RNA silencing is a common term for homology-dependent silencing phenomena found in the majority of eukaryotic species. RNA silencing pathways share several conserved components. The common denominator of these pathways is the presence of specific, short (21-25 nt) RNA molecules generated from different double-stranded RNA substrates by a specific RNase III activity. Short RNA molecules serve as a template for sequence-specific effects including transcriptional silencing, mRNA degradation, and inhibition of translation. This review will discuss possible roles of RNA silencing pathways in mouse oocytes and early embryos as well as the use of RNA silencing for experimental inhibition of gene expression in this model system.

• MeSH
• embryo savčí metabolismus   MeSH
• myši MeSH
• oocyty metabolismus   MeSH
• RNA interference * MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

It has been well established that trans-acting small RNAs guide promoter methylation leading to its inactivation and gene silencing at the transcriptional level (TGS). Here we addressed the question of the influence of the locus structure and epigenetic modifications of the target locus on its susceptibility for being paramutated by trans-acting small RNA molecules. Silencing was induced by crossing a 35S promoter silencer locus 271 with two different 35S-driven transgene loci, locus 2 containing a highly expressed single copy gene and locus 1 containing an inverted posttranscriptionally silenced (PTGS) repeat of this gene. Three generations of exposure to RNA signals from the 271 locus were required to complete silencing and methylation of the 35S promoter within locus 2. Segregating methylated locus 2 epialleles were obtained only from the third generation of hybrids, and this methylation was not correlated with silencing. Strikingly, only one generation was required for the PTGS locus 1 to acquire complete TGS and 35S promoter methylation. In this case, paramutated locus 1 epialleles bearing methylated and inactive 35S promoters segregated already from the first generation of hybrids. The results support the hypothesis that PTGS loci containing a palindrome structure and methylation in the coding region are more sensitive to paramutation by small RNAs and exhibit a strong tendency to formation of meiotically transmissible TGS epialleles. These features contrast with a non-methylated single copy transgenic locus that required several generations of contact with RNA silencing molecules to become imprinted in a stable epiallele.

• MeSH
• alely MeSH
• epigeneze genetická MeSH
• genetická transkripce MeSH
• geneticky modifikované rostliny genetika   MeSH
• genomový imprinting MeSH
• malá interferující RNA genetika   MeSH
• metylace DNA * MeSH
• promotorové oblasti (genetika) MeSH
• regulace genové exprese u rostlin * MeSH
• RNA interference MeSH
• tabák genetika   MeSH
• transgeny genetika   MeSH
• umlčovací elementy transkripční genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• malá interferující RNA MeSH

We aimed to establish an efficient RNA interference (RNAi) system in the industrially important filamentous fungus Trichoderma koningii using the DsRed protein as a reporter of the silencing process. To accomplish this, a DsRed expression cassette was transformed into T. koningii, and a recombinant strain that stably expressed DsRed was obtained. Next, a vector-directing expression of a DsRed hairpin RNA was constructed and transformed into the T. koningii recipient strain. Approximately 79 % of transformants displayed a decrease in DsRed fluorescence, and expression of DsRed in some transformants appeared to be fully suppressed. Characterization of randomly selected transformants by genomic DNA PCR analysis, real-time PCR quantification, and western blot confirmed downregulation of gene expression at different levels. The RNA silencing approach described here for T. koningii is effective, and the DsRed reporter gene provides a convenient tool for identification of silenced fungal transformants by their DsRed fluorescence compared to the control strain. The results of this study demonstrate the power of RNAi in T. koningii, which supports the use of this technology for strain development programs and functional genomics studies in industrial fungal strains.

• MeSH
• fluorescence MeSH
• genový knockdown metody   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• luminescentní proteiny analýza   genetika   MeSH
• malá interferující RNA genetika   MeSH
• mikrobiální genetika metody   MeSH
• rekombinace genetická MeSH
• reportérové geny MeSH
• RNA interference * MeSH
• stanovení celkové genové exprese MeSH
• transformace genetická MeSH
• Trichoderma genetika   MeSH
• western blotting MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fluorescent protein 583 MeSH Prohlížeč
• luminescentní proteiny MeSH
• malá interferující RNA MeSH

