Spemann organizer transcriptome induction by early β-Catenin, Wnt, Nodal and Siamois signals in Xenopus laevis
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ABSTRACT:
ORGANISM(S): Xenopus laevis
PROVIDER: GSE93195 | GEO | 2017/03/15
SECONDARY ACCESSION(S): PRJNA360282
REPOSITORIES: GEO
Similar Datasets
Project description:Studies on the early embryonic development of Xenopus laevis contributed much to the understanding of vertebrate patterning. Gastrula stages are of particular interest because establishment of the axis and germ layer formation take place during these stages. While many genes belonging to several signaling pathways including FGF, Wnt and TGF-beta, have been implicated in patterning the gastrula embryo, the hierarchical interactions between these factors are incompletely known. To study this question, we took advantage of microarray technology to create a regional gene expression profile for the Xenopus gastrula. Stage 10 Xenopus embryos were dissected into four portions. The dorsal marginal zone including the blastopore and some ectoderm and dorsal yolk plug, composed mostly of endomesoderm; the ventral marginal zone, also containing a portion of the yolk plug; the animal cap, dissected just above the floor of the blastocoel; and the vegetal region, composed of the central part of the yolk plug. To avoid possible cross contamination that might blur the microrarray data, thin junctional regions between the explants were removed. The dissected explants were homogenized in Stat 60 (TEL TEST), RNA was precipitated by isopropanol, treated with DNase I, and purified using the RNeasy kit (Qiagen). Biotinylated probe was prepared from 100 ng total RNA using the OVATION RNA amplification system (Nugen Technologies, Inc). The probes were hybridized to Affymetrix Xenopus Chips containing features that represent about 15,000 genes according to the manufactureâs instructions. Hybridized arrays were further processed by the GeneChip Fluidics system (Affymetrix), and signals were detected by the GeneChip Scanner (Affymetrix). Gene expression profiles were analyzed by the GCOS software (Affymetrix). The analysis showed that 100 transcripts were enriched in the dorsal explant (dorsal vs. ventral, signal log2 ratio>1.5), including the known dorsal markers Chordin, gsc, Admp; 90 transcripts were enriched in the ventral explant (ventral vs. dorsal, signal log2 ratio>1.5) including Sizzled, bambi, PV.1; 449 transcripts were enriched in the vegetal explant (vegetal vs. dorsal, vegetal vs. ventral, vegetal vs. animal cap, all signal log2 ratio>1.5), including Mixer, Sox17ï¡.; 70 transcripts were enriched in the animal cap (animal cap vs. vegetal, signal log2 ratio>1.5; animal cap vs. dorsal, signal log2 ratio>1; animal cap vs. ventral, signal log2 ratio>1) including Epidermal type I cytokeratin and forkhead-2. RT-PCR was used to check the enrichment of some of the unknown genes; the enrichment of 8 of 9 ventral genes, and 9 of 12 dorsal genes was confirmed in these experiments. Experiment Overall Design: Ceate a regional gene expression profile in Xenopus gastrula, and predict gene expression pattern by comparing gene expression in different explant.
2008-06-16 | E-GEOD-8990 | biostudies-arrayexpress
Project description:The dorsoventral gradient of BMP signaling plays an essential role in embryonic patterning, with high BMP signal activating ventral-lateral mesoderm markers directly, and low BMP signal inducing neural tissues. The Zinc finger SWIM domain-containing protein 4 (zswim4) is expressed in the dorsal blastopore lip at the onset of Xenopus gastrula and then enriched at the forming neuroectoderm at mid-gastrula stages. Overexpression of zswim4 in Xenopus embryos causes inhibition of the anterior axis and shortened, curved body, and knockdown or knockout of zswim4 disturbed embryonic body axis formation and head development. The expression of ventral-lateral mesoderm marker genes was reduced after zswim4 overexpression and increased in embryos with zswim4 knockdown. Neural marker genes were repressed in zswim4 morphant. Mechanistically Zswim4 attenuates BMP signal through reducing protein stability of Smad1 in both Xenopus embryos and HEK293T cells. Zswim4 interacts with Smad1 and promotes ubiquitination of Smad1 in HEK293T cells. To identify the interaction partner of Zswim4 in regulating Smad1 stability, we performed SILAC based IP in HEK293T cells, and the precipitates were analyzed by Mass Spectrometry.
