessity of spatial inhomogeneity in the Polar forcing for the buckling instability. The ensuing buckling leads to Filament deformation, undulation, and change of its direction of motion in the numerical simulations. Repeated Filament buckling in two types of motor protein concentration landscape results in diffusive transport of a Polar Filament on scales much larger than the mean-free path and the average duration between Filament buckling events.
Mustafa Yaman - One of the best experts on this subject based on the ideXlab platform.
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First report and spore ultrastructure of Vairimorpha plodiae (Opisthokonta: Microspora) from Plodia interpunctella (Lepidoptera: Pyralidae) in Turkey
Acta Parasitologica, 2016Co-Authors: Mustafa Yaman, F. Pınar Güngör, Beyza Gonca Güner, Renate Radek, Andreas LindeAbstract:The present study describes the first isolation and characterization of Vairimorpha plodiae , a microsporidian pathogen of Plodia interpunctella (Lepidoptera: Pyralidae), from Turkey. We present characteristic light and electron microscopical features of the spores. Fresh binucleate spores are oval and measure 4.48 ± 0.23 (4.01–4.84) μm in length and 2.21 ± 0.15 (1.91–2.48) μm in width. Ultrastructural studies showed that the spore wall measures 150 to 200 nm and consists of a clear endospore (125–150 nm) and an electron-dense, uniform, thin exospore (30–50 nm). The Polar Filament is isofilar and with 10–12 coils. The well-developed Polaroplast consists of two parts with thin lamellae anteriorly and thick, irregularly arranged lamellae posteriorly. The identity of our isolate is discussed.
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Ultrastructure, characteristic features and occurrence of Nosema leptinotarsae Lipa, 1968, a microsporidian pathogen of Leptinotarsa decemlineata (Coleoptera, Chrysomelidae)
Acta Parasitologica, 2011Co-Authors: Mustafa Yaman, Andreas Linde, Renate Radek, Nejla Özcan, Jerzy J. LipaAbstract:This paper presents the ultrastructure and characteristic features of Nosema leptinotarsae infecting L. decemlineata collected in Trabzon (Turkey). Fresh spores are oval, 4.69 ± 0.19 μm in length and 2.43 ± 0.12 μm in width (n = 50). The spore wall is thick and measures 180 to 250 nm and consists of a clear endospore (130 to 170 nm) and an electron-dense, uniform exospore (50 to 80 nm). The Polar Filament is isofilar and has 15–16 coils. The well-developed Polaroplast has a lamellated structure with thin lamellae. The ultrastructural features of Nosema leptinotarsae differ from those of other microsporidia infecting chrysomelids.
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A microsporidian pathogen of the predatory beetle Rhizophagus grandis (Coleoptera: Rhizophagidae).
Folia parasitologica, 2010Co-Authors: Mustafa Yaman, Jaroslav Weiser, Renate Radek, Cicek AydinAbstract:A new Microsporidium sp. infects Rhizophagus grandis Gyllenhall, a beetle which preys on the bark beetle Dendroctonus micans Kugellan in Turkey. Mature spores are single, uninucleate, oval in shape (3.75 +/- 0.27 microm in length by 2.47 +/- 0.13 microm in width), with a subapically fixed Polar Filament. The Polar Filament is anisofilar, coiled in 7-8 normal and 3-4 reduced coils. Other characteristic features of the microsporidium are the four/five nuclear divisions to form 16/32 (commonly 16) spores, subpersistent sporophorous vesicles (pansporoblasts) remaining till formation of the endospore, and the vesicles dissolved with free mature spores. The Polaroplast is divided into three zones: an amorphous zone, dense layers, and a lamellartubular area extending to the central part of the spore.
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unikaryon phyllotretae sp n protista microspora a new microsporidian pathogen of phyllotreta undulata coleoptera chrysomelidae
European Journal of Protistology, 2010Co-Authors: Mustafa Yaman, Jaroslav Weiser, Renate Radek, Bhen Sikina ToguebayeAbstract:Abstract The microsporidium Unikaryon phyllotretae sp. n., a new pathogen of Phyllotreta undulata, is described based on light microscopic and ultrastructural characteristics. Microscopic examination of parasitized individuals revealed two types of spores. The majority of the spores were of the first type, which are oval and measured 2.74±0.17×1.93±0.17 μm when fresh. Fresh spores of the second type (very rare) are elongated and measured 4.39±0.18×1.61±0.20 μm. All life stages have single nuclei. Sporogony ends with uninucleate single sporoblasts and spores. The spores were only observed in Malpighian tubules. The isofilar Polar Filament of the parasite has six to eight coils, and a well-developed Polaroplast was of the lamellated type, with closely packed anterior lamellae and loosely packed posterior lamellae.
