DamID of Dam::EMR-1 in Caenorhabditis elegans L1 larvae
Ontology highlight
ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
PROVIDER: GSE126028 | GEO | 2019/04/12
REPOSITORIES: GEO
Similar Datasets
Project description:Laminopathies are caused by mutations in components of the nuclear envelope (NE). While most NE components are widely expressed, laminopathies affect only a subset of tissues. However, the understanding of the molecular mechanisms that explain this phenomenon is still elusive. Here we have performed a genome wide DamID analysis in adult C. elegans nematodes comparing the DNA association profile of two components of the NE, Lamin/LMN-1 and Emerin/EMR-1. Although both proteins were associated to silent DNA, EMR-1 showed a predominant role in the anchoring of muscle and neuronal promoters to the nuclear periphery. Deletion of either EMR-1 or LEM-2, another integral NE protein, caused local changes in nuclear architecture with both increased and decreased LMN-1 association. Comparison of Dam::LMN-1 and Dam::EMR-1 DNA assotiation in wild type strains and Dam::LMN-1 DNA association in wild type, lem-2(tm1582) and emr-1(gk119) mutant backgrounds.
2013-12-02 | E-GEOD-44188 | biostudies-arrayexpress
Project description:Laminopathies are caused by mutations in components of the nuclear envelope (NE). While most NE components are widely expressed, laminopathies affect only a subset of tissues. However, the understanding of the molecular mechanisms that explain this phenomenon is still elusive. Here we have performed a genome wide DamID analysis in adult C. elegans nematodes comparing the DNA association profile of two components of the NE, Lamin/LMN-1 and Emerin/EMR-1. Although both proteins were associated to silent DNA, EMR-1 showed a predominant role in the anchoring of muscle and neuronal promoters to the nuclear periphery. Deletion of either EMR-1 or LEM-2, another integral NE protein, caused local changes in nuclear architecture with both increased and decreased LMN-1 association.
2013-12-02 | GSE44188 | GEO
Project description:Genomic regions preferentially associate with regions of similar transcriptional activity, partitioning genomes into active and inactive compartments within the nucleus. Here we explored mechanisms controlling genome compartment organization in C. elegans and investigated roles for compartments in regulating gene expression. The distal arms of C. elegans chromosomes, which are enriched for heterochromatic histone modifications including H3K9me, interact with each other both in cis and in trans, while interacting less frequently with central regions of chromosomes, leading to genome compartmentalization. Arms are anchored to the nuclear periphery via the nuclear envelope protein CEC-4, which binds to H3K9me. By performing genome-wide chromosome conformation capture experiments (Hi-C), we showed that eliminating H3K9me1/me2/me3 through mutations in the methyltransferase genes met-2 and set-25 significantly impaired formation of genome compartments. cec-4 mutations also impaired compartmentalization, but to a lesser extent. We found that H3K9me promotes compartmentalization through two distinct mechanisms: perinuclear anchoring of chromosome arms via CEC-4 to promote their cis association, and an anchoring-independent mechanism that compacts individual chromosome arms. In both met-2 set-25 and cec-4 mutants, no dramatic changes in gene expression were found for genes that switched compartments or for genes that remained in their original compartment, suggesting that compartment strength does not dictate gene expression levels. Furthermore, H3K9me, but not perinuclear anchoring, also contributes to formation of another prominent feature of chromosome organization, megabase-scale topologically associating domains on X that are established by the dosage-compensation condensin complex. Our results demonstrate that H3K9me plays crucial roles in regulating genome organization at multiple levels.
