The two vertebrate Gsk-3 isoforms, Gsk-3a and Gsk-3b, are encoded by distinct genetic loci and exhibit mostly redundant function in murine embryonic stem cells (ESCs). Here we report that deletion of both Gsk-3a and Gsk-3b in mouse ESCs results in significant changes in gene expression. In contrast, deletion of either Gsk-3a or Gsk-3b individually had little effect on gene expression. These data support the notion that Gsk-3 isoforms are functionally redundant in embryonic stem cells. In addition, we did not find the expected upregulation of known Wnt target genes. Our data suggests that Gsk-3-meidated regulation of gene expression in embryonic stem cells is complex, and likely involves affects on numerous signaling pathways.
No associated publication
Specimen part
View SamplesThe two vertebrate Gsk-3 isoforms, Gsk-3a and Gsk-3b, are encoded by distinct genetic loci and exhibit mostly redundant function in murine embryonic stem cells (ESCs). Here we report that deletion of both Gsk-3a and Gsk-3b in mouse ESCs results in misregulated expression of imprinted genes and hypomethylation of corresponding imprinted loci. Treatment of wild-type ESCs with small molecule inhibitors of Gsk-3 phenocopies the DNA hypomethylation of imprinted loci observed in Gsk-3 null ESCs. We provide evidence that DNA hypomethylation in Gsk-3 null ESCs is due to a reduction in the levels of the de novo DNA methyltransferase, Dnmt3a2.
Phosphatidylinositol 3-kinase (PI3K) signaling via glycogen synthase kinase-3 (Gsk-3) regulates DNA methylation of imprinted loci.
Specimen part
View SamplesPofut1 is an essential gene that glycosylates proteins containing EGF-like repeats, including Notch Receptors (NotchRs). Work in mice and in Drosophila has shown that O-fucosylation by Pofut1 is required for NotchR ligands to bind to and activate NotchRs. As such, Pofut1 deletion in skeletal myofibers allows for an analysis of potential functions and molecular changes of Pofut1 in skeletal muscle that derive from its expression in skeletal myofibers. In this study we compared gene expression profiles between quadriceps muscles in mice where Protein O-fucosyltransferase 1 (Pofut1) was deleted specifically in skeletal myofibers via use of a human skeletal alpha actin Cre transgene (Scre) and a loxP flanked Pofut1 gene (SCreFF) and mice which bore the only the Scre transgene but did not have floxed Pofut1 alleles (SCre++).
Deletion of <i>Pofut1</i> in Mouse Skeletal Myofibers Induces Muscle Aging-Related Phenotypes in <i>cis</i> and in <i>trans</i>.
Age, Specimen part
View SamplesReduced NotchR signaling has been implicated in the reduced division and differentiation of stem cells in a number of tissues. The Protein-O-fucosyltransferase 1 gene (Pofut1) encodes a glycosyltransferase that O-fucosylates EGF-repeat-containing proteins, including Notch Receptors (NotchRs), and absence of Pofut1 glycosylation on NotchRs inhibits ligand-induced NotchR signaling.
No associated publication
Age, Specimen part
View SamplesThe transcription co-factor FOG1 interacts with the chromatin remodeling complex NuRD to mediate gene activation and gene repression during hematopoiesis. We have generated mice with a targeted mutation in the endogenous Fog1 locus that results in an N-ternimal mutation in FOG1 that disrupts the interaction with NuRD.
Pleiotropic platelet defects in mice with disrupted FOG1-NuRD interaction.
Specimen part
View SamplesmicroRNA miR-144/451 is highly expressed during erythropoiesis. We deleted the miR-144/451 gene locus in mice and compared the transcriptomes of miR-144/451-null bone marrow erythroid precursors to stage-matched wild-type control cells.
miR-451 protects against erythroid oxidant stress by repressing 14-3-3zeta.
Specimen part
View SamplesPseudoautosomal regions (PAR1 and PAR2) in eutherians retain homologous regions between the X and Y chromosomes that play a critical role in the obligatory X-Y crossover during male meiosis. Genes that reside in the PAR1 are exceptional in that they are rich in repetitive sequences and undergo a very high rate of recombination. Remarkably, murine PAR1 homologs have translocated to various autosomes, reflecting the complex recombination history during the evolution of the mammalian X chromosome. We now report that the SNF2-type chromatin remodeling protein ATRX controls the expression of eutherians ancestral PAR1 genes that have translocated to autosomes in the mouse. In addition, we have identified two potentially novel mouse PAR1 orthologs. We propose that the ancestral PAR1 genes share a common epigenetic environment that allows ATRX to control their expression.
The SWI/SNF protein ATRX co-regulates pseudoautosomal genes that have translocated to autosomes in the mouse genome.
Sex
View SamplesInterferon is effective at inducing complete remissions in patients with Chronic Myelogenous Leukemia (CML), and evidence supports an immune mechanism. Here we show that the Type I Interferons (alpha and beta) regulate expression of the Interferon consensus sequence binding protein (ICSBP) in bcr-abl transformed cells and as shown previously for ICSBP, induce a vaccine-like immunoprotective effect in a murine model of bcr-abl induced leukemia. We identify the chemokines CCL6 and CCL9 as genes prominently induced by the Type I Interferons and ICSBP, and demonstrate that these immunomodulators are required for the immunoprotective effect of ICSBP expression. Insights into the role of these chemokines in the anti-leukemic response of interferons suggest new strategies for immunotherapy of CML.
ICSBP-mediated immune protection against BCR-ABL-induced leukemia requires the CCL6 and CCL9 chemokines.
No sample metadata fields
View SamplesGenomic technologies have unmasked molecularly distinct subgroups among tumors of the same histological type; but understanding the biologic basis of these subgroups has proved difficult since their defining alterations are often numerous, and the cellular origins of most cancers remain unknown. We sought to decipher complex genomic data sets by matching the genetic alterations contained within these, with candidate cells of origin, to generate accurate disease models. Using an integrated genomic analysis we first identified subgroups of human ependymoma: a form of neural tumor that arises throughout the central nervous system (CNS). Validated alterations included amplifications and homozygous deletions of genes not yet implicated in ependymoma. Matching the transcriptomes of human ependymoma subgroups to those of distinct types of mouse radial glia (RG)neural stem cells (NSCs) that we identified previously to be a candidate cell of origin of ependymoma - allowed us to select RG types most likely to represent cells of origin of disease subgroups. The transcriptome of human cerebral ependymomas that amplify EPHB2 and delete INK4A/ARF matched most closely that of embryonic cerebral Ink4a/Arf-/- RG: remarkably, activation of EphB2 signaling in this RG type, but not others, generated highly penetrant ependymomas that modeled accurately the histology and transcriptome of one human cerebral tumor subgroup (subgroup D). Further comparative genomic analysis revealed selective alterations in the copy number and expression of genes that regulate neural differentiation, particularly synaptogenesis, in both mouse and human subgroup D ependymomas; pinpointing this pathway as a previously unknown target of ependymoma tumorigenesis. Our data demonstrate the power of comparative genomics to sift complex genetic data sets to identify key molecular alterations in cancer subgroups.
Cross-species genomics matches driver mutations and cell compartments to model ependymoma.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A mouse model of the most aggressive subgroup of human medulloblastoma.
Specimen part
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