BACKGROUND: Plant transformation via Agrobacterium tumefaciens is characterized by integration of commonly low number of T-DNAs at random positions in the genome. When integrated into an active gene region, promoterless reporter genes placed near the T-DNA border sequence are frequently transcribed and even translated to reporter proteins, which is the principle of promoter- and gene-trap lines. RESULTS: Here we show that even internal promotorless regions of T-DNAs are often transcribed. Such spontaneous transcription was observed in the majority of independently transformed tobacco BY-2 lines (over 65%) and it could effectively induce silencing if an inverted repeat was present within the T-DNA. We documented that the transcription often occurred in both directions. It was not directly connected with any regulatory elements present within the T-DNAs and at least some of the transcripts were initiated outside of the T-DNA. The likeliness of this read-through transcription seemed to increase in lines with higher T-DNA copy number. Splicing and presence of a polyA tail in the transcripts indicated involvement of Pol II, but surprisingly, the transcription was able to run across two transcription terminators present within the T-DNA. Such pervasive transcription was observed with three different T-DNAs in BY-2 cells and with lower frequency was also detected in Arabidopsis thaliana. CONCLUSIONS: Our results demonstrate unexpected pervasive read-through transcription of T-DNAs. We hypothesize that it was connected with a specific chromatin state of newly integrated DNA, possibly affected by the adjacent genomic region. Although this phenomenon can be easily overlooked, it can have significant consequences when working with highly sensitive systems like RNAi induction using an inverted repeat construct, so it should be generally considered when interpreting results obtained with the transgenic technology.

• Klíčová slova
• GFP, Inverted repeat, Promoterless, RNAi, Read-through transcription, T-DNA, Tobacco BY-2 cell line,
• MeSH
• Agrobacterium tumefaciens genetika   MeSH
• Arabidopsis genetika   MeSH
• buněčné linie MeSH
• DNA bakterií genetika   MeSH
• genetická transkripce * MeSH
• geneticky modifikované rostliny MeSH
• messenger RNA genetika   MeSH
• obrácené repetice genetika   MeSH
• promotorové oblasti (genetika) genetika   MeSH
• reportérové geny MeSH
• tabák genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA bakterií MeSH
• messenger RNA MeSH
• T-DNA MeSH Prohlížeč

In plants, 5S rRNA genes (5S rDNA) encoding 120-nt structural RNA molecules of ribosomes are organized in tandem arrays comprising thousands of units. Failure to correctly terminate transcription would generate longer inaccurately processed transcripts interfering with ribosome biogenesis. Hence multiple termination signals occur immediately after the 5S rRNA coding sequence. To obtain information about the efficiency of termination of 5S rDNA transcription in plants we analyzed 5S rRNA pools in three Nicotiana species, N. sylvestris, N. tomentosiformis and N. tabacum. In addition to highly abundant 120-nt 5S rRNA transcripts, we also detected RNA species composed of a genic region and variable lengths of intergenic sequences. These genic-intergenic RNA molecules occur at a frequency severalfold lower than the mature 120-nt transcripts, and are posttranscriptionally modified by polyadenylation at their 3' end in contrast to 120-nt transcripts. An absence of 5S small RNAs (smRNA) argue against a dominant role for the smRNA biosynthesis pathway in the degradation of aberrant 5S rRNA in Nicotiana. This work is the first description of polyadenylated 5S rRNA species in higher eukaryotes originating from a read-through transcription into the intergenic spacer. We propose that polyadenylation may function in a "quality control" pathway ensuring that only correctly processed molecules enter the ribosome biogenesis.

• MeSH
• Arabidopsis genetika   MeSH
• genetická transkripce * MeSH
• intergenová DNA * MeSH
• malá interferující RNA metabolismus   MeSH
• messenger RNA metabolismus   MeSH
• modely genetické MeSH
• molekulární sekvence - údaje MeSH
• polyadenylace * MeSH
• regulace genové exprese u rostlin * MeSH
• RNA ribozomální 5S genetika   MeSH
• sekvence nukleotidů MeSH
• sekvenční homologie nukleových kyselin MeSH
• tabák genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• intergenová DNA * MeSH
• malá interferující RNA MeSH
• messenger RNA MeSH
• RNA ribozomální 5S MeSH

