Transcription profiling of animal caps from Danio rerio embryos expressing GFP or vhnf1 and treated with FGF8 or BSA protein
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ABSTRACT: Zebrafish embryo animal cap explants were differentiated by injection of vhnf1 mRNA into the one-cell stage embryo, and treatment of excised explants with applied FGF8 protein. To identify unique targets of the combination of vhnf1+FGF8, each factor was applied alone and in combination, and differences in gene expression used to identify unique targets of vhnf1+FGF8.
Project description:Pronephric explants were dissected in the presence or absence of hedgehog signaling. Targets from pooled biological samples were examined in triplicate and the expression profiles were determined using Affymetrix Xenopus Genechip 1 arrays. Experiment Overall Design: 3 bhh treated pooled explants and 3 untreated pooled explants were analyzed
Project description:Animal pole tissue explants were dissected from either untreated embryos or embryos injected with 1 ng of Notch Intracellular Domain RNA (NICD) at the two cell stage. Tissue explants were dissected and cultured until sibling embryos reached embryonic stage 20. Each array hybridization represents a biological replicate containing approximately 100 tissue explants. Expression profiles were determined using Affymetrix Xenopus Genechip 1 arrays. Experiment Overall Design: 4 untreated pooled explants, 2 NICD treated explants
Project description:Small pieces (<0.5 cm of diameter) were isolated from distal regions of 125 day male human fetal lung and cultured on floating poly-carbonate membranes on top of serum and growth factor free medium under air-liquid interface conditons (ALI). ALI explants underwent changes in gene expression indicative of alveolar epithelial cell differentiation under these conditions. scRNA-sequencing was performed on fetal tissue prior to culture (day 0) and day 3, 6, 9 and 12 of ALI explant culture.
Project description:Purpose: We wished to obtain spatial expression profiles of transcription factor gene expression and expression of other genes. Methods: Embryos were dissected and RNA-seq was performed to determine expression levels of genes. Comparisons between explanted regions permits determination of spatial enrichment of gene expression. mRNA-seq performed on 5 dissected regions of NF stage 10.5 X. tropicalis embryos and stage-matched sibling whole embryos. Experiment performed in duplicate.
Project description:The response of ectodermal explants, neuralized by noggin and treated with cycloheximide, following activation of hormone-inducible zic1 injected into the parent embryos compared to those from beta globin injected embryos as controls, is expected to provide information on the direct targets of the Zic1 transcription factor. Experiment Overall Design: Activation of zic1 in ectodermal explants following inhibition of new protein synthesis allowed the direct targets of zic1 to be identified by comparison with controls. After RNA extraction, purification and checks with PCR with actin primers for any mesoderm contamination samples were prepared for hybridization to Xenopus laevis Affymetrix GeneChip arrays.
Project description:The goal of this study is to investigate the molecular mechanism of lhx1 on regulation of pronephros formation during the early embryonic development. In the vertebrate embryo the kidney is derived from the intermediate mesoderm. The LIM-class homeobox transcription factor lhx1 is expressed early in the intermediate mesoderm and is one of the first genes to be expressed in the nephric mesenchyme. The animal cap cells can be induced by treatment of activin and retinoic acid to differentiate into pronephros tissue. In this study we investigated the role of Lhx1 in differentiation of pronephros by depleting lhx1 in the organ culture system. We generated the gene expression profile of early pronephros tissue, and demonstrated that expression of genes from all the kidney domains is affected by the absence of lhx1. Taken together our results highlight an essential role for Lhx1 in pronephros formation. lhx1 is involved in driving specification of intermediate mesoderm into nephrogenic mesenchyme. Lhx1 is initially expressed throughout the entire intermediate mesoderm. To determine the role of lhx1 pronephros formation, we performed a microarray analysis using an explant culture system. Xenopus tissue explants can be surgically isolated and cultured under specific conditions to be driven towards many distinct tissue types. Formation of pronephric cell fates is induced by culturing isolated explants in the presence of Activin and RA (AcRA). Treatment of dissected explants of stage 9 blastulae embryos with 10ng/ml Activin and 1x10-4 M retinoic acid can induce differentiation of the pluripotent ectoderm into pan-kidney tissue. For this experiment, both blastomeres of 2-cell embryos were injected with a total of 800pg lhx1 DEED-AS. Explants were dissected and treated with AcRA and expression of pax8 at stage 15 (based on timing of paired control whole embryos) was analyzed. We observed a lack of induction of pax8 expression in lhx1-depleted explants under AcRA treatment conditions in which expression of this gene is normally induced. Based on this observation, microarray analysis was carried out to identify genes whose expression is affected by the absence of lhx1. Explants of injected embryos with 800pg of lhx1 DEED-AS were dissected, treated with pronephric tissue inductive conditions (AcRA) and harvested after 24 hours incubation at 14C (Fig. S5B). The sibling control embryos reached stage 12.5. Explants from uninjected embryos +AcRA and -AcRA as well as explants from DEED injected embryos -AcRA were also harvested. Approximately 12 caps were pooled for each RNA preparation and the analysis was performed using triplicates.
