Project description:The functional structure of all biologically active molecules is dependent on intra- and inter-molecular interactions. This is especially evident for RNA molecules whose functionality, maturation, and regulation requires formation of correct secondary structure through encoded base-pairing interactions. Unfortunately, intra- and inter-molecular base-pairing information is lacking for most RNAs. Here, we use high-throughput sequencing to interrogate all base-paired RNA in Arabidopsis thaliana, and identify ~200 new small (sm)RNA-producing substrates of RNA-DEPENDENT RNA POLYMERASE 6. Our comprehensive analysis of paired RNAs reveals conserved functionality within introns and both 5’ and 3’ untranslated regions (UTRs) of mRNAs, as well as a novel population of functional RNAs, many of which are the precursors of smRNAs. Finally, we identify intra-molecular base-pairing interactions to produce a genome-wide collection of RNA secondary structure models. These findings highlight the importance of base-paired RNAs in eukaryotes, and present an approach that should be widely applicable for the analysis of this key structural feature of RNA. Double-stranded (dsRNA) specific RNA sequencing (dsRNA-seq) in the unopened flowerbuds of wild-type col-0 plants and rdr6 mutant plants, including 2 samples of col-0 dsRNA (1X- or 2X- Ribominus-treated samples) and 1 sample of rdr6 dsRNA. Corresponding two smRNA libraries (smRNA-seq) of both wild-type col-0 plants and rdr6 mutant plants of the same tissue are also presented.
Project description:The secondary structure of RNA is necessary for its maturation, regulation, and processing. However, the global influence of RNA folding in eukaryotes is still unclear. Here, we identify evolutionarily conserved features of RNA secondary structure in metazoans by applying our high-throughput, sequencing-based, structure-mapping approach to Drosophila melanogaster and Caenorhabditis elegans. This analysis reveals key structural patterns across protein-coding transcripts that indicate RNA folding is influential to protein translation and microRNA-mediated targeting and/or regulation of mRNAs in animals. Additionally, we uncover a novel population of highly base-paired RNAs, many of which are likely functional, long, non-coding RNAs. Finally, we identify and characterize ~180 structural motifs of mRNAs that are under positive or negative selection in these metazoans, thereby revealing a large set of RNA structures that are likely functional. Overall, our findings highlight the significance of secondary structure within RNA molecules, and provide the first comprehensive evidence of widespread RNA secondary structure conservation in animals. Double-stranded (dsRNA) specific RNA sequencing (dsRNA-seq) and single-stranded (ssRNA) specific RNA sequencing (ssRNA-seq) in Drosophila DL1 cells and C. elegans mixed stage N2 worms. Each of the four samples (dsRNA/Dmel, ssRNA/Dmel, dsRNA/Cel, and ssRNA/Cel) was sequenced separately on both Illumina GA-IIx and Hiseq2000, giving a total of eight datasets. Two corresponding smRNA libraries (smRNA-seq) of the same DL1 cells and mixed stage N2 worms are also presented.
Project description:The functional structure of all biologically active molecules is dependent on intra- and inter-molecular interactions. This is especially evident for RNA molecules whose functionality, maturation, and regulation requires formation of correct secondary structure through encoded base-pairing interactions. Unfortunately, intra- and inter-molecular base-pairing information is lacking for most RNAs. Here, we use high-throughput sequencing to interrogate all base-paired RNA in Arabidopsis thaliana, and identify ~200 new small (sm)RNA-producing substrates of RNA-DEPENDENT RNA POLYMERASE 6. Our comprehensive analysis of paired RNAs reveals conserved functionality within introns and both 5’ and 3’ untranslated regions (UTRs) of mRNAs, as well as a novel population of functional RNAs, many of which are the precursors of smRNAs. Finally, we identify intra-molecular base-pairing interactions to produce a genome-wide collection of RNA secondary structure models. These findings highlight the importance of base-paired RNAs in eukaryotes, and present an approach that should be widely applicable for the analysis of this key structural feature of RNA.