Recent reports have begun unraveling the details of various roles of individual eukaryotic translation initiation factor 3 (eIF3) subunits in translation initiation. Here we describe functional characterization of two essential Saccharomyces cerevisiae eIF3 subunits, g/Tif35 and i/Tif34, previously suggested to be dispensable for formation of the 48S preinitiation complexes (PICs) in vitro. A triple-Ala substitution of conserved residues in the RRM of g/Tif35 (g/tif35-KLF) or a single-point mutation in the WD40 repeat 6 of i/Tif34 (i/tif34-Q258R) produces severe growth defects and decreases the rate of translation initiation in vivo without affecting the integrity of eIF3 and formation of the 43S PICs in vivo. Both mutations also diminish induction of GCN4 expression, which occurs upon starvation via reinitiation. Whereas g/tif35-KLF impedes resumption of scanning for downstream reinitiation by 40S ribosomes terminating at upstream open reading frame 1 (uORF1) in the GCN4 mRNA leader, i/tif34-Q258R prevents full GCN4 derepression by impairing the rate of scanning of posttermination 40S ribosomes moving downstream from uORF1. In addition, g/tif35-KLF reduces processivity of scanning through stable secondary structures, and g/Tif35 specifically interacts with Rps3 and Rps20 located near the ribosomal mRNA entry channel. Together these results implicate g/Tif35 and i/Tif34 in stimulation of linear scanning and, specifically in the case of g/Tif35, also in proper regulation of the GCN4 reinitiation mechanism.

• MeSH
• aminokyselinové motivy genetika   MeSH
• eukaryotický iniciační faktor 3 chemie   genetika   metabolismus   MeSH
• fungální RNA metabolismus   MeSH
• messenger RNA genetika   metabolismus   MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• podjednotky proteinů chemie   genetika   metabolismus   MeSH
• proteosyntéza * MeSH
• ribozomální proteiny chemie   genetika   metabolismus   MeSH
• ribozomy genetika   metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   genetika   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   metabolismus   MeSH
• sekundární struktura proteinů MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• substituce aminokyselin MeSH
• terciární struktura proteinů MeSH
• transkripční faktory bZIP genetika   metabolismus   MeSH
• vazba proteinů MeSH
• western blotting MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• eukaryotický iniciační faktor 3 MeSH
• fungální RNA MeSH
• GCN4 protein, S cerevisiae MeSH Prohlížeč
• messenger RNA MeSH
• podjednotky proteinů MeSH
• ribozomální proteiny MeSH
• RPS20 protein, S cerevisiae MeSH Prohlížeč
• RPS3 protein, S cerevisiae MeSH Prohlížeč
• Saccharomyces cerevisiae - proteiny MeSH
• transkripční faktory bZIP MeSH

Chimeric genes are significant sources of evolutionary innovation that are normally created when portions of two or more protein coding regions fuse to form a new open reading frame. In plant mitochondria astonishingly high numbers of different novel chimeric genes have been reported, where they are generated through processes of rearrangement and recombination. Nonetheless, because most studies do not find or report nucleotide variation within the same chimeric gene, evolution after the origination of these chimeric genes remains unstudied. Here we identify two alleles of a complex chimera in Silene vulgaris that are divergent in nucleotide sequence, genomic position relative to other mitochondrial genes, and expression patterns. Structural patterns suggest a history partially influenced by gene conversion between the chimeric gene and functional copies of subunit 1 of the mitochondrial ATP synthase gene (atp1). We identified small repeat structures within the chimeras that are likely recombination sites allowing generation of the chimera. These results establish the potential for chimeric gene divergence in different plant mitochondrial lineages within the same species. This result contrasts with the absence of diversity within mitochondrial chimeras found in crop species.

• MeSH
• alely MeSH
• DNA primery genetika   MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• genetická transkripce MeSH
• genetická variace MeSH
• genom rostlinný MeSH
• kodon MeSH
• křížení genetické MeSH
• messenger RNA metabolismus   MeSH
• mitochondriální geny * MeSH
• modely genetické MeSH
• molekulární evoluce MeSH
• mozaicismus MeSH
• polymerázová řetězová reakce MeSH
• pravděpodobnostní funkce MeSH
• proteiny huseníčku genetika   MeSH
• protonové ATPasy genetika   MeSH
• regulace genové exprese MeSH
• rekombinace genetická MeSH
• rostlinné geny MeSH
• Silene genetika   MeSH
• Southernův blotting MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• ATP1 protein, Arabidopsis MeSH Prohlížeč
• DNA primery MeSH
• kodon MeSH
• messenger RNA MeSH
• proteiny huseníčku MeSH
• protonové ATPasy MeSH

