Tahyna virus (TAHV), a mosquito-borne bunyavirus (California group), is frequently associated with inapparent or influenza-like (Valtice fever) infections in humans, rarely leading to atypical pneumonia or meningitis. Field TAHV strains exhibit a high variability in their biological properties with respect to virulence for laboratory mouse, temperature-sensitivity or character of plaques in cell culture. In consideration of the variations in the antigenic properties TAHV and its potential genetic variability, we analyzed complete nucleotide sequences of the small (S) and medium (M) genomic segments of field TAHV strains with different combinations of phenotypic markers. S segment was highly conservative in all analyzed TAHV strains. Within the M segment, the highest variability was observed in the G(C) gene encoding viral envelope protein and to a less extent also in the NSm gene. However, 5' and 3' non-coding regions of M segment, as well as in G(N) gene exhibited highly conservative pattern, indicating its functional importance, but minor or no role in the determination of biological properties of TAHV field strains.

• MeSH
• 3' nepřekládaná oblast MeSH
• 5' nepřekládaná oblast MeSH
• fylogeneze MeSH
• genetická variace MeSH
• genom virový MeSH
• kalifornská encefalitida virologie   MeSH
• konzervovaná sekvence MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• myši MeSH
• plakové testy MeSH
• proteiny virového obalu genetika   MeSH
• RNA virová genetika   MeSH
• sekvenční analýza DNA MeSH
• sekvenční homologie MeSH
• shluková analýza MeSH
• virulence MeSH
• viry kalifornské encefalitidy genetika   izolace a purifikace   patogenita   MeSH
• vysoká teplota MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Ťahyňa virus (TAHV), a member of the Bunyaviridae family (California complex), is an important but neglected human mosquito-borne pathogen. The virus genome is composed of three segments, i.e., small (S), medium (M), and large (L). Previous studies on genetic variability of viruses within the California complex were focused on S and M segments, but the L segment remains relatively unstudied. To assess the genetic variation and the relation to virus phenotype we analyzed the L segment sequences of biologically diverse TAHV strains isolated in the Czech Republic and Slovakia. Phylogenetic analysis covering all available sequences of the L segment of TAHV clearly revealed two distinguished lineages, tentatively named as "European" and "Asian". The L segment strains within the European lineage are highly conserved (identity 99.3%), whilst Asian strains are more genetically diverse (identity 97%). Based on sequence comparison with other bunyaviruses, several non-synonymous nucleotide substitutions unique for TAHV in the L segment were identified. We also identified specific residue substitutions in the endonuclease domain of TAHV compared with the La Crosse virus. Since the endonuclease domain of the La Crosse virus has been resolved, we employed an all energy landscape algorithm to analyze the ligand migration of a viral polymerase inhibitor. This allowed us to demonstrate, at the atomic level, that this viral polymerase inhibitor randomly explored the specific residue substitutions in the endonuclease domain of the TAHV L segment.

• MeSH
• antivirové látky farmakologie   MeSH
• fylogeneze MeSH
• genetická variace MeSH
• genom virový genetika   MeSH
• genotyp MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• RNA virová genetika   MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční analýza DNA MeSH
• sekvenční seřazení MeSH
• virová léková rezistence genetika   MeSH
• virové proteiny genetika   MeSH
• viry kalifornské encefalitidy účinky léků   genetika   izolace a purifikace   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Hantaviruses, well-known human pathogens, have only recently been identified on the African continent. Tigray virus (TIGV) was found in Ethiopia in 2012 in a Murinae species, Stenocephalemys albipes, but the genetic data obtained at that time were too limited to correctly assess its phylogenetic position within the hantavirus tree. We used high throughput sequencing to determine the complete genome of TIGV, which showed a typical hantavirus organisation. The large (L), medium (M), and small (S) genome segments were found to be 6532, 3594 and 1908 nucleotides long, respectively, and the 5' and 3' termini for all three segments were predicted to form the panhandle-like structure typical for bunyaviruses. Nucleotide-based phylogenetic analyses revealed that all three coding segments cluster in the phylogroup III sensu Guo et al. (2013). However, while TIGV S segment is basal to the Murinae-associated hantaviruses, the M and L segments are basal to the Soricomorpha-associated hantaviruses. TIGV is the first Murinae-borne hantavirus showing this inconsistent segmental clustering in the hantavirus phylogenetic tree. We finally propose non-exclusive scenarios that could explain the original phylogenetic position of TIGV.

