• MeSH
• nematodózy veterinární   MeSH
• ovce MeSH
• parazitární nemoci střev veterinární   MeSH
• rozvojové země MeSH

• MeSH
• hlístice anatomie a histologie   MeSH
• ryby parazitologie   MeSH

• MeSH
• finanční podpora výzkumu jako téma MeSH
• nematodózy epidemiologie   MeSH
• nemoci ryb parazitologie   terapie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• přehledy MeSH
• Geografické názvy
• Japonsko MeSH

• MeSH
• alergeny MeSH
• cestodózy diagnóza   klasifikace   prevence a kontrola   přenos   terapie   MeSH
• členovci imunologie   patogenita   MeSH
• infekce červy třídy Trematoda diagnóza   klasifikace   prevence a kontrola   přenos   terapie   MeSH
• infekční lékařství metody   MeSH
• infestace ektoparazity prevence a kontrola   přenos   terapie   MeSH
• nematodózy diagnóza   klasifikace   prevence a kontrola   přenos   terapie   MeSH
• parazitární nemoci MeSH
• Pentastomida imunologie   patogenita   MeSH
• protozoální infekce diagnóza   klasifikace   prevence a kontrola   přenos   terapie   MeSH
• zoonózy klasifikace   patologie   prevence a kontrola   přenos   terapie   MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• infekční lékařství
• parazitologie
• NLK Publikační typ
• publikace WHO

• MeSH
• ryby parazitologie   MeSH
• Trichinelloidea anatomie a histologie   MeSH

Sedentary plant-parasitic cyst nematodes are biotrophs that cause significant losses in agriculture. Parasitism is based on modifications of host root cells that lead to the formation of a hypermetabolic feeding site (a syncytium) from which nematodes withdraw nutrients. The host cell cycle is activated in an initial cell selected by the nematode for feeding, followed by activation of neighboring cells and subsequent expansion of feeding site through fusion of hundreds of cells. It is generally assumed that nematodes manipulate production and signaling of the plant hormone cytokinin to activate cell division. In fact, nematodes have been shown to produce cytokinin in vitro; however, whether the hormone is secreted into host plants and plays a role in parasitism remained unknown. Here, we analyzed the spatiotemporal activation of cytokinin signaling during interaction between the cyst nematode, Heterodera schachtii, and Arabidopsis using cytokinin-responsive promoter:reporter lines. Our results showed that cytokinin signaling is activated not only in the syncytium but also in neighboring cells to be incorporated into syncytium. An analysis of nematode infection on mutants that are deficient in cytokinin or cytokinin signaling revealed a significant decrease in susceptibility of these plants to nematodes. Further, we identified a cytokinin-synthesizing isopentenyltransferase gene in H. schachtii and show that silencing of this gene in nematodes leads to a significant decrease in virulence due to a reduced expansion of feeding sites. Our findings demonstrate the ability of a plant-parasitic nematode to synthesize a functional plant hormone to manipulate the host system and establish a long-term parasitic interaction.

• MeSH
• Arabidopsis * genetika   metabolismus   parazitologie   MeSH
• cytokininy genetika   metabolismus   MeSH
• hlístice fyziologie   MeSH
• interakce hostitele a parazita fyziologie   MeSH
• molekulární sekvence - údaje MeSH
• nemoci rostlin parazitologie   MeSH
• sekvence nukleotidů MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

PURPOSE: Data on helminth parasites in hammerhead sharks are scarce and, therefore, new examinations of these hosts are needed to recognize the species composition of their parasites, including nematodes. METHODS: Helminthological examinations of hammerhead sharks, Sphyrna lewini (Griffith et Smith) (209 specimens) and Sphyrna mokarran (Rüppell) (57 specimens) (Sphyrnidae, Carcharhiniformes), from off the northern coast of Australia revealed one new and one insufficiently known species of intestinal nematode parasites. These were studied with the use of light and scanning electron microscopy. RESULTS: Both nematode species are described. Piscicapillaria bursata sp. nov. (Capillariidae) from S. mokarran (type host) and S. lewini differs from its congeners mainly in the spicule length (330 µm), body length of gravid females 12.80-21.26 mm and in possessing a subterminal female anus. The specimens of Parascarophis sphyrnae Campana-Rouget, 1955 (Cystidicolidae) (type species of Parascarophis Campana-Rouget, 1955) collected from S. lewini made it possible to redescribe the female and, for the first time, to describe the male; the same species was also found in S. mokarran. Amended diagnosis of Parascarophis is provided. Parascarophis is mainly characterized by the presence of lateral alae, a unique feature within the Cystidicolidae, and by the cephalic structures (presence of a cuticular hood and a pair of anterolateral plate-like structures in the mouth). CONCLUSIONS: In addition to the discovery of a new nematode species, Pi. bursata sp. nov., the finding of Pa. sphyrnae in Australian waters represents a new geographical record of this parasite outside the Atlantic Ocean. The species of Parascarophis previously described from teleosts, P. bharatii Agrawal, 1965, P. oteroi Arya, 1992 and P. mulloidi Imam, Tawfik et Abdel Hady, 1982, are designated as species inquirendae and incertae sedis. The finding of P. sphyrnae in Australian waters represents a new geographical record of this parasite outside the Atlantic Ocean. Pa. sphyrnae had not been reported previously from beyond the Atlantic Ocean.

