Expression profile of Chicken Early Embryonic Endodermal Tissues
ABSTRACT: In vertebrates the endoderm which gives rise to the epithelial lining of the digestive tract becomes regionalized along its antero-posterior axis after gastrulation. The molecular basis of the initial step of this regionalization has largely remained unclear. Using chick model, we generated high-quality transcriptomic datasets of different stages/regions of the endoderm and analyzed their molecular heterogeneity. Total RNA from HH stage 4-5 entire definitive endoderm, HH stages 10-11 foregut endoderm and HH stages 8-10 mid/hindgut endoderm were purified. 5 μg of RNA from each sample were used to screen Affymetrix Chicken Genome Array without an amplification step.
Project description:The definitive endoderm germ layer is the provenance of multiple internal organs, including the lungs, liver, pancreas and intestines. Molecular events driving initial endoderm germ layer specification and subsequent anterior-posterior patterning of endoderm into distinct organ primordia remain largely cryptic. Through microarray analyses, we captured genome-wide transcriptional dynamics driving successive stages of endoderm development with the intent of identifying novel regulatory genes or diagnostic markers that respectively drive or mark endoderm committment. HES3 human embryonic stem cells (hESCs) were differentiated into highly homogeneous endodermal progenitor populations, and microarray analyses were conducted of six different populations at different tiers of the endodermal lineage hierarchy: undifferentiated hESCs, anterior primitive streak (day 1 of in vitro differentiation), definitive endoderm (day 3) and anterior foregut, posterior foregut or midgut/hindgut patterned endoderm populations (day 7). Additionally, we compared hESCs differentiated using two alternative endoderm induction protocols, serum-based or AFBLy-based differentiation (both day 3 of differentiation).
Project description:A major role of yolk sac endoderm is the uptake of lipids and other constituents from the yolk and transfer of these components into the embryonic circulation. The molecular basis of the initial step of this regionalization has largely remained unclear. Using chick as a model system, we generated high-quality transcriptomic datasets of different stages of the yolksac endoderm and analyzed their molecular heterogeneity. Two independent samples of total RNA were isolated from yolk sac endodermal tissues on embryonic day 1, 2, 3, and 4. 5 μg of RNA from each sample (total of 8 samples) were used to screen Affymetrix Chicken Genome Array without an amplification step.
Project description:The foregut definitive endoderm is the precursor of many tissues including the liver, pancreas, thyroid, lungs, trachea and oesophagus. However, networks and pathways involved in the early development of the definitive endoderm of mammals are not well studied. To identify genes with potential roles in the early development of the foregut definitive endoderm in mouse embryos, we performed microarray analysis to compare the gene expression profile of foregut endoderm and non-endodermal tissues from early somite-stage mouse embryos. ARC/s embryos at 4- to 5-somite stages were collected and the anterior intestinal portal was isolated by digestion with trypsin and pancreatin and mechanical dissection. Ectoderm and mesoderm tissues were dissected from the head folds and the heart, and combined as the non-endoderm tissues for comparison of gene expression profiles. RNA was extracted from 15-20 pooled samples of endoderm or ectoderm plus mesoderm cells and subjected to two rounds of linear amplification and labelling according to standard methods (Affymetrix). The amplified products were hybridized to Affymetrix mouse MOE430 GeneChips. The experiment was performed twice. RNA amplification labelling, hybridization and scanning were performed by the Australian Genome Research Facility. GC-RMA data normalization and further analysis were performed using GenePattern software.
Project description:Endoderm cells undergo a sequence of fate choices to generate insulin-secreting β cells. Studies of chromatin transitions during this process have been limited to the pancreatic progenitor stage that can be reconstituted from stem cells in vitro, with a gap in understanding the induction of endocrine cells. To address this, we established conditions for isolating endoderm cells, pancreatic progenitors, and endocrine cells from different staged embryos and performed genome wide analysis of the H3K27me3 mark of the repressive Polycomb complex. During the transition from endoderm to pancreas progenitors and during the transition from pancreas progenitors to endocrine cells, genes that lose the H3K27me3 mark typically encode transcriptional regulators, whereas genes that acquire the mark typically are involved in cell biology morphogenesis. Precocious depletion of the EZH2, a H3K27 methylase, at the pancreas progenitor stage enhanced the production of endocrine cells, leading to a later increase in pancreatic beta cells. Similarly, pharmacologic inhibition of EZH2 in embryonic pancreatic tissue explants and human embryonic stem cell cultures led to an increase in endocrine progenitors in vitro. These findings reveal a repeating target gene pattern in H3K27me3 dynamics and provide a means to modulate β cell development from stem cells. Analyzed five FACS-sorted tissues in early mouse embryo; for each tissue we sequenced H3K27me3 and input; no replicates
Project description:Foregut organogenesis is regulated by inductive interactions between the endoderm and the adjacent mesoderm. We identified genes induced in the foregut progenitors by the adjacent mesoderm. We used microarrays to detail the global programme of early foregut endoderm gene expression resulting from mesoderm induction and identified distinct classes of up-regulated genes during this process. Xenopus foregut endoderm explants cultured from Stages 15 to 23 either intact with mesoderm or as endoderm alone. Total RNA was isolated from the endoderm of these two culture conditions in quadruplicate and were subjected to Affymetrix microarray analysis.
