Geminin represses mesendoderm cell fate acquisition in embryoid bodies
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE39676 | GEO | 2014/07/01
SECONDARY ACCESSION(S): PRJNA171385
REPOSITORIES: GEO
Similar Datasets
Project description:Geminin is a small nucleoprotein that neuralizes ectoderm in the Xenopus embryo. Geminin promotes neural fate acquisition of mouse embryonic stem cells: Geminin knockdown during neural fate acquisition decreased expression of neural precursor cell markers (Pax6, Sox1), while increasing expression of Pitx2, Lefty1 and Cited2, genes involved in formation of the mouse node. Here we differentiated mouse embryonic stem cells into embryoid bodies to study Geminin's ability to repress primitive streak mesendoderm fate acquisition. We used microarrays to define the sets of genes that are regulated by Geminin during cell fate acquisition in embryoid bodies, using Dox-inducible Geminin knockdown or overexpression mouse embryonic stem cell lines. ES cell lines for Geminin over-expression (GemOE) were treated without or with Dox from day 3 to day 5 of EB differentiation and were collected on days 4 or 5 for microarray analysis. Gem knockdown (KD) ES cell lines were treated without or with Dox from day 0 to day 4 of EB differentiation and were collected on day 4 for microarray analysis.
2014-07-01 | E-GEOD-39676 | biostudies-arrayexpress
Project description:Formation of the complex vertebrate nervous system begins when pluripotent cells of the early embryo are directed to acquire a neural fate. Although cell intrinsic controls play an important role in this process, the molecular nature of this regulation is not well defined. Here we assessed the role for Geminin, a nuclear protein expressed in embryonic cells, in neural fate acquisition from mouse embryonic stem (ES) cells. While Geminin knockdown does not affect the ability of ES cells to maintain or exit pluripotency, we found that it significantly impairs their ability to acquire a neural fate. Conversely, Geminin overexpression promotes neural gene expression, even in the presence of growth factor signaling that antagonizes neural transcriptional responses. These data demonstrate that Geminin’s activity contributes to mammalian neural cell fate acquisition. We investigated the mechanistic basis of this phenomenon and found that Geminin maintains a hyperacetylated and open chromatin conformation at neural genes. Interestingly, recombinant Geminin protein also rapidly alters chromatin acetylation and accessibility even when Geminin is combined with nuclear extract and chromatin in vitro. These findings define a novel activity for Geminin in regulation of chromatin structure. Together, these data support a role for Geminin as a cell intrinsic regulator of neural fate acquisition that promotes expression of neural genes by regulating chromatin accessibility and histone acetylation. Mouse embryonic stem cells were differentiated for two days in N2B27 medium, with or without Doxycycline-inducible shRNAmir knockdown of Geminin and compared by microarray. Three independent experiments were conducted, using two different mouse embryonic stem cell lines for Doxycycline-inducible knockdown of Geminin. The two ES lines express unique shRNAmir sequences targeting Geminin (shRNAmir #9 and #11) to control for off-target effects.
2011-03-18 | E-GEOD-25737 | biostudies-arrayexpress
Project description:The nucleoprotein Geminin (Gmnn) promotes neural cell fate acquisition of embryonic stem cells, while knockdown reduces the efficiency of neural gene activation. This occurs, at least in part, through Geminin’s ability to promote histone hyperacetylation at neural genes, to activate their expression. In mouse models in vivo, Geminin deficiency in the embryonic neural tube between embryonic days 8.5-10.5 also reduces the expression of genes controlling neural specification and/or differentiation, contributing to neural tube defects. To determine where Geminin binding and Gmnn-dependent acetylation occurs throughout the genome, we performed ChIP-chip analysis (these data) and ChIP-seq analysis (GSE77246) to define Geminin-bound chromatin locations in mouse embryonic stem cells (ESCs) and in ESC-derived neuroectoderm. We also performed ChIP-chip analysis of H3K9 acetylation in ESC-derived neuroectoderm, with or without Doxycycline-dependent Gmnn knockdown, to define the requirements for Geminin activity for histone acetylation of promoters during neural fate specification.