• MeSH
• genom virový genetika   MeSH
• genomika MeSH
• hantavirové infekce veterinární   virologie   MeSH
• Hantavirus genetika   MeSH
• Murinae virologie   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Etiopie MeSH

BACKGROUND AND AIMS: In ferns, apomixis is an important mode of asexual reproduction. Although the mechanisms of fern reproduction have been studied thoroughly, most previous work has focused on cases in which ferns reproduce either exclusively sexually or exclusively asexually. Reproduction of ferns with potentially mixed systems and inheritance of apomixis remains largely unknown. This study addresses reproduction of the pentaploid Dryopteris × critica, a hybrid of triploid apomictic D. borreri and tetraploid sexual D. filix-mas. METHODS: Spore size, abortion percentage and number of spores per sporangium were examined in pentaploid plants of D. × critica grown in an experimental garden. The sporangial content of leaf segments was cultivated on an agar medium, and DNA ploidy levels were estimated by DAPI flow cytometry in 259 gametophytes or sporophytes arising from the F2 generation of the pentaploid hybrid. KEY RESULTS: The hybrid is partly fertile (89-94% of aborted spores) and shows unstable sporogenesis with sexual and apomictic reproduction combined. The number of spores per sporangium varied from approx. 31 to 64. Within a single sporangium it was possible to detect formation of either only aborted spores or various mixtures of aborted and well-developed reduced spores and unreduced diplospores. The spores germinated in viable gametophytes with two ploidy levels: pentaploid (5x, from unreduced spores) and half of that (approx. 2·5x, from reduced spores). Moreover, 2-15% of gametophytes (both 2·5x and 5x) formed a viable sporophyte of the same ploidy level due to apogamy. CONCLUSIONS: This study documents the mixed reproductive mode of a hybrid between apomictic and sexual ferns. Both sexual reduced and apomictic unreduced spores can be produced by a single individual, and even within a single sporangium. Both types of spores give rise to viable F2 generation gametophytes and sporophytes.

• MeSH
• apomixie * MeSH
• délka genomu MeSH
• DNA rostlinná metabolismus   MeSH
• Dryopteris genetika   fyziologie   MeSH
• gametogeneze rostlin genetika   fyziologie   MeSH
• genom rostlinný MeSH
• haploidie * MeSH
• klíčení MeSH
• křížení genetické MeSH
• průtoková cytometrie MeSH
• spory cytologie   fyziologie   MeSH
• tetraploidie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A positive selection system using phosphomannose isomerase was employed for Agrobacterium tumefaciens mediated transformation of lettuce (Lactuca sativa L. var. 'Achát'). It was shown that the mannose-based selection system works very well with the lettuce genotype used, reaching up to 25% transformation efficiency on the medium with 20 g/L mannose and 20 g/L sucrose. The best transformation efficacy with the commonly-used kanamycin at 100 mg/L as a selection agent was 21%. Southern blot analyses of thirteen chosen mannose-resistant regenerants revealed that some of them have clonal origin, about one-half harbour a single T-DNA copy and one plant contains an incomplete T-DNA segment with only the left part of T-DNA with the pmi gene present in the genomic DNA. The following Northern analysis showed transcriptional activity of the introduced pmi gene in all plants analysed with very high differences in the level of pmi specific mRNA. The results demonstrate that both mannose and kanamycin provide comparable transformation efficiencies in our lettuce genotype. An alternative selection method with mannose as a selection agent is now available for lettuce transgenosis.

