Publications by authors named "Radek R"

Nephridiophagids are unicellular fungi (Chytridiomycota) that infect the Malpighian tubules of insects. Most species have been found in cockroach hosts and belong to the genus . Three additional genera have been described from beetles and an earwig.

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The care-kill response determines whether a sick individual will be treated or eliminated from an insect society, but little is known about the physiological underpinnings of this process. We exploited the stepwise infection dynamics of an entomopathogenic fungus in a termite to explore how care-kill transitions occur, and identify the chemical cues behind these shifts. We found collective responses towards pathogen-injected individuals to vary according to severity and timing of pathogen challenge, with elimination, via cannibalism, occurring sooner in response to a severe active infection.

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An ant-pathogenic neogregarine in Temnothorax affinis and T. parvulus (Hymenoptera: Formicidae) is described based on morphological and ultrastructural characteristics. The pathogen infects the hypodermis of the ants.

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The soil-feeding habit is an evolutionary novelty found in some advanced groups of termites. The study of such groups is important to revealing interesting adaptations to this way-of-life. The genus Verrucositermes is one such example, characterized by peculiar outgrowths on the head capsule, antennae and maxillary palps, which are not found in any other termite.

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Spirotrichonymphea, one of the six classes of phylum Parabasalia, are characterized by bearing many flagella in spiral rows, and they occur exclusively in the guts of termites. Phylogenetic relationships among the 13 described genera are not well understood due to complex morphological evolution and a paucity of molecular data. One such understudied genus is Spironympha.

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Gastrophysa viridula DeGeer 1775, the green dock leaf beetle, belongs to a group of beneficial insects, which can be used as a classical biological control agent against sorrels (Rumex sp., Polygonaceae). Therefore, any infection by pathogenic organisms in this beetle is undesirable.

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Most members of the family () are associated with vertebrate hosts. However, a diverse clade of uncultured, putatively free-living treponemes comprising several genus-level lineages is present in other anoxic environments. The only cultivated representative to date is Treponema zuelzerae, isolated from freshwater mud.

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Nephridiophagids are unicellular fungi (Chytridiomycota), which infect the Malpighian tubules of insects. While most life cycle features are known, the effects of these endobionts on their hosts remain poorly understood. Here, we present results on the influence of an infection of the cockroach Blattella germanica with Nephridiophaga blattellae (Ni = Nephridiophaga-infected) on physical, physiological, and reproductive fitness parameters.

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The increasing number of new fungal species described from all over the world along with the use of genetics to define taxa, has dramatically changed the classification system of early-diverging fungi over the past several decades. The number of phyla established for non-Dikarya fungi has increased from 2 to 17. However, to date, both the classification and phylogeny of the basal fungi are still unresolved.

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Spirochetes of the genus Treponema are surprisingly abundant in termite guts, where they play an important role in reductive acetogenesis. Although they occur in all termites investigated, their evolutionary origin is obscure. Here, we isolated the first representative of 'termite gut treponemes' from cockroaches, the closest relatives of termites.

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Purpose: The aim of this study was to investigate and document the characteristic electron microscopic features of the oocyst of Adelina melolonthae, a coccidian pathogen of the European cockchafer, Melolontha melolontha (Coleoptera: Scarabaeidae).

Methods: Larvae of M. melolontha were collected at Ordu, Turkey.

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Nephridiophagids are unicellular eukaryotes that parasitize the Malpighian tubules of numerous insects. Their life cycle comprises multinucleate vegetative plasmodia that divide into oligonucleate and uninucleate cells, and sporogonial plasmodia that form uninucleate spores. Nephridiophagids are poor in morphological characteristics, and although they have been tentatively identified as early-branching fungi based on the SSU rRNA gene sequences of three species, their exact position within the fungal tree of live remained unclear.

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The symbiotic gut flagellates of lower termites form host-specific consortia composed of Parabasalia and Oxymonadida. The analysis of their coevolution with termites is hampered by a lack of information, particularly on the flagellates colonizing the basal host lineages. To date, there are no reports on the presence of oxymonads in termites of the family Stolotermitidae.