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A New Microsporidian of the Genus Nosema, Parasite of Chaetocnema tibialis (Coleoptera: Chrysomelidae) from Turkey
Acta Protozoologica, 2008Co-Authors: Mustafa Yaman, Renate Radek, Bhen Sikina ToguebayeAbstract:A new microsporidian parasite was discovered in Chaetocnema tibialis (Coleoptera: Chrysomelidae) in Turkey. The life cycle of the new species was examined by light and electron microscopy. It parasitizes the Malpighian tubules of C. tibialis. All development stages are in direct contact with the host cell cytoplasm and have paired nuclei (diplokaryon). Fresh spores are elongated and measure 3.82 ± 0.3 × 1.3±0.2μm. The spores possess two spherical nuclei, 8-10 coils of the Polar Filament and a posterior vacuole. All morphological and ultrastructural features indicate that the described microsporidium belongs to the genus Nosema. The microsporidian parasite presented here differs from Nosema chaetocnemae in spore size, number of Polar Filament coils, tissue specificity and locality. Therefore the parasite is considered to be a new microsporidian parasite of C. tibialis. This new species has been named Nosema tokati sp. n. after the name of its host's location.
Wilfried Haas - One of the best experts on this subject based on the ideXlab platform.
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Analysis of rainbow trout Oncorhynchus mykiss epidermal mucus and evaluation of semiochemical activity for Polar Filament discharge in Myxobolus cerebralis actinospores.
Journal of fish biology, 2010Co-Authors: Dennis M. Kallert, S. Ponader, S. Adelt, P. Kaese, R. Geyer, Wilfried Haas, Mansour El-matbouliAbstract:As myxozoan actinospores are stimulated by fish epidermal mucus to attach to their hosts via extrusion of Filaments from specialized organelles, the Polar capsules, mucus components were tested for discharge triggering activity on Myxobolus cerebralis actinospores. Using various methodological approaches, a selective exclusion of candidate substances based on experimental outcome is provided and the physiochemical traits of the putative agents are explored to create a basis for the isolation of the host recognition chemostimuli. Activity was detected in compounds that can be characterized as small molecular, amphiphilic to slightly hydrophobic organic substances. They were separable by chromatographic methods using reversed phase C18 supports. An active fraction was isolated by solid phase extraction comprising at least nine UV-detectable constituents as shown by thin-layer chromatography. By means of biochemical fractionation and analysis of host fish mucus, non-volatile inorganic electrolytes, all volatiles, free L-amino acids, glycoproteins, bound and free hexoses, sialic acids, glycans, proteins, urea, amines and inositols were shown not to trigger Polar Filament discharge. The results contribute to the identification of the attachment host cues and enable a more focused laboratory activation of myxozoan actinospores.
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Myxozoan transmission via actinospores: New insights into mechanisms and adaptations for host invasion
Parasitology, 2007Co-Authors: Dennis M. Kallert, S. Ponader, Mansour El-matbouli, Edit Eszterbauer, Wilfried HaasAbstract:Various mechanisms that enable and improve transmission success of myxozoan actinospore stages towards fish hosts are described, based upon a combination of experimental data and functional analysis of morphological characters. For this purpose, laboratory-reared actinospores of Myxobolus cerebralis, Myxobolus parviformis, Henneguya nuesslini and Myxobolus pseudodispar were employed to exemplarily investigate aspects of host attachment and invasion. The process of Polar Filament discharge of M. cerebralis actinospores was analysed, showing that full discharge occurs in less than 10 msec. Additionally, a mechanism that rapidly contracts the discharged Filament after discharge is described for the first time. Its purpose is most likely to bring the actinospore apex rapidly into intimate contact with the surface of the host. Unlike M. cerebralis, M. parviformis actinospores did not discharge Polar Filaments after mechanical and chemical stimulation, suggesting a different mode of triggering. For H. nuesslini actinospores, experimental results indicated that Polar Filament discharge is independent of external calcium-ion concentration but is influenced by osmolality. After attachment of an actinospore and prior to penetration into the host, an ensheathed unit ('endospore'), containing the sporoplasm, was emitted from the valves in a manner which varied from species to species. Experimentally induced sporoplasm emission was time-dependent and was found to be independent of Polar Filament discharge in H. nuesslini. Remarkably, it could be concluded that the sporoplasm is able to recognize host-stimuli while still within the intact spore. An updated summary of the sequential course of events during host recognition and invasion by actinospores is given.