Genetic variability of Polish tomato black ring virus isolates and their satellite RNAs     

Aleksandra Zarzyńska-Nowak  Beata Hasiów-Jaroszewska  Daria Budzyńska  Katarzyna Trzmiel 《Plant pathology》2020,69(6):1034-1041

Tomato black ring virus (TBRV), a member of the Nepovirus genus, is a serious plant pathogen distributed worldwide. It causes significant damage to several economically important crops, such as artichoke or strawberry. The TBRV bipartite genome consists of two polyadenylated single-stranded positive-sense RNA molecules, which may be accompanied by subviral particles such as defective interfering RNAs (DI RNAs) and satellite RNAs (satRNAs). In this study, we obtained the complete genome sequence of six TBRV isolates originating from different hosts and determined the presence of eight TBRV satRNAs. Subsequently, genetic variability, recombination, phylogenetic and selection pressure analyses were performed. The results revealed that the TBRV population is genetically diverse. The occurrence of potential recombination events, evidence of positive selection pressure acting on particular codons and the diversification of satRNAs within the TBRV population indicated that the virus mutates and can rapidly adapt to new environmental conditions or hosts. The presented data shed some light on TBRV evolutionary dynamics and epidemiology.  相似文献   

Investigation of genome polymorphism and seed coat anatomy of species of section Adenolinum from the genus Linum     

Olga Yu. Yurkevich  Alena A. Naumenko-Svetlova  Nadezhda L. Bolsheva  Tatiana E. Samatadze  Olga A. Rachinskaya  Anna V. Kudryavtseva  Daria A. Zelenina  Alexander A. Volkov  Alexander V. Zelenin  Olga V. Muravenko 《Genetic Resources and Crop Evolution》2013,60(2):661-676

Twelve species of section Adenolinum from genus Linum have been studied using cytogenetic methods (DAPI/C-banding, Ag-NOR staining, FISH with 5S and 26S rDNA probes), RAPD analysis, and seed surface ultrastructure and seed coat anatomy investigation. Karyotype analysis revealed that these species have a chromosome number of 2n = 18 or 2n = 36. The DAPI/C-banding patterns enabled the identification of all chromosomes and revealed the similarities in chromosome patterns in all of the studied species. It was found that 18-chromosome plants are diploids, whereas 36-chromosome forms are tetraploids. In diploid species, 5S and 26S rRNA genes are located in similar positions on a single pair of chromosomes or on two chromosome pairs in tetraploids. Ag-NOR staining showed NOR activity in both genomes of tetraploids. RAPD analysis and seed coat anatomy investigation revealed some interspecies differences. Species from nearby areas have more similar RAPD characteristics compared with more geographically distant species. The results of this study may serve as an additional argument in favour of a monophyletic origination of the Adenolinum species and its strong isolation from other Linum species.  相似文献   

Source indicator of commercial humic products: UV-Vis and fluorescence proxies     

Olga Yakimenko  Daria Khundzhua  Aleksei Izosimov  Viktor Yuzhakov  Svetlana Patsaeva 《Journal of Soils and Sediments》2018,18(4):1279-1291

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Tyzzer's disease in cats experimentally infected with feline leukaemia virus     

A.M. Bennett  C.R. Huxtable  Daria N. Love 《Veterinary microbiology》1977,2(1):49-56

Three cases of feline Tyzzer's disease have occurred, since 1971, in kittens infected experimentally with feline leukaemia virus (FeLV). It is suggested that the immunosuppression induced by FeLV may have predisposed the kittens to fatal infections with Bacillus piliformis.Clinical, pathological and ultrastructural features of the disease are described.  相似文献   

A pathological study of the salivary glands of rabid dogs in the Philippines     

Hassadin BOONSRIROJ  Daria Llenaresas MANALO  Kazunori KIMITSUKI  Taichi SHIMATSU  Nozomi SHIWA  Harumi SHINOZAKI  Yurika TAKAHASHI  Naoto TANAKA  Satoshi INOUE  Chun-Ho PARK 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):35-42

Rabies is a zoonotic disease caused by the rabies virus. While the salivary glands are important as exit and propagation sites for the rabies virus, the mechanisms of rabies excretion remain unclear. Here, we investigated the histopathology of the salivary glands of rabid dogs and analyzed the mechanism of excretion into the oral cavity. Mandibular and parotid glands of 22 rabid dogs and three control dogs were used. Mild to moderate non-suppurative sialadenitis was observed in the mandibular glands of 19 of the 22 dogs, characterized by loss of acinar epithelium and infiltration by lymphoplasmacytic cells. Viral antigens were detected in the mucous acinar epithelium, ganglion neurons and myoepithelium. Acinar epithelium and lymphocytes were positive for anti-caspase-3 antibodies and TUNEL staining. In contrast, no notable findings were observed in the ductal epithelial cells and serous demilune. In the parotid gland, the acinar cells, myoepithelium and ductal epithelium all tested negative. These findings confirmed the path through which the rabies virus descends along the facial nerve after proliferation in the brain to reach the ganglion neurons of the mandibular gland, subsequently traveling to the acinar epithelium via the salivary gland myoepithelium. Furthermore, the observation that nerve endings passing through the myoepithelium were absent from the ductal system suggested that viral proliferation and cytotoxicity could not occur there, ensuring that secretions containing the virus are efficiently excreted into the oral cavity.  相似文献   