Project description:In vertebrates the endoderm which gives rise to the epithelial lining of the digestive tract becomes regionalized along its antero-posterior axis after gastrulation. The molecular basis of the initial step of this regionalization has largely remained unclear. Using chick model, we generated high-quality transcriptomic datasets of different stages/regions of the endoderm and analyzed their molecular heterogeneity. Overall design: Total RNA from HH stage 4-5 entire definitive endoderm, HH stages 10-11 foregut endoderm and HH stages 8-10 mid/hindgut endoderm were purified. 5 μg of RNA from each sample were used to screen Affymetrix Chicken Genome Array without an amplification step.
Project description:Expression profiling of mouse embryos at E2.5, E3.5, E4.25, E4.5, E5.5 E6.0 to identify genes regulated during development of the ICM (inner cell mass), TE (Trophectoderm) and PrE (Primative endoderm) Keywords: development dupicate analysis of time points
Project description:To glean an appreciation of the holistic genetic activity in the gastrulating mouse embryo, we performed a genome-wide spatial transcriptome analysis (Stereo-seq), using a low-cell number sequencing protocol on laser microdissected samples of epiblast cells with retained positional address. The 3D transcriptome reveals that (i) the epiblast is partitioned into transcription domains corresponding to regions of epiblast where cells are endowed specifically with ectoderm and mesendoderm potency, (ii) novel lineage markers are identified as genes expressed in epiblast domains populated by cells displaying different lineage fates, (iii) functionally related gene regulatory circuitry and signaling pathways are acting in concert in the transcriptional domains, and (iv) the spatial information provides reference zipcodes for mapping the prospective address of cell samples from different embryos and stem cell lines. The quantified expression data can also be visualized as “3D digitized whole mount in situ hybridization” of all the expressed transcripts in the epiblast. (i) By using laser-microdissection, we carried out transcriptome profiling on embryo sections at a high resolution of ~20 cells per sample with the spatial information preserved. We then constructed a comprehensive spatial transcriptome map in the mid-gastrulation embryo that is visualized in a 3D embryonic model based on the sequencing data. Embryo position (A/L/P/R) and section (1-11) descriptors: A stands for laser capture microdissected samples from the anterior epiblast of the embryo; P for posterior; L for the left lateral epiblast of the embryo; R for the right lateral. The section is collected from distal to proximal, and the section 1 to 11 is the cryosection order, covering the whole embryonic part of a late mid-streak embryo. Section 1 is the most distal section and 11 is the most proximal section. (ii) Additional samples are RNA-seq data of 70 single cells from E7.0 mouse embryo. These 70 samples were randomly picked from the anterior or posterior embryonic half.
Project description:Mouse embryonic stem cells containing a Sox17-GFP construct were differentiated using growth factors (Activin A and Wnt3A) to definitive endoderm. Sox17-GFP(+) cells were sorted using fluorescence activated cell sorting and either used for total RNA harvest OR continued in culture in the presence of primary pancreatic mesenchymal cell lines. At the end of 6 serial passages on mesenchyme, the Sox17-GFP(+) cells were again sorted and the RNA was harvested for arrays. Samples were prepared as described in summary, with technical duplicates for each of the following 3 categories: 1. Unpassaged (P0) endoderm, 2. Endoderm passaged 6 times (P6) on mesenchyme 1, and 3. Endoderm passaged 6 times (P6) on mesenchyme 2.
Project description:This dataset uses DNase-seq to profile the genome-wide DNase I hypersensitivity of mES and mES-derived cells along an early pancreatic lineage and provides the locations of putative Transcription Factor (TF) binding sites using the PIQ algorithm. DNase-seq takes advantage of the preferential cutting of DNase I in open chromatin and steric blockage of of DNase I by tightly bound TFs that protect associated genomic DNA sequences. After deep sequencing of DNase I–digested genomic DNA from intact nuclei, genome-wide data on chromatin accessibility as well as TF-specific DNase I protection profiles that reveal the genomic binding locations of a majority of TFs are obtained. Such TF signature ‘DNase profiles’ reflect the effect of the TF on DNA shape and local chromatin architecture, extending hundreds of base pairs from a TF binding site, and these profiles are centered on ‘DNase footprints’ at the binding motif itself, which reflects the biophysics of protein-DNA binding. An algorithm, PIQ, is then applied that models the specific profile of each factor, and in combination with sequence information predicts the likely binding locations of over 700 TFs genome wide. This dataset includes DNase-seq hypersensitivity data from 6 mES-derived cell types: mESC, Mesendoderm, Mesoderm, Endoderm, Intestinal Endoderm, and Prepancreatic Endoderm. For each cell type, TF binding site predictions are made based on the identification TF-specific DNase-seq profiles over any of 1331 possible binding motifs. After significance thesholding, genome-wide binding site predictions for <700 TFs are included.