2016-12-01 | GSE81450 | GEO
Project description:Formation of the complex vertebrate nervous system begins when pluripotent cells of the early embryo are directed to acquire a neural fate. Although cell intrinsic controls play an important role in this process, the molecular nature of this regulation is not well defined. Here we assessed the role for Geminin, a nuclear protein expressed in embryonic cells, in neural fate acquisition from mouse embryonic stem (ES) cells. While Geminin knockdown does not affect the ability of ES cells to maintain or exit pluripotency, we found that it significantly impairs their ability to acquire a neural fate. Conversely, Geminin overexpression promotes neural gene expression, even in the presence of growth factor signaling that antagonizes neural transcriptional responses. These data demonstrate that Geminin’s activity contributes to mammalian neural cell fate acquisition. We investigated the mechanistic basis of this phenomenon and found that Geminin maintains a hyperacetylated and open chromatin conformation at neural genes. Interestingly, recombinant Geminin protein also rapidly alters chromatin acetylation and accessibility even when Geminin is combined with nuclear extract and chromatin in vitro. These findings define a novel activity for Geminin in regulation of chromatin structure. Together, these data support a role for Geminin as a cell intrinsic regulator of neural fate acquisition that promotes expression of neural genes by regulating chromatin accessibility and histone acetylation.
2011-03-18 | GSE25737 | GEO
Project description:Geminin represses mesendoderm cell fate acquisition in embryoid bodies
| PRJNA171385 | ENA
Project description:Cell intrinsic factors that control neuroectoderm specification of early embryonic cells include the nucleoprotein Geminin (Gmnn) and the Zic family of zinc finger transcription factors. Gmnn modulates chromatin state to activate neural gene expression during neural cell fate acquisition, while Gmnn deficiency in the forming neural plate disrupts transcriptional programs that control neural cell specification, neural plate patterning and neurogenesis, resulting in neural tube defects. Likewise, Zic1 over-expression promotes neural gene expression, while heterozygous deletion of Zic1/4 leads to Dandy-Walker malformation, the most common congenital cerebellar malformation. During embryonic development, Geminin and Zic1 expression is enriched in neuroectoderm from gastrula stages, with broad expression in the forming CNS during post-gastrula stages, when neural tube closure and neurogenesis are initiated. To gain a greater understanding of the molecular events that regulate neural cell specification, here we used ChIP-seq to define genome-wide chromatin binding profiles for Gmnn in embryonic stem cells (ESCs) and for Gmnn and Zic1 during specification of ESCs into neuroectoderm.
2016-12-01 | GSE77246 | GEO
Project description:Geminin-regulated genes during neural fate acquisition of mouse embryonic stem cells
| PRJNA134085 | ENA
Project description:Transcriptional targets of neurogenin (Ngnr1) were identified by over-expression of an inducible form of neurogenin in Xenopus ectodermal explants. The effects of co-expressing the nucleoprotein geminin on Ngnr1-dependent target gene transactivation were defined. Regulating the transition from lineage-restricted progenitors to terminally differentiated cells is a central aspect of nervous system development. Here, we investigated the role of the nucleoprotein geminin in regulating neurogenesis at a mechanistic level during both Xenopus primary neurogenesis and mammalian neuronal differentiation in vitro. The latter work utilized both neural cells derived from embryonic stem and embryonal carcinoma cells in vitro and neural stem cells from mouse forebrain. In all of these contexts, geminin antagonized the ability of neural bHLH transcription factors to activate transcriptional programs promoting neurogenesis. Furthermore, geminin promoted a bivalent chromatin state, characterized by the presence of both activating and repressive histone modifications, at genes encoding transcription factors that promote neurogenesis. This epigenetic state restrains the expression of genes that regulate commitment of undifferentiated stem and neuronal precursor cells to neuronal lineages. Geminin is highly expressed in undifferentiated neuronal precursor cells but is downregulated prior to differentiation. Therefore, these data support a model whereby geminin promotes the neuronal precursor cell state by modulating both the epigenetic status and expression of genes encoding neurogenesis-promoting factors. Additional developmental signals acting in these cells can then control their transition toward terminal neuronal or glial differentiation during mammalian neurogenesis. A dexamethasone-inducible (GR ligand binding domain fused) form of Xenopus neurogenin-related 1, NgnrGR, was over-expressed in Xenopus embryonic ectodermal explants, in the presence or absence of over-expressed geminin. Induction of Ngnr1 activity was used to define direct targets as previously described (EMBO J. 26(24): 5093-5108). The ability of geminin to suppress Ngnr1-dependent transactivation of its target gene programs was determined.