2024-05-22 | PXD035207 | Pride
Project description:Studies on the early embryonic development of Xenopus laevis contributed much to the understanding of vertebrate patterning. Gastrula stages are of particular interest because establishment of the axis and germ layer formation take place during these stages. While many genes belonging to several signaling pathways including FGF, Wnt and TGF-beta, have been implicated in patterning the gastrula embryo, the hierarchical interactions between these factors are incompletely known. To study this question, we took advantage of microarray technology to create a regional gene expression profile for the Xenopus gastrula. Stage 10 Xenopus embryos were dissected into four portions. The dorsal marginal zone including the blastopore and some ectoderm and dorsal yolk plug, composed mostly of endomesoderm; the ventral marginal zone, also containing a portion of the yolk plug; the animal cap, dissected just above the floor of the blastocoel; and the vegetal region, composed of the central part of the yolk plug. To avoid possible cross contamination that might blur the microrarray data, thin junctional regions between the explants were removed. The dissected explants were homogenized in Stat 60 (TEL TEST), RNA was precipitated by isopropanol, treated with DNase I, and purified using the RNeasy kit (Qiagen). Biotinylated probe was prepared from 100 ng total RNA using the OVATION RNA amplification system (Nugen Technologies, Inc). The probes were hybridized to Affymetrix Xenopus Chips containing features that represent about 15,000 genes according to the manufacture’s instructions. Hybridized arrays were further processed by the GeneChip Fluidics system (Affymetrix), and signals were detected by the GeneChip Scanner (Affymetrix). Gene expression profiles were analyzed by the GCOS software (Affymetrix). The analysis showed that 100 transcripts were enriched in the dorsal explant (dorsal vs. ventral, signal log2 ratio>1.5), including the known dorsal markers Chordin, gsc, Admp; 90 transcripts were enriched in the ventral explant (ventral vs. dorsal, signal log2 ratio>1.5) including Sizzled, bambi, PV.1; 449 transcripts were enriched in the vegetal explant (vegetal vs. dorsal, vegetal vs. ventral, vegetal vs. animal cap, all signal log2 ratio>1.5), including Mixer, Sox17; 70 transcripts were enriched in the animal cap (animal cap vs. vegetal, signal log2 ratio>1.5; animal cap vs. dorsal, signal log2 ratio>1; animal cap vs. ventral, signal log2 ratio>1) including Epidermal type I cytokeratin and forkhead-2. RT-PCR was used to check the enrichment of some of the unknown genes; the enrichment of 8 of 9 ventral genes, and 9 of 12 dorsal genes was confirmed in these experiments. Keywords: Xenopus, gastrula, explant, gene expression, embryonic, gene regulation
2007-11-01 | GSE8990 | GEO
Project description:Multilevel logical model encompassing the Nodal and BMP pathways together with key transcription factors setting the dorsal-ventral axis in the sea urchin P. lividus embryo. This model accounts for the specification of wild-type ventral ectoderm, ciliary band and dorsal ectoderm, and further recapitulates sophisticated mutant phenotypes.
2021-01-06 | MODEL2002190001 | BioModels
Project description:We studied the transcriptomic differences between ventralised and dorsalised Xenopus tropicalisembryos as a result of UV irradiation and LiCl treatment, respectvely. Both manipulations have been used by researchers to perturb the establishment of the dorso-ventral axis, however the whole transcriptomes of the resulting embryos have never been fully characterised or compared. We show that ventralized embryos are transcriptionally closer related to untreated embryos than dorsalized embryos. Furthermore comparison to dissected ventral and dorsal parts of an unperturbed gastrula embryo indicates that UV and LiCl treatment indeed enriches for ventral and dorsal cells, respectively.
