Project description:Gene positioning and regulation of nuclear architecture are thought to influence gene expression. Here, we show that in mouse olfactory neurons, silent olfactory receptor (OR) genes from different chromosomes converge in a small number of heterochromatic foci. These foci are OR-exclusive and form in a cell-type-specific and differentiation- dependent manner. The aggregation of OR genes is developmentally synchronous with the downregulation of Lamin b Receptor (LBR) and can be reversed by ectopic expression of LBR in mature olfactory neurons. LBR-induced reorganization of nuclear architecture and redistribution of OR loci results in misregulation of OR transcription and disruption of the targeting specificity of the olfactory neurons. Our observations are consistent with a model of spatial regulation of OR expression and provide evidence for the instructive role of nuclear architecture and compartmentalization in gene regulation and differentiation. A complex probe was made by array capture to label mouse olfactory receptor genes by DNA FISH; this microarray data verifies the composition of that probe. Probe was made by array capture and elution from a custom olfactory receptor genomic region tiling array. Probe was verified on a chr1-4 tiling array.
Project description:Gene positioning and regulation of nuclear architecture are thought to influence gene expression. Here, we show that in mouse olfactory neurons, silent olfactory receptor (OR) genes from different chromosomes converge in a small number of heterochromatic foci. These foci are OR-exclusive and form in a cell-type-specific and differentiation- dependent manner. The aggregation of OR genes is developmentally synchronous with the downregulation of Lamin b Receptor (LBR) and can be reversed by ectopic expression of LBR in mature olfactory neurons. LBR-induced reorganization of nuclear architecture and redistribution of OR loci results in misregulation of OR transcription and disruption of the targeting specificity of the olfactory neurons. Our observations are consistent with a model of spatial regulation of OR expression and provide evidence for the instructive role of nuclear architecture and compartmentalization in gene regulation and differentiation. A complex probe was made by array capture to label mouse olfactory receptor genes by DNA FISH; this microarray data verifies the composition of that probe.
Project description:Lamins, the major components of the nuclear lamina, have diverse functions in many cellular processes. Despite broad expression, lamins have been implicated in cell type-specific roles in development, aging and disease by regulating gene expression. Yet, due to the lack of in depth lineage-specific functional studies, it remains unclear whether or how lamins regulate cell type-specific functions. Using targeted knockout of lamin B1 in the olfactory sensory neuron lineage, we show that lamin B1 is not required for early stages of olfactory sensory neuron differentiation but is needed for formation of mature neurons that properly respond to odor stimulation. Lamin B1 mutant cells exhibited decreased expression of genes involved in mature neuron function, increased expression of genes atypical of the olfactory lineage and clustered nuclear pore distribution. These results demonstrate that the universally expressed lamin B1 regulates cell type-specific gene expression and terminal differentiation.
Project description:Lamins, the major components of the nuclear lamina, have diverse functions in many cellular processes. Despite broad expression, lamins have been implicated in cell type-specific roles in development, aging and disease by regulating gene expression. Yet, due to the lack of in depth lineage-specific functional studies, it remains unclear whether or how lamins regulate cell type-specific functions. Using targeted knockout of lamin B1 in the olfactory sensory neuron lineage, we show that lamin B1 is not required for early stages of olfactory sensory neuron differentiation but is needed for formation of mature neurons that properly respond to odor stimulation. Lamin B1 mutant cells exhibited decreased expression of genes involved in mature neuron function, increased expression of genes atypical of the olfactory lineage and clustered nuclear pore distribution. These results demonstrate that the universally expressed lamin B1 regulates cell type-specific gene expression and terminal differentiation.
Project description:The genome is partitioned into topologically associated domains and genomic compartments with shared chromatin valence. This architecture is constrained by the DNA polymer, which precludes interactions between genes on different chromosomes. Here we report a marked divergence from this pattern of nuclear organization that occurs in mouse olfactory sensory neurons. Chromatin conformation capture using in situ Hi-C on fluorescence-activated cell-sorted olfactory sensory neurons and their progenitors shows that olfactory receptor gene clusters from 18 chromosomes make specific and robust interchromosomal contacts that increase with differentiation of the cells. These contacts are orchestrated by intergenic olfactory receptor enhancers, the 'Greek islands', which first contribute to the formation of olfactory receptor compartments and then form a multi-chromosomal super-enhancer that associates with the single active olfactory receptor gene. The Greek-island-bound transcription factor LHX2 and adaptor protein LDB1 regulate the assembly and maintenance of olfactory receptor compartments, Greek island hubs and olfactory receptor transcription, providing mechanistic insights into and functional support for the role of trans interactions in gene expression.
