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RNA

About: RNA is a research topic. Over the lifetime, 111695 publications have been published within this topic receiving 5475262 citations. The topic is also known as: ribonucleic acid.


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Journal ArticleDOI
TL;DR: There appears to be a negative correlation between mutation rate and genome size among RNA viruses, and nucleotide substitutions are on average four times more common than insertions/deletions (indels) in retroviruses.
Abstract: Accurate estimates of virus mutation rates are important to understand the evolution of the viruses and to combat them. However, methods of estimation are varied and often complex. Here, we critically review over 40 original studies and establish criteria to facilitate comparative analyses. The mutation rates of 23 viruses are presented as substitutions per nucleotide per cell infection (s/n/c) and corrected for selection bias where necessary, using a new statistical method. The resulting rates range from 10 8 to10 6 s/n/c for DNA viruses and from 10 6 to 10 4 s/n/c for RNA viruses. Similar to what has been shown previously for DNA viruses, there appears to be a negative correlation between mutation rate and genome size among RNA viruses, but this result requires further experimental testing. Contrary to some suggestions, the mutation rate of retroviruses is not lower than that of other RNA viruses. We also show that nucleotide substitutions are on average four times more common than insertions/deletions (indels). Finally, we provide estimates of the mutation rate per nucleotide per strand copying, which tends to be lower than that per cell infection because some viruses undergo several rounds of copying per cell, particularly double-stranded DNA viruses. A regularly updated virus mutation rate data set will be available at www.uv.es/rsanjuan/virmut.

1,096 citations

Journal ArticleDOI
Ci Chu1, Kun Qu1, Franklin L. Zhong1, Steven E. Artandi1, Howard Y. Chang1 
TL;DR: ChIRP-seq of three lncRNAs reveal that RNA occupancy sites in the genome are focal, sequence-specific, and numerous, and generally applicable to illuminate the intersection of RNA and chromatin with newfound precision genome wide.

1,095 citations

Journal ArticleDOI
24 Nov 2017-Science
TL;DR: A type VI CRISPR-Cas system containing the programmable single-effector RNA-guided ribonuclease Cas13 is profiled in order to engineer a Cas13 ortholog capable of robust knockdown and REPAIR presents a promising RNA-editing platform with broad applicability for research, therapeutics, and biotechnology.
Abstract: Nucleic acid editing holds promise for treating genetic disease, particularly at the RNA level, where disease-relevant sequences can be rescued to yield functional protein products. Type VI CRISPR-Cas systems contain the programmable single-effector RNA-guided ribonuclease Cas13. We profiled type VI systems in order to engineer a Cas13 ortholog capable of robust knockdown and demonstrated RNA editing by using catalytically inactive Cas13 (dCas13) to direct adenosine-to-inosine deaminase activity by ADAR2 (adenosine deaminase acting on RNA type 2) to transcripts in mammalian cells. This system, referred to as RNA Editing for Programmable A to I Replacement (REPAIR), which has no strict sequence constraints, can be used to edit full-length transcripts containing pathogenic mutations. We further engineered this system to create a high-specificity variant and minimized the system to facilitate viral delivery. REPAIR presents a promising RNA-editing platform with broad applicability for research, therapeutics, and biotechnology.

1,095 citations

Journal ArticleDOI
11 Mar 2010-Nature
TL;DR: A novel differential approach selective for the 5′ end of primary transcripts is presented, establishing a paradigm for mapping and annotating the primary transcriptomes of many living species and discovering hundreds of transcriptional start sites within operons, and opposite to annotated genes.
Abstract: Genome sequencing of Helicobacter pylori has revealed the potential proteins and genetic diversity of this prevalent human pathogen, yet little is known about its transcriptional organization and noncoding RNA output. Massively parallel cDNA sequencing (RNA-seq) has been revolutionizing global transcriptomic analysis. Here, using a novel differential approach (dRNA-seq) selective for the 5' end of primary transcripts, we present a genome-wide map of H. pylori transcriptional start sites and operons. We discovered hundreds of transcriptional start sites within operons, and opposite to annotated genes, indicating that complexity of gene expression from the small H. pylori genome is increased by uncoupling of polycistrons and by genome-wide antisense transcription. We also discovered an unexpected number of approximately 60 small RNAs including the epsilon-subdivision counterpart of the regulatory 6S RNA and associated RNA products, and potential regulators of cis- and trans-encoded target messenger RNAs. Our approach establishes a paradigm for mapping and annotating the primary transcriptomes of many living species.

1,094 citations

Journal ArticleDOI
TL;DR: Results suggest that virus-encoded suppressors of gene silencing have distinct modes of action, are targeted against distinct components of the host gene-silencing machinery, and that there is dynamic evolution of theHost and viral components associated with the gene- silencing mechanism.
Abstract: In transgenic and nontransgenic plants, viruses are both initiators and targets of a defense mechanism that is similar to posttranscriptional gene silencing (PTGS). Recently, it was found that potyviruses and cucumoviruses encode pathogenicity determinants that suppress this defense mechanism. Here, we test diverse virus types for the ability to suppress PTGS. Nicotiana benthamiana exhibiting PTGS of a green fluorescent protein transgene were infected with a range of unrelated viruses and various potato virus X vectors producing viral pathogenicity factors. Upon infection, suppression of PTGS was assessed in planta through reactivation of green fluorescence and confirmed by molecular analysis. These experiments led to the identification of three suppressors of PTGS and showed that suppression of PTGS is widely used as a counter-defense strategy by DNA and RNA viruses. However, the spatial pattern and degree of suppression varied extensively between viruses. At one extreme, there are viruses that suppress in all tissues of all infected leaves, whereas others are able to suppress only in the veins of new emerging leaves. This variation existed even between closely related members of the potexvirus group. Collectively, these results suggest that virus-encoded suppressors of gene silencing have distinct modes of action, are targeted against distinct components of the host gene-silencing machinery, and that there is dynamic evolution of the host and viral components associated with the gene-silencing mechanism.

1,094 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
20233,706
20227,117
20214,436
20204,465
20193,923