Maintaining cell fate relies on robust mechanisms that prevent the differentiation of specified cells into other cell types. This is especially critical during embryogenesis, when extensive cell proliferation, patterning and migration events take place. Here we show that vertebrate primordial germ cells (PGCs) are protected from reprogramming into other cell types by the RNA-binding protein Dead end (Dnd). PGCs knocked down for Dnd lose their characteristic morphology and adopt that of various somatic cell types. Concomitantly, they gain a gene expression profile reflecting differentiation into cells of different germ layers, in a process that we could direct by expression of specific cell-fate determinants. Importantly, we visualized these events within live zebrafish embryos, which provide temporal information regarding cell reprogramming. Our results shed light on the mechanisms controlling germ cell fate maintenance and are relevant for the formation of teratoma, a tumor class composed of cells from more than one germ layer. Overall design: Transcriptome profiling of 13hpf sorted germ cells of zebrafish embryos injected with either control or dead end Morpholino
The Vertebrate Protein Dead End Maintains Primordial Germ Cell Fate by Inhibiting Somatic Differentiation.
Specimen part, Cell line, Subject
View SamplesWorldwide, more than 1 billion people are affected by infestations with soil-transmitted helminths and also in veterinary medicine helminthiases are a severe thread to livestock due to emerging resistances against the common anthelmintics. Proanthocyanidins have been increasingly investigated for their anthelmintic properties, however, except for an interaction with certain proteins of the nematodes, not much is known about their mode of action. To investigate the anthelmintic activity on a molecular level, a transcriptome analysis was performed in Caenorhabditis elegans after treatment with purified and fully characterized oligomeric procyanidins (OPC). The OPCs had previously been obtained from a hydro-ethanolic (1:1) extract from the leaves of Combretum mucronatum, a plant which is traditionally used in West Africa for the treatment of helminthiasis, therefore, also the crude extract was included in the study. Significant changes in differential gene expression were observed mainly for proteins related to the intestine, many of which were located extracellularly or within cellular membranes. Among the up-regulated genes, several hitherto undescribed orthologues of structural proteins in humans were identified, but also genes that are potentially involved in the worms defense against tannins. For example, T22D1.2, an orthologue of human basic salivary proline-rich protein (PRB) 2, and numr-1 (nuclear localized metal responsive) were found to be strongly up-regulated. Down-regulated genes were mainly associated with lysosomal activity, glycoside hydrolysis or the worms innate immune response. No major differences were found between the groups treated with purified OPCs versus the crude extract. Investigations using GFP reporter gene constructs of T22D1.2 and numr-1 corroborated the intestine as the predominant site of the anthelmintic activity.
Transcriptome analysis reveals molecular anthelmintic effects of procyanidins in C. elegans.
Specimen part, Treatment
View SamplesStaphylococcus aureus thymidine-dependent small-colony variants (TD-SCVs) are frequently isolated from patients with chronic S. aureus infections after long-term treatment with trimethoprim-sulfamethoxazole (TMP-SMX). In TD-SCVs, mutations of thymidylate synthase (thyA, TS), essential for DNA synthesis, occur. However, it has never been shown, that TMP-SMX is responsible for the induction and selection of TD-SCVs. Short-term exposure of TMP-SMX induced the TD-SCV phenotype morphologically as shown in transmission electron-microscopy and on the transcriptional level by qRT-PCR in wild-type S. aureus, while selection of TD-SCVs with thyA mutations occurred only rarely after long-term exposure. In reversion experiments with clinical TD-SCVs, all revertants revealed compensating mutations at the initially identified mutation site. Whole DNA microarray analysis of a thyA deletion mutant (thyA), which exhibited the typical TD-SCV phenotype, identified tremendous alterations compared to the wild-type. Important virulence regulators such as agr, arlRS, sarA and major virulence determinants including hla, hlb, sspA, sspB and geh were down-regulated, while genes associated with the colonization capacity like fnbA, fnbB, spa, clfB, sdrC and sdrD were up-regulated. The expression of genes involved in pyrimidine and purine metabolism as well as in nucleotide interconversion changed significantly. The thyA-mutant was attenuated in virulence in both, a Caenorhabditis elegans killing model and an acute murine pneumonia model. Furthermore, competition experiments in vitro and in vivo (using a chronic pneumonia mouse model) revealed a survival and growth advantage of the thyA-mutant under low thymidine conditions and TMP-SMX exposure. In conclusion, our results clearly show for the first time that TMP-SMX induces the TD-SCV phenotype after short-term exposure in S. aureus and that long-term exposure selects thyA mutations providing an advantage for TD-SCVs under specified conditions. Thus, our results help to understand the dynamic processes of induction and selection of S. aureus TD-SCVs during TMP-SMX exposure.
