A developmentally programmed splicing failure attenuates the DNA damage response during mammalian zygotic genome activation
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE163205 | GEO | 2022/04/27
REPOSITORIES: GEO
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Project description:Zygotic genome activation (ZGA) is essential for early embryo development. Here, we reported that ZGA is initiated at 16-cell stage in sheep, as extensive alterations in gene expression and DNA methylation patterns, along with elevated levels of RNA polymerase II and developmental arrest was found at the 16-cell embryos. To uncover the sophisticated RNA metabolism during ZGA, we conducted weighted gene co-expression network analysis and identified 1957 critical maternal genes. Using dapars, we found 1058 and 933 lengthened alternative polyadenylation (APA) events, and genes exhibiting shorten APA were highly expressed in both sheep and mice ZGA-stage embryos. Using rMATs, we reported 2675 and 1963 genes showed exon skipping during ZGA in sheep and mice. These genes are related to RNA binding, translation, gamete generation, and reproduction.
2024-06-20 | GSE270269 | GEO
Project description:Although the function of DNA methylation in gene promoter regions is well established in transcriptional repression, the function of the evolutionarily conserved widespread distribution of DNA methylation in gene body regions remains incompletely understood. Here, we show that DNA methylation is enriched in included alternatively spliced exons (ASEs) and inhibiting DNA methylation results in aberrant splicing of ASEs. The methyl-CpG binding protein MeCP2 is enriched in included ASEs, particularly those that are also highly DNA methylated, and inhibition of DNA methylation disrupts specific targeting of MeCP2 to exons. Interestingly, ablation of MeCP2 results in increased nucleosome acetylation and aberrant skipping events of ASEs. We further show that inhibition of histone deacetylases leads to a highly significant overlap of exon skipping events caused by knocking-down MeCP2. Together, our data indicate that intragenic DNA methylation operates in exon definition to modulate alternative splicing and can enhance exon recognition via recruitment of the multifunctional protein MeCP2, which thereby maintains local histone hypoacetylation through its established interaction with HDACs. MeCP2 ChIP-Seq in IMR90 and HCT116 cells
2013-08-13 | E-GEOD-47677 | biostudies-arrayexpress
Project description:Although the function of DNA methylation in gene promoter regions is well established in transcriptional repression, the function of the evolutionarily conserved widespread distribution of DNA methylation in gene body regions remains incompletely understood. Here, we show that DNA methylation is enriched in included alternatively spliced exons (ASEs) and inhibiting DNA methylation results in aberrant splicing of ASEs. The methyl-CpG binding protein MeCP2 is enriched in included ASEs, particularly those that are also highly DNA methylated, and inhibition of DNA methylation disrupts specific targeting of MeCP2 to exons. Interestingly, ablation of MeCP2 results in increased nucleosome acetylation and aberrant skipping events of ASEs. We further show that inhibition of histone deacetylases leads to a highly significant overlap of exon skipping events caused by knocking-down MeCP2. Together, our data indicate that intragenic DNA methylation operates in exon definition to modulate alternative splicing and can enhance exon recognition via recruitment of the multifunctional protein MeCP2, which thereby maintains local histone hypoacetylation through its established interaction with HDACs. RNA-Seq in IMR90 and HCT116
2013-08-13 | E-GEOD-47488 | biostudies-arrayexpress
Project description:Although the function of DNA methylation in gene promoter regions is well established in transcriptional repression, the function of the evolutionarily conserved widespread distribution of DNA methylation in gene body regions remains incompletely understood. Here, we show that DNA methylation is enriched in included alternatively spliced exons (ASEs) and inhibiting DNA methylation results in aberrant splicing of ASEs. The methyl-CpG binding protein MeCP2 is enriched in included ASEs, particularly those that are also highly DNA methylated, and inhibition of DNA methylation disrupts specific targeting of MeCP2 to exons. Interestingly, ablation of MeCP2 results in increased nucleosome acetylation and aberrant skipping events of ASEs. We further show that inhibition of histone deacetylases leads to a highly significant overlap of exon skipping events caused by knocking-down MeCP2. Together, our data indicate that intragenic DNA methylation operates in exon definition to modulate alternative splicing and can enhance exon recognition via recruitment of the multifunctional protein MeCP2, which thereby maintains local histone hypoacetylation through its established interaction with HDACs.