Swallowtail butterflies show positive edge responses predicted by resource use     

Jenna C. Siu  Daria Koscinski  Nusha Keyghobadi 《Landscape Ecology》2016,31(9):2115-2131

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Immunogenicity of purified lipopolysaccharide or protein–oligosaccharide conjugates of Pasteurella multocida type 6:B in mice     

Narasiman Muniandy  Daria N. Love  T.K.S. Mukkur 《Comparative immunology, microbiology and infectious diseases》1998,21(4):257-279

Purified lipopolysaccharide (LPS) of Pasteurella multocida type 6:B, while toxic at higher doses, was protective at lower dose levels against experimentally-induced pasteurellosis in mice. However, the observed protection was abrogated if such LPS was digested with proteinase K prior to use in immunisation. The O-antigen polysaccharide side-chain (OS) of LPS did not appear to contribute to the observed protection as judged by the fact that immunisation of mice with purified OS or OS-protein conjugates, all of which were non-toxic, failed to confer protection against challenge with homologous virulent organisms. This was despite generation of significant levels of OS-specific antibodies, predominantly either of the IgM or IgG isotypes, in immunised mice.

Résumé

Le lipopolysaccharide purifié (LPS) de Pasteurella multocida type 6:B, toxique à haute dose, est protecteur à faible dose contre la pasteurellose expérimentale de la souris. Cependant, la protection observée est supprimée si le LPS est soumis à l'action de la protéinase K avant immunisation. L'antigène O polysaccharidique du LPS ne semble pas contribuer à la protection observée si l'on en juge par le fait que l'immunisation des souris à l'aide de l'antigène O purifé ou conjugué avec des protéines -- non toxiques -- ne confère pas de protection contre une épreuve virulente homologue. Ceci en dépit de l'apparition de taux significatif d'anticorps anti O principalement soit du type IgM ou IgG chez la souris.  相似文献   

PATHOGENICITY OF A STRAIN OF FELINE CALICIVIRUS FOR DOMESTIC KITTENS     

Daria N. Love B.V.Sc  Ph.D. 《Australian veterinary journal》1975,51(12):541-546

A strain of feline calicivirus, isolated from a cheetah exhibiting ulcerative glossitis and conjunctivitis, was administered by aerosol to 4 domestic cats and by contact to a fifth cat. Despite the limited number of animals available for the experiment, the pathogenicity of the virus strain for domestic cats was established. In aerosol-infected animals, clinical signs were referable to infection of both upper and lower respiratory tracts. The virus produced an interstitial pneumonia which, early in infection, was uncomplicated by secondary bronchopneumonia. The in-contact cat exhibited clinical signs referable to infection of the oral cavity only and no lesions were noted in the lower respiratory tract at autopsy. Ulcerative glossitis was a feature of the disease in aerosol-infected and in-contact cats. The virus was isolated from the pharynx of all cats for up to 21 days after infection and from the tonsils at autopsy. The tonsils were considered to be a probable site of multiplication of virus in "carrier" cats.  相似文献   

Bacteria use type IV pili to walk upright and detach from surfaces     

Gibiansky ML  Conrad JC  Jin F  Gordon VD  Motto DA  Mathewson MA  Stopka WG  Zelasko DC  Shrout JD  Wong GC 《Science (New York, N.Y.)》2010,330(6001):197

Bacterial biofilms are structured multicellular communities involved in a broad range of infections. Knowing how free-swimming bacteria adapt their motility mechanisms near surfaces is crucial for understanding the transition between planktonic and biofilm phenotypes. By translating microscopy movies into searchable databases of bacterial behavior, we identified fundamental type IV pili-driven mechanisms for Pseudomonas aeruginosa surface motility involved in distinct foraging strategies. Bacteria stood upright and "walked" with trajectories optimized for two-dimensional surface exploration. Vertical orientation facilitated surface detachment and could influence biofilm morphology.  相似文献   

The potential for aquaculture of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) in southern Croatia     

Melita Peharda  Daria Ezgeta-Balić  John Davenport  Nedo Vrgoč 《Aquaculture International》2013,21(3):639-653

To assess the potential of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) for aquaculture in southern Croatia, we analyzed their survival and growth rates under two experimental conditions—suspended culture and on-bottom culture. Furthermore, we investigated feeding on zooplankton by these two species in suspended culture conditions and compared them with previously published results of their feeding on zooplankton in the natural benthic environment. Experimental studies were conducted in Mali Ston Bay (Adriatic Sea) from December 2009 to December 2010. Differences were observed in terms of survival of tagged M. barbatus and A. noae—specimens of M. barbatus exhibited much better survival rates both in suspended culture and in on-bottom cages than did A. noae. Growth of A. noae under both culture conditions was essentially negligible, while M. barbatus grew several times faster in suspended culture than on the bottom. Values for the growth constant K and L _inf for M. barbatus in suspended culture were 0.45 year^?1 and 55.9 mm, while corresponding values for on-bottom culture were 0.09 year^?1 and 58.6 mm, respectively. Zooplankters were present in the stomachs of 86.3 % of M. barbatus and 86.4 % of A. noae. Most abundant taxa were bivalve larvae followed by tintinnids, copepods, unidentified eggs and gastropod larvae. In conclusion, this study clearly shows that M. barbatus is a promising candidate for suspended aquaculture in southern Croatia.  相似文献