Project description:The Xenopus POU class V transcription factor XOct-25 has been shown to inhibit BMP-dependent epidermal differentiation and promote neural induction in the ectoderm during early embryogenesis. In order to identify genes that act downstream of XOct-25, transcriptional profile of Xenopus ectodermal cells overexpressing XOct-25 was compared with control cells by using a DNA microarray method. Two independent experiments. Each experiment contains ectodermal cells overexpressing XOct-25 and corresponding control cells. Xenopus embryos were injected at the 8-cell stage with mRNA encoding GR-XOct-25, a hormone-inducible version of XOct-25. Explants from stage 9 embryos were treated with or without dexamethazone (DEX) until the sibling embryos reached stage 10.5, when they were used for RNA extraction. The explants cultured without DEX was used as a control sample. biological replicates: Sample name XOct-exp 1, Sample name XOct-exp 2
Project description:We screened for differentially expressed genes in the developing notochord using the Affymetrix microarray system in Xenopus laevis. At late gastrula, we dissected four regions from the embryo, anterior mesoderm, posterior mesoderm, notochord and presomitic mesoderm. Three types of comparison were carried out to generate a list of predominantly notochord expressed genes: (1) Posterior mesoderm vs. anterior mesoderm; notochord genes are expected to be increased since the notochord is located in the posterior mesoderm. (2) Posterior mesoderm vs. whole embryos; notochord genes are expected to be increased. (3) Notochord vs. somite. This comparison sub-divided the group of posterior mesodermal genes identified in (1) and (2). All tissues are dissected using tungsten needles. We first dissected dorsal tissue above the archenteron from late gastrula to early neurula. To loosen tissue, we treated the dissected dorsal explant in a 1% cysteine solution (pH 7.4) and removed the neuroectodermal layer. Anterior mesoderm was dissected corresponding to about the anterior one-third of the archenteron roof, and the rest was collected as posterior mesoderm. The posterior mesodermal explant was dissected into notochord and somites, following a clearly visible border between the two tissues. The accuracy of all dissection was confirmed by RT-PCR of marker genes.
Project description:The cost of Carica papaya production through seed-based propagation is increased by sex segregation, making in vitro techniques a more appealing option for clonal propagation. Inducing embryogenic callus with 2,4-dichlorophenoxyacetic acid (2,4-D) hold the potential to large-scale cloning, although the molecular mechanisms underlying this process are still not well understood. In this study, we performed a temporal analysis in the proteome of C. papaya callus to identify the key players involved in embryogenic differentiation. Mature zygotic embryos were used as explants and treated with 20 μM 2,4-D to induce embryogenic callus. Total proteins were extracted at 0, 7, 14, and 21 days (T0, T7, T14, and T21), and 1407 proteins were identified using bottom-up proteomic approach. Comparative proteomics revealed 957 differentially accumulated proteins (DAPs) (p<0.05 and log2FC >0.585 or <-0.585) in at least one comparison between the analyzed induction times points. The clustering analysis revealed four clusters with distinct patterns of protein accumulation throughout the embryogenic callus induction treatment. The cluster 1 contains 386 DAPs that accumulated at all analyzed times after treatment with 2,4-D. In contrast, cluster 2 contains 165 DAPs that decrease in abundance during the induction. The cluster 3 contains 251 proteins that are most abundant just after the start of incubation in 2,4-D (T7) and cluster 4 grouped 155 proteins that accumulate after callus formation. Functional analysis revealed that proteins involved with reserve storage and seed maturation were more abundant in the explant at T0 and decreased as callus formation progressed. Biological processes involving carbohydrate and amino acid metabolism, aerobic respiration, and protein catabolic processes were enriched after induction treatment. Regulatory proteins, including histone deacetylase (HDT3) and argonaute 1, were more abundant after the start of induction treatment with 2,4-D, suggesting their role in acquisition of embryogenic competence. Predicted protein-protein networks revealed the regulatory role of proteins 14.3.3 accumulated during callus induction and the association of proteins involved in oxidative phosphorylation, hormone response, and SAM metabolism. Our findings emphasize the modulation of the proteome at different stages during embryogenic callus initiation and identify regulatory proteins that might be involved with the activation of this process.
Project description:Transcriptional profiling of small and large intestinal explants cultured in the absence or in the presence of EGF (50 ng/mL). Two-condition experiment, control intestinal explants vs EGF intestinal explants