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GSE7674
Mus musculus
6 Downloadable Samples
Affymetrix Mouse Expression 430A Array (moe430a)
Description
Whereas DNA methylation is essential for genomic imprinting, the importance of histone methylation in the allelic repression of imprinted genes is unclear. Imprinting control regions (ICRs