Lavender cryptic virus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1248478 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Carrot cryptic virus Genome sequencing and assembly
| PRJNA316526 | ENA
Project description:Suppressing spurious cryptic transcription by a repressive intragenic chromatin state featuring trimethylated lysine 36 on histone H3 (H3K36me3) and DNA methylation is critical for maintaining self-renewal capacity in mouse embryonic stem cells. In yeast and nematodes, such cryptic transcription is elevated with age, and reducing the levels of age-associated cryptic transcription extends yeast lifespan. Whether cryptic transcription is also increased during mammalian aging is unknown. We show for the first time an age-associated elevation in cryptic transcription in several stem cell populations, including murine hematopoietic stem cells (mHSCs) and neuronal stem cells (NSCs) and human mesenchymal stem cells (hMSCs). Using DECAP-seq, we mapped and quantified age-associated cryptic transcription in hMSCs aged in vitro. Regions with significant age-associated cryptic transcription have a unique chromatin signature: decreased H3K36me3 and increased H3K4me1, H3K4me3, and H3K27ac with age. Furthermore, genomic regions undergoing such age-dependent chromatin changes resemble known promoter sequences and are bound by the promoter-associated protein TBP even in young cells. Hence, the more permissive chromatin state at intragenic cryptic promoters likely underlies the increase of cryptic transcription in aged mammalian stem cells.
2021-07-15 | GSE156406 | GEO
Project description:The disruption of chromatin structure can result in transcription initiation from cryptic promoters within gene bodies. While the passage of RNA polymerase II is a well-characterized chromatin-disrupting force, numerous factors, including histone chaperones, normally stabilize chromatin on transcribed genes, thereby repressing cryptic transcription. DNA replication, which requires a partially overlapping set of histone chaperones, is also inherently disruptive to chromatin, but a role for DNA replication in cryptic transcription has never been examined. In this study, we tested the hypothesis that, in the absence of chromatin-stabilizing factors, DNA replication can promote cryptic transcription in S. cerevisiae. Using a novel fluorescent reporter assay, we show that multiple factors, including Asf1, CAF-1, Rtt106, Spt6, and FACT, block transcription from a cryptic promoter, but are entirely or partially dispensable in G1-arrested cells, suggesting a requirement for DNA replication in chromatin disruption. Collectively, these results demonstrate that transcription fidelity is dependent on numerous factors that function to assemble chromatin on nascent DNA.
2023-12-06 | GSE249469 | GEO
Project description:Maintaining transcriptional fidelity is essential for precise gene regulation and genome stability. Despite this, cryptic antisense transcription, occurring opposite to canonical coding sequences, is a pervasive feature across all domains of life. How such potentially harmful cryptic sites are regulated remains incompletely understood. Here, we show that nucleosome arrays within gene bodies play a key role in suppressing cryptic transcription. Using the fission yeast Schizosaccharomyces pombe as a model, we demonstrate that CHD1-family chromatin remodelers coordinate with the transcription elongation machinery, specifically the PAF complex, to position nucleosomes at sites of cryptic transcription initiation within gene bodies. In the absence of CHD1, AT-rich sequences within gene bodies lose nucleosome occupancy, exposing promoter-like sequences that drive cryptic initiation. While cryptic transcription is generally detrimental, we identify a subset of antisense transcripts that encode critical meiotic genes, suggesting that cryptic transcription can also serve as a source of regulatory innovation. These findings underscore the essential role of nucleosome remodelers in maintaining transcriptional fidelity and reveal their broader contributions to cellular homeostasis and evolutionary adaptability.
2025-08-19 | GSE302388 | GEO
Project description:Maintaining transcriptional fidelity is essential for precise gene regulation and genome stability. Despite this, cryptic antisense transcription, occurring opposite to canonical coding sequences, is a pervasive feature across all domains of life. How such potentially harmful cryptic sites are regulated remains incompletely understood. Here, we show that nucleosome arrays within gene bodies play a key role in suppressing cryptic transcription. Using the fission yeast Schizosaccharomyces pombe as a model, we demonstrate that CHD1-family chromatin remodelers coordinate with the transcription elongation machinery, specifically the PAF complex, to position nucleosomes at sites of cryptic transcription initiation within gene bodies. In the absence of CHD1, AT-rich sequences within gene bodies lose nucleosome occupancy, exposing promoter-like sequences that drive cryptic initiation. While cryptic transcription is generally detrimental, we identify a subset of antisense transcripts that encode critical meiotic genes, suggesting that cryptic transcription can also serve as a source of regulatory innovation. These findings underscore the essential role of nucleosome remodelers in maintaining transcriptional fidelity and reveal their broader contributions to cellular homeostasis and evolutionary adaptability.
2025-08-19 | GSE302387 | GEO
Project description:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296716 | GEO
Project description:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296714 | GEO
Project description:Mislocalization of the nuclear protein TDP43 is a hallmark of ALS and FTD and leads to de-repression and inclusion of cryptic exons, which represent promising biomarkers of TDP43 pathology. However, most cryptic exons to date have been identified from in vitro models, limiting our understanding of any tissue and/or cell-specific splices. We meta-analyzed published bulk RNA-Seq datasets representing 1,778 RNAseq profiles of ALS and FTD post mortem tissue, and in vitro models with experimentally depleted TDP43. We identified novel cryptic splices and mapped out their tissue-specificity, demonstrating subsets with distinct cortical and spinal cord enrichment. Novel events were validated by RNA-Seq and RT-qPCR in a new spinal cord cohort, and analysis of single-nucleus datasets localized cortical splices to layer-specific neuronal populations. This catalog of cryptic splices is the first step towards the development of biomarkers for cell type-specific TDP43 pathology.
2024-03-28 | GSE255683 | GEO
Project description:Suppressing spurious cryptic transcription by a repressive intragenic chromatin state featuring trimethylated lysine 36 on histone H3 (H3K36me3) and DNA methylation is critical for maintaining self-renewal capacity in mouse embryonic stem cells. In yeast and nematodes, such cryptic transcription is elevated with age, and reducing the levels of age-associated cryptic transcription extends yeast lifespan. Whether cryptic transcription is also increased during mammalian aging is unknown. We show for the first time an age-associated elevation in cryptic transcription in several stem cell populations, including murine hematopoietic stem cells (mHSCs) and neuronal stem cells (NSCs) and human mesenchymal stem cells (hMSCs). Using DECAP-seq, we mapped and quantified age-associated cryptic transcription in hMSCs aged in vitro. Regions with significant age-associated cryptic transcription have a unique chromatin signature: decreased H3K36me3 and increased H3K4me1, H3K4me3, and H3K27ac with age. Furthermore, genomic regions undergoing such age-dependent chromatin changes resemble known promoter sequences and are bound by the promoter-associated protein TBP even in young cells. Hence, the more permissive chromatin state at intragenic cryptic promoters likely underlies the increase of cryptic transcription in aged mammalian stem cells.
2021-07-15 | GSE168063 | GEO