The patterning of the facial midline involves early specification of neural crest cells to form skeletal tissues that support the upper jaw . In order to understand the molecular mechanisms involved we have taken advantage of a beak duplication model developed in the chicken embryo. Here we can induce the transformation of the side of the beak into a second midline that is easily identifiable by the formation of a supernumerary egg tooth. The phenotype is induced by implanting two microscopic beads, one soaked in retinoic acid and the other soaked in Noggin into the side of the head of the chicken embryo. Here we use microarrays to profile expression of maxillary mesenchyme 16h after placing the beads. A subset of genes were validated using in situ hybridization and QPCR. The aims of the study are to test the function of these genes using retroviral transgenesis, knockdown with morpholinos or expression of secreted proteins and their application to the embryo.
Identification and functional analysis of novel facial patterning genes in the duplicated beak chicken embryo.
Specimen part, Treatment
View SamplesThe face is one of the three regions most frequently affected by congenital defects in humans. In order to understand the molecular mechanisms involved it is necessary to have a more complete picture of gene expression in the embryo. Here we use microarrays to profile expression in chicken facial prominences, post neural crest migration and prior to differentiation of mesenchymal cells. Chip-wide analysis revealed that maxillary and mandibular prominences had similar expression profiles while the frontonasal mass chips were distinct. Of the 3094 genes that were differentially expressed in one or more regions of the face, a group of 56 genes was subsequently validated with quantitative PCR and a subset examined with in situ hybridization. Microarrays trends were consistent with the QPCR data for the majority of genes (81%). On the basis of QPCR and microarray data, groups of genes that characterize each of the facial prominences can be determined.
Whole genome microarray analysis of chicken embryo facial prominences.
Specimen part
View SamplesThe wheat gene Lr34 (Yr18/Pm38/Sr57/Ltn1) encodes a putative ABCG-type of transporter and is a unique source of disease resistance providing durable and partial resistance against multiple fungal pathogens. Lr34 has been found to be functional as a transgene in barley.
The wheat resistance gene Lr34 results in the constitutive induction of multiple defense pathways in transgenic barley.
Specimen part
View SamplesThe mycotoxin deoxynivalenol (DON) is a secondary metabolite from Fusarium species and is frequently present on wheat and other cereals. The main effects of DON are a reduction of the feed intake and reduced weight gain of broilers. At the molecular level DON binds to the 60S ribosomal subunit and inhibits subsequently protein synthesis at the translational level. It has been suggested that cells and tissues with high protein turnover rate, like the liver and small intestine, are most affected by DON. However, little is known about other effects of DON e.g. at the transcriptional level. Therefore we decided to perform a microarray analysis, which allows us the investigation of thousands of transcripts in one experiment.
Fusarium mycotoxin-contaminated wheat containing deoxynivalenol alters the gene expression in the liver and the jejunum of broilers.
Age, Specimen part, Treatment
View SamplesPtf1a was identified as the essential transcription factor which controls pancreatic exocrine enzyme expression. With lineage tracing eperiments Ptf1a was recognized as an important pancreatic progenitor transcription factor and Ptf1a null mice do not develop a pancreas.
RNA profiling and chromatin immunoprecipitation-sequencing reveal that PTF1a stabilizes pancreas progenitor identity via the control of MNX1/HLXB9 and a network of other transcription factors.
Specimen part
View SamplesTime course of early development of peripheral nerve, from embryonic day 9.5 to postnatal day 0.
Efficient isolation and gene expression profiling of small numbers of neural crest stem cells and developing Schwann cells.
No sample metadata fields
View SamplesRegulation of mRNA stability by RNA-protein interactions contributes significantly to quantitative aspects of gene expression. We have identified potential mRNA targets of the AU-rich element binding protein AUF1. Myc-tagged AUF1 p42 was induced in mouse NIH-3T3 cells and RNA-protein complexes isolated using anti-myc tag antibody beads. Bound mRNAs were analyzed with Affymetrix microarrays. We have identified 508 potential target mRNAs that were at least 3-fold enriched compared to control cells without myc-AUF1. 22.3% of the enriched mRNAs had an AU-rich cluster in the ARED Organism database, against 16.3% of non-enriched control mRNAs. The enrichment towards AU-rich elements was also visible by AREScore with an average value of 5.2 in the enriched mRNAs versus 4.2 in the control group. Yet, many mRNAs were enriched without a high ARE score suggesting that AUF1 has a broader binding spectrum than standard AUUUA repeats. AUF1 did not preferentially bind to unstable mRNAs. Still, some enriched mRNAs were highly unstable, as those of TNFSF11 (known as RANKL), KLF10, HES1, CCNT2, SMAD6, and BCL6. We have mapped some of the instability determinants. HES1 mRNA appeared to have a coding region determinant. Detailed analysis of the RANKL and BCL6 3UTR revealed for both that full instability required two elements, which are conserved in evolution. In RANKL mRNA both elements are AU-rich and separated by 30 bases, while in BCL6 mRNA one is AU-rich and 60 bases from a non AU-rich element that potentially forms a stem-loop structure.
Short-lived AUF1 p42-binding mRNAs of RANKL and BCL6 have two distinct instability elements each.
Cell line
View SamplesEstrogens and progesterone control mammary gland development and breast carcinogenesis via their cognate receptors expressed in a subset of cells of the luminal layer of the mammary epithelium. The extracellular matrix (ECM) including the basement membrane (BM) is important in breast physiology and tumorigenesis but how epithelial hormone receptor signaling and ECM are linked mechanistically is unclear. We identify the secreted protease Adamts18 as critical intermediary. Luminal estrogen and progesterone receptor signaling via upregulation of Wnt4 expression and ensuing canonical Wnt signaling activation in basal cells control Adamts18 expression there. The protease has an epithelial-intrinsic role in stem cell activation. We identify multiple binding partners in the interstitial ECM and BM and show that ADAMTS18 cleaves fibronectin in vitro. Its deletion results in increased fibronectin, collagen I and IV, and laminin deposition in pubertal glands. Adamts18 interacts genetically with Col18a1, which encodes a proteoglycan that is BM-specific, in stem cell regulation. Adamts18 inactivation impairs Hippo signaling and reduces Fgfr2 expression and signaling, which are vital for stem cell function. Our findings link epithelial hormone signaling to BM remodeling by Adamts18, and define the BM as an essential stem cell niche component.
The secreted protease Adamts18 links hormone action to activation of the mammary stem cell niche.
No sample metadata fields
View SamplesDiffuse large B-cell lymphoma (DLBCL) represents the most common form of lymphoma. We could show that in DLBCL cell lines the transcription factor NFAT is constitutively activated and drives the survival of a DLBCL subset. Aim of the analysis was to identify NFAT target genes in a NFAT-dependent (HBL-1) or -independent (HT) DLBCL cell line. To block NFAT activity, the DLBCL cells were treated with the calcineurin inhibitor cyclosporin A (CsA) up to 48 h. With this approach, we identified several survival-related NFAT target genes in HBL-1 cells that might explain the toxic effects of calcineurin inhibitors.
Targeting chronic NFAT activation with calcineurin inhibitors in diffuse large B-cell lymphoma.
Treatment
View SamplesRNA-seq profiling was conducted on clinically-annotated human pancreatic adenocarcinoma cancer tissues Overall design: We measured the transcriptome in 51 clinically-annotated human pancreatic adenocarcinoma cancer tissues
RNA sequencing of pancreatic adenocarcinoma tumors yields novel expression patterns associated with long-term survival and reveals a role for ANGPTL4.
Age, Subject
View Samples