Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Properties of repression condensates in living Ciona embryos.

ABSTRACT: Recent studies suggest that transcriptional activators and components of the pre-initiation complex (PIC) form higher order associations-clusters or condensates-at active loci. Considerably less is known about the distribution of repressor proteins responsible for gene silencing. Here, we develop an expression assay in living Ciona embryos that captures the liquid behavior of individual nucleoli undergoing dynamic fusion events. The assay is used to visualize puncta of Hes repressors, along with the Groucho/TLE corepressor. We observe that Hes.a/Gro puncta have the properties of viscous liquid droplets that undergo limited fusion events due to association with DNA. Hes.a mutants that are unable to bind DNA display hallmarks of liquid-liquid phase separation, including dynamic fusions of individual condensates to produce large droplets. We propose that the DNA template serves as a scaffold for the formation of Hes condensates, but limits the spread of transcriptional repressors to unwanted regions of the genome.

SUBMITTER: Treen N

PROVIDER: S-EPMC7946874 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

ERK signaling dissolves ERF repression condensates in living embryos.

Project description:Phase separation underlies the organization of the nucleus, including the biogenesis of nucleoli and the packaging of heterochromatin. Here we explore the regulation of transcription factor condensates involved in gene repression by ERK signaling in gastrulating embryos of a simple proto-vertebrate (Ciona). ERK signaling induces nuclear export of the transcriptional repressor Ets-2 repressive factor (ERF), which has been linked to various human developmental disorders. Using high-resolution imaging, we show that ERF is localized within discrete nuclear condensates that dissolve upon ERK activation. Interestingly, we observe dynamic pulses of assembly and dissociation during interphase, providing visualization of a nuclear phase separation process regulated by cell signaling. We discuss the implications of these observations for producing sharp on/off switches in gene activity and suppressing noise in cell-cell signaling events.

| S-EPMC8892517 | biostudies-literature

Tissue-specific genome editing in Ciona embryos by CRISPR/Cas9.

Project description:The CRISPR/Cas9 system has ushered in a new era of targeted genetic manipulations. Here, we report the use of CRISPR/Cas9 to induce double-stranded breaks in the genome of the sea squirt Ciona intestinalis. We use electroporation to deliver CRISPR/Cas9 components for tissue-specific disruption of the Ebf (Collier/Olf/EBF) gene in hundreds of synchronized Ciona embryos. Phenotyping of transfected embryos in the 'F0' generation revealed that endogenous Ebf function is required for specification of Islet-expressing motor ganglion neurons and atrial siphon muscles. We demonstrate that CRISPR/Cas9 is sufficiently effective and specific to generate large numbers of embryos carrying mutations in a targeted gene of interest, which should allow for rapid screening of gene function in Ciona.

| S-EPMC4302896 | biostudies-other

Cold-induced Arabidopsis FRIGIDA nuclear condensates for FLC repression.

Project description:Plants use seasonal temperature cues to time the transition to reproduction. In Arabidopsis thaliana, winter cold epigenetically silences the floral repressor locus FLOWERING LOCUS C (FLC) through POLYCOMB REPRESSIVE COMPLEX 2 (PRC2)1. This vernalization process aligns flowering with spring. A prerequisite for silencing is transcriptional downregulation of FLC, but how this occurs in the fluctuating temperature regimes of autumn is unknown2-4. Transcriptional repression correlates with decreased local levels of histone H3 trimethylation at K36 (H3K36me3) and H3 trimethylation at K4 (H3K4me3)5,6, which are deposited during FRIGIDA (FRI)-dependent activation of FLC7-10. Here we show that cold rapidly promotes the formation of FRI nuclear condensates that do not colocalize with an active FLC locus. This correlates with reduced FRI occupancy at the FLC promoter and FLC repression. Warm temperature spikes reverse this process, buffering FLC shutdown to prevent premature flowering. The accumulation of condensates in the cold is affected by specific co-transcriptional regulators and cold induction of a specific isoform of the antisense RNA COOLAIR5,11. Our work describes the dynamic partitioning of a transcriptional activator conferring plasticity in response to natural temperature fluctuations, thus enabling plants to effectively monitor seasonal progression.

| S-EPMC8612926 | biostudies-literature

Cytochalasin treatment of Ciona embryos

Project description:Cleavage and morphogenesis of Ciona embryos was blocked by treatment with cytochalasin B prior to gastrulation. Drug treated embryos and DMSO treated controls were harvested at stage 19.5 (after control embryos had undergone neurulation and were completing notochord intercalation). Only 55 genes showed a significant difference in expression between the two treatments.