2020-04-21 | GSE144252 | GEO
Project description:Genomic regions preferentially associate with regions of similar transcriptional activity, partitioning genomes into active and inactive compartments within the nucleus. Here we explored mechanisms controlling genome compartment organization in C. elegans and investigated roles for compartments in regulating gene expression. The distal arms of C. elegans chromosomes, which are enriched for heterochromatic histone modifications including H3K9me, interact with each other both in cis and in trans, while interacting less frequently with central regions of chromosomes, leading to genome compartmentalization. Arms are anchored to the nuclear periphery via the nuclear envelope protein CEC-4, which binds to H3K9me. By performing genome-wide chromosome conformation capture experiments (Hi-C), we showed that eliminating H3K9me1/me2/me3 through mutations in the methyltransferase genes met-2 and set-25 significantly impaired formation of genome compartments. cec-4 mutations also impaired compartmentalization, but to a lesser extent. We found that H3K9me promotes compartmentalization through two distinct mechanisms: perinuclear anchoring of chromosome arms via CEC-4 to promote their cis association, and an anchoring-independent mechanism that compacts individual chromosome arms. In both met-2 set-25 and cec-4 mutants, no dramatic changes in gene expression were found for genes that switched compartments or for genes that remained in their original compartment, suggesting that compartment strength does not dictate gene expression levels. Furthermore, H3K9me, but not perinuclear anchoring, also contributes to formation of another prominent feature of chromosome organization, megabase-scale topologically associating domains on X that are established by the dosage-compensation condensin complex. Our results demonstrate that H3K9me plays crucial roles in regulating genome organization at multiple levels.
2020-04-21 | GSE144251 | GEO
Project description:RNA-seq for monitoring expression levels in mutants that do not anchor chromatin at the nuclear periphery. RNA-seq of depleted rRNA samples of early embryo extracts for three different genotypes: wild-type, cec-4_delta and met-2 set-25_delta_delta, in two independent biological replicas
2015-12-11 | E-GEOD-74067 | biostudies-arrayexpress
Project description:Heterochromatin protein 1 (HP1) proteins are important regulators of heterochromatin mediated gene silencing and chromosome structure and it is well known as the reader of the heterochromatin mark methylation of histone H3 lysine 9 (H3K9me). In Drosophila three different histone lysine methyl transferases (HKMTs) are associated with the methylation of H3K9; Su(var)3-9, Setdb1 and G9a. To gain insights on the dependence of HP1a on the three different HKMTs, the division of labor between these methyl transferases and the dependence of HP1a on H3K9me we have studied HP1a binding in relation to H3K9me in mutants of these HKMTs. We show that Su(var)3-9 is responsible for the HP1a H3K9me-dependent binding in pericentromeric regions while Setdb1 controls the HP1a H3K9me-dependent binding to cytological region 2L:31 and together with POF chromosome 4. HP1a binds to the promoters and within gene bodies of active genes in these three regions. More importantly, HP1a bound at promoters of active genes are independent of H3K9me and POF and is associated to heterochromatin protein 2 (HP2) and open chromatin. Our results supports a model where HP1a nucleates with high affinity independent of H3K9me in promoters of active genes and then spreads via H3K9 methylation and transient looping contacts with those H3K9me target sites. In total 44 samples; 2 replicates for each genotype and for each ChIP (HP1a, H3K9me2 and H3K9me3)
2012-12-21 | E-GEOD-38366 | biostudies-arrayexpress
Project description:Development in multicellular organisms is governed by a carefully orchestrated program of gene expression controlled by both genetic and epigenetic factors1,2. Histone H3 lysine 9 methylation (H3K9me) is the defining modification of heterochromatin, which is thought to have two main functions. It silences satellite repeats and transposable elements to ensure genome stability3, and stabilizes differentiated states by repressing tissue-specific genes4,5. Not surprisingly, the loss of appropriately targeted heterochromatin is associated with cancer, loss of tissue integrity, and aging5-8. How H3K9me restricts transcription is unknown. Here we show that in C. elegans H3K9me2 is required to silence different sets of genes in embryos and differentiated post-mitotic cells. During nematode development H3K9me is lost from genes that define cell-type identity and is gained at genes expressed at prior stages or in alternative tissues. We found that a continuous deposition of H3K9me2 is necessary to maintain silencing in terminally differentiated cells. Its loss leads to DNA decompaction, but this is not sufficient to derepress H3K9me-marked genes. Instead, gene derepression in differentiated tissues requires distinct sets of transcription factors (TF) that aberrantly activate enhancers or promoters. Tissue-specific H3K9me distribution thus contributes critically to cell-type specific TF binding providing a rationale for how a limited set of TFs can control complex organismal development9,10.
