Xenopus laevis
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PROVIDER: PRJNA223418 | ENA |
REPOSITORIES: ENA
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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:Genome-wide analysis of dorsal and ventral transcriptomes of the Xenopus laevis gastrula
| PRJNA303056 | ENA
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: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:During Xenopus gastrulation, dorsal stabilization of β-Catenin at the earliest stage and subsequent target genes expression are critical for dorsal-ventral axis determination. However, many β-Catenin targets that mediate this process are still unkown. Here through RNA-seq analysis of β-Catenin knockdown embryos and self-regulating dorsal and ventral half embryos at early gastrula, we define an early β-Catenin gene signature that is downregulated by β-Catenin MO and enriched in dorsal gastrula tissues. This gene signature includes classic Spemann organizer genes, as well as other novel genes. Further analyses revealed that the early β-Catenin gene signature is positively correlated with LiCl treated, Wnt8 and Siamois mRNA-induced genes, consistent with their early role in dorsal-ventral axis formation. Our results also show that St 10.5 is the appropriate stage to uncover β-Catenin target genes that regulate dorsal-ventral patterning than St 9. Meanwhile, the multi-growth factor antagonist Cerberus inhibits part of the early β-Catenin gene signature and also controls the expression of a unique set of genes. Our findings provide new insight into the pivotal role of β-catenin in dorsal-ventral axis determination and can serve a fruitful resource for this field.
2017-03-15 | GSE93195 | GEO
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:Animal embryos have the remarkable property of self-organization. Over 125 years ago Hans Driesch separated the two blastomeres of sea urchin embryos and obtained twins, in what was the foundational experiment of experimental embryology. Since then, embryonic twinning has been obtained experimentally in many animals by diverse methods. In a recent study, we developed bisection methods that generate identical twins reliably from Xenopus blastula embryos. In the present study we investigated the transcriptome of regenerating half-embryos after sagittal and dorsal-ventral (D-V) bisections. Individual embryos were operated at midblastula with an eyelash hair and cultured until early gastrula (stage 10.5) or late gastrula (Stage 12) and analyzed the transcriptome of each half-embryo by RNAseq. Because many genes are activated by wound healing, stringent analyses were used to identify genes upregulated in identical twins but not in either dorsal or ventral fragments. At early gastrula cell division-related genes such as histones were identified, whereas at late gastrula pluripotency genes (such as sox2) and germ layer determining genes (such as eomesodermin, ripply2 and activing receptor ACVRI) and a number of secretory pathway components (serpinH1, fucoleptin and sialyl transferase). These findings are consistent with a model in which cell division is required to heal damage, while maintaining pluripotency to permit formation of the organizer with a displacement of 900 from its original site. In addition, the extensive transcriptomic data presented here (30 RNA-seq libraries of individual whole or regenerating half-embryos) provides a useful resource for data mining gene expression during early vertebrate development.
2019-02-01 | GSE124563 | GEO
Project description:apcdd1, a gene mutated in hereditary hypotrychosis simplex, is a maternally expressed gene in Xenopus embryos, required for correct formation of anterior and dorsal structures. Initial data suggested Apcdd1 functions as zyogtic Wnt inhibitor. Here we indentify genes regulated by Apcdd1 in the organizer area of early gastrula stage embryos
2019-10-15 | GSE138834 | GEO
Project description:During embryogenesis, the pancreas develops from separate dorsal and ventral buds, which fuse to form the mature pancreas. Little is known about the functional differences between these two buds or the relative contribution of cells derived from each portion to the pancreas after fusion. To follow the fate of dorsal or ventral bud derived cells in the pancreas after fusion, we produced chimeric Elas-GFP transgenic/wild type embryos in which either dorsal or ventral pancreatic bud cells expressed GFP. We found that ventral pancreatic cells migrate extensively into the dorsal pancreas after fusion, whereas the converse does not occur. Moreover, we found that annular pancreatic tissue is composed exclusively of ventral pancreas derived cells. To identify ventral pancreas specific genes that may play a role in pancreatic bud fusion, we isolated individual dorsal and ventral pancreatic buds, prior to fusion, from stage 38/39 Xenopus laevis tadpoles and compared their gene expression profiles. Morpholino-mediated knockdown of one of these ventral specific genes, transmembrane 4 superfamily member 3 (tm4sf3), inhibited dorsal-ventral pancreatic bud fusion as well as acinar cell differentiation. Conversely, overexpression of tm4sf3 promoted the development of annular pancreas. Our results are the first to define molecular and behavioral differences between the dorsal and ventral pancreas, and suggest an unexpected role for the ventral pancreas in pancreatic bud fusion. Experiment Overall Design: We analyzed two samples of dorsal and two samples of ventral pancreatic buds.
2009-06-01 | E-GEOD-13603 | biostudies-arrayexpress