Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Histone modification in early and late Drosophila embryos.

ABSTRACT: Levels of histone acetylation and phosphorylation have been contrasted in two developmental states of Drosophila melanogaster. The 0-2 h nuclei of the syncitial blastula are characterized by rapid mitoses and DNA replication, but there is very little transcription. In the 18 h embryo there is considerable transcription and the mitotic rate is much slower. It has been found that (1) histone H1 from 2h nuclei is not highly phosphorylated. This observation is not in accord with the view that H1 hyperphosphorylation is essential to mitosis, but is compatible with the hypothesis that H1 phosphorylation in Drosophila species is related to heterochromatization. (2) Histone H4 from 2 h embryos shows high levels of the diacetyl form (H4-Ac2), which is principally outside the nucleus. This accords with the hypothesis that H4-Ac2 is the form in which H4 is deposited on to newly replicated DNA and shows that H4 acetylation is linked not only to transcription. (3) Histone H3 acetylation is similar in 2h and in 18h embryos. As with H4, this acetylation probably correlates with chromatin assembly and is not transcription-related. (4) Histone H2B carries no modification in 2h or in 18h embryos, and H2A shows a single modification in 2h embryos and two in 18 h embryos. H2B modification is thus not essential either in mitosis or replication, whereas H2A modification is important in one or both processes. (5) The nucleosomal protein D2 is equally present in 2h and 18 h embryos.

SUBMITTER: Giancotti V

PROVIDER: S-EPMC1153344 | biostudies-other | 1984 Mar

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Reprogramming histone modification patterns to coordinate gene expression in early zebrafish embryos.

Project description:BackgroundMulticellular organisms require precise gene regulation during ontogeny, and epigenetic modifications, such as DNA methylation and histone modification, facilitate this precise regulation. The conservative reprogramming patterns of DNA methylation in vertebrates have been well described. However, knowledge of how histone modifications are passed on from gametes to early embryos is limited, and whether histone modification reprogramming is conserved is not clear.ResultsWe profiled H3K4me3/H3K27me3 modifications in gametes and early embryos in zebrafish and found that the patterns in gene promoter regions have been largely set to either co-occupied or active states in gametes and then passed on to early embryos. Co-occupied states are partially maintained, while active states are largely restored to nearly match the sperm's pattern prior to zygotic genome activation (ZGA). However, repressive H3K27me3 modifications in promoter regions are largely discarded in early embryos. Prior to ZGA, patterns of genes that initialize ZGA are converted to nonrepressive states to coordinate gene expression. Moreover, promoter peaks that mark stage-specific genes are hypermethylated, and histone modifications in these regions are erased independently of DNA methylation reprogramming. Furthermore, comparative analysis revealed that the functions of co-occupied and active genes passed on from gametes are conserved in vertebrates. Gene age preferences by co-occupied and active histone modifications are also confirmed in vertebrates.ConclusionsOur data provide fundamental resources for understanding H3K4me3/H3K27me3 modifications in early zebrafish embryos. The data also reveal that the reprogramming progress of histone modifications is conserved in vertebrates and coordinates with gene expression during ZGA.

| S-EPMC6437866 | biostudies-literature

Genome-wide Tinman binding sites in early and late Drosophila embryos

Project description:The Drosophila transcription factor Tinman (Tin) is involved in embryonic heart development. We have analyzed genomic binding sites for Tin using a ChIP-chip strategy, making use of our high-quality antibody and Affymetrix Drosophila Tiling Arrays. We sampled to time points (early: 3-5.5h AEL and late: 5-8h AEL) that see distinct Tin expression in the embryo. Our data analysis yielded 2548 binding events in early and 988 binding events in late embryos. Our results are described in Jin et al. "Genome-wide screens for in vivo Tinman binding sites identify cardiac enhancers with diverse functional architectures"; submitted to PLoS Genetics

2012-10-17 | GSE41628 | GEO

Lipid droplets control the maternal histone supply of Drosophila embryos.

