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
Project description:RNA-seq technology was used to identify differentially localized transcripts from Xenopus laevis and Xenopus tropicalis stage VI oocytes. Besides the discovery of a group of novel animally enriched RNAs, this study revealed a surprisingly low conservation of vegetal RNA localization between the two frog species. mRNA profiles of Xenopus laevis and Xenopus tropicalis animal and vegetal oocyte halves were generated by RNA-seq technology. For Xenopus laevis, animal and vegetal oocyte RNA preparations from two different females were generated in duplicates. For Xenopus tropicalis, animal and vegetal oocyte RNA preparations from two different females were analyzed.
Project description:The aim of the approach was to use RNAseq analysis to identify genes expressed in Xenopus epicardium that were affected by embryonic depletion of the epicardial transcription factor Tcf21 compared to control-MO injected siblings. Both upregulated and downregulated genes were validated by RT-PCR and whole embryo in situ hybridization to validate gene expression and assess spatio-temporal distribution of genes of interest within the heart and epicardium. Approximately 70-100 stage 44-46 Xenopus laevis hearts were dissected to isolate total mRNA from which poly-adenylated RNA was extracted using the Illumina standard protocol. This experiment represents one replicate from pooled hearts. mRNA profiles of stage 44-45 Xenopus laevis sibling hearts from control or Tcf21-depleted embryos, were generated by deep sequencing using Illumina GAII.
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.
Project description:In Xenopus laevis, a number of studies identified vegetal factors that specify the germ line, endoderm and dorsal axis, but there are few studies demonstrating roles for animal-enriched maternal mRNAs. Therefore, we carried out a microarray analysis to identify novel maternal transcripts enriched in animal blastomeres. We sought to maximize differences between animal and vegetal samples. To that end, we dissected 8-cell embryos into animal blastomeres and vegetal blastomeres, and further dissected the vegetal blastomeres into vegetal-most halves (VP) and equatorial regions (discarded).
Project description:Here we describe a base-resolution DNA methylation map of Xenopus laevis gastrula (st.10.5) embryos generated by whole genome bisulfite sequencing
Project description:The Notch signaling pathway functions in a number of processes during embryologic development, especially the maintenance or aquisition of cell fate. We purturb the Notch signalling pathway in embryonic Xenopus laevis in order to 1) better characterize the downstream targets of Notch signalling, and 2) determine the extent to which early embryos can recover from transient purturbations to critical signalling pathways, if at all. Xenopus laevis embryos were unilaterally injected at the two cell stage with either GFP, GFP and ICD (Notch intracellular domain, an up-regulator of the Notch pathway), or GFP and DBM (domain-binding mutant, a downregulator of the Notch pathway). At stages 18, 28, and 38, for each injection, pooled total RNA from 10 embryos was extracted. Extraction was performed for three biological replicates for each time/injection condition. cDNA from total RNA was hybridized on Affymetrix Xenopus laevis Genome 2.0 arrays.