In plants, posttranscriptional gene silencing (PTGS) is induced by small RNAs (sRNAs) generated from various dsRNA precursors. To assess the impact of dsRNA origin, we compared downregulation of GFP expression triggered by inverted repeat (IR), antisense (AS) and unterminated sense (UT) transcripts transiently expressed from the estradiol-inducible promoter. The use of homogeneously responding tobacco BY-2 cell lines allowed monitoring the onset of silencing and its reversibility. In this system, IR induced the strongest and fastest silencing accompanied by dense DNA methylation. At low induction, silencing in individual cells was binary (either strong or missing), suggesting that a certain threshold sRNA level had to be exceeded. The AS variant specifically showed a deviated sRNA-strand ratio shifted in favor of antisense orientation. In AS lines and weakly induced IR lines, only the silencer DNA was methylated, but the same target GFP sequence was not, showing that DNA methylation accompanying PTGS was influenced both by the level and origin of sRNAs, and possibly also by the epigenetic state of the locus. UT silencing appeared to be the least effective and resembled classical sense PTGS. The best responding UT lines behaved relatively heterogeneously possibly due to complexly arranged T-DNA insertions. Unlike IR and AS variants that fully restored GFP expression upon removal of the inducer, only partial reactivation was observed in some UT lines. Our results pointed out several not yet described phenomena and differences between the long-known silencer variants that may direct further research and affect selection of proper silencer variants for specific applications.

• Klíčová slova
• DNA methylation, PTGS, RNAi, Tobacco BY-2 cell line, dsRNA, siRNA,
• MeSH
• DNA bakterií MeSH
• dvouvláknová RNA genetika   MeSH
• metylace DNA MeSH
• posttranskripční úpravy RNA * MeSH
• regulace genové exprese u rostlin * MeSH
• reportérové geny MeSH
• RNA interference * MeSH
• RNA rostlin genetika   MeSH
• tabák genetika   MeSH
• umlčovací elementy transkripční MeSH
• umlčování genů * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA bakterií MeSH
• dvouvláknová RNA MeSH
• RNA rostlin MeSH
• T-DNA MeSH Prohlížeč

Auxin and cytokinin belong to the 'magnificent seven' plant hormones, having tightly interconnected pathways leading to common as well as opposing effects on plant morphogenesis. Tremendous progress in the past years has yielded a broad understanding of their signalling, metabolism, regulatory pathways, transcriptional networks, and signalling cross-talk. One of the rapidly expanding areas of auxin and cytokinin research concerns their RNA regulatory networks. This review summarizes current knowledge about post-transcriptional gene silencing, the role of non-coding RNAs, the regulation of translation, and alternative splicing of auxin- and cytokinin-related genes. In addition, the role of tRNA-bound cytokinins is also discussed. We highlight the most recent publications dealing with this topic and underline the role of RNA processing in auxin- and cytokinin-mediated growth and development.

• Klíčová slova
• Auxin, RNA processing, cytokinin, gene silencing, miRNA, non-coding RNA, splicing, tRNA.,
• MeSH
• alternativní sestřih * MeSH
• cytokininy genetika   metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• nekódující RNA metabolismus   MeSH
• regulace genové exprese u rostlin * MeSH
• regulátory růstu rostlin genetika   metabolismus   MeSH
• RNA interference * MeSH
• vývoj rostlin MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• cytokininy MeSH
• kyseliny indoloctové MeSH
• nekódující RNA MeSH
• regulátory růstu rostlin MeSH

Here, we describe a protocol to prepare and administer glucan-encapsulated RNAi particles (GeRPs), for specific delivery of siRNA and subsequent gene silencing in Kupffer cells (KCs) in mice. This technology is based on baker's yeast and allows gene manipulation in macrophages in a tissue-specific manner depending on the route of administration and the model that is used. GeRP administered by intravenous injection in mice are delivered to KCs. Therefore, using the GeRP technology to silence genes provides a unique method to study the function of factors expressed by KCs in the regulation of liver function.