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Social insects employ a range of behaviours to protect their colonies against disease, but little is known about how such collective behaviours are orchestrated. This is especially true for the social Blattodea (termites). We developed an experimental approach that allowed us to explore how the social response to disease is co-ordinated by multistep host-pathogen interactions.

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Calcineurin is involved in development and cell differentiation of the social amoeba Dictyostelium discoideum. However, since knockouts of the calcineurin-encoding genes are not possible in D. discoideum it is assumed that the phosphatase also plays a crucial role during vegetative growth of the amoebae.

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Natural clays and synthetic nanofibres can have a severe impact on human health. After several decades of research, the molecular mechanism of how asbestos induces cancer is not well understood. Different fibres, including asbestos, can penetrate cell membranes and introduce foreign DNA in bacterial and eukaryotic cells.

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We isolated a novel member of the phylum Verrucomicrobia from the hindgut of the cockroach Shelfordella lateralis. Strain Ho45 is a yellow-pigmented, motile coccus that represents a new genus-level lineage with less than 93% sequence similarity to the 16S rRNA genes of other species in the family Opitutaceae. Ultrastructural analysis revealed a Gram-negative cell envelope with an outer membrane and a periplasmic space.

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We examined 34 lepidopteran species belonging to 12 families to determine presence and prevalence of microsporidian pathogens. The insects were collected from May 2009 to July 2012 from 44 sites in Bulgaria. Nosema species were isolated from Archips xylosteana, Tortrix viridana, Operophtera brumata, Orthosia cerasi, and Orthosia cruda.

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The guts of lower termites are inhabited by host-specific consortia of cellulose-digesting flagellate protists. In this first investigation of the symbionts of the family Serritermitidae, we found that Glossotermes oculatus and Serritermes serrifer each harbor similar parabasalid morphotypes: large Pseudotrichonympha-like cells, medium-sized Leptospironympha-like cells with spiraled bands of flagella, and small Hexamastix-like cells; oxymonadid flagellates were absent. Despite their morphological resemblance to Pseudotrichonympha and Leptospironympha, a SSU rRNA-based phylogenetic analysis identified the two larger, trichonymphid flagellates as deep-branching sister groups of Teranymphidae, with Leptospironympha sp.

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TRPV3 is a nonselective cation channel activated by temperatures above 33°C and is reported to be localized in keratinocytes and nervous tissue. To investigate a role for TRPV3 in pain modulation, we conducted a series of in vivo electrophysiological studies on spinal and brain nociceptive neurons. Structurally diverse TRPV3 receptor antagonists reduced responses of spinal wide dynamic range (WDR) neurons to low-intensity mechanical stimulation in neuropathic rats, but only CNS-penetrant antagonists decreased elevated spontaneous firing.

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Chrysomela populi (Coleoptera: Chrysomelidae) is the most abundant and most important pest species that causes damage to poplar trees. Members of the family Chrysomelidae are frequently infected by protist pathogens but no neogregarine has been reported to date at the species level. In the present study we identify a new neogregarine pathogen from the chrysomelid C.

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Two novel, obligately anaerobic Firmicutes from the family Erysipelotrichaceae were isolated from the intestinal tracts of a cockroach (strain ErySL, Shelfordella lateralis) and a scarab beetle larva (strain Pei061, Pachnoda ephippiata). Phylogenetic analysis indicated that the strains belong to a monophyletic group of hitherto uncultured bacteria from insect guts that are only distantly related to any described species (<90% 16S rRNA gene sequence similarity). Ultrastructural analysis revealed a Gram-positive cell envelope and, in the case of strain ErySL, a wide electron-lucent space between the cytoplasmic membrane and cell wall.

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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.

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Termite gut flagellates are typically colonized by specific bacterial symbionts. Here we describe the phylogeny, ultrastructure and subcellular location of 'Candidatus Adiutrix intracellularis', an intracellular symbiont of Trichonympha collaris in the termite Zootermopsis nevadensis. It represents a novel, deep-branching clade of uncultured Deltaproteobacteria widely distributed in intestinal tracts of termites and cockroaches.

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Only about 20 species of microsporidia have been described from mites. All except one species produce typical spores with a long polar filament and a polaroplast. This paper is the first study of an atypical microsporidium infection in a feather mite (Falculifer rostratus).

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