The first embryonic cell divisions rely on maternally stored mRNA and proteins. The zygotic genome is initially transcriptionally silenced and activated later in a process called zygotic genome activation (ZGA). ZGA in any species is still a poorly understood process; the timing of transcription onset is controversial and the identity of the first transcribed genes unclear. Zebrafish, Danio rerio, is a rapidly developing vertebrate model, which is accessible to experimentation and global studies before, during and after ZGA. Overall design: To accurately determine the onset of ZGA and to identify the first transcripts in zebrafish, we developed a metabolic labeling method, utilizing the ribonucleotide analog 4-thio-UTP, which allows efficient and specific affinity purification of newly transcribed RNA. Using deep sequencing, we characterized the onset of transcription in zebrafish embryos at 128-, 256-, and 512-cell stages. We identified 592 nuclear-encoded zygotically transcribed genes, comprising 670 transcript isoforms. Mitochondrial genomes were highly transcribed at all time points. Further, bioinformatic analysis revealed an enrichment of transcription factors and miRNAs among the newly transcribed genes, suggesting mechanistic roles for the early genes that are required to activate subsequent gene expression programs in development. Interestingly, analysis of gene-architecture revealed that zygotically transcribed genes are often intronless and short, reducing transcription and processing time of the transcript. The newly generated dataset enabled us to compare zygotically transcribed genes over a broad phylogenetic distance with fly and mouse early zygotic genes. This analysis revealed that short gene length is a common characteristic for early zygotically expressed genes. However, we detected a poor level of overlap for shared orthologs.
The earliest transcribed zygotic genes are short, newly evolved, and different across species.
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View SamplesCyclosporin A induces expression of proapoptotic factors when cells are challenged by increased tonicity
Cyclosporin-A induced toxicity in rat renal collecting duct cells: interference with enhanced hypertonicity induced apoptosis.
Specimen part, Treatment
View SamplesCoilin iCLIP data revealed 42 novel human snoRNAs of intronic origin. To validate their expression and estimate abundance of novel and annotated snoRNAs, we performed RNA-seq on polyA- and rRNA-depleted RNA isolated from HeLa cells. Results show that expression of novel snoRNAs is comparable to the previously annotated snoRNAs. Overall design: 1 replicate of RNA depleted of polyA and ribosomal RNA.
The coilin interactome identifies hundreds of small noncoding RNAs that traffic through Cajal bodies.
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View SamplesThe heat shock response (HSR) is a mechanism to cope with proteotoxic stress by inducing the expression of molecular chaperones and other heat shock response genes. The HSR is evolutionarily well conserved and has been widely studied in bacteria, cell lines and lower eukaryotic model organisms. However, mechanistic insights into the HSR in higher eukaryotes, in particular in mammals, are limited. We have developed an in vivo heat shock protocol to analyze the HSR in mice and dissected heat shock factor 1 (HSF1)-dependent and -independent pathways. Whilst the induction of proteostasis-related genes was dependent on HSF1, the regulation of circadian function related genes, indicating that the circadian clock oscillators have been reset, was independent of its presence. Furthermore, we demonstrate that the in vivo HSR is impaired in mouse models of Huntington's disease but we were unable to corroborate the general repression of transcription after a heat shock found in lower eukaryotes. Overall design: RNA-Seq was performed on mRNA isolated from quadriceps femoris muscle of 24 mice. These mice were of wild type, R6/2, and Hsf1-/- genotypes. Two mice of each genotype were tested in four conditions: (1) heat shock, (2) control heat shock, (3) HSP90 inhibition (NVP-HSP990), and (4) HSP90 inhibition vehicle.
HSF1-dependent and -independent regulation of the mammalian in vivo heat shock response and its impairment in Huntington's disease mouse models.
Age, Specimen part, Treatment, Subject
View SamplesCaspase-8 is a cystein protease involved in regulating apoptosis. The function of caspase-8 was studied in the intestinal epithelium, using mice with an intestinal epithelial cell specific deletion of caspase-8.
Caspase-8 regulates TNF-α-induced epithelial necroptosis and terminal ileitis.