Inactivation of thyA in Staphylococcus aureus attenuates virulence and has a strong impact on metabolism and virulence gene expression.
Time
View SamplesRNA-seq libraries were generated on thymic epithelial cell (TEC) subsets from thymic samples (11 days to 3 months of age). Cells were sorted to isolate cortical TEC (cTEC), MHC low medullary TEC (mTEClo) and MHC high medullary TEC (mTEChi). Between 7,575 and 50,000 cells were isolated for each sample. TEC were isolated using CD45 MACS depletion followed by the sorting protocol described in Stoeckler et al. J Vis Exp 2013 (PMID 24084687; doi: 10.3791/50951). The study has been granted ethical approval and is publicly listed (IRAS ID 156910, CPMS 19587). Overall design: 1 sample for each of cTEC, mTEClo and mTEChi were generated on a total of 3 individuals (~50,000 cells per sample) and 3 replicates for each of cTEC, mTEClo and mTEChi were generated on 1 individual (7,575 cells per sample)
Keratinocyte growth factor impairs human thymic recovery from lymphopenia.
Specimen part, Subject
View SamplesMammalian nephrons are the physiological subunits of mammalian kidneys which consist of different highly apicobasally polarized epithelial cell types. In epithelial cells polarization is controlled by evolutionary conserved CRB, PAR, or SRIB complexes. Here, we focused on the role of Pals1/Mpp5 in the nephron. Pals1, a core component of the apical membrane determining CRB complex, is highly expressed in renal tubular epithelial and glomerular epithelial cells (podocytes). Surprisingly, haplo-deficient mice, lacking one Pals1/Mpp5 allele in the nephron developed a strong phenotype, accompanied by cyst formation and severe renal filtration barrier defects, which subsequently lead to death after 6-8 weeks. Supporting studies in Drosophila nephrocytes, and epithelial cell culture models elucidated the role of Pals1 as a dose dependent upstream regulator of the crosstalk between Hippo- and TGF-signaling during nephrogenesis.
Pals1 Haploinsufficiency Results in Proteinuria and Cyst Formation.
Specimen part
View SamplesAberrant activation of the Akt pathway has been implicated in several human pathologies including cancer. However, current knowledge on the involvement of Akt signaling in development is limited. Previous data have suggested that Akt-mediated signaling may be an essential mediator of epidermal homeostasis through cell autonomous and non-cell autonomous mechanisms. Here we report the developmental consequences of deregulated Akt activity in the basal layer of stratified epithelia, mediated by the expression of a constitutively active Akt1
Constitutively active Akt induces ectodermal defects and impaired bone morphogenetic protein signaling.
Age, Specimen part
View SamplesWe purified Atoh1-GFP positive hair cells from organotypic cultures of P1 cochlea 3 hours after 0.5mM gentamicin treatment and performed RNA sequencing to profile the early transcriptional response of hair cells to aminoglycoside antibiotics. Overall design: Levels of mRNA in gentamicin-treated hair cells (three replicates) were compared to untreated hair cells (three replicates). GFP negative, non-hair cells populations from treated organs were compared to those from untreated organs (three replicates for each condition).
Early transcriptional response to aminoglycoside antibiotic suggests alternate pathways leading to apoptosis in sensory hair cells in the mouse inner ear.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Clonal Variation in Drug and Radiation Response among Glioma-Initiating Cells Is Linked to Proneural-Mesenchymal Transition.
Specimen part, Cell line
View SamplesIntra-tumor heterogeneity is a hallmark of glioblastoma multiforme, and thought to negatively affect treatment efficacy. Here we establish libraries of glioma-initiating cell (GIC) clones from patient samples and find extensive molecular and phenotypic variability between clones, including a wide range of responses to radiation and drugs. This widespread variability was observed as a continuum of multitherapy resistance phenotypes linked to a proneural-to-mesenchymal shift in the transcriptome.
Clonal Variation in Drug and Radiation Response among Glioma-Initiating Cells Is Linked to Proneural-Mesenchymal Transition.
Specimen part, Cell line
View SamplesThis study aimed to characterize differences in gene expression in piglets inoculated with porcine circovirus type 2 (PCV2), the essential causative agent of postweaning multisystemic wasting syndrome (PMWS). Comparisons between control and PCV2-inoculated pigs were done at five different time points: 1, 2, 5, 8, and 29 days post-inoculation.
Time course differential gene expression in response to porcine circovirus type 2 subclinical infection.
Age, Specimen part
View Samples