The selection of proper reference genes and materials is critical in the design of PCR experiments, especially for differential expression studies. In this study, we propose a method to identify robust endogenous control miRNAs in the visceral adipose tissue of C57BL/6J mice with non-alcoholic fatty liver disease induced by alternating Western and control diets. This study outlines a comprehensive methodology for the analysis of microRNA endogenous controls using microfluidic cards in conjunction with miRNA profiling through small RNA sequencing and subsequent validation by quantitative PCR and the RefFinder algorithm. Criteria included were fold change, p-value, reads per million, and gene stability assessment. A set of six putative endogenous microRNAs was identified (miR-331-3p, let-7a-5p, miR-1839-5p, miR-151a-5p, let-7d-5p, and let-7c-5p). Subsequent validation and analysis using the RefFinder algorithm assessed the stability of the selected genes, and a combination of the three most stable endogenous miRNA controls (miR-331-3p, let-7a- 5p, and miR-1839-5p) exhibiting consistent expression patterns with minimal variability was set. Given the absence of universal endogenous controls, individual evaluation of normalizers for each experiment is imperative for accurate miRNA expression measurements. This approach, which combines multiple techniques and assessments, provides a reliable strategy for identifying and validating endogenous controls in miRNA studies.

• MeSH
• algoritmy MeSH
• mikro RNA * genetika   metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nealkoholová steatóza jater * genetika   patologie   metabolismus   MeSH
• nitrobřišní tuk * metabolismus   patologie   MeSH
• regulace genové exprese MeSH
• stanovení celkové genové exprese metody   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• mikro RNA * MeSH

The adenosine deaminase acting on RNA (ADAR) enzymes are essential for neuronal function and innate immune control. ADAR1 RNA editing prevents aberrant activation of antiviral dsRNA sensors through editing of long, double-stranded RNAs (dsRNAs). In this review, we focus on the ADAR2 proteins involved in the efficient, highly site-specific RNA editing to recode open reading frames first discovered in the GRIA2 transcript encoding the key GLUA2 subunit of AMPA receptors; ADAR1 proteins also edit many of these sites. We summarize the history of ADAR2 protein research and give an up-to-date review of ADAR2 structural studies, human ADARBI (ADAR2) mutants causing severe infant seizures, and mouse disease models. Structural studies on ADARs and their RNA substrates facilitate current efforts to develop ADAR RNA editing gene therapy to edit disease-causing single nucleotide polymorphisms (SNPs). Artificial ADAR guide RNAs are being developed to retarget ADAR RNA editing to new target transcripts in order to correct SNP mutations in them at the RNA level. Site-specific RNA editing has been expanded to recode hundreds of sites in CNS transcripts in Drosophila and cephalopods. In Drosophila and C. elegans, ADAR RNA editing also suppresses responses to self dsRNA.

• Klíčová slova
• ADAR, ADARB1, dsRNA, neurons, recoding RNA editing,
• MeSH
• adenosindeaminasa * metabolismus   MeSH
• AMPA receptory genetika   metabolismus   MeSH
• antivirové látky MeSH
• Caenorhabditis elegans genetika   MeSH
• Drosophila genetika   MeSH
• dvouvláknová RNA genetika   MeSH
• genetická terapie MeSH
• lidé MeSH
• myši MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• ADARB1 protein, human MeSH Prohlížeč
• adenosindeaminasa * MeSH
• AMPA receptory MeSH
• antivirové látky MeSH
• dvouvláknová RNA MeSH
• proteiny vázající RNA MeSH

The kinetoplastids are unicellular flagellates that derive their name from the 'kinetoplast', a region within their single mitochondrion harboring its organellar genome of high DNA content, called kinetoplast (k) DNA. Some protein products of this mitochondrial genome are encoded as cryptogenes; their transcripts require editing to generate an open reading frame. This happens through RNA editing, whereby small regulatory guide (g)RNAs direct the proper insertion and deletion of one or more uridines at each editing site within specific transcript regions. An accurate perspective of the kDNA expansion and evolution of their unique uridine insertion/deletion editing across kinetoplastids has been difficult to achieve. Here, we resolved the kDNA structure and editing patterns in the early-branching kinetoplastid Trypanoplasma borreli and compare them with those of the well-studied trypanosomatids. We find that its kDNA consists of circular molecules of about 42 kb that harbor the rRNA and protein-coding genes, and 17 different contigs of approximately 70 kb carrying an average of 23 putative gRNA loci per contig. These contigs may be linear molecules, as they contain repetitive termini. Our analysis uncovered a putative gRNA population with unique length and sequence parameters that is massive relative to the editing needs of this parasite. We validated or determined the sequence identity of four edited mRNAs, including one coding for ATP synthase 6 that was previously thought to be missing. We utilized computational methods to show that the T. borreli transcriptome includes a substantial number of transcripts with inconsistent editing patterns, apparently products of non-canonical editing. This species utilizes the most extensive uridine deletion compared to other studied kinetoplastids to enforce amino acid conservation of cryptogene products, although insertions still remain more frequent. Finally, in three tested mitochondrial transcriptomes of kinetoplastids, uridine deletions are more common in the raw mitochondrial reads than aligned to the fully edited, translationally competent mRNAs. We conclude that the organization of kDNA across known kinetoplastids represents variations on partitioned coding and repetitive regions of circular molecules encoding mRNAs and rRNAs, while gRNA loci are positioned on a highly unstable population of molecules that differ in relative abundance across strains. Likewise, while all kinetoplastids possess conserved machinery performing RNA editing of the uridine insertion/deletion type, its output parameters are species-specific.