• MeSH
• hlístice klasifikace   genetika   růst a vývoj   izolace a purifikace   MeSH
• nematodózy parazitologie   veterinární   MeSH
• nemoci ryb parazitologie   MeSH
• parazitární nemoci střev parazitologie   veterinární   MeSH
• žraloci parazitologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Austrálie MeSH

Parasitic nematodes transition between dramatically different free-living and parasitic stages, with correctly timed development and migration crucial to successful completion of their lifecycle. However little is known of the mechanisms controlling these transitions. microRNAs (miRNAs) negatively regulate gene expression post-transcriptionally and regulate development of diverse organisms. Here we used microarrays to determine the expression profile of miRNAs through development and in gut tissue of the pathogenic nematode Haemonchus contortus. Two miRNAs, mir-228 and mir-235, were enriched in infective L3 larvae, an arrested stage analogous to Caenorhabditis elegans dauer larvae. We hypothesized that these miRNAs may suppress development and maintain arrest. Consistent with this, inhibitors of these miRNAs promoted H. contortus development from L3 to L4 stage, while genetic deletion of C. elegans homologous miRNAs reduced dauer arrest. Epistasis studies with C. elegans daf-2 mutants showed that mir-228 and mir-235 synergise with FOXO transcription factor DAF-16 in the insulin signaling pathway. Target prediction suggests that these miRNAs suppress metabolic and transcription factor activity required for development. Our results provide novel insight into the expression and functions of specific miRNAs in regulating nematode development and identify miRNAs and their target genes as potential therapeutic targets to limit parasite survival within the host.

• MeSH
• Caenorhabditis elegans genetika   MeSH
• cholesteny farmakologie   MeSH
• delece genu MeSH
• druhová specificita MeSH
• genová ontologie MeSH
• Haemonchus účinky léků   genetika   růst a vývoj   MeSH
• larva MeSH
• messenger RNA genetika   metabolismus   MeSH
• mikro RNA biosyntéza   genetika   MeSH
• proteiny Caenorhabditis elegans genetika   MeSH
• receptor inzulinu genetika   MeSH
• RNA helmintů biosyntéza   genetika   MeSH
• vývojová regulace genové exprese účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In 1989, samples of some freshwater fishes collected in Vientiane Province (R. Mekong basin) in Laos were examined for helminths. This material comprised 11 species of parasitic nematodes (7 adults and 4 larvae), including 3 species new to science: Camallanus (Camallanus) hampalae sp. n. from Hampala macrolepidota, Procamallanus (Punctocamallanus) punctatus sp. n. from Mystus rhegma and Mystus sp., and Rhabdochona (Globochona) equispiculata sp. n. from Hampala macrolepidota and H. dispar. Zeylanema Yeh, 1960 is considered a subgenus of the genus Camallanus, Dentocamallanus subgen. n. (type species C. (D.) sweeti (Moorthy, 1937)) is proposed for the species of Paracamallanus with teeth in the buccal capsule, and Punctocamallanus subgen. n. (type species P. (P.) punctatus sp. n.) for the species of Procamallanus with the buccal capsule ornamented with punctations. The name Rhabdochona wangi nom. nov. is proposed for R. bagarii Wang et Guo, 1983 (a homonym to R. bagarii Gupta et Srivastava, 1982) and Camallanus gomtii Gupta et Verma, 1978 is newly synonymized with Neocamallanus ophiocephali (Pearse, 1933). All the nematodes are recorded from Laos for the first time. The parasites are briefly described and illustrated and some problems concerning their taxonomy and geographical distribution are discussed.

• MeSH
• hlístice anatomie a histologie   klasifikace   MeSH
• larva anatomie a histologie   MeSH
• nematodózy parazitologie   veterinární   MeSH
• nemoci ryb parazitologie   MeSH
• ryby MeSH
• sladká voda MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Laos MeSH

An examination of a small sample of four species of frogs (Cophixalus riparius, Phrynomantis humicola, Ph. stictogaster, Ph. wilhelmana) from Papua New Guinea yielded altogether 5 species of nematodes, 2 of them being new to science. These include: Cosmocercella phrynomantisi sp. n. (type host Ph. humicola), Spinicaudinae gen. sp., Parathelandros andersoni sp. n. (type host C. riparius), Oswaldocruzia bakeri, and Paracapillaria spratti. C. phrynomantisi sp. n. differs from congeneric species mainly in the length of spicules (0.180 mm) and the character, arrangement and number of caudal papillae in the male, while P. andersoni sp. n. is characterized mainly by the presence of four well developed spines on the male tail. Pseudocapillaria spratti is redescribed in detail and it is transferred to Paracapillaria as P. spratti (Moravec et Sey, 1986) comb. n. Capillaria combesi Chabaud et Knoepffler, 1985 is transferred to Amphibiocapillaria Moravec, 1982 and Capillaria petiti Justine et Bain, 1987 to Pseudocapillaria Freitas, 1959. A survey of the endohelminths (excluding Hirudinea) hitherto reported from New Guinea amphibians is presented.

• MeSH
• cizopasní červi izolace a purifikace   MeSH
• helmintóza parazitologie   MeSH
• helmintózy zvířat * MeSH
• hlístice anatomie a histologie   klasifikace   MeSH
• nematodózy parazitologie   veterinární   MeSH
• parazitární nemoci střev parazitologie   veterinární   MeSH
• žáby parazitologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Papua Nová Guinea MeSH