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: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 structures of RNA molecules are often important for their function and regulation, yet there are no experimental techniques for genome-scale measurement of RNA structure. Here, we describe a novel strategy termed Parallel Analysis of RNA Structure (PARS), which is based on deep sequencing fragments of RNAs that were treated with structure-specific enzymes, thus providing simultaneous in-vitro profiling of the secondary structure of thousands of RNA species at single nucleotide resolution. We apply PARS to profile the secondary structure of the mRNAs of the budding yeast S. cerevisiae and obtain structural profiles for over 3000 distinct transcripts. Analysis of these profiles reveals several RNA structural properties of yeast transcripts, including the existence of more secondary structure over coding regions compared to untranslated regions, a three-nucleotide periodicity of secondary structure across coding regions, and a relationship between the efficiency with which an mRNA is translated and the lack of structure over its translation start site. PARS is readily applicable to other organisms and to profiling RNA structure in diverse conditions, thus enabling studies of the dynamics of secondary structure at a genomic scale. RNA sample was treated with one of two structure-specific enzymes (RNase V1 or RNase S1). Four independent V1 experiments and three independent S1 experiments were carried out. Processed data file linked below. Data processing involves merging (or rather log-ratio-ing) the 7 lanes of SOLiD sequencing data against each other. Also linked below are the genome and transcriptome FASTA files used for mapping, and the annotation file having the format: gene_ID, chromosome, start, end, feature. Start and end are 1-based; feature is "Transcript" for the entire transcript (including introns), "Intron", "Exon", "5UTR" or "3UTR". Genome-wide measurement of RNA secondary structure in yeast, Kertesz et al., Nature Volume:467, Pages:103-107, Date published:(02 September 2010) http://www.nature.com/nature/journal/v467/n7311/abs/nature09322.html
Project description:Post-transcriptional regulation in eukaryotes requires cis- and trans-acting features and factors including RNA secondary structure, and RNA-binding proteins (RBPs). However, a comprehensive view of the structural and RBP interaction landscape of RNAs in the nucleus has yet to be compiled for any organism. Here, we use our ribonuclease-mediated structure and RBP binding site mapping approach on Arabidopsis seedling nuclei in vivo to globally profile these features within the nuclear compartment. We reveal opposing patterns of secondary structure and RBP binding levels throughout native messenger RNAs that demarcate alternative splicing and polyadenylation. We also uncover a collection of protein bound sequence motifs, and identify their structural contexts, co-occurrences in transcripts encoding functionally related proteins, and interactions with putative RBPs. Finally, we identify a nuclear role for the chloroplast RBP, CP29A. In total, we provide the first simultaneous view of the RNA secondary structure and RBP interaction landscapes in a eukaryotic nucleus. Protein interaction profile sequencing (PIP-seq) in Arabidopsis seedling nuclei. These are crosslinked with formaldehyde and treated with two RNases (ssRNase and dsRNase) with two replicates
Project description:The structures of RNA molecules are often important for their function and regulation, yet there are no experimental techniques for genome-scale measurement of RNA structure. Here, we describe a novel strategy termed Parallel Analysis of RNA Structure (PARS), which is based on deep sequencing fragments of RNAs that were treated with structure-specific enzymes, thus providing simultaneous in-vitro profiling of the secondary structure of thousands of RNA species at single nucleotide resolution. We apply PARS to profile the secondary structure of the mRNAs of the budding yeast S. cerevisiae and obtain structural profiles for over 3000 distinct transcripts. Analysis of these profiles reveals several RNA structural properties of yeast transcripts, including the existence of more secondary structure over coding regions compared to untranslated regions, a three-nucleotide periodicity of secondary structure across coding regions, and a relationship between the efficiency with which an mRNA is translated and the lack of structure over its translation start site. PARS is readily applicable to other organisms and to profiling RNA structure in diverse conditions, thus enabling studies of the dynamics of secondary structure at a genomic scale.
Project description:Messenger RNA secondary structure is critical to all aspects of post-transcriptional regulation. However, the global regulatory and evolutionary significance of mRNA secondary structure remains largely illusive. Here, we describe a transcriptome-wide analysis of RNA secondary structure in humans and two non-human primates, based on a high-throughput, nuclease-mediated, structure mapping approach. Using this methodology, we uncover global patterns of mRNA secondary structure, which we find to be conserved through primate evolution. We provide evidence for secondary structure-based regulatory pathways, which impact on gene expression through associations with translational machinery and RNA-binding proteins, including components of the microprocessor complex. Our results lend support to an unexpected, conserved mechanism by which highly structured regions of mRNAs serve as processing sites for small RNAs, resulting in subsequent turnover. Global mRNA secondary structure analysis in primate transcriptomes using high-throughput, nuclease-mediated, structure mappinng approaches of dsRNA-seq and ssRNA-seq, also with polyA+ mRNA-seq, smRNA-seq (small RNA), and genome-wide mapping of uncapped and cleaved transcripts (GMUCT); these NGS-seq experiments were carried out in three primate brains as well as three different cell lines, both in in vitro and in vivo.
