Filters
Technology
Platform
SRP034941
Caenorhabditis elegans
8 Downloadable Samples
Illumina HiSeq 2000
Description
RNA 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
Publication Title
The DEAD box helicase RDE-12 promotes amplification of RNAi in cytoplasmic foci in C. elegans.
Sample Metadata Fields
Subject
View Samples- Rattus norvegicus
- 30 Downloadable Samples
Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Liver 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.
Publication Title
Characterization of polybrominated diphenyl ether toxicity in Wistar Han rats and use of liver microarray data for predicting disease susceptibilities.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 16 Downloadable Samples
- Illumina Genome Analyzer, Illumina HiSeq 2000
Description
Estrogen 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.
Publication Title
Research resource: Aorta- and liver-specific ERα-binding patterns and gene regulation by estrogen.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 15 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Human cardiomyopathies often lead to heart failure, a major cause of morbidity and mortality in industrialized nations. Described here is a phenotypic characterization of cardiac function and genome-wide expression from C3H/HeJ, C57BL/6J, and B6C3F1/J male mice. Histopathologic analysis identified a low-grade background cardiomyopathy (murine progressive cardiomyopathy) in eight of nine male C3H/HeJ mice (age nine to ten weeks), but not in male C57BL/6J and in only of ten male B6C3F1/J mice. The C3H/HeJ mouse had an increased heart rate and a shorter RR interval compared to the B6C3F1/J and C57BL/6J mice. Cardiac genomic studies indicated the B6C3F1/J mice exhibited an intermediate gene expression phenotype relative to the 2 parental strains. Disease-centric enrichment analysis indicated a number of cardiomyopathy-associated genes were induced in B6C3F1/J and C3H/HeJ mice, including Myh7, My14, and Lmna and also indicated differential expression of genes associated with metabolic (e.g., Pdk2) and hypoxic stress (e.g. Hif1a). A novel coexpression and integrated pathway network analysis indicated Prkaa2, Pdk2, Rhoj, and Sgcb are likely to play a central role in the pathophysiology of murine progressive cardiomyopathy in C3H/HeJ mice. Our studies indicate that genetically determined baseline differences in cardiac phenotype have the potential to influence the results of cardiotoxicity studies.
Publication Title
Comparative phenotypic assessment of cardiac pathology, physiology, and gene expression in C3H/HeJ, C57BL/6J, and B6C3F1/J mice.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 4 Downloadable Samples
- Illumina HiSeq 2000
Description
We compare transcriptomic profiles of intestinal epithelial cells obtained from the small intestine of germ-free and conventionally-caged mice. Intestinal epithelial cells were harvested from the intestine of conventional or germ-free C57Bl6J mice. Directional polyA RNA-seq was performed on RNA fom cells using standard Illumina protocols. Microbiota induce decreased expression of the Clec2e gene. Overall design: Intestinal epithelial cells were harvested from the intestine of conventional or germ-free C57Bl6J mice.
Publication Title
Microbiota Inhibit Epithelial Pathogen Adherence by Epigenetically Regulating C-Type Lectin Expression.
Sample Metadata Fields
Subject
View Samples- Mus musculus
- 15 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Characterization of Peroxisome Proliferator-Activated Receptor alpha (PPAR(alpha)) - Independent Effects of PPAR(alpha) Activators in the Rodent Liver: Di-(2-ethylhexyl) phthalate Activates the Constitutive Activated Receptor
Publication Title
Characterization of peroxisome proliferator-activated receptor alpha--independent effects of PPARalpha activators in the rodent liver: di-(2-ethylhexyl) phthalate also activates the constitutive-activated receptor.
Sample Metadata Fields
Sex, Age, Treatment
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
To 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.
Publication Title
Localized methylation in the key regulator gene endothelin-1 is associated with cell type-specific transcriptional silencing.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 240 Downloadable Samples
- NextSeq 500
Description
Although 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.
Publication Title
Paternal nicotine exposure alters hepatic xenobiotic metabolism in offspring.
Sample Metadata Fields
Sex, Specimen part, Cell line, Subject
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
The nuclear receptor peroxisome proliferator-activated receptor alpha (PPAR) regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by heat shock (HS) through activation by HS factor-1 (HSF1). We hypothesized that there are interactions on a genetic level between PPAR and the HS response mediated by HSF1. Wild-type and PPAR-null mice were exposed to HS, the PPAR agonist WY-14,643 (WY), or both; gene and protein expression was examined in the livers of the mice 4 or 24 hrs after HS. Gene expression profiling identified a number of Hsp family members that were altered similarly in both mouse strains. However, most of the targets of HS did not overlap between strains. A subset of genes was shown by microarray and RT-PCR to be regulated by HS in a PPAR-dependent manner. HS also down-regulated a large set of mitochondrial genes specifically in PPAR-null mice that are known targets of PPARg co-activator 1 (PGC-1) family members. Pretreatment of PPAR-null mice with WY increased expression of PGC-1b and target genes and prevented the down-regulation of the mitochondrial genes by HS. A comparison of HS genes regulated in our dataset with those identified in wild-type and HSF1-null mouse embryonic fibroblasts indicated that although many HS genes are regulated independently of both PPAR and HSF1, a number require both factors for HS responsiveness. These findings demonstrate that the PPAR genotype has a dramatic effect on the transcriptional targets of HS and support an expanded role for PPAR in the regulation of proteome maintenance genes after exposure to diverse forms of environmental stress including HS.
Publication Title
Analysis of the heat shock response in mouse liver reveals transcriptional dependence on the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha).
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus
- 16 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
We characterized gene expression changes in the developing mouse liver at gestational days (GD) 11.5, 12.5, 13.5, 14.5, 16.5, and 19.5 and in the neonate (postnatal day (PND) 7 and 30) using full-genome microarrays and compared these changes to that in the adult liver. The fetal liver, and to a lesser extent the neonatal liver, exhibited dramatic differences in gene expression compared to adults. Canonical pathway analysis of the fetal liver signature demonstrated increases in functions important in cell replication and DNA fidelity whereas most metabolic pathways of intermediary metabolism were suppressed. Comparison of the dataset to a number of previously published datasets revealed 1) a striking similarity between the fetal liver and that of the pancreas in both mice and humans, 2) a nucleated erythrocyte signature in the fetus and 3) suppression of most xenobiotic metabolism genes throughout development, except a number of transporters associated with expression in hematopoietic cells.
Publication Title
Transcriptional ontogeny of the developing liver.
Sample Metadata Fields
Specimen part
View Samples