• Klíčová slova
• ATPase 6, Euglenozoa, Maxicircle, Metakinetoplastina, Mitochondrion, RNA editing, U-indel editing, Uridine insertion/deletion editing, guide RNA,
• Publikační typ
• časopisecké články MeSH

The mRNA differential display technique was performed to investigate the differences of gene expression in the longissimus muscle tissues from Meishan and Large White pigs. One novel gene that was differentially expressed was identified through semi-quantitative RT-PCR and the cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the gene is not homologous to any of the known porcine genes. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 337 amino acids that has high homology with the solute carrier family 9 isoform 3 regulator 2 isoform a of four species--human (92 %), mouse (91 %), rat (90 %), rabbit (87 %)--so that this gene can be defined as swine SLC9A3R2 gene. The phylogenetic tree analysis revealed that the swine SLC9A3R2 gene has the closest genetic relationship with the SLC9A3R2 gene of human. This gene is structured in seven exons and six introns as revealed by computer-assisted analysis. The tissue expression analysis indicated that the swine SLC9A3R2 gene is differentially expressed in different tissues. Our experiment is the first to establish the primary foundation for further research on the swine SLC9A3R2 gene.

• MeSH
• druhová specificita MeSH
• exony genetika   MeSH
• fylogeneze MeSH
• introny genetika   MeSH
• kosterní svaly metabolismus   MeSH
• křížení genetické MeSH
• molekulární sekvence - údaje MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční analýza DNA MeSH
• sekvenční seřazení MeSH
• stanovení celkové genové exprese MeSH
• Sus scrofa genetika   metabolismus   MeSH
• techniky amplifikace nukleových kyselin MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Adenosine deaminases acting on RNA (ADARs) convert adenosine to inosine in dsRNA. ADAR editing in pre-mRNAs recodes open reading frames and alters splicing, mRNA structure and interactions with miRNAs. Here, we review ADAR gene expression, splice forms, posttranslational modifications, subcellular localizations and functions of ADAR protein isoforms. ADAR1 edits cellular dsRNA to prevent aberrant activation of cytoplasmic antiviral dsRNA sensors; ADAR1 mutations lead to aberrant expression of interferon in Aicardi Goutières syndrome (AGS), a human congenital encephalopathy. We review related studies on mouse Adar1 mutant phenotypes, their rescues by preventing signaling from the antiviral RIG-I-like Sensors (RLRs), as well as Adar1 mechanisms in innate immune suppression and other roles of Adar1, including editing-independent effects. ADAR2, expressed primarily in CNS, edits glutamate receptor transcripts; regulation of ADAR2 activity in response to neuronal activity mediates homeostatic synaptic plasticity of vertebrate AMPA and kainite receptors. In Drosophila, synapses and synaptic proteins show dramatic decreases at night during sleep; Drosophila Adar, an orthologue of ADAR2, edits hundreds of mRNAs; the most conserved editing events occur in transcripts encoding synapse-associated proteins. Adar mutant flies exhibit locomotion defects associated with very increased sleep pressure resulting from a failure of homeostatic synaptic processes. A study on Adar2 mutant mice identifies a new role in circadian rhythms, acting indirectly through miRNAs such as let-7 to modulate levels of let-7 target mRNAs; ADAR1 also regulates let-7 miRNA processing. Drosophila ADAR, an orthologue of vertebrate ADAR2, also regulates let-7 miRNA levels and Adar mutant flies have a circadian mutant phenotype.

• Klíčová slova
• ADAR, Circadian rhythm, Epitranscriptome, Innate immunity, RNA editing, Sleep, dsRNA, microRNA,
• MeSH
• adenosindeaminasa genetika   metabolismus   MeSH
• cirkadiánní hodiny * MeSH
• editace RNA * MeSH
• lidé MeSH
• přirozená imunita * MeSH
• spánek * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• adenosindeaminasa MeSH