80 research outputs found
RNA-DamID reveals cell-type-specific binding of roX RNAs at chromatin-entry sites.
No full textThousands of long noncoding RNAs (lncRNAs) have been identified in eukaryotic genomes, many of which are expressed in spatially and temporally restricted patterns. Nonetheless, the roles of the majority of these transcripts are still unknown. One of the mechanisms by which lncRNAs function is through the modulation of chromatin states. To assess the functions of lncRNAs, we developed RNA-DamID, a novel approach that detects lncRNA-genome interactions in a cell-type-specific manner in vivo with high sensitivity and accuracy. Identifying the cell-type-specific genome occupancy of lncRNAs is vital to understanding their mechanisms of action in development and disease. We used RNA-DamID to investigate targeting of the lncRNAs in the Drosophila dosage-compensation complex (DCC) and show that initial targeting is cell-type specific
Mapping RNA-Chromatin Interactions In Vivo with RNA-DamID.
No full textLong-noncoding RNAs (lncRNAs) are emerging as regulators of development and disease. lncRNAs are expressed in exquisitely precise expression patterns in vivo and many interact with chromatin to regulate gene expression. However, the limited sensitivity of RNA-purification techniques has precluded the identification of genomic targets of cell-type specific lncRNAs. RNA-DamID is a powerful new approach to understand the mechanisms by which lncRNAs act in vivo. RNA-DamID is highly sensitive and accurate, and can resolve cell-type-specific chromatin binding patterns without cell isolation. The determinants of RNA-chromatin interactions can be identified with RNA-DamID by analyzing RNA and protein cofactor mutants. Here we describe how to implement RNA-DamID and the design considerations to take into account to accurately identify lncRNA-chromatin interactions in vivo
DamID as a versatile tool for understanding gene regulation
No full textThe interaction of proteins and RNA with chromatin underlies the regulation of gene expression. The ability to profile easily these interactions is fundamental for understanding chromatin biology DNA adenine methyltransferase identification (DamID) profiles genome-wide protein-DNA interactions without antibodies, fixation or protein pull-downs. Recently, DamID has been adapted for applications beyond simple assaying of protein-DNA interactions, such as for studying RNA-chromatin interactions, chromatin accessibility and long-range chromosome interactions. Here, we provide an overview of DamID and introduce improvements to the technology, discuss their applications and compare alternative methodologies
Soft case-based reasoning
No full textAuthor name used in this publication: Simon ShiuVersion of RecordPublishedVoR allowe
Determining knot groups by finite quotients
No full textWe prove that hyperbolic 2-bridge knots are determined amongst all compact 3-manifolds by the profinite completions of their knot groups.The authors wish to withdraw this article. The attempted proof of Theorem 1.1 is incorrect because of its dependence on the statement of Theorem 2.2 in this article. The first author\u27s attempted proof of Theorem 2.2 (arXiv:2308.00266v2) is incorrec
Retinitis Pigmentosa GTPase Regulator (RPGR) protein isoforms in mammalian retina:insights into X-linked Retinitis Pigmentosa and associated ciliopathies
No full textMutations in the cilia-centrosomal protein Retinitis Pigmentosa GTPase Regulator (RPGR) are a frequent cause of retinal degeneration. The RPGR gene undergoes complex alternative splicing and encodes multiple protein isoforms. To elucidate the function of major RPGR isoforms (RPGR 1-19 and RPGR ORF15), we have generated isoform-specific antibodies and examined their expression and localization in the retina. Using sucrose-gradient centrifugation, immunofluorescence and co-immunoprecipitation methods, we show that RPGR isoforms localize to distinct sub-cellular compartments in mammalian photoreceptors and associate with a number of cilia-centrosomal proteins. The RCC1-like domain of RPGR, which is present in all major RPGR isoforms, is sufficient to target it to the cilia and centrosomes in cultured cells. Our findings indicate that multiple isotypes of RPGR may perform overlapping yet somewhat distinct transport-related functions in photoreceptors
Freedom of expression: cell-type-specific gene profiling
No full textCell fate and behavior are results of differential gene regulation, making techniques to profile gene expression in specific cell types highly desirable. Many methods now enable investigation at the DNA, RNA and protein level. This review introduces the most recent and popular techniques, and discusses key issues influencing the choice between these such as ease, cost and applicability of information gained. Interdisciplinary collaborations will no doubt contribute further advances, including not just in single cell type but single-cell expression profiling
Overcoming challenges and dogmas to understand the functions of pseudogenes
No full textPseudogenes are defined as regions of the genome that contain defective copies of genes. They exist across almost all forms of life, and in mammalian genomes are annotated in similar numbers to recognized protein-coding genes. Although often presumed to lack function, growing numbers of pseudogenes are being found to play important biological roles. In consideration of their evolutionary origins and inherent limitations in genome annotation practices, we posit that pseudogenes have been classified on a scientifically unsubstantiated basis. We reflect that a broad misunderstanding of pseudogenes, perpetuated in part by the pejorative inference of the 'pseudogene' label, has led to their frequent dismissal from functional assessment and exclusion from genomic analyses. With the advent of technologies that simplify the study of pseudogenes, we propose that an objective reassessment of these genomic elements will reveal valuable insights into genome function and evolution
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