Project description:BACKGROUND:Histones are essential for chromatin packing, yet free histones not incorporated into chromatin are toxic. While in most cells multiple regulatory mechanisms prevent accumulation of excess histones, early Drosophila embryos contain massive extranuclear histone stores, thought to be essential for development. Excess histones H2A, H2B, and H2Av are bound to lipid droplets, ubiquitous fat storage organelles especially abundant in embryos. It has been proposed that sequestration on lipid droplets allows safe transient storage of supernumerary histones. RESULTS:Here, we critically test this sequestration hypothesis. We find that histones are anchored to lipid droplets via the previously uncharacterized protein Jabba: Jabba localizes to droplets, coimmunoprecipitates with histones, and is necessary to recruit histones to droplets. Jabba mutants lack the maternal H2A, H2B, and H2Av deposits altogether; presumably, these deposits are eliminated unless sequestered on droplets. Jabba mutant embryos compensate for this histone deficit by translating maternal histone mRNAs. However, when histone expression is mildly compromised, the maternal histone protein deposits are essential for proper early mitoses and for viability. CONCLUSIONS:A growing number of proteins from other cellular compartments have been found to transiently associate with lipid droplets. Our studies provide the first insight into mechanism and functional relevance of this sequestration. We conclude that sequestration on lipid droplets allows embryos to build up extranuclear histone stores and provides histones for chromatin assembly during times of high demand. This work reveals a novel aspect of histone metabolism and establishes lipid droplets as functional storage sites for unstable or detrimental proteins.

| S-EPMC3513403 | biostudies-literature

Drosophila early embryos LC-MSMS

Project description:Cytoplasmic polyadenylation is a mechanism to promote mRNA translation in a wide variety of biological contexts.The conserved RNA-binding protein family CPEB has been shown to mediate canonical cytoplasmic polyadenylation of target transcripts. We have previously reported evidence for RNA-interference factor Dicer-2 as a component of a non-canonical complex, that operates independent of CPEB in Drosophila. In this study, we investigate Dicer-2 mRNA targets and protein co-factors in cytoplasmic polyadenylation. Using RIP‐Seq analysis we identify hundreds of potential Dicer-2 target transcripts, ~60% of which were previously found as targets of the cytoplasmic poly(A) polymerase Wispy, suggesting widespread roles of Dicer-2 in cytoplasmic polyadenylation. Large-scale immunoprecipitation and mass spectrometry revealed Ataxin-2 and Twenty-four among the high-confidence interactors of Dicer-2. Complex analyses indicated that both factors form an RNA‐independent complex with Dicer‐2, and mediate interactions of Dicer‐2 with Wispy. Functional poly(A)‐test analyses showed that Twenty‐four and Ataxin-2 are required for cytoplasmic polyadenylation of a subset of Dicer‐2 targets. Our results reveal components of a novel cytoplasmic polyadenylation complex that operates during Drosophila early embryogenesis.

2022-08-30 | PXD030281 | Pride

Transcriptional Timers Regulating Mitosis in Early Drosophila Embryos.

Project description:The development of an embryo requires precise spatiotemporal regulation of cellular processes. During Drosophila gastrulation, a precise temporal pattern of cell division is encoded through transcriptional regulation of cdc25(string) in 25 distinct mitotic domains. Using a genetic screen, we demonstrate that the same transcription factors that regulate the spatial pattern of cdc25(string) transcription encode its temporal activation. We identify buttonhead and empty spiracles as the major activators of cdc25(string) expression in mitotic domain 2. The effect of these activators is balanced through repression by hairy, sloppy paired 1, and huckebein. Within the mitotic domain, temporal precision of mitosis is robust and unaffected by changing dosage of rate-limiting transcriptional factors. However, precision can be disrupted by altering the levels of the two activators or two repressors. We propose that the additive and balanced action of activators and repressors is a general strategy for precise temporal regulation of cellular transitions during development.

| S-EPMC5386176 | biostudies-literature

Genome-wide Tinman binding sites in early and late Drosophila embryos

2012-10-17 | E-GEOD-41628 | biostudies-arrayexpress

Vestigial is required during late-stage muscle differentiation in Drosophila melanogaster embryos.

