Similar Datasets
Project description:Mammalian genomes contain hundreds of lamina-associated domains (LADs), which are large, often megabase-sized heterochromatin domains that are anchored to the nuclear lamina (NL). Even though LADs play a key role in the spatial organization of the genome and potently repress gene activity, it is not yet understood how their interactions with the NL are encoded in their DNA. Here, we investigated the principles that govern LAD-NL interactions by taking a "LAD scrambling" approach. This approach relies on 1) local "hopping" of a Sleeping Beauty transposon to randomly insert loxP sites within and around a LAD of choice; and 2) Cre-mediated recombination between the loxP sites. This approach is highly efficient, enabling us to establish a large collection of clonal cell lines with deletions and inversions up to ~2Mb in size, spanning LAD and their flanking inter-LAD sequences. Mapping of NL interactions in these clones revealed that a single LAD contacts the NL through multiple regions. These regions act cooperatively and redundantly; however, some have more affinity for the NL and can boost NL contacts of neighbouring sequences. We also observed a crosstalk between two neighbouring LADs, when close enough to each other. Finally, changes in the heterochromatin mark H3K9me3 only partially mirrored changes in NL contacts. They also correlated more with gene expression changes than NL contacts did. These principles of LAD - NL interactions provide insight into the overall architecture of the genome and the impact on gene regulation.
2023-12-19 | GSE250306 | GEO
Project description:Mammalian genomes contain hundreds of lamina-associated domains (LADs), which are large, often megabase-sized heterochromatin domains that are anchored to the nuclear lamina (NL). Even though LADs play a key role in the spatial organization of the genome and potently repress gene activity, it is not yet understood how their interactions with the NL are encoded in their DNA. Here, we investigated the principles that govern LAD-NL interactions by taking a "LAD scrambling" approach. This approach relies on 1) local "hopping" of a Sleeping Beauty transposon to randomly insert loxP sites within and around a LAD of choice; and 2) Cre-mediated recombination between the loxP sites. This approach is highly efficient, enabling us to establish a large collection of clonal cell lines with deletions and inversions up to ~2Mb in size, spanning LAD and their flanking inter-LAD sequences. Mapping of NL interactions in these clones revealed that a single LAD contacts the NL through multiple regions. These regions act cooperatively and redundantly; however, some have more affinity for the NL and can boost NL contacts of neighbouring sequences. We also observed a crosstalk between two neighbouring LADs, when close enough to each other. Finally, changes in the heterochromatin mark H3K9me3 only partially mirrored changes in NL contacts. They also correlated more with gene expression changes than NL contacts did. These principles of LAD - NL interactions provide insight into the overall architecture of the genome and the impact on gene regulation.
2023-12-19 | GSE250085 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2019-06-28 | GSE133275 | GEO
Project description:Transcriptionally inactive genes are often positioned at the nuclear lamina (NL), as part of large lamina-associated domains (LADs). Activation of such genes is often accompanied by repositioning toward the nuclear interior. How this process works and how it impacts flanking chromosomal regions are poorly understood. We addressed these questions by systematic activation or inactivation of individual genes, followed by detailed genome-wide analysis of NL interactions, replication timing, and transcription patterns. Gene activation inside LADs typically causes NL detachment of the entire transcription unit, but rarely more than 50-100 kb of flanking DNA, even when multiple neighboring genes are activated. The degree of detachment depends on the expression level and the length of the activated gene. Loss of NL interactions coincides with a switch from late to early replication timing, but the latter can involve longer stretches of DNA. Inactivation of active genes can lead to increased NL contacts. These extensive datasets are a resource for the analysis of LAD rewiring by transcription and reveal a remarkable flexibility of interphase chromosomes.
| S-EPMC7073462 | biostudies-literature
Project description:Progenitor cells differentiate into specialized cell types through coordinated expression of lineage-specific genes and modification of complex chromatin configurations. We demonstrate that a histone deacetylase (Hdac3) organizes heterochromatin at the nuclear lamina during cardiac progenitor lineage restriction. Specification of cardiomyocytes is associated with reorganization of peripheral heterochromatin, and independent of deacetylase activity, Hdac3 tethers peripheral heterochromatin containing lineage-relevant genes to the nuclear lamina. Deletion of Hdac3 in cardiac progenitor cells releases genomic regions from the nuclear periphery, leading to precocious cardiac gene expression and differentiation into cardiomyocytes; in contrast, restricting Hdac3 to the nuclear periphery rescues myogenesis in progenitors otherwise lacking Hdac3. Our results suggest that availability of genomic regions for activation by lineage-specific factors is regulated in part through dynamic chromatin-nuclear lamina interactions and that competence of a progenitor cell to respond to differentiation signals may depend upon coordinated movement of responding gene loci away from the nuclear periphery.
| S-EPMC5683101 | biostudies-literature
Project description:Regulation of gene expression is highly conserved between vertebrates, yet the genomic binding patterns of transcription factors are poorly conserved, suggesting that other mechanisms may contribute. The spatial organization of chromosomes in the nucleus is known to affect gene activity, but it is unclear to what extent this organization is conserved in evolution. Genome-wide maps of nuclear lamina (NL) interactions show that human and mouse chromosomes have highly similar folding patterns inside the nucleus. Breaks in synteny are often located at transition points between NL interacting and intra-nuclear regions. Data were compared against data from Peric-Hupkes, Meuleman et al. (Molecular Cell, 2010). LaminB1-chromatin interactions were assayed in human ESCs and human HT1080 cells. LaminA-chromatin interactions were assayed in human HT1080 cells. For the all samples there were 2 biological replicates, that were hybridized in a dye-swap design.
2012-10-10 | E-GEOD-22428 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below.
2017-10-12 | GSE97878 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2015-09-24 | GSE69423 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2017-08-17 | GSE76605 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2018-10-10 | GSE64149 | GEO