scholarly journals DPPA2 and DPPA4 are necessary to establish a totipotent state in mouse embryonic stem cells

2018 ◽  
Author(s):  
Alberto De Iaco ◽  
Alexandre Coudray ◽  
Julien Duc ◽  
Didier Trono
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Chromatin Accessibility ◽  
Early Embryo ◽  
Zygotic Genome Activation ◽  
Cell Stage ◽  
Oocyte Expression ◽  
Genome Activation ◽  
Zygotic Genome

AbstractAfter fertilization of the transcriptionally silent oocyte, expression from both parental chromosomes is launched through so-called zygotic genome activation (ZGA), occurring in the mouse at the 2-cell stage. Amongst the first elements to be transcribed are the Dux gene, the product of which secondarily induces a wide array of ZGA genes, and a subset of evolutionary recent LINE-1 retrotransposons, which regulate chromatin accessibility in the early embryo. The maternally-inherited factors that activate Dux and LINE-1 transcription have so far remained unknown. Here we identify the paralog proteins DPPA2 and DPPA4 as responsible for this process.

scholarly journals DPPA2 and DPPA4 are dispensable for mouse zygotic genome activation and preimplantation development

2021 ◽  
Author(s):  
Zhiyuan Chen ◽  
Zhenfei Xie ◽  
Yi Zhang
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Preimplantation Development ◽  
Dependent Manner ◽  
Maternal Factors ◽  
Zygotic Genome Activation ◽  
Cell Embryo ◽  
Genome Activation ◽  
Zygotic Genome

How maternal factors in oocytes initiate zygotic genome activation (ZGA) remains elusive. Recent studies indicate that DPPA2 and DPPA4 are required for establishing a 2-cell embryo-like (2C-like) state in mouse embryonic stem cells (ESCs) in a DUX-dependent manner. These results suggest that DPPA2 and DPPA4 are essential maternal factors that regulate Dux and ZGA in embryos. By analyzing maternal knockout and maternal-zygotic knockout embryos, we unexpectedly found that Dux activation, ZGA, and preimplantation development are normal in embryos without DPPA2 or DPPA4. Thus, unlike in ESCs/2C-like cells, DPPA2 and DPPA4 are dispensable for ZGA and preimplantation development.

scholarly journals CHD7 promotes neural progenitor differentiation in embryonic stem cells via altered chromatin accessibility and nascent gene expression

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hui Yao ◽  
Douglas F. Hannum ◽  
Yiwen Zhai ◽  
Sophie F. Hill ◽  
Ricardo D.’Oliveira Albanus ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Chromatin Remodeling ◽  
Embryonic Stem ◽  
Neural Progenitor ◽  
Chromatin Accessibility ◽  
Nervous System Development ◽  
Conditional Knockout ◽  
Glial Differentiation ◽  
Cell Stage

Abstract CHARGE syndrome, a rare multiple congenital anomaly condition, is caused by haploinsufficiency of the chromatin remodeling protein gene CHD7 (Chromodomain helicase DNA binding protein 7). Brain abnormalities and intellectual disability are commonly observed in individuals with CHARGE, and neuronal differentiation is reduced in CHARGE patient-derived iPSCs and conditional knockout mouse brains. However, the mechanisms of CHD7 function in nervous system development are not well understood. In this study, we asked whether CHD7 promotes gene transcription in neural progenitor cells via changes in chromatin accessibility. We used Chd7 null embryonic stem cells (ESCs) derived from Chd7 mutant mouse blastocysts as a tool to investigate roles of CHD7 in neuronal and glial differentiation. Loss of Chd7 significantly reduced neuronal and glial differentiation. Sholl analysis showed that loss of Chd7 impaired neuronal complexity and neurite length in differentiated neurons. Genome-wide studies demonstrated that loss of Chd7 leads to modified chromatin accessibility (ATAC-seq) and differential nascent expression (Bru-Seq) of neural-specific genes. These results suggest that CHD7 acts preferentially to alter chromatin accessibility of key genes during the transition of NPCs to neurons to promote differentiation. Our results form a basis for understanding the cell stage-specific roles for CHD7-mediated chromatin remodeling during cell lineage acquisition.