2021-08-01 | GSE167165 | GEO
Project description:Development in multicellular organisms is governed by a carefully orchestrated program of gene expression controlled by both genetic and epigenetic factors1,2. Histone H3 lysine 9 methylation (H3K9me) is the defining modification of heterochromatin, which is thought to have two main functions. It silences satellite repeats and transposable elements to ensure genome stability3, and stabilizes differentiated states by repressing tissue-specific genes4,5. Not surprisingly, the loss of appropriately targeted heterochromatin is associated with cancer, loss of tissue integrity, and aging5-8. How H3K9me restricts transcription is unknown. Here we show that in C. elegans H3K9me2 is required to silence different sets of genes in embryos and differentiated post-mitotic cells. During nematode development H3K9me is lost from genes that define cell-type identity and is gained at genes expressed at prior stages or in alternative tissues. We found that a continuous deposition of H3K9me2 is necessary to maintain silencing in terminally differentiated cells. Its loss leads to DNA decompaction, but this is not sufficient to derepress H3K9me-marked genes. Instead, gene derepression in differentiated tissues requires distinct sets of transcription factors (TF) that aberrantly activate enhancers or promoters. Tissue-specific H3K9me distribution thus contributes critically to cell-type specific TF binding providing a rationale for how a limited set of TFs can control complex organismal development9,10.
2021-08-01 | GSE167167 | GEO
Project description:Development in multicellular organisms is governed by a carefully orchestrated program of gene expression controlled by both genetic and epigenetic factors1,2. Histone H3 lysine 9 methylation (H3K9me) is the defining modification of heterochromatin, which is thought to have two main functions. It silences satellite repeats and transposable elements to ensure genome stability3, and stabilizes differentiated states by repressing tissue-specific genes4,5. Not surprisingly, the loss of appropriately targeted heterochromatin is associated with cancer, loss of tissue integrity, and aging5-8. How H3K9me restricts transcription is unknown. Here we show that in C. elegans H3K9me2 is required to silence different sets of genes in embryos and differentiated post-mitotic cells. During nematode development H3K9me is lost from genes that define cell-type identity and is gained at genes expressed at prior stages or in alternative tissues. We found that a continuous deposition of H3K9me2 is necessary to maintain silencing in terminally differentiated cells. Its loss leads to DNA decompaction, but this is not sufficient to derepress H3K9me-marked genes. Instead, gene derepression in differentiated tissues requires distinct sets of transcription factors (TF) that aberrantly activate enhancers or promoters. Tissue-specific H3K9me distribution thus contributes critically to cell-type specific TF binding providing a rationale for how a limited set of TFs can control complex organismal development9,10.
2021-08-01 | GSE167166 | GEO
Project description:Point mutations in nuclear structural protein laminA produce rare and generally tissue-specific diseases called laminopathies. The introduction of a human Emery Dreifuss Muscular Dystrophy (EDMD)-inducing mutation (laminA-Y45C) into C. elegans lamin (LMN-Y59C), recapitulates many EDMD phenotypes, and results in hyper-sequestration of heterochromatic arrays at the nuclear periphery. Using muscle-specific Emerin Dam-ID we show that the LMN-Y59C mutation also leads to misorganization of endogenous chromatin. We find increased perinuclear anchoring primarily along chromosome arms, and enhanced release of chromosomal cores. Coincidentally, Y59C worms have reduced locomotion and compromised sarcomere integrity. By coupling this mutation with deletion of the perinuclear chromodomain protein CEC-4, which tethers H3K9-methylated chromatin, we rescue the EDMD-like physiology and ultrastructural defects in sarcomeres. It further counteracts the altered spatial organization of chromosomal sequences, particularly along chromosomal arms. The data in this submission refer to the identification of chromatin enriched at the nuclear periphery (as measured by interaction with Dam::EMR-1) in muscle cells of L3/L4 control animals or cec-4 mutants expressing either GFP::LMN-1 (wild type lamin) or GFP::LMN-1(Y59C).
2020-12-31 | GSE135850 | GEO