• MeSH
• Agrobacterium tumefaciens genetika   MeSH
• geneticky modifikované rostliny MeSH
• mannosa-6-fosfátisomerasa genetika   MeSH
• salát (hlávkový) enzymologie   genetika   růst a vývoj   MeSH
• selekce (genetika) MeSH
• transformace genetická MeSH
• výhonky rostlin enzymologie   genetika   růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Východiska: Nízkostupňové gliomy představují heterogenní skupinu primárních mozkových nádorů. Jejich současná dia­gnostika je založena hlavně na histologické klasifikaci. S rozvojem molekulární cytogenetiky však bylo objeveno několik markerů umožňujících lépe definovat daný gliomový subtyp. Cílem studie bylo sledovat získané chromozomové aberace v buňkách nízkostupňových gliomů molekulárně cytogenetickými metodami a hledat nové genomové změny, které by mohly souviset s progresí nádoru. Soubor pacientů a metody: Technikami interfázní fluorescenční in situ hybridizace (I‑FISH) a single nucleotide polymorphism (SNP) array jsme vyšetřili vzorky od 41 pacientů s histologicky potvrzenými nízkostupňovými gliomy (19 žen a 22 mužů, medián věku 42 let). Výsledky: Kromě nejčastější známé aberace, tj. kombinované delece krátkých ramen chromozomu 1 a dlouhých ramen chromozomu 19 (u 81,25 % pacientů), jsme u pacientů s oligodendrogliomy detekovali další rekurentní aberace – delece krátkých a/nebo dlouhých ramen chromozomu 4 (25 % nemocných), delece krátkých ramen chromozomu 9 (18,75 % pacientů), delece dlouhých ramen chromozomu 13 a monozomii chromozomu 18 (18,75 % pacientů). U pacientů s astrocytomy jsme často pozorovali deleci krátkých ramen chromozomu 1 (24 % nemocných), amplifikaci dlouhých ramen chromozomu 7 (16 % nemocných), deleci dlouhých ramen chromozomu 13 (20 % nemocných), segmentální uniparentální disomii (UPD) na krátkých ramenech chromozomu 17 (60 % pacientů) a deleci dlouhých ramen chromozomu 19 (28 % nemocných). U jednoho pacienta jsme pozorovali tzv. chromothripsis chromozomu 10. Závěr: V pilotní studii jsme kombinací metod I‑FISH a SNP array detekovali nejen známé chromozomové změny, které jsou typické pro jednotlivé subtypy nádorů, ale také nové nebo méně časté rekurentní aberace. Jejich úlohu v progresi nádorových buněk, stejně jako jejich význam z hlediska klasifikace nízkostupňových gliomů však bude nezbytné ověřit v dalších studiích na větších souborech nemocných.

Background: Low-grade gliomas represent a heterogeneous group of primary brain malignancies. The current dia­gnostics of these tumors rely strongly on histological classification. With the development of molecular cytogenetic methods several genetic markers were described, conributing to a better distinction of glial subtypes. The aim of this study was to assess the frequency of acquired chromosomal aberrations in low‑grade gliomas and to search for new genomic changes associated with higher risk of tumor progression. Patients and Methods: We analysed bio­psy specimens from 41 patients with histological dia­gnosis of low-grade glioma using interphase fluorescence in situ hybridization (I‑FISH) and single nucleotide polymorphism (SNP) array techniques (19 females and 22 males, medium age 42 years). Results: Besides notorious and most frequent finding of combined deletion of 1p/19q (81.25% patients) several other recurrent aberrations were described in patients with oligodendrogliomas: deletions of p and q arms of chromosome 4 (25% patients), deletions of the short arms of chromosome 9 (18.75% patients), deletions of the long arms of chromosome 13 and monosomy of chromosome 18 (18.75% patients). In bio­psy specimens from patients with astrocytomas, we often observed deletion of 1p (24% patients), amplification of the long arms of chromosome 7 (16% patients), deletion of the long arm of chromosome 13 (20% patients), segmental uniparental disomy (UPD) of the short arms of chromosome 17 (60% patients) and deletion of the long arms of chromosome 19 (28% patients). In one patient we detected a shuttered chromosome 10 resulting from chromothripsis. Conclusion: Using a combination of I‑FISH and SNP array, we detected not only known chromosomal changes but also new or less frequent recur­rent aberrations. Their role in cancer‑cell progression and their impact on low‑grade gliomas classification remains to be elucidated in a larger cohort of patients. Key words: oligodendroglioma – astrocytoma – SNP array – interphase FISH – glioma This work was supported by grants of Internal Grant Agency of the Czech Ministry of Health No. NT/13212-4, PRVOUK-P27/LF1/1 a RVO-VFN64165. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers. Submitted: 5. 11. 2013 Accepted: 29. 1. 2014