2013-08-13 | GSE47677 | GEO
Project description:Although the function of DNA methylation in gene promoter regions is well established in transcriptional repression, the function of the evolutionarily conserved widespread distribution of DNA methylation in gene body regions remains incompletely understood. Here, we show that DNA methylation is enriched in included alternatively spliced exons (ASEs) and inhibiting DNA methylation results in aberrant splicing of ASEs. The methyl-CpG binding protein MeCP2 is enriched in included ASEs, particularly those that are also highly DNA methylated, and inhibition of DNA methylation disrupts specific targeting of MeCP2 to exons. Interestingly, ablation of MeCP2 results in increased nucleosome acetylation and aberrant skipping events of ASEs. We further show that inhibition of histone deacetylases leads to a highly significant overlap of exon skipping events caused by knocking-down MeCP2. Together, our data indicate that intragenic DNA methylation operates in exon definition to modulate alternative splicing and can enhance exon recognition via recruitment of the multifunctional protein MeCP2, which thereby maintains local histone hypoacetylation through its established interaction with HDACs.
2013-08-13 | GSE47488 | GEO
Project description:MSI (Microsatellite Instability) colorectal cancer (CRC) show improved survival, are less prone to metastasis and show poor response to chemotherapy (compared to MSS tumors). The underlying reasons for these characteristics are still not understood and no specific therapeutic approach for MSI colon tumours (15% of CRC overall) has yet been developed.
The MSI process is oncogenic when it affects DNA repeat sequences that have a functional role, e.g. Small Coding Repeats (SCR). MSI also frequently affects Long Non-Coding Repeats (LNCR) in tumour DNA. In contrast to SCR, only a few LNCR are endowed with biological activity. Consequently, this area has received very little attention. Our group recently identified HSP110 mutant chaperone protein in MSI CRC that was generated by somatic deletion of a LNCR. Of interest, HSP110 mutant (due to exon skipping) have anti-oncogenic properties and the survival of MSI CRC patients receiving chemotherapy is positively associated with HSP110 mutations in tumour DNA.
The aim of the current project is to identify additional clinically relevant MSI-associated splicing aberrations due to mutations in LNCR located in splice acceptor sites. The four main steps are as follows:
1. To identify exon/intron sites affected by aberrant splicing events due to MSI in CRC . All RNASeq data will be exploited to identify recurrent splicing aberrations (mostly exon skipping) that occur specifically in MSI colon tumours;
2. To investigate for possible functional links between MSI and any detected aberrant splicing events . All specific aberrant splicing events detected by RNAseq in MSI CRC samples will be first confirmed (quantitative RT-PCR) in order to eliminate false positive cases. For validated exon candidates, the allelic profiles of adjacent intronic LNCR will be analysed (PCR and fluorescence genotyping) in CRC cell lines and primary tumours (MSI and MSS), as well as in matching normal mucosa samples in order to assess their polymorphic status;
3. To identify splicing events and LNCR mutations with clinical relevance in MSI CRC patients . All LNCR with a confirmed role in gene splicing in MSI CRC will be analysed. The clinical relevance of candidate genes will be assessed using multivariate survival regression models for Relapse- Free Survival, with interaction terms (response to chemotherapy);
4. To initiate functional studies on a limited number of clinically relevant, cancer-related genes whose splicing is perturbed in MSI cancer cells, and to develop biological tools to simplify screening in future clinical assays Similar to HSP110, we will focus on 4 or 5 mutant proteins that are promising drug therapeutic targets. Functional assays will be developed to further elucidate their role in the pathophysiology of MSI tumours. We also aim to develop biological tools for these candidate genes, such as the detection of wild-type or mutant proteins by immunohistochemistry.
| 2266966 | ecrin-mdr-crc
Project description:Zebrafish embryos are transcriptional silent until activation of the zygotic genome during the 10th cell cycle. Onset of transcription is followed by cellular and morphological changes involving cell speciation and gastrulation. Previous genome-wide surveys of transcriptional changes only assessed gene expression levels; however, recent studies have shown the necessity to map isoform-specific transcriptional changes. Here we perform isoform discovery and quantification on transcriptome sequences from before and after zebrafish zygotic genome activation (ZGA). We identify novel isoforms and isoform switches during ZGA for genes related to cell adhesion, pluripotency and DNA methylation. Isoform switching events include alternative splicing and changes in transcriptional start sites and in 3’ untranslated regions. New isoforms are identified even for well-characterized genes such as pou5f1, sall4 and dnmt1. Genes involved in cell-cell interactions such as f11r and magi1 display isoform switches with alterations of coding sequences. We also detect over 1000 transcripts that acquire a longer 3’ terminal exon when transcribed zygotically relative to the maternal transcript counterparts. ChIP-seq data mapped onto skipped exon events reveals a correlation between histone H3K36trimethylation peaks and the skipped exons, suggesting epigenetic marks being part of alternative splicing regulation. The novel isoforms and isoform switches reported here include regulators of the transcriptional, cellular and morphological changes taking place around ZGA. Our data display an array of isoform-related functional changes and represent a valuable resource complementary to existing early embryo transcriptomes. Examination H3K36me3 in zebrafish whole embryos at the Post-MBT stage