Project description:The somatic muscles of Drosophila develop in a complex pattern that is repeated in each embryonic hemi-segment. During early development, progenitor cells fuse to form a syncytial muscle, which further differentiates via expression of muscle-specific factors that induce specific responses to external signals to regulate late-stage processes such as migration and attachment. Initial communication between somatic muscles and the epidermal tendon cells is critical for both of these processes. However, later establishment of attachments between longitudinal muscles at the segmental borders is largely independent of the muscle-epidermal attachment signals, and relatively little is known about how this event is regulated. Using a combination of null mutations and a truncated version of Sd that binds Vg but not DNA, we show that Vestigial (Vg) is required in ventral longitudinal muscles to induce formation of stable intermuscular attachments. In several muscles, this activity may be independent of Sd. Furthermore, the cell-specific differentiation events induced by Vg in two cells fated to form attachments are coordinated by Drosophila epidermal growth factor signaling. Thus, Vg is a key factor to induce specific changes in ventral longitudinal muscles 1-4 identity and is required for these cells to be competent to form stable intermuscular attachments with each other.

| S-EPMC2947467 | biostudies-literature

Calcium Spikes in Epithelium: study on Drosophila early embryos.

Project description:Calcium ion acts in nearly every aspect of cellular life. The versatility and specificity required for such a ubiquitous role is ensured by the spatio-temporal dynamics of calcium concentration variations. While calcium signal dynamics has been extensively studied in cell cultures and adult tissues, little is known about calcium activity during early tissue morphogenesis. We monitored intracellular calcium concentration in Drosophila gastrula and revealed single cell calcium spikes that were short-lived, rare and showed strong variability among embryos. We quantitatively described the spatio-temporal dynamics of these spikes and analyzed their potential origins and nature by introducing physical and chemical perturbations. Our data highlight the inter- and intra-tissue variability of calcium activity during tissue morphogenesis.

| S-EPMC4510484 | biostudies-literature

Dynamic pattern of histone H3 core acetylation in human early embryos.

Project description:After fertilization, highly differentiated sperm and oocyte are reprogrammed to totipotent embryo, which subsequently cleavages and develops into an individual through spatial-temporal differentiation. Histone modifications play critical roles to coordinate with other reprogramming events in early stages of embryogenesis. However, most of studies focus on modifications at N-terminus of histones, those at nucleosome core were not well understood. Here, we characterize the three key acetylation events in the histone H3 core, H3K56/K64/K122ac, in early human embryos. The three residues localize at DNA entry-exit position of the nucleosome. Globally, H3K56ac, H3K64ac and H3K122ac were detectable throughout preimplantation stages, with H3K64ac levels being relatively stronger and H3K122ac levels being much weaker. Besides, H3K56ac level had a peak at two-cell stage. Moreover, we found that LINEs also peak at two-cell stage, and H3K56ac was enriched at young LINE-1 in human ESCs, supporting that H3K56ac is an important driving force for young LINE-1 activation in human preimplantation embryos. Our results suggest that acetylation in the nucleosome core of histone H3 is dynamic and various during preimplantation development, and may drive diverse chromatin remodeling events in this developmental window.

| S-EPMC7513859 | biostudies-literature

Chiffon triggers global histone H3 acetylation and expression of developmental genes in Drosophila embryos.

Project description:The histone acetyltransferase Gcn5 is critical for gene expression and development. In Drosophila, Gcn5 is part of four complexes (SAGA, ATAC, CHAT and ADA) that are essential for fly viability and have key roles in regulating gene expression. Here, we show that although the SAGA, ADA and CHAT complexes play redundant roles in embryonic gene expression, the insect-specific CHAT complex uniquely regulates expression of a subset of developmental genes. We also identify a substantial decrease in histone acetylation in chiffon mutant embryos that exceeds that observed in Ada2b, suggesting broader roles for Chiffon in regulating histone acetylation outside of the Gcn5 complexes. The chiffon gene encodes two independent polypeptides that nucleate formation of either the CHAT or Dbf4-dependent kinase (DDK) complexes. DDK includes the cell cycle kinase Cdc7, which is necessary for maternally driven DNA replication in the embryo. We identify a temporal switch between the expression of these chiffon gene products during a short window during the early nuclear cycles in embryos that correlates with the onset of zygotic genome activation, suggesting a potential role for CHAT in this process. This article has an associated First Person interview with the first author of the paper.

| S-EPMC8917357 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data