Microarrays of gene expression in mouse germinal center B cells photoactivated in the light zone or dark zone, and of nave cells for comparison.
Germinal center dynamics revealed by multiphoton microscopy with a photoactivatable fluorescent reporter.
Specimen part
View SamplesCell differentiation requires epigenetic modulation of tissue-specific genes and activities of master transcriptional regulators, which are recognized for their dominant control over cellular programs. Using novel epigenomic methods, we characterized enhancer elements specifically modified in differentiating intestinal epithelial cells and found enrichment of transcription factor-binding motifs corresponding to CDX2, a master regulator of the intestine. Directed investigation revealed surprising lability in CDX2 occupancy of the genome, with redistribution from hundreds of sites occupied only in progenitors to thousands of new sites in mature cells. Knockout mice confirmed distinct Cdx2 requirements in dividing and differentiated adult intestinal cells, including responsibility for the active enhancer configuration associated with maturity. Dynamic CDX2 occupancy corresponds with condition-specific gene expression and, importantly, to differential co-occupancy with other tissue-restricted transcription factors: HNF4A in mature cells and GATA6 in progenitors. These results reveal dynamic, context-specific functions and mechanisms of a master transcription factor within a cell lineage.
Differentiation-specific histone modifications reveal dynamic chromatin interactions and partners for the intestinal transcription factor CDX2.
Specimen part, Cell line
View SamplesComparison of Mpl-/- mouse LSK cells, either treated with control (GFP) or Mpl lentivirus. Lineage negative bone marrow cells were isolated and transduced and transplanted into Mpl-/- recipient mice. After transplantation and follow up mice were sacrificed and LSK (lineage negative, Sca-1 positive, cKit positive) cells were isolated by FACS. RNA was isolated using RNeasy Micro Kit (Qiagen GmbH, Hilden, Germany) and RNA was amplified for microarray hybridization using the Nugen Ovation system (Nugen Technologies, AC Bemmel, Netherlands). The resulting material was hybridized to Affymetrix Mouse 430 2.0 arrays. RMA normalization and summarization was performed in R 2.10 using Bioconductor packages. The aim was to show the normalization of Mpl associated gene expression.
Lentiviral gene transfer regenerates hematopoietic stem cells in a mouse model for Mpl-deficient aplastic anemia.
Specimen part
View SamplesThe four transcription factors Oct4, Sox2, Klf4, and c-Myc can induce pluripotency in mouse and human fibroblasts. We previously described direct reprogramming of adult mouse neural stem cells (NSCs) by Oct4 and either Klf4 or c-Myc. NSCs endogenously express Sox2, c-Myc, and Klf4 as well as several intermediate reprogramming markers. Here we report that exogenous expression of the germline-specific transcription factor Oct4 is sufficient to generate pluripotent stem cells from adult mouse NSCs. These one-factor induced pluripotent stem (1F iPS) cells are similar to embryonic stem cells in vitro and in vivo. Not only can these cells be efficiently differentiated into NSCs, cardiomyocytes and germ cells in vitro, but they are also capable of teratoma formation and germline transmission in vivo. Our results demonstrate that Oct4 is required and sufficient to directly reprogram NSCs to pluripotency.
Oct4-induced pluripotency in adult neural stem cells.
No sample metadata fields
View SamplesWe examined the transcriptional function of cyclin D1 in mouse development using two approaches. First, we queried association of cyclin D1 with the genome of E14.5 mouse embryos using ChIP-on-chip approach. We observed binding of cyclin D1 to several promoter regions. Second, we compared gene expression profiles between wild-type and cyclin D1-null retinas. We observed several transcripts with altered levels in cyclin D1-null organs.
Transcriptional role of cyclin D1 in development revealed by a genetic-proteomic screen.
No sample metadata fields
View SamplesCyclin D1 belongs to the core cell cycle machinery1, and it is frequently overexpressed in human cancers2. The full repertoire of cyclin D1 functions in normal development and in cancer cells is currently unknown. To address this question, here we introduce a novel approach that allows one to determine the set of cyclin D1-interacting proteins (D1 interactome) and cyclin D1-bound genomic fragments (D1 cistrome) in essentially any mouse organ, at any point of development or at any stage of cancer progression. Using this approach, we detected several novel tissue-specific interactors of cyclin D1. A significant number of these partners represent proteins involved in transcription. We show, using genome-wide location analysis3, that cyclin D1 occupies promoters of a very large number of genes in the developing mouse, where it binds in close proximity to transcription start sites. Bioinformatics analyses of cyclin D1-bound genomic segments in the developing embryo revealed DNA recognition sequences for several transcription factors. By querying SAGE libraries4, promoter CpG content5 and gene expression profiles of cyclin D1-null organs, we demonstrate that cyclin D1 binds promoters of highly expressed genes, and that it functions to activate or to repress gene expression in vivo. Analyses of cyclin D1 transcriptional targets reveal that cyclin D1 contributes to cell proliferation by upregulating genes required for S-phase entry and progression. Hence, cyclin D1 plays a broad transcriptional regulatory function in vivo during normal mouse development.
Transcriptional role of cyclin D1 in development revealed by a genetic-proteomic screen.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Combined targeting of JAK2 and Bcl-2/Bcl-xL to cure mutant JAK2-driven malignancies and overcome acquired resistance to JAK2 inhibitors.
Specimen part, Disease, Disease stage
View SamplesAffymetrix Human Gene 1.1 ST Array profiling of 285 primary medulloblastoma samples.
Subgroup-specific structural variation across 1,000 medulloblastoma genomes.
Sex, Age
View Samples