• Klíčová slova
• SNP array, interfázní FISH,
• MeSH
• amplifikace genu MeSH
• astrocytom * genetika   patologie   MeSH
• chromozomální aberace MeSH
• chromozomální delece MeSH
• cytogenetické vyšetření MeSH
• delece genu MeSH
• DNA sondy MeSH
• dospělí MeSH
• gliom * genetika   patologie   MeSH
• hybridizace in situ fluorescenční MeSH
• jednonukleotidový polymorfismus MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory mozku * genetika   patologie   MeSH
• oligodendrogliom * genetika   patologie   MeSH
• pilotní projekty MeSH
• statistika jako téma MeSH
• uniparentální disomie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

• MeSH
• klinické lékařství MeSH
• oftalmologie MeSH
• věda MeSH

• Konspekt
• Ortopedie. Chirurgie. Oftalmologie
• Učební osnovy. Vyučovací předměty. Učebnice
• NLK Obory
• oftalmologie
• věda a výzkum
• NLK Publikační typ
• učebnice vysokých škol

• MeSH
• klinické lékařství MeSH
• oftalmologie MeSH
• věda MeSH

• Konspekt
• Učební osnovy. Vyučovací předměty. Učebnice
• Ortopedie. Chirurgie. Oftalmologie
• NLK Obory
• oftalmologie
• věda a výzkum
• NLK Publikační typ
• učebnice vysokých škol

KEY MESSAGE: Transient 5-azacytidine treatment of leaf explants from potato plants with transcriptionally silenced transgenes allows de novo regeneration of plants with restored transgene expression at the whole plant level. Transgenes introduced into plant genomes frequently become silenced either at the transcriptional or the posttranscriptional level. Transcriptional silencing is usually associated with DNA methylation in the promoter region. Treatments with inhibitors of maintenance DNA methylation were previously shown to allow reactivation of transcriptionally silenced transgenes in single cells or tissues, but not at the whole plant level. Here we analyzed the effect of DNA methylation inhibitor 5-azacytidine (AzaC) on the expression of two silenced reporter genes encoding green fluorescent protein (GFP) and neomycin phosphotransferase (NPTII) in potato plants. Whereas no obvious reactivation was observed in AzaC-treated stem cuttings, transient treatment of leaf segments with 10 μM AzaC and subsequent de novo regeneration of shoots on the selective medium with kanamycin resulted in the production of whole plants with clearly reactivated expression of previously silenced transgenes. Reactivation of nptII expression was accompanied by a decrease in cytosine methylation in the promoter region of the gene. Using the plants with reactivated GFP expression, we found that re-silencing of this transgene can be accidentally triggered by de novo regeneration. Thus, testing the incidence of transgene silencing during de novo regeneration could be a suitable procedure for negative selection of transgenic lines (insertion events) which have an inclination to be silenced. Based on our analysis of non-specific inhibitory effects of AzaC on growth of potato shoots in vitro, we estimated that AzaC half-life in the culture media is approximately 2 days.

• MeSH
• azacytidin farmakologie   MeSH
• geneticky modifikované rostliny účinky léků   genetika   metabolismus   MeSH
• metylace DNA účinky léků   genetika   MeSH
• regulace genové exprese u rostlin účinky léků   genetika   MeSH
• Solanum tuberosum účinky léků   genetika   metabolismus   MeSH
• transgeny účinky léků   genetika   MeSH
• umlčování genů MeSH
• zelené fluorescenční proteiny genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• klinické lékařství MeSH
• oftalmologie MeSH
• věda MeSH

• Konspekt
• Učební osnovy. Vyučovací předměty. Učebnice
• Ortopedie. Chirurgie. Oftalmologie
• NLK Obory
• oftalmologie
• věda a výzkum
• NLK Publikační typ
• učebnice vysokých škol