2012-11-01 | E-GEOD-40629 | biostudies-arrayexpress
Project description:During the maternal-to-zygotic transition (MZT), transcriptionally silent embryos rely on post-transcriptional regulation of maternal mRNAs until zygotic genome activation (ZGA). RNA-binding proteins (RBPs) are important regulators of post-transcriptional RNA processing events, yet their identities and functions during developmental transitions in vertebrates remain largely unexplored. Using mRNA interactome capture, we identified 227 RBPs in zebrafish embryos before and during ZGA, hereby named the zebrafish MZT mRNAbound proteome. This protein constellation consists of many conserved RBPs, with additional embryo- and stage-specific mRNA interactors that likely reflect the dynamics of RNA-protein interactions during MZT. The enrichment of numerous splicing factors like hnRNP proteins before ZGA was surprising, because maternal mRNAs were found to be fully spliced. To address potentially unique roles of RBPs in embryogenesis, we focused on hnRNP A1. iCLIP and subsequent mRNA reporter assays revealed a function for hnRNP A1 in the regulation of poly(A) tail length and translation of maternal mRNAs through sequence-specific association with 3’UTRs before ZGA. Comparison of iCLIP data from two developmental stages revealed that hnRNP A1 dissociates from maternal mRNAs at ZGA and instead regulates the nuclear processing of pri-miR-430 transcripts, which we validated experimentally. The shift from cytoplasmic to nuclear RNA targets was accompanied by a dramatic translocation of hnRNP A1 and other pre-mRNA splicing factors to the nucleus in a transcription-dependent manner. Thus, our study identifies global changes in RNA-protein interactions during vertebrate MZT and shows that hnRNP A1 RNA-binding activities are spatially and temporally coordinated to regulate RNA metabolism during early development.
2017-03-27 | PXD006098 | Pride
Project description:Exon skipping technologies enable exclusion of targeted exons from mature mRNA transcripts, which has broad applications in molecular and cellular biology, medicine and biotechnology. Existing exon skipping techniques include antisense oligonucleotides, targetable nucleases and base editors, which, while effective for specific applications at some target exons, remain hindered by shortcomings preventing their broader implementation including transient effects in the case of oligonucleotides or limiting PAM motifs, sequence context preferences for deaminases, and undesirable cryptic splicing in the case of gene editing tools. To overcome these limitations, we created SPLICER, a toolbox of next-generation base editors consisting of near-PAMless Cas9 nickase variants fused with different deaminases for simultaneous editing of splice acceptor (SA) and splice donor (SD) sequences. Synchronized SA and SD editing not only improves exon skipping rates but also reduces aberrant outcomes such as cryptic splicing and intron retention. SPLICER enables editing of exon splice sites with high efficiency, including many exons refractory to splicing reprogramming by the native SpCas9 BEs. To demonstrate the therapeutic potential of SPLICER, we targeted APP exon 17, which contains the amino acid residues responsible for the formation of Aβ plaques in Alzheimer’s disease. SPLICER enabled precise and highly efficient exon skipping, which reduced the formation of Aβ42 peptides in vitro while inducing DNA editing and exon skipping in vivo within a humanized mouse model of Alzheimer’s disease. Overall, SPLICER is a widely applicable and highly efficient toolbox for exon skipping with broad therapeutic applications.
2023-12-10 | GSE246587 | GEO
Project description:Exon skipping technologies enable exclusion of targeted exons from mature mRNA transcripts, which has broad applications in molecular and cellular biology, medicine and biotechnology. Existing exon skipping techniques include antisense oligonucleotides, targetable nucleases and base editors, which, while effective for specific applications at some target exons, remain hindered by shortcomings preventing their broader implementation including transient effects in the case of oligonucleotides or limiting PAM motifs, sequence context preferences for deaminases, and undesirable cryptic splicing in the case of gene editing tools. To overcome these limitations, we created SPLICER, a toolbox of next-generation base editors consisting of near-PAMless Cas9 nickase variants fused with different deaminases for simultaneous editing of splice acceptor (SA) and splice donor (SD) sequences. Synchronized SA and SD editing not only improves exon skipping rates but also reduces aberrant outcomes such as cryptic splicing and intron retention. SPLICER enables editing of exon splice sites with high efficiency, including many exons refractory to splicing reprogramming by the native SpCas9 BEs. To demonstrate the therapeutic potential of SPLICER, we targeted APP exon 17, which contains the amino acid residues responsible for the formation of Aβ plaques in Alzheimer’s disease. SPLICER enabled precise and highly efficient exon skipping, which reduced the formation of Aβ42 peptides in vitro while inducing DNA editing and exon skipping in vivo within a humanized mouse model of Alzheimer’s disease. Overall, SPLICER is a widely applicable and highly efficient toolbox for exon skipping with broad therapeutic applications.
2023-12-10 | GSE246586 | GEO