2012-12-06 | E-GEOD-39658 | biostudies-arrayexpress
Project description:Regulating the transition from lineage-restricted progenitors to terminally differentiated cells is a central aspect of nervous system development. Here, we investigated the role of the nucleoprotein Geminin in regulating neurogenesis at a mechanistic level during both Xenopus primary neurogenesis and mammalian neuronal differentiation in vitro. The latter work utilized both neural cells derived from embryonic stem and embryonal carcinoma cells in vitro and neural stem cells from mouse forebrain. In all of these contexts, Geminin antagonized the ability of neural bHLH transcription factors to activate transcriptional programs promoting neurogenesis. Furthermore, Geminin promoted a bivalent chromatin state, characterized by the presence of both activating and repressive histone modifications, at genes encoding transcription factors that promote neurogenesis. This epigenetic state restrains the expression of genes that regulate commitment of undifferentiated stem and neuronal precursor cells to neuronal lineages. Geminin is highly expressed in undifferentiated neuronal precursor cells but is downregulated prior to differentiation. Therefore, these data support a model whereby Geminin promotes the neuronal precursor cell state by modulating both the epigenetic status and expression of genes encoding neurogenesis-promoting factors. Additional developmental signals acting in these cells can then control their transition toward terminal neuronal or glial differentiation during mammalian neurogenesis. A mouse embryonic stem (ES) cell line for inducible knockdown of the small nucleoprotein Geminin was utilized. ES cells were used to generate neural precursor cells by monolayer culture in N2B27 media for 5 days, and doxycycline-inducible knockdown of Geminin was performed from day 3. Changes in gene expression resulting from Geminin knockdown were assessed by RNA sequencing. Three experimental replicates were generated for Geminin knockdown (plus Dox) with a corresponding no-Dox control. These were subjected to sequencing, and data were analyzed using TopHat and Cufflinks/Cuffdiff. Transcripts were considered as differentially expressed upon Gem knockdown if data met statistical significance cutoffs in Cuffdiff (sufficient sequence alignments were obtained for analysis and transcript had significant change in FPKM value (normalized transcript abundance; fragments per kb of exon per million fragments mapped) between the no Dox and plus Dox sample pairs) in at least two of the three replicates.
2012-12-06 | E-GEOD-39657 | biostudies-arrayexpress
Project description:Geminin cooperates with Polycomb to restrain multi-lineage commitment in the early embryo: Transient maintenance of a pluripotent embryonic cell population followed by the onset of multi-lineage commitment is a fundamental aspect of development. However, molecular regulation of this transition is not well characterized in vivo. Here we demonstrate that the nuclear protein Geminin is required to restrain commitment and spatially restrict mesoderm, endoderm, and non-neural ectoderm to their proper locations in the Xenopus embryo. We used microarray analyses to demonstrate that Geminin overexpression represses many genes associated with cell commitment and differentiation, while elevating expression levels of genes that maintain pluripotent early and immature neurectodermal cell states. We characterized Geminin’s relationship to cell signaling and found that Geminin broadly represses Activin-, FGF-, and BMP-mediated cell commitment. Conversely, Geminin knockdown enhances commitment responses to growth factor signaling and causes ectopic mesodermal, endodermal, and epidermal fate commitment in the embryo. We also characterized Geminin’s functional relationship with transcription factors that had similar activities and found that Geminin represses commitment independent of Oct4 ortholog (Oct25/60) activities, but depends upon intact Polycomb repressor function. Consistent with this, chromatin immunoprecipitation assays directed at mesodermal genes demonstrate that Geminin promotes Polycomb binding and Polycomb-mediated repressive histone modifications, while inhibiting modifications associated with gene activation. This work defines Geminin as an essential regulator of the embryonic transition from pluripotency through early multi-lineage commitment, and demonstrates that functional cooperativity between Geminin and Polycomb contributes to this process.
2010-12-06 | GSE25158 | GEO