• Klíčová slova
• Diabetes, Gene silencing, Inflammation, Insulin sensitivity, Intravenous administration, Kupffer cells, Mouse liver, Obesity, RNAi delivery,
• MeSH
• glukany genetika   MeSH
• játra fyziologie   MeSH
• Kupfferovy buňky fyziologie   MeSH
• makrofágy fyziologie   MeSH
• malá interferující RNA genetika   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• RNA interference fyziologie   MeSH
• umlčování genů fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glukany MeSH
• malá interferující RNA MeSH

ADAR RNA editing enzymes (adenosine deaminases acting on RNA) that convert adenosine bases to inosines were first identified biochemically 30 years ago. Since then, studies on ADARs in genetic model organisms, and evolutionary comparisons between them, continue to reveal a surprising range of pleiotropic biological effects of ADARs. This review focuses on Drosophila melanogaster, which has a single Adar gene encoding a homolog of vertebrate ADAR2 that site-specifically edits hundreds of transcripts to change individual codons in ion channel subunits and membrane and cytoskeletal proteins. Drosophila ADAR is involved in the control of neuronal excitability and neurodegeneration and, intriguingly, in the control of neuronal plasticity and sleep. Drosophila ADAR also interacts strongly with RNA interference, a key antiviral defense mechanism in invertebrates. Recent crystal structures of human ADAR2 deaminase domain-RNA complexes help to interpret available information on Drosophila ADAR isoforms and on the evolution of ADARs from tRNA deaminase ADAT proteins. ADAR RNA editing is a paradigm for the now rapidly expanding range of RNA modifications in mRNAs and ncRNAs. Even with recent progress, much remains to be understood about these groundbreaking ADAR RNA modification systems.

• Klíčová slova
• ADAR, Drosophila melanogaster, RNA editing, RNA modification, dsRNA, epitranscriptome,
• MeSH
• adenosindeaminasa chemie   genetika   metabolismus   MeSH
• Drosophila melanogaster genetika   metabolismus   MeSH
• editace RNA * MeSH
• exprese genu MeSH
• interakční proteinové domény a motivy MeSH
• izoenzymy MeSH
• lidé MeSH
• messenger RNA genetika   MeSH
• molekulární evoluce MeSH
• nervový systém metabolismus   MeSH
• obratlovci MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• RNA interference MeSH
• substrátová specifita MeSH
• vazba proteinů MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• Adar protein, Drosophila MeSH Prohlížeč
• adenosindeaminasa MeSH
• izoenzymy MeSH
• messenger RNA MeSH
• proteiny Drosophily MeSH
• proteiny vázající RNA MeSH

Radiation exposure can evoke cellular stress responses. Emerging recognition that long non-coding RNAs (lncRNAs) act as regulators of gene expression has broadened the spectra of molecules controlling the genomic landscape upon alterations in environmental conditions. Knowledge of the mechanisms responding to low dose irradiation (LDR) exposure is very limited yet most likely involve subtle ancillary molecular pathways other than those protecting the cell from direct cellular damage. The discovery that transcription of the lncRNA PARTICLE (promoter of MAT2A- antisense radiation-induced circulating lncRNA; PARTICL) becomes dramatically instigated within a day after LDR exposure introduced a new gene regulator onto the biological landscape. PARTICLE affords an RNA binding platform for genomic silencers such as DNA methyltransferase 1 and histone tri-methyltransferases to reign in the expression of tumor suppressors such as its neighboring MAT2A in cis as well as WWOX in trans. In silico evidence offers scope to speculate that PARTICLE exploits the abundance of Hoogsten bonds that exist throughout mammalian genomes for triplex formation, presumably a vital feature within this RNA silencer. PARTICLE may provide a buffering riboswitch platform for S-adenosylmethionine. The correlation of PARTICLE triplex formation sites within tumor suppressor genes and their abundance throughout the genome at cancer-related hotspots offers an insight into potential avenues worth exploring in future therapeutic endeavors.

• Klíčová slova
• epigenetics, histone, long non-coding RNA, methyltransferase, radiation, triplex,
• MeSH
• dávka záření MeSH
• DNA-(cytosin-5)-methyltransferasa 1 genetika   MeSH
• genom lidský účinky záření   MeSH
• genomika MeSH
• histonové methyltransferasy genetika   MeSH
• lidé MeSH
• methioninadenosyltransferasa genetika   MeSH
• nádorové supresorové proteiny genetika   MeSH
• nádory genetika   radioterapie   MeSH
• oxidoreduktasa obsahující WW doménu genetika   MeSH
• promotorové oblasti (genetika) genetika   MeSH
• radiační expozice škodlivé účinky   MeSH
• regulace genové exprese u nádorů účinky záření   MeSH
• RNA dlouhá nekódující genetika   MeSH
• RNA interference účinky záření   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA-(cytosin-5)-methyltransferasa 1 MeSH
• DNMT1 protein, human MeSH Prohlížeč
• histonové methyltransferasy MeSH
• MAT2A protein, human MeSH Prohlížeč
• methioninadenosyltransferasa MeSH
• nádorové supresorové proteiny MeSH
• oxidoreduktasa obsahující WW doménu MeSH
• RNA dlouhá nekódující MeSH
• WWOX protein, human MeSH Prohlížeč

