Mammalian genomes contain numerous DNA elements with potential transcription regulatory function but unknown target genes. We used transgenic, gain-of-function mice with an ectopic copy of the beta-globin locus control region (LCR) to better understand how regulatory elements dynamically search the genome for target genes. We find that the LCR samples a restricted nuclear sub-volume in which it forms preferential contacts with genes controlled by shared transcription factors. One contacted gene, betah1, located on another chromosome, is upregulated, providing genetic demonstration that mammalian enhancers can function between chromosomes. Upregulation is not pan-cellular but confined to selected jackpot cells significantly enriched for inter-chromosomal LCR-betah1 interactions. This implies that long-range DNA contacts are relatively stable and cell-specific and, when functional, cause variegated expression. We refer to this as spatial effect variegation (SEV). The data provide a dynamic and mechanistic framework for enhancer action, important for assigning function to the one- and three-dimensional structure of DNA.
Variegated gene expression caused by cell-specific long-range DNA interactions.
Specimen part, Disease
View SamplesIsoniazid induced varying degrees of hepatic steatosis in an inbred strain Mouse Diversity Panel (MDP) study. RNA was isolated from all animals for analysis of gene expression changes in the liver. The objective of this study was to identify gene expression changes that drive isoniazid-induced steatosis.
A systems biology approach utilizing a mouse diversity panel identifies genetic differences influencing isoniazid-induced microvesicular steatosis.
Sex, Specimen part, Treatment
View SamplesFetal and adult -globin gene expression is tightly regulated during human development. Fetal globin genes are transcriptionally silenced during embryogenesis through the process of hemoglobin switching. Efforts to understand the transcriptional mechanism(s) behind fetal globin silencing have led to novel strategies to derepress fetal globin expression in the adult, which could alleviate symptoms in hereditary b-globin disorders including sickle cell disease (SCD) and -thalassemia. We identified a novel zinc finger protein, pogo transposable element with zinc finger domain (Pogz), expressed in mouse and human hematopoietic stem and progenitor cells, which represses embryonic b-like globin gene expression in mice. Ablation of Pogz expression in adult hematopoietic cells in vivo results in persistence of embryonic b-like globin expression without significantly affecting erythroid development or mouse survival. Elevated embryonic -like globin expression correlates with reduced expression of Bcl11a, a known repressor of embryonic -like globin expression, in Pogz-/- fetal liver cells. Pogz binds to the Bcl11a promoter, and, to erythroid specific intragenic regulatory regions. Importantly, Pogz+/- mice develop normally, but show elevated embryonic b-like globin expression in peripheral blood cells, demonstrating that reducing Pogz levels results in persistence of embryonic b-like globin expression. Finally, knockdown of POGZ in primary human CD34+ hematopoietic stem and progenitor cell derived erythroblasts, reduces BCL11A expression and increases fetal hemoglobin expression. These findings are significant since new therapeutic targets and strategies are needed to treat the increasing global burden of b-globin disorders.
POGZ Is Required for Silencing Mouse Embryonic β-like Hemoglobin and Human Fetal Hemoglobin Expression.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Induction and transcriptional regulation of the co-inhibitory gene module in T cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
IRF-8 extinguishes neutrophil production and promotes dendritic cell lineage commitment in both myeloid and lymphoid mouse progenitors.
Specimen part
View SamplesWhile most blood lineages are assumed to mature through a single cellular and developmental route downstream of hematopoietic stem cells (HSCs), dendritic cells (DCs) can be derived from both myeloid and lymphoid progenitors in vivo. To determine how distinct progenitors can generate similar downstream lineages, we examined the transcriptional changes that accompany loss of in vivo myeloid potential as common myeloid progenitors (CMPs) differentiate into common dendritic cell progenitors (CDPs), and as lymphoid-primed multipotent progenitors (LMPPs) differentiate into all lymphoid progenitors (ALPs). Microarray studies revealed that Interferon regulatory factor 8 (IRF-8) expression increased during each of these transitions. Competitive reconstitutions using Irf8-/- bone marrow demonstrated cell-intrinsic defects in the formation of CDPs and all splenic dendritic cell subsets. Irf8-/- CMPs and, unexpectedly, Irf8-/- ALPs produced more neutrophils in vivo than their wild type counterparts at the expense of DCs. Retroviral expression of IRF-8 in multiple progenitors led to reduced neutrophil production and increased numbers of DCs, even in the granulocyte-macrophage progenitor (GMP), which does not normally possess conventional DC potential. These data suggest that IRF-8 represses a neutrophil module of development and promotes convergent DC development from multiple lymphoid and myeloid progenitors autonomously of cellular context.
IRF-8 extinguishes neutrophil production and promotes dendritic cell lineage commitment in both myeloid and lymphoid mouse progenitors.
Specimen part
View SamplesProductive rearrangement of the immunoglobulin heavy chain locus triggers a major developmental checkpoint that promotes limited clonal expansion of pre-B cells, culminating in cell cycle arrest and rearrangement of the kappa () or lambda () light-chain loci. B lineage cells lacking the related transcription factors IRF-4 and IRF-8 undergo a developmental arrest at the cycling pre-B cell stage and are blocked for light-chain recombination. Using Irf-4,8-/- pre-B cells we demonstrate that two pathways converge to synergistically drive light-chain rearrangement, a process that is not simply activated by cell cycle exit. One pathway is directly dependent on IRF-4, whose expression is elevated by pre-BCR signaling. IRF-4 targets the 3 and enhancers to increase locus accessibility and positions a kappa allele away from pericentromeric heterochromatin. The other pathway is triggered by attenuation of IL-7 signaling and results in activation of the intronic enhancer via binding of the transcription factor, E2A. Intriguingly, IRF-4 regulates the expression of CXCR4 and promotes the migration of pre-B cells in response to the chemokine CXCL12. We propose that IRF-4 coordinates the two pathways regulating light-chain recombination by positioning pre-B cells away from IL-7 expressing stromal cells.
Regulation of immunoglobulin light-chain recombination by the transcription factor IRF-4 and the attenuation of interleukin-7 signaling.
No sample metadata fields
View SamplesWe used a novel probe-level microarray analysis, revealing connections between mRNA processing and lymphoid neoplasia, in a mouse leukemia model. Characteristic differences in mRNA processing, primarily in the 3-untranslated region, distinguished histologically similar tumor subtypes with different survival characteristics. Gene sets with specific processing in each tumor subtype defined signatures useful for tumor subclassification, as demonstrated by internal cross-validation with up to 80% discrimination accuracy. A combination of mRNA expression and sequence analysis suggested that differences in isoform abundance likely arose from both alternative polyadenylation and differential degradation.
Global changes in processing of mRNA 3' untranslated regions characterize clinically distinct cancer subtypes.
Specimen part
View SamplesThis study was designed to define erythropoietin (EPO) regulated genes in murine bone marrow erythroid progenitor cells at two stages of development, designated E1, and E2. E1 cells correspond to CFUe- like progenitors, while E2 cells are proerythroblasts.
Defining an EPOR- regulated transcriptome for primary progenitors, including Tnfr-sf13c as a novel mediator of EPO- dependent erythroblast formation.
Sex, Specimen part, Treatment
View SamplesTwo T7 based methods One round of Amplification (Affymetrix) and Two round of Amplification were compared to two Ribo-SPIA based systems, RiboSPIA and pico Ribo SPIA systems. Data for Pico-RiboSPIA are listed here.
Microarray-based comparison of three amplification methods for nanogram amounts of total RNA.
No sample metadata fields
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