Project description:Encoded model contains complete kinetics of infection for coxsackievirus B3 (CVB3), a compact and fast-acting RNA virus. The model consists of separable, detailed modules describing viral binding-delivery, translation-replication, and encapsidation. Specific module activities are dampened by the type I interferon response to viral double-stranded RNAs (dsRNAs), which is itself disrupted by viral proteinases
Project description:Plant virus infection involves the production of viral small RNAs (vsRNAs) with the potential to associate with distinct Argonaute (AGO)-containing silencing complexes and mediate diverse silencing effects on RNA and chromatin. We used multiplexed, high-throughput pyrosequencing to profile populations of vsRNAs from plants infected with viruses from different genera. Sense and antisense vsRNAs of 20 to 24 nucleotides (nts) spread throughout the entire viral genomes in an overlapping configuration; virtually all genomic nucleotide positions were represented in the dataset. We present evidence to suggest that every genomic position could be a putative cleavage site for vsRNA formation, although viral genomes contain specific regions that serve as preferential sources of vsRNA production. Hotspots for vsRNAs of 21-, 22-, and 24-nt usually coincide in the same genomic regions, indicating similar target affinities among Dicer-like (DCL) enzymes. In the light of our results, the overall contribution of perfectly base paired double-stranded RNA and imperfectly base paired structures within single-stranded RNA to vsRNA formation is discussed. Our census of vsRNAs extends the current view of the distribution and composition of vsRNAs in virus-infected plants, and contributes to define a more comprehensive scenario of vsRNA biogenesis and their regulatory functions in plants Raw data files are available on our FTP site: ftp://ftp.ncbi.nlm.nih.gov/pub/geosup/Series/GSE16996 10 samples examined: Arabidopsis plants infected with TRV, TuMV or CMV; Nicothiana benthamiana plants infected with CymRSV, PVX or PMMoV; Cucumis melo plants infected with MNSV, quimeric MNSV or WMV and Solanum lycopersicum plants infected with TYLCV.
Project description:The secondary structure of RNA is necessary for its maturation, regulation, and processing. However, the global influence of RNA folding in eukaryotes is still unclear. Here, we identify evolutionarily conserved features of RNA secondary structure in metazoans by applying our high-throughput, sequencing-based, structure-mapping approach to Drosophila melanogaster and Caenorhabditis elegans. This analysis reveals key structural patterns across protein-coding transcripts that indicate RNA folding is influential to protein translation and microRNA-mediated targeting and/or regulation of mRNAs in animals. Additionally, we uncover a novel population of highly base-paired RNAs, many of which are likely functional, long, non-coding RNAs. Finally, we identify and characterize ~180 structural motifs of mRNAs that are under positive or negative selection in these metazoans, thereby revealing a large set of RNA structures that are likely functional. Overall, our findings highlight the significance of secondary structure within RNA molecules, and provide the first comprehensive evidence of widespread RNA secondary structure conservation in animals.
Project description:Reverse-stranded paired-end 75 base-pair RNA sequencing libraries of 93 metastatic FFPE samples were constructed using Illumina Total RNA Stranded Kits. Ribosomal RNAs (rRNAs) were depleted by using the Ribo-Zero rRNA Removal Kit (Illumina). Libraries were sequenced on a HiSEQ2500 machine. Five samples were re-sequenced using paired-end 50 base-pair libraries due to the smaller insert sizes.
Project description:Parallel RNA silencing pathways regulate gene expression in plants, either by transcriptional gene silencing via RNA-dependent DNA methylation (RdDM), or by post-transcriptional silencing targeting mRNAs. Both pathways rely on distinct Dicer-like proteins to cleave double-stranded RNA into small-interfering RNAs. Experiments to determine the subcellular localization of Dicer-like proteins in Arabidopsis revealed that DCL4 is predominantly expressed as a transcriptional start site isoform that encodes a cytoplasmic protein. A second, longer DCL4 transcript isoform encodes a nuclear-localization signal and its expression is repressed by DNA methylation. Consequently this isoform is induced when promoter methylation decreases due to infection with a bacterial pathogen or during silique development. Nuclear DCL4 produces unique populations of small RNAs, called DCL4NLS isoform-dependent siRNAs (disiRNAs), which function via a post-transcriptional silencing effector, but whose precursors are generated by the RdDM pathway. Arabidopsis cells can thus respond to genome methylation changes by modulating DCL4 localization, which in turn recruits PTGS factors to reinforce RNA silencing.
Project description:Abstract: As part of the zebrafish genome annotation project the 3 prime ends of genes were pulled down on polyT beads and sequenced on the Illumina Genome Analyzer to identify alternative 3 prime ends in a range of tissues and developmental stages. <br> Study description: Total RNA from a range of developmental stages and adult tissues were chemically fragmented, pulled down on polyT magnetic beads and double stranded cDNA was synthesized. The cDNA was BpmI digested to release from the beads and to leave a 6 T base tail. Illumina sequencing libraries were made followed by 76 base paired-end sequencing.