Project description:The genome is partitioned into topologically associated domains and genomic compartments with shared chromatin valence. This architecture is constrained by the DNA polymer, which precludes interactions between genes on different chromosomes. Here we report a marked divergence from this pattern of nuclear organization that occurs in mouse olfactory sensory neurons. Chromatin conformation capture using in situ Hi-C on fluorescence-activated cell-sorted olfactory sensory neurons and their progenitors shows that olfactory receptor gene clusters from 18 chromosomes make specific and robust interchromosomal contacts that increase with differentiation of the cells. These contacts are orchestrated by intergenic olfactory receptor enhancers, the 'Greek islands', which first contribute to the formation of olfactory receptor compartments and then form a multi-chromosomal super-enhancer that associates with the single active olfactory receptor gene. The Greek-island-bound transcription factor LHX2 and adaptor protein LDB1 regulate the assembly and maintenance of olfactory receptor compartments, Greek island hubs and olfactory receptor transcription, providing mechanistic insights into and functional support for the role of trans interactions in gene expression.
Project description:The genome is partitioned into topologically associated domains and genomic compartments with shared chromatin valence. This architecture is constrained by the DNA polymer, which precludes interactions between genes on different chromosomes. Here we report a marked divergence from this pattern of nuclear organization that occurs in mouse olfactory sensory neurons. Chromatin conformation capture using in situ Hi-C on fluorescence-activated cell-sorted olfactory sensory neurons and their progenitors shows that olfactory receptor gene clusters from 18 chromosomes make specific and robust interchromosomal contacts that increase with differentiation of the cells. These contacts are orchestrated by intergenic olfactory receptor enhancers, the 'Greek islands', which first contribute to the formation of olfactory receptor compartments and then form a multi-chromosomal super-enhancer that associates with the single active olfactory receptor gene. The Greek-island-bound transcription factor LHX2 and adaptor protein LDB1 regulate the assembly and maintenance of olfactory receptor compartments, Greek island hubs and olfactory receptor transcription, providing mechanistic insights into and functional support for the role of trans interactions in gene expression.
Project description:The genome is partitioned into topologically associated domains and genomic compartments with shared chromatin valence. This architecture is constrained by the DNA polymer, which precludes interactions between genes on different chromosomes. Here we report a marked divergence from this pattern of nuclear organization that occurs in mouse olfactory sensory neurons. Chromatin conformation capture using in situ Hi-C on fluorescence-activated cell-sorted olfactory sensory neurons and their progenitors shows that olfactory receptor gene clusters from 18 chromosomes make specific and robust interchromosomal contacts that increase with differentiation of the cells. These contacts are orchestrated by intergenic olfactory receptor enhancers, the 'Greek islands', which first contribute to the formation of olfactory receptor compartments and then form a multi-chromosomal super-enhancer that associates with the single active olfactory receptor gene. The Greek-island-bound transcription factor LHX2 and adaptor protein LDB1 regulate the assembly and maintenance of olfactory receptor compartments, Greek island hubs and olfactory receptor transcription, providing mechanistic insights into and functional support for the role of trans interactions in gene expression.
Project description:The genome is partitioned into topologically associated domains and genomic compartments with shared chromatin valence. This architecture is constrained by the DNA polymer, which precludes interactions between genes on different chromosomes. Here we report a marked divergence from this pattern of nuclear organization that occurs in mouse olfactory sensory neurons. Chromatin conformation capture using in situ Hi-C on fluorescence-activated cell-sorted olfactory sensory neurons and their progenitors shows that olfactory receptor gene clusters from 18 chromosomes make specific and robust interchromosomal contacts that increase with differentiation of the cells. These contacts are orchestrated by intergenic olfactory receptor enhancers, the 'Greek islands', which first contribute to the formation of olfactory receptor compartments and then form a multi-chromosomal super-enhancer that associates with the single active olfactory receptor gene. The Greek-island-bound transcription factor LHX2 and adaptor protein LDB1 regulate the assembly and maintenance of olfactory receptor compartments, Greek island hubs and olfactory receptor transcription, providing mechanistic insights into and functional support for the role of trans interactions in gene expression.
Project description:The genome is partitioned into topologically associated domains and genomic compartments with shared chromatin valence. This architecture is constrained by the DNA polymer, which precludes interactions between genes on different chromosomes. Here we report a marked divergence from this pattern of nuclear organization that occurs in mouse olfactory sensory neurons. Chromatin conformation capture using in situ Hi-C on fluorescence-activated cell-sorted olfactory sensory neurons and their progenitors shows that olfactory receptor gene clusters from 18 chromosomes make specific and robust interchromosomal contacts that increase with differentiation of the cells. These contacts are orchestrated by intergenic olfactory receptor enhancers, the 'Greek islands', which first contribute to the formation of olfactory receptor compartments and then form a multi-chromosomal super-enhancer that associates with the single active olfactory receptor gene. The Greek-island-bound transcription factor LHX2 and adaptor protein LDB1 regulate the assembly and maintenance of olfactory receptor compartments, Greek island hubs and olfactory receptor transcription, providing mechanistic insights into and functional support for the role of trans interactions in gene expression.