Project description:Due to difficulties inherent in designating conservation units for effective species management and conservation, the use of multiple complementary sources of information is required to identify and assess the designation of conservation units based on the degree of variation among populations within a species. In this study, we combined estimates of microsatellite and transcriptomic variation to assess the population structure and potential for adaptive variation of threatened Atlantic salmon, Salmo salar, among rivers in the Bay of Fundy. In general, population structure identified by genetic differentiation was consistent with the patterns of variation in gene expression. Both data sets provided clear indication of strong regional differentiation between rivers located within the inner Bay of Fundy relative to rivers located within the outer Bay of Fundy or the Southern Uplands region. There was also support for more refined population structure; there was some differentiation in both microsatellite and gene expression patterns between salmon from rivers in the two regions of the inner Bay of Fundy: Chignecto Bay and Minas Basin. Consistent patterns apparent in the genetic and transcriptomic dataset indicate that Atlantic salmon populations from the inner and outer Bay of Fundy reflect unique genetic lineages, with some evidence of unique genetic legacies between regions of the inner Bay of Fundy, and even between individual rivers within a region. Consistency of the microarray data across two years helps to validate the use of this technique as a useful tool in assessment of variation among wild populations for species conservation.
Project description:Post-transcriptional regulation in eukaryotes requires cis- and trans-acting features and factors including RNA secondary structure, and RNA-binding proteins (RBPs). However, a comprehensive view of the structural and RBP interaction landscape of RNAs in the nucleus has yet to be compiled for any organism. Here, we use our ribonuclease-mediated structure and RBP binding site mapping approach on Arabidopsis seedling nuclei in vivo to globally profile these features within the nuclear compartment. We reveal opposing patterns of secondary structure and RBP binding levels throughout native messenger RNAs that demarcate alternative splicing and polyadenylation. We also uncover a collection of protein bound sequence motifs, and identify their structural contexts, co-occurrences in transcripts encoding functionally related proteins, and interactions with putative RBPs. Finally, we identify a nuclear role for the chloroplast RBP, CP29A. In total, we provide the first simultaneous view of the RNA secondary structure and RBP interaction landscapes in a eukaryotic nucleus.
Project description:Due to difficulties inherent in designating conservation units for effective species management and conservation, the use of multiple complementary sources of information is required to identify and assess the designation of conservation units based on the degree of variation among populations within a species. In this study, we combined estimates of microsatellite and transcriptomic variation to assess the population structure and potential for adaptive variation of threatened Atlantic salmon, Salmo salar, among rivers in the Bay of Fundy. In general, population structure identified by genetic differentiation was consistent with the patterns of variation in gene expression. Both data sets provided clear indication of strong regional differentiation between rivers located within the inner Bay of Fundy relative to rivers located within the outer Bay of Fundy or the Southern Uplands region. There was also support for more refined population structure; there was some differentiation in both microsatellite and gene expression patterns between salmon from rivers in the two regions of the inner Bay of Fundy: Chignecto Bay and Minas Basin. Consistent patterns apparent in the genetic and transcriptomic dataset indicate that Atlantic salmon populations from the inner and outer Bay of Fundy reflect unique genetic lineages, with some evidence of unique genetic legacies between regions of the inner Bay of Fundy, and even between individual rivers within a region. Consistency of the microarray data across two years helps to validate the use of this technique as a useful tool in assessment of variation among wild populations for species conservation. Atlantic salmon samples used in this analysis were collected from Mactaquac and Coldbrook Biodiversity Centres on the east coast of Canada. In year one, eight individuals were hybridized per strain (five strains; 40 individuals in total). This design incorporated dye-swap replicates in which two slides were hybridized with the same pair of individuals, but the dyes were swapped for one of the slides. Therefore, in year one a total of 40 slides were used. Because of the large number of populations assessed in year two (12), dyes were balanced across slides to maximize biological replication. Six individuals were hybridized per strain; three of these were labelled with Cy3, and three were labelled with Cy5 (for a total of 36 arrays in year two).
Project description:Messenger RNA secondary structure is critical to all aspects of post-transcriptional regulation. However, the global regulatory and evolutionary significance of mRNA secondary structure remains largely illusive. Here, we describe a transcriptome-wide analysis of RNA secondary structure in humans and two non-human primates, based on a high-throughput, nuclease-mediated, structure mapping approach. Using this methodology, we uncover global patterns of mRNA secondary structure, which we find to be conserved through primate evolution. We provide evidence for secondary structure-based regulatory pathways, which impact on gene expression through associations with translational machinery and RNA-binding proteins, including components of the microprocessor complex. Our results lend support to an unexpected, conserved mechanism by which highly structured regions of mRNAs serve as processing sites for small RNAs, resulting in subsequent turnover.