Specimen part
View SamplesPurpose: Transcriptome profiling (RNA-seq) to microarray to evaluate transcriptional changes in the heart of HD mouse models Methods: Heart mRNA profiles of 4-weeks-old wild-type (WT) and R6/2 transgenic; 15-weeks-old WT and R6/2 transgenic mice; 8-month-old WT and HdhQ150 knock-in mice; 22-month-old WT and HdhQ150 knock-in mice were generated by deep sequencing, in triplicate, using Illumina Hi-seq 2000. Conclusions: Our study showed that there is no major transcriptional deregulation in the heart of mouse models of HD. Overall design: Heart mRNA profiles of 4-weeks-old wild-type (WT) and R6/2 transgenic; 15-weeks-old WT and R6/2 transgenic mice; 8-month-old WT and HdhQ150 knock-in mice; 22-month-old WT and HdhQ150 knock-in mice were generated by deep sequencing, in triplicate, using Illumina Hi-seq 2000.
Dysfunction of the CNS-heart axis in mouse models of Huntington's disease.
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View SamplesCell Line: This experiment was designed to measure the transcriptional responses to four kinase inhibitors across a five-logarithm dose range. The A549 human lung cancer cell line was treated with dasatinib, imatinib or nilotinib (4 hours and 20 hours) or PD0325901 (4 hours). Treatments used a 12-point dose range (30 uM with 3-fold dilutions down to 0.17 nM; 0.5% DMSO vehicle for all treatments). Experimental design prevented row or column handling effects being confounded with dose effect.
Transcriptional profiling of the dose response: a more powerful approach for characterizing drug activities.
Disease, Cell line, Compound, Time
View SamplesGene expression profiling on IL-10-secreting and non-secreting murine Th1 cells, stimulated in the presence or absence of the Notch ligand Delta-like 4 (Dll4), was performed to identify transcription factors co-expressed with IL-10.
Role of Blimp-1 in programing Th effector cells into IL-10 producers.
Specimen part
View SamplesTo uncover molecular mechanisms specifically involved in the pathogenesis of colitis-associated colon cancer (CAC), we studied tumorigenesis in experimental models of CAC and sporadic CRC that mimic characteristics of human CRC. Using comparative whole genome expression profiling, we observed differential expression of epiregulin (Ereg) in mouse models of colitis-associated, but not sporadic colorectal cancer. Similarly, highly significant upregulation of Ereg expression was found in cohorts of patients with colitis-associated cancer in inflammatory bowel disease but not in sporadic colorectal cancer. Furthermore, tumor-associated fibroblasts were identified as major source of Ereg in colitis-associated neoplasias. Functional studies showed that Ereg-deficient mice, although more prone to colitis, are strongly protected from colitis-associated tumors, and data from serial endoscopic studies revealed that Ereg promotes growth rather than initiation of tumors.
Tumor fibroblast-derived epiregulin promotes growth of colitis-associated neoplasms through ERK.
Sex, Specimen part
View SamplesUsing various exposure conditions, we studied the induction of DNA-protein crosslinks (DPX) by formaldehyde (FA) and their removal in primary human nasal epithelial cells (HNEC). DPX were indirectly measured by the alkaline comet assay as the reduction of gamma ray induced DNA migration. DPX are the most relevant primary DNA alterations induced by FA and the comet assay is a very sensitive method for the detection of FA-induced DPX. In parallel experiments, we investigated changes in gene expression by using a full genome human microarray. After a single treatment with FA (50 to 200 M), concentration and time-dependent changes in gene expression were seen under conditions that also induced genotoxicity. Repeated treatments with low FA concentrations (20 and 50 M) did not lead to a significant induction of DPX but repeated treatments with 50 M FA changed the expression of more than 100 genes. Interestingly, the expression of genes involved in the main pathway for FA detoxification and the repair of DPX were not specifically enhanced. A high degree of overlap was seen among the pattern of gene changes induced by FA in HNEC in comparison to recently published array studies for nasal epithelial cells from rats exposed to FA in vivo. Our results suggest that HNEC are a suited in vitro model for the characterization of FA-induced toxicity and the relationship between genotoxic and other cytotoxic effects.
Gene expression changes in primary human nasal epithelial cells exposed to formaldehyde in vitro.
Specimen part, Treatment
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