scholarly journals Maternal Dppa2 and Dppa4 are dispensable for zygotic genome activation but important for offspring survival

Development ◽  
2021 ◽  
Vol 148 (24) ◽  
Author(s):  
Oana Kubinyecz ◽  
Fatima Santos ◽  
Deborah Drage ◽  
Wolf Reik ◽  
Melanie A. Eckersley-Maslin
Keyword(s):  
Null Allele ◽  
Embryonic Stem ◽  
Offspring Survival ◽  
Zygotic Genome Activation ◽  
Molecular Events ◽  
Genome Activation ◽  
Mitotic Chromatin ◽  
Zygotic Genome

ABSTRACT Zygotic genome activation (ZGA) represents the initiation of transcription following fertilisation. Despite its importance, we know little of the molecular events that initiate mammalian ZGA in vivo. Recent in vitro studies in mouse embryonic stem cells have revealed developmental pluripotency associated 2 and 4 (Dppa2/4) as key regulators of ZGA-associated transcription. However, their roles in initiating ZGA in vivo remain unexplored. We reveal that Dppa2/4 proteins are present in the nucleus at all stages of preimplantation development and associate with mitotic chromatin. We generated conditional single and double maternal knockout mouse models to deplete maternal stores of Dppa2/4. Importantly, Dppa2/4 maternal knockout mice were fertile when mated with wild-type males. Immunofluorescence and transcriptome analyses of two-cell embryos revealed that, although ZGA took place, there were subtle defects in embryos that lacked maternal Dppa2/4. Strikingly, heterozygous offspring that inherited the null allele maternally had higher preweaning lethality than those that inherited the null allele paternally. Together, our results show that although Dppa2/4 are dispensable for ZGA transcription, maternal stores have an important role in offspring survival, potentially via epigenetic priming of developmental genes.

Expression of eukaryotic elongation initiation factor 1A differentially marks zygotic genome activation in biparental and parthenogenetic porcine embryos and correlates with in vitro developmental potential

2008 ◽  
Vol 20 (7) ◽  
pp. 818 ◽  
Author(s):  
Luca Magnani ◽  
Christine M. Johnson ◽  
Ryan A. Cabot
Keyword(s):  
Expression Profile ◽  
Initiation Factor ◽  
In Vitro Fertilisation ◽  
Zygotic Genome Activation ◽  
Cell Stage ◽  
Developmental Potential ◽  
Genome Activation ◽  
Parthenogenetic Embryos ◽  
Zygotic Genome

Zygotic genome activation (ZGA) is a major event during cleavage development. In vitro manipulation of mammalian embryos (including embryo culture) can result in developmental arrest around the time of ZGA. Eukaryotic elongation initiation factor 1A (eIF1A) has been used as a marker for ZGA in some mammalian species. We hypothesised expression of eIF1A can be used to assess ZGA in the pig; we also hypothesised that the expression profile of eIF1A can be used to assess developmental potential in vitro. The aims of the present study were to determine the expression pattern of eIF1A during porcine cleavage development and to assess its expression levels in embryos of different quality. We used a real-time reverse transcription–polymerase chain reaction assay to quantify eIF1A transcripts at different time points during cleavage development in porcine embryos produced by parthenogenetic activation (PA) and in vitro fertilisation (IVF). We found that eIF1A is activated at the two-cell stage in IVF embryos and at the four-cell stage in PA embryos. We showed that the increase in transcript levels observed in parthenogenetic embryos is dependent on de novo transcription. We found altered levels of eIF1A transcripts in parthenogenetic embryos that presented as either two- or eight-cell embryos 48 h after activation compared with four-cell embryos at the same time point. Our work supports the hypothesis that eIF1A is a marker of porcine ZGA and its expression profile can be used to assess embryo quality.