2017-09-19 | GSE102141 | GEO

ciHMX overexpression in Ciona intestinalis embryos

Project description:We recently showed HMX is expressed in bipolar tail neurons (BTN) in early embryos of Ciona intestinalis. In order to assess the function of the homeobox transcription factor in this cell fate, we used an overexpression strategy. ciHMX was overexpressed in the epidermis, followed by RNAseq of experimental and control embryos. We then looked for differential expression of BTN fate markers, testing if HMX is able to regulate BTN fate determination.

2021-11-26 | GSE141046 | GEO

Protocol to electroporate DNA plasmids into Ciona robusta embryos at the 1-cell stage.

Project description:Electroporation is a technique to introduce DNA constructs into cells using electric current. Here, we present a protocol to electroporate DNA plasmids into Ciona robusta embryos at the 1-cell stage. We describe steps for setting up and conducting electroporation. We then detail procedures for collecting, fixing, and mounting embryos and counting expression. This protocol can be used to study the expression of enhancers via reporter assays, manipulating cells using genes or modified genes such as dominant negatives, and genome editing. For complete details on the use and execution of this protocol, please refer to Song, et al.1.

| S-EPMC11269276 | biostudies-literature

Ciona savignyi embryos 4D Label-free Quantitative Phosphoproteomics

Project description:Formation of tubular system is crucial for embryogenesis and adult metabolism. However，the underlying mechanisms remain largely unclear. We demonstrated that a dual specificity tyrosine-phosphorylation-regulated kinase 1 (DYRK1), the protein kinase, which was upregulated during lumenogenesis and required for ascidian notochord extracellular lumen expansion. Here, we applied 4D Label-free Quantitative Phosphoproteomics and aimed to find out the potential substrates (phosphoproteins) that were regulated by DYRK1during ascidian Ciona notochord lumen expansion.

2023-01-04 | PXD039234 |

Visualization of Transvection in Living Drosophila Embryos.

Project description:How remote enhancers interact with appropriate target genes persists as a central mystery in gene regulation. Here, we exploit the properties of transvection to explore enhancer-promoter communication between homologous chromosomes in living Drosophila embryos. We successfully visualized the activation of an MS2-tagged reporter gene by a defined developmental enhancer located in trans on the other homolog. This trans-homolog activation depends on insulator DNAs, which increase the stability-but not the frequency-of homolog pairing. A pair of heterotypic insulators failed to mediate transvection, raising the possibility that insulator specificity underlies the formation of chromosomal loop domains. Moreover, we found that a shared enhancer co-activates separate PP7 and MS2 reporter genes incis and intrans. Transvecting alleles weakly compete with one another, raising the possibility that they share a common pool of the transcription machinery. We propose that transvecting alleles form a trans-homolog "hub," which serves as a scaffold for the accumulation of transcription complexes.

| S-EPMC6092965 | biostudies-literature

Immobilisation of living coral embryos and larvae.

Project description:Embedding and immobilisation of living cells and microorganisms is used in a variety of research and commercial applications. Here we report the successful extended immobilisation of coral larvae in a low-gelling temperature agarose. Embryos and larvae of five broadcast-spawning Scleractinian species were immobilised in agarose gel and tested in a series of exploratory survival and settlement assays. The optimal developmental stage for immobilisation was after ciliation at approximately 24?hours post-fertilisation, after which, survival of immobilised larvae of all species was nearly 100%. In long-term assays, 50% of Montipora digitata larvae survived immobilised for 89 days. Furthermore, immobilised larvae of multiple species, that were released from the agarose, generally remained capable of settlement. These results demonstrate that the immobilisation of the early life-history stages of corals is possible for a variety of applications in basic and applied science.

| S-EPMC6787016 | biostudies-literature

A multicassette Gateway vector set for high throughput and comparative analyses in ciona and vertebrate embryos.

Project description:BackgroundThe past few years have seen a vast increase in the amount of genomic data available for a growing number of taxa, including sets of full length cDNA clones and cis-regulatory sequences. Large scale cross-species comparisons of protein function and cis-regulatory sequences may help to understand the emergence of specific traits during evolution.Principal findingsTo facilitate such comparisons, we developed a Gateway compatible vector set, which can be used to systematically dissect cis-regulatory sequences, and overexpress wild type or tagged proteins in a variety of chordate systems. It was developed and first characterised in the embryos of the ascidian Ciona intestinalis, in which large scale analyses are easier to perform than in vertebrates, owing to the very efficient embryo electroporation protocol available in this organism. Its use was then extended to fish embryos and cultured mammalian cells.ConclusionThis versatile vector set opens the way to the mid- to large-scale comparative analyses of protein function and cis-regulatory sequences across chordate evolution. A complete user manual is provided as supplemental material.

| S-EPMC1976267 | 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