2018-05-04 | GSE107424 | GEO
Project description:Asymmetric signalling centres in the early embryo are essential for axis formation in vertebrates. These regions, namely the dorsal morula, yolk syncytial layer, and distal hypoblast/anterior visceral endoderm (in amphibians, teleosts and mammals, respectively), require the localised stabilisation of nuclear Beta-catenin (Ctnnb1), implying that localised Wnt/Beta-catenin signalling activity is critical in their establishment. However, it is becoming increasingly apparent that the stabilisation of Beta-catenin in this context may be initiated independently of secreted Wnt growth factor activity. In Xenopus, dorsal Beta-catenin stabilisation is initiated by a requisite microtubule-mediated symmetry-breaking event in the fertilised egg: “cortical rotation”. Vegetally-localised wnt11b mRNA has been implicated upstream of Beta-catenin in this context, as has the dorsal enrichment of Wnt ligand-independent activators of Beta-catenin, but the extent that each of these processes contribute to axis formation in this paradigm remains unclear. Here we describe a maternal effect mutation in Xenopus laevis wnt11b.L, generated by CRISPR mutagenesis. We demonstrate a maternal requirement for timely and complete gastrulation morphogenesis and a zygotic requirement for proper left-right asymmetry. We also show that a subset of maternal wnt11b mutants have axis and dorsal gene expression defects, and we find that microtubule assembly and cortical rotation are reduced in wnt11b mutant eggs, leading to less organised and directed vegetal microtubule arrays. mRNA sequencing was used to determine the extent of dorsal and other gene dysregulation during gastrulation.
2022-05-02 | GSE195806 | GEO
Project description:RNA sequencing has allowed high-throughput screening of differential gene expression in many tissues and organisms. Xenopus laevis is a classical embryological and cell-free extract model system, but its genomic sequence had been lacking due to difficulties arising from allotetraploidy. There is currently much excitement surrounding the release of the completed X. laevis genome (version 9.1) by the Joint Genome Institute (JGI), which provides a platform for genome-wide studies. Here we present a deep RNA-seq dataset of transcripts expressed in dorsal and ventral lips of the early Xenopus gastrula embryo using the new genomic information, which was further annotated by blast searches against the human proteome. Overall, our findings confirm previous results from differential screenings using other methods that uncovered classical dorsal genes such as Chordin, Noggin and Cerberus, as well as ventral genes such as Sizzled, Ventx, Wnt8 and BAMBI. Complete transcriptome-wide Excel files of mRNAs suitable for data mining are presented, which include many novel dorsal- and ventral-specific genes. RNA-seq was very quantitative and reproducible, and allowed us to define dorsal and ventral signatures useful for gene set expression analyses (GSEA). As an example of a new gene, we present here data on an organizer-specific secreted protein tyrosine kinase known as Pkdcc (protein kinase domain containing, cytoplasmic) or Vlk (vertebrate lonesome kinase). Overexpression experiments indicate that Pkdcc can act as a negative regulator of Wnt/ β-catenin signaling independently of its kinase activity. We conclude that RNA-seq in combination with the Xenopus laevis complete genome now available provides a powerful tool for unraveling cell-cell signaling pathways during embryonic induction.
2016-06-20 | GSE75278 | GEO
Project description:The role of the hippocampus in learning and memory has been widely studied. However, studies of differences along the longitudinal axis indicate that the hippocampus is perhaps not a singular structure, but instead it is thought that the dorsal and ventral poles of the hippocampus have functional differences. An anatomical gradient of hippocampal inputs along the dorsal-ventral axis supports this notion. It has been recently shown that there is transcriptional differentiation along the longitudinal axis of the adult hippocampus, coinciding with functional and anatomical gradients. Understanding the development of the dorsal-ventral hippocampal axis will further our understanding of the different hippocmapal functional contributions along the longitudinal axis. However, analysis of transcriptional gradients along the dorsal ventral axis have not been studied in the neonatal rat during development. We performed an extensive bead-chip based geneome-wide analysis of transcriptional differences in dorsal, intermediate, and ventral hippocampal tissue of rats aged postnatal day 0 (P0), P9, P18 and P60.