scholarly journals The miR-430 locus with extreme promoter density is a transcription body organizer, which facilitates long range regulation in zygotic genome activation

2021 ◽  
Author(s):  
Yavor Hadzhiev ◽  
Lucy Wheatley ◽  
Ledean Cooper ◽  
Federico Ansaloni ◽  
Celina Whalley ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Gene Cluster ◽  
Core Promoter ◽  
Single Copy ◽  
Early Embryo ◽  
Zygotic Genome Activation ◽  
Pol Ii ◽  
A Minor ◽  
Genome Activation ◽  
Zygotic Genome

In anamniote embryos the major wave of zygotic genome activation (ZGA) starts during the mid-blastula transition. This major wave of ZGA is facilitated by several mechanisms, including dilution of repressive maternal factors and accumulation of activating transcription factors during the fast cell division cycles preceding the mid-blastula transition. However, a set of genes escape global genome repression and are activated substantially earlier, during what is called, the minor wave of genome activation. While the mechanisms underlying the major wave of genome activation have been studied extensively, the minor wave of genome activation is little understood. In zebrafish the earliest expressed RNA polymerase II (Pol II) transcribed genes are activated in a pair of large transcription bodies depleted of chromatin, abundant in elongating Pol II and nascent RNAs (Hadzhiev et al., 2019; Hilbert et al., 2021). This transcription body includes the miR-430 gene cluster required for maternal mRNA clearance. Here we explored the genomic, chromatin organisation and cis-regulatory mechanisms of the minor wave of genome activation occurring in the transcription body. By long read genome sequencing we identified a remarkable cluster of miR-430 genes with over 300 promoters and spanning 0.6 Mb, which represent the highest promoter density of the genome. We demonstrate that the miR-430 gene cluster is required for the formation of the transcription body and acts as a transcription organiser for minor wave activation of a set of zinc finger genes scattered on the same chromosome arm, which share promoter features with the miR-430 cluster. These promoter features are shared among minor wave genes overall and include the TATA-box and sharp transcription start site profile. Single copy miR-430 promoter transgene reporter experiments indicate the importance of promoter-autonomous mechanisms regulating escape from global repression of the early embryo. These results together suggest that formation of the transcription body in the early embryo is the result of high promoter density coupled to a minor wave-specific core promoter code for transcribing key minor wave ZGA genes, which are required for the overhaul of the transcriptome during early embryonic development.

scholarly journals Genetic control of pluripotency epigenome determines differentiation bias in mouse embryonic stem cells

2021 ◽  
Author(s):  
Candice Byers ◽  
Catrina Spruce ◽  
Haley J. Fortin ◽  
Anne Czechanski ◽  
Steven C. Munger ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Cell Fate ◽  
Genetic Regulation ◽  
Embryonic Stem ◽  
Regulatory Elements ◽  
Chromatin Accessibility ◽  
Embryoid Bodies ◽  
Cell Fate Decisions

AbstractGenetically diverse pluripotent stem cells (PSCs) display varied, heritable responses to differentiation cues in the culture environment. By harnessing these disparities through derivation of embryonic stem cells (ESCs) from the BXD mouse genetic reference panel, along with C57BL/6J (B6) and DBA/2J (D2) parental strains, we demonstrate genetically determined biases in lineage commitment and identify major regulators of the pluripotency epigenome. Upon transition to formative pluripotency using epiblast-like cells (EpiLCs), B6 quickly dissolves naïve networks adopting gene expression modules indicative of neuroectoderm lineages; whereas D2 retains aspects of naïve pluripotency with little bias in differentiation. Genetic mapping identifies 6 major trans-acting loci co-regulating chromatin accessibility and gene expression in ESCs and EpiLCs, indicating a common regulatory system impacting cell state transition. These loci distally modulate occupancy of pluripotency factors, including TRIM28, P300, and POU5F1, at hundreds of regulatory elements. One trans-acting locus on Chr 12 primarily impacts chromatin accessibility in ESCs; while in EpiLCs the same locus subsequently influences gene expression, suggesting early chromatin priming. Consequently, the distal gene targets of this locus are enriched for neurogenesis genes and were more highly expressed when cells carried B6 haplotypes at this Chr 12 locus, supporting genetic regulation of biases in cell fate. Spontaneous formation of embryoid bodies validated this with B6 showing a propensity towards neuroectoderm differentiation and D2 towards definitive endoderm, confirming the fundamental importance of genetic variation influencing cell fate decisions.

Exchanges of histone methylation and variants during mouse zygotic genome activation

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Mingtian Deng ◽  
Baobao Chen ◽  
Zifei Liu ◽  
Yu Cai ◽  
Yongjie Wan ◽  
...  
Keyword(s):  
Histone Methylation ◽  
Histone Variants ◽  
Chromatin Accessibility ◽  
Mouse Embryos ◽  
Zygotic Genome Activation ◽  
Male And Female ◽  
Histone 3 ◽  
Female Pronucleus ◽  
Genome Activation ◽  
Zygotic Genome

SummaryMinor and major zygotic genome activation (ZGA) are crucial for preimplantation development. During this process, histone variants and methylation influence chromatin accessibility and consequently regulated the expression of zygotic genes. However, the detailed exchanges of these modifications during ZGA remain to be determined. In the present study, the epigenetic modifications of histone 3 on lysine 9 (H3K9), 27 (H3K27) and 36 (H3K36), as well as four histone variants were determined during minor and major ZGA and in post-ZGA stages of mouse embryos. Firstly, microH2A1, H3K27me3 and H3K36me3 were asymmetrically stained in the female pronucleus during minor ZGA but lost staining in major ZGA. Secondly, H3K9me2 and H3K9me3 were strongly stained in the female pronucleus, but weakly stained in the male pronucleus and disappeared after ZGA. Thirdly, H2A.Z and H3.3 were symmetrically stained in male and female pronuclei during minor ZGA. Moreover, H3K27me2 was not statistically changed during mouse early development, while H3K36me2 was only detected in 2- and 4-cell embryos. In conclusion, our data revealed dynamics of histone methylation and variants during mice ZGA and provided details of their exchange in mice embryogenesis. Moreover, we further inferred that macroH2A1, H2A.Z, H3K9me2/3 and H3K27me2/3 may play crucial roles during mouse ZGA.

scholarly journals Pleomorphic Adenoma Gene 1 Is Needed For Timely Zygotic Genome Activation and Early Embryo Development

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elo Madissoon ◽  
Anastasios Damdimopoulos ◽  
Shintaro Katayama ◽  
Kaarel Krjutškov ◽  
Elisabet Einarsdottir ◽  
...  
Keyword(s):  
Pleomorphic Adenoma ◽  
Embryo Development ◽  
Early Embryo ◽  
Zygotic Genome Activation ◽  
Early Embryo Development ◽  
Genome Activation ◽  
Zygotic Genome

scholarly journals Multi-omics analysis of chromatin accessibility and interactions with transcriptome by HiCAR

2020 ◽  
Author(s):  
Xiaolin Wei ◽  
Yu Xiang ◽  
Ruocheng Shan ◽  
Derek T Peters ◽  
Tongyu Sun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Long Range ◽  
Spatial Interaction ◽  
Embryonic Stem ◽  
Cost Effective ◽  
Chromatin Accessibility ◽  
Open Chromatin ◽  
Low Input ◽  
Chromatin Interactions

The long-range interactions of cis-regulatory elements (cREs) play a central role in regulating the spatial-temporal gene expression program of multi-cellular organism. cREs are characterized by the presence of accessible (or open) chromatin, which can be identified at genome-wide scale with assays such as ATAC-seq, DHS-seq, and FAIRE-seq. However, it remains technically challenging to comprehensively identify the long-range physical interactions that occur between cREs, especially in a cost effective manner using low-input samples. Here, we report HiCAR (High-throughput Chromosome conformation capture on Accessible DNA with mRNA-seq co-assay), a method that enables simultaneous assessment of cis-regulatory chromatin interactions and chromatin accessibility, as well as evaluation of the transcriptome, which represents the functional output of chromatin structure and accessibility. Unlike immunoprecipitation-based methods such as HiChIP, PLAC-seq, and ChIA-PET, HiCAR does not require target-specific antibodies and thus can comprehensively capture the cis-regulatory chromatin contacts anchored at accessible regulatory DNA regions and associated with diverse epigenetic modifications and transcription factor binding. Compared to Trac-looping, another method designed to capture interactions between accessible chromatin regions, HiCAR produced a 17-fold greater yield of informative long-range cis- reads at a similar sequencing depth and required 1,000-fold fewer cells as input. Applying HiCAR to H1 human embryonic stem cells (hESCs) revealed 46,792 cis-regulatory chromatin interactions at 5kb resolution. Interestingly, we found that epigenetically poised, bivalent, and repressed cREs exhibit comparable spatial interaction activity to those transcriptionally activated cREs. Using machine learning approaches, we predicated 22 epigenome features that are potentially important for the spatial interaction activity of cREs in H1 hESC. Lastly, we also identified long-range cis-regulatory chromatin interactions in GM12878 and mouse embryonic stem cells with HiCAR. Our results demonstrate that HiCAR is a robust and cost-effective multi-omics assay, which is broadly applicable for simultaneous analysis of genome architecture, chromatin accessibility, and the transcriptome using low-input samples.

Analysis of ferrochelatase expression during hematopoietic development of embryonic stem cells

Blood ◽  
2000 ◽  
Vol 95 (11) ◽  
pp. 3568-3577
Author(s):  
Scott T. Magness ◽  
Antonio Tugores ◽  
David A. Brenner
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Translational Control ◽  
Fluorescent Protein ◽  
Embryonic Stem ◽  
Erythroid Cell ◽  
Egfp Expression ◽  
Cell Stage ◽  
Cis Element

Ferrochelatase, the last enzyme in the heme pathway, chelates protoporphyrin IX and iron to form heme and is mutated in protoporphyria. The ferrochelatase gene is expressed in all tissues at low levels to provide heme for essential heme-containing proteins and is up-regulated during erythropoiesis for the synthesis of hemoglobin. The human ferrochelatase promoter contains 2 Sp1 cis-elements and GATA and NF–E2 sites, all of which bind their cognatetrans-acting factors in vitro. To investigate the role of these elements during erythropoiesis, we introduced expression of the green fluorescent protein (EGFP) transgenes driven by various ferrochelatase promoter fragments into a single locus in mouse embryonic stem cells. EGFP expression was monitored during hematopoietic differentiation in vitro using flow cytometry. We show that a promoter fragment containing the Sp1 sites, the NF–E2 and GATA elements, was sufficient to confer developmental-specific expression of the EGFP transgene, with an expression profile identical to that of the endogenous gene. In this system the −0.275 kb NF–E2 cis-element is required for erythroid-enhanced expression, the GATA cis-element functions as a stage-specific repressor and enhancer, and elements located between −0.375kb and −1.1kb are necessary for optimal levels of expression. Ferrochelatase mRNA increased before the primitive erythroid-cell stage without a concomitant increase in ferrochelatase protein, suggesting the presence of a translational control mechanism. Because of the sensitivity of this system, we were able to assess the effect of an A-to-G polymorphism identified in the promoters of patients with protoporphyria. There was no effect of the G haplotype on transcriptional activity of the −1.1 kb transgene.

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