The uridine insertion/deletion RNA editing of kinetoplastid mitochondrial transcripts is performed by complex machinery involving a number of proteins and multiple protein complexes. Here we describe the effect of silencing of TbRGG1 gene by RNA interference on RNA editing in procyclic stage of Trypanosoma brucei. TbRGG1 is an essential protein for cell growth, the absence of which results in an overall decline of edited mRNAs, while the levels of never-edited RNAs remain unaltered. Repression of TbRGG1 expression has no effect on the 20S editosome and MRP1/2 complex. TAP-tag purification of TbRGG1 coisolated a novel multiprotein complex, and its association was further verified by TAP-tag analyses of two other components of the complex. TbRGG1 interaction with this complex appears to be mediated by RNA. Our results suggest that the TbRGG1 protein functions in stabilizing edited RNAs or editing efficiency and that the associated novel complex may have a role in mitochondrial RNA metabolism. We provisionally name it putative mitochondrial RNA-binding complex 1 (put-MRB complex 1).

• MeSH
• DNA primery genetika   MeSH
• editace RNA MeSH
• multiproteinové komplexy genetika   metabolismus   MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• RNA interference MeSH
• RNA mitochondriální MeSH
• RNA protozoální genetika   metabolismus   MeSH
• RNA genetika   metabolismus   MeSH
• sekvence nukleotidů MeSH
• stabilita RNA MeSH
• Trypanosoma brucei brucei genetika   růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• DNA primery MeSH
• multiproteinové komplexy MeSH
• proteiny vázající RNA MeSH
• protozoální proteiny MeSH
• RNA mitochondriální MeSH
• RNA protozoální MeSH
• RNA MeSH
• TBRGG1 protein, Trypanosoma brucei MeSH Prohlížeč

Global transcription silencing occurs in the oocyte during its final phase of growth. The particular mechanism of this silencing is not well understood. Here, we investigated the silencing of RNA polymerase II transcription in porcine oocytes. First, we investigated the transcriptional activity of germinal vesicle oocytes derived from stimulated and non-stimulated gilts, but no transcriptional activity was observed. Second, we focused on the fate of RNA polymerase II in growing and fully grown oocytes. Active and inactive forms of RNA polymerase II were detected in growing oocytes by immunofluorescence and Western blots. In contrast, only the inactive form of RNA polymerase II was detected in fully grown oocytes. To evaluate if the inactive form of RNA polymerase II is released from DNA, the oocytes were subsequently permeabilized and fixed in one step. After this modified fixation protocol, the immunofluorescent labeling was negative in fully grown oocytes, but remained unchanged (positive) in growing oocytes. These results indicate that the inactive form of RNA polymerase II is not bound to DNA during the oocyte growth. Finally, based on Western blot analysis of different stages of oocyte maturation, the inactive form of RNA polymerase II was detected in metaphase I but not in metaphase II. Our study confirmed the global transcription silencing of fully grown oocytes. Compared with other mammalian species (e.g., mouse), the mechanism of RNA polymerase II silencing in porcine oocytes seems to be similar, despite some differences in dynamics.

• MeSH
• adenosin chemie   metabolismus   MeSH
• autoradiografie MeSH
• fosforylace MeSH
• genetická transkripce MeSH
• gonadotropiny metabolismus   MeSH
• imunohistochemie MeSH
• izotopové značení MeSH
• myši MeSH
• oocyty chemie   růst a vývoj   metabolismus   fyziologie   MeSH
• prasata MeSH
• RNA-polymerasa II chemie   genetika   metabolismus   MeSH
• umlčování genů * MeSH
• uridin chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosin MeSH
• gonadotropiny MeSH
• RNA-polymerasa II MeSH
• uridin MeSH