2015-05-01 | E-MTAB-2617 | biostudies-arrayexpress
Project description:To identify evolutionarily conserved Beta-catenin protein interactions, Beta-catenin mRNA from various metazoans was injected into Xenopus embryos and immunopurified at gastrula stage. Beta-catenin complexes were then separated on an SDS-PAGE gel and subjected mass spectrometric analysis
2023-07-08 | PXD035167 | JPOST Repository
Project description:Studies of the Xenopus organizer have laid the foundation for our understanding of the conserved signaling pathways that pattern vertebrate embryos during gastrulation. Here, we use this wealth of knowledge as leverage in the design and analysis of a genomic visualization of organizer-related gene transcription. Using ectopic expression of the two major activities of the organizer, BMP and Wnt inhibition, as well as endogenous tissues, we generate a focused set of samples that represent different aspects of organizer signaling. The genomic expression values of each sample are then measured with oligonucleotide arrays. From this data, genes regulated by organizer signaling are selected and then clustered by their patterns of regulation. A new GO biological process annotation of the Xenopus genome allows us to rapidly identify clusters that are highly enriched for known gastrula patterning genes. Within these clusters, we can predict the expression patterns of unknown genes with remarkable accuracy, leading to the discovery of new organizer-related gastrula stage expression patterns for 19 genes. Moreover, the patterns of gene response observed within these clusters allow us to parse apart the contributions of BMP and Wnt inhibition in organizer function. We find that the majority of gastrula patterning genes respond transcriptionally to these activities according to only a few stereotyped patterns, allowing us to describe suites of genes that are likely to share similar regulatory mechanisms. These suites of genes demonstrate a mechanism where BMP inhibition initiates the organizer program before gastrulation, and Wnt inhibition maintains and drives the organizer program during gastrulation. Experiment Overall Design: In order to describe and separate the genomic expression changes induced by the two main organizing activities, BMP inhibition and Wnt inhibition, we created a panel of gastrula stage ventral tissues that ectopically overexpressed one or both of these activities, and compared these samples to endogenous dorsal and ventral gastrula stage tissue. Two well-studied organizer secreted factors, Noggin and Dickkopf-1 (Dkk-1), were used to ectopically inhibit BMP and Wnt signaling, respectively. Four different overexpression mixtures were injected ventrally into 4-cell embryos: noggin and eGFP (anti-BMP); noggin, dkk-1, and eGFP (anti-BMP and anti-Wnt); dkk-1 and eGFP (anti-Wnt); and eGFP alone. eGFP mRNA was used to trace targeting. Plasmid DNA was used for noggin and dkk-1 overexpression, instead of mRNA, in order to limit ectopic expression of these genes to post-MBT stages, more closely mimicking the endogenous regulation of these genes. The ventrally injected embryos were grown to early stage 10, sorted for appropriately targeted eGFP florescence, and then bisected between the dorsal and ventral halves at either stage 10 (early gastrula) or stage 11.5 (late gastrula). For the noggin and/or dkk-1 injected embryos, only the ventral halves of the embryos were saved, eliminating endogenous organizer tissues. For the embryos injected with only eGFP, both the ventral and dorsal halves were saved, creating separate ventral and dorsal control conditions. These five conditions were each generated twice at both stage 10 and 11.5, with each set of five samples coming from a single clutch of embryos, creating twenty total tissue samples from 4 different clutches. For each batch of injections some sorted embryos were allowed to develop through tailbud stages in order to validate the phenotypes induced by our constructs. Total RNA was then isolated from the twenty tissue samples and applied to Affymetrix oligonucleotide arrays.
2007-10-05 | E-GEOD-3368 | biostudies-arrayexpress