Embryonic stem (ES) cells and ES cell-derived progeny characterized by nestin expression (including neural progenitors) were studied (three independent experiments). The mouse ES cell line R1 was cultured on a feeder layer of mouse embryonic fibroblasts (FL). ES cells were differentiated into nestin-positive cells for 4+8 days and 4+11 days according to the differentiation protocol by Rolletschek et al. (Mechanisms of Development 105, 93-104, 2001).
Pluripotency associated genes are reactivated by chromatin-modifying agents in neurosphere cells.
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View SamplesEstrogen has vascular protective effects in premenopausal women and in women under 60 receiving hormone replacement therapy. However, estrogen also increases risks of breast and uterine cancers and of venous thromboses linked to upregulation of coagulation factors in the liver. In mouse models, the vasoprotective effects of estrogen are mediated by the estrogen receptor alpha (ERa) transcription factor. Here, through next generation sequencing approaches, we show that almost all of the genes regulated by 17-b-estradiol (E2) differ between mouse aorta and mouse liver, and that this is associated with a distinct genomewide distribution of ERa on chromatin. Bioinformatic analysis of E2-regulated promoters and ERa binding site sequences identify several transcription factors that may determine the tissue specificity of ERa binding and E2-regulated genes, including the enrichment of NFkB, AML1 and AP-1 sites in the promoters of E2 downregulated inflammatory genes in aorta but not liver. The possible vascular-specific functions of these factors suggests ways in which the protective effects of estrogen could be promoted in the vasculature without incurring negative effects in other tissues. Our results also highlight the likely importance of rapid signaling of membrane-associated ERa to cellular kinases (altering the activities of transcription factors other than ER itself) in determining tissue specific transcriptional responses to estrogen. Overall design: The aortas or liver fragments of wild-type C57/BL6 mice were incubated ex vivo with 10nM E2 or ethanol vehicle for 4 hours before harvesting for RNA collection. Each condition was performed with two biological replicates, and each replicate contained aortas or liver fragments from 4 mice.
Research resource: Aorta- and liver-specific ERα-binding patterns and gene regulation by estrogen.
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View SamplesTo determine if aberrant activation of endothelin-1 (Et1) could lead to the dysregulation of many downstream genes, we exposed fibroblasts to exogenous ET1 peptide and assayed for transcriptional changes by microarray. Mouse dermal fibroblasts were treated with exogenous Et1 peptide for 24 hours. ET1 treatment resulted in significant expression changes primarily downregulation of a number of genes. In particular, Tgf2 and Tgf3 were among the downregulated genes, which in turn alter the expression status of their many target genes. These data suggest that the stable silencing of Et1 is important for the phenotypic stability of dermal fibroblasts, and perhaps many other cell types as well.
Localized methylation in the key regulator gene endothelin-1 is associated with cell type-specific transcriptional silencing.
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View SamplesAlthough it is increasingly accepted that some paternal environmental conditions can influence phenotypes in future generations, it generally remains unclear whether the phenotypes induced in offspring represent specific responses to particular aspects of the paternal exposure history, or whether they represent a more generic response to paternal “quality of life”. To establish a paternal effect model based on a known ligand-receptor interaction and thereby enable pharmacological interrogation of the specificity of the offspring response, we explored the effects of paternal nicotine administration on offspring phenotype in mouse. We show that chronic paternal exposure to nicotine prior to reproduction induced a broad protective response to multiple xenobiotics in the next generation. This effect manifested as increased survival following an injection of toxic levels of either nicotine or of cocaine, was specific to male offspring, and was only observed after offspring were first acclimated to sublethal doses of nicotine or cocaine. Mechanistically, the reprogrammed state was characterized by enhanced clearance of nicotine in drug-acclimated animals, accompanied by hepatic upregulation of genes involved in xenobiotic metabolism. Surprisingly, this protective effect could also be induced by paternal exposure to a nicotinic receptor antagonist as well as to nicotine, suggesting that paternal xenobiotic exposure, rather than nicotinic receptor signaling, is likely to be responsible for programming of offspring drug resistance. Taken together, our data show that paternal drug exposure can induce a protective phenotype in offspring by enhancing metabolic tolerance to xenobiotics in the environment. Overall design: Hepatocytes were isolated from 8 week-old male F1 animals from control (TA) and nicotine-exposed (NIC) fathers, and allowed to adhere to the bottom of the well for three hours. Nonadherent cells were then removed, and fresh culture medium was then added. Cells were harvested at different time points in Trizol, and total RNA was extracted. Strand specific libraries were prepared from all samples, and sequenced on Illumina NextSeq500.
Paternal nicotine exposure alters hepatic xenobiotic metabolism in offspring.
Sex, Specimen part, Cell line, Subject
View SamplesSbrI and SbrR are an extracytoplasmic function sigma factor and its cognate anti-sigma factor, respectively. To identify the SbrIR regulon, we measured gene expression in wild type PAO1 , PAO1 sbrR, and PAO1 sbrIR mutants using microarrays.
σ Factor and Anti-σ Factor That Control Swarming Motility and Biofilm Formation in Pseudomonas aeruginosa.
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View SamplesLiver gene transcripts patterns were used to characterize toxicity from exposure to polybrominated diphenyl ethers (PBDEs), flame retardant components. In this study, Wistar Han dams were exposed by gavage to the PBDE mixture (DE71) starting at gestation day 6 (GD 6) and continuing to weaning on postnatal day 21 (PND 21). Offspring from the dams began PBDE direct dosing on PND 12 and were dosed daily through PND 21. After weaning, they were dosed 5 days per week for another 13 weeks. Liver samples were collected at PND 22 and week 13 for liver gene expression analysis and interrogated with the Affymetrix Rat Genome 230 2.0 Array.
Characterization of polybrominated diphenyl ether toxicity in Wistar Han rats and use of liver microarray data for predicting disease susceptibilities.
Sex, Specimen part
View SamplesBackground: The prefrontal cortex is important in regulating sleep and mood. Diurnally regulated genes in the prefrontal cortex may be controlled by the circadian system, by the sleep-wake states, or by cellular metabolism or environmental responses. Bioinformatics analysis of these genes will provide insights into a wide-range of pathways that are involved in the pathophysiology of sleep disorders and psychiatric disorders with sleep disturbances. Results: We examined gene expression in the mouse prefrontal cortex at four time points during the 24-hour (12-hour light:12-hour dark) cycle by microarrays, and identified 3,890 transcripts corresponding to 2,927 genes with diurnally regulated expression patterns. We show that 16% of the genes identified in our study are orthologs of identified clock, clock controlled or sleep/wakefulness induced genes in the mouse liver and SCN, rat cortex and cerebellum, or Drosophila head. The diurnal expression patterns were confirmed in 16 out of 18 genes in an independent set of RNA samples. The diurnal genes fall into eight temporal categories with distinct functional attributes, as assessed by the Gene Ontology classification and by the analysis of enriched transcription factor binding sites. Conclusions: Our analysis demonstrates that ~10% of transcripts have diurnally regulated expression patterns in the mouse prefrontal cortex. Functional annotation of these genes will be important for the selection of candidate genes for behavioural mutants in the mouse and for genetic studies of disorders associated with anomalies in the sleep:wake cycle and circadian rhythms.
Genome-wide expression profiling and bioinformatics analysis of diurnally regulated genes in the mouse prefrontal cortex.
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View SamplesRNA interference (RNAi) is a potent mechanism for down-regulating gene expression. Conserved RNAi pathway components are found in animals, plants, fungi and other eukaryotes. In C. elegans, the RNAi response is greatly amplified by the synthesis of abundant secondary siRNAs. Exogenous double stranded RNA is processed by Dicer and RDE-1/Argonaute into primary siRNA that guides target mRNA recognition. The RDE-10/RDE-11 complex and the RNA dependent RNA polymerase RRF-1 then engage the target mRNA for secondary siRNA synthesis. However, the molecular link between primary siRNA production and secondary siRNA synthesis remains largely unknown. Furthermore, it is unclear if the sub-cellular sites for target mRNA recognition and degradation coincide with sites where siRNA synthesis and amplification occur. In the C. elegans germline, cytoplasmic P granules at the nuclear pores and perinuclear Mutator foci contribute to target mRNA surveillance and siRNA amplification, respectively. We report that RDE-12, a conserved FG domain containing DEAD-box helicase, localizes in P-granules and cytoplasmic foci that are enriched in RSD-6 but are excluded from the Mutator foci. Our results suggest that RDE-12 promotes secondary siRNA synthesis by orchestrating the recruitment of RDE-10 and RRF-1 to primary siRNA targeted mRNA in distinct cytoplasmic compartments. Overall design: Examination of exogenous dsRNA trigger derived siRNA in wildtype and rde-12 mutant animals
The DEAD box helicase RDE-12 promotes amplification of RNAi in cytoplasmic foci in C. elegans.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Developmental and evolutionary basis for drought tolerance of the Anopheles gambiae embryo.
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View SamplesIn order to examine the gene expression in the course of mosquito embryogenesis, microarray assays were performed on staged A. gambiae embryos, from fertilization to 52 hours of development (which is close to hatching at ~50 hours post-fertilization). RNA was extracted from staged embryos roughly every three hours after fertilization, and then hybridized to the A. gambiae transcriptome microarray.
Developmental and evolutionary basis for drought tolerance of the Anopheles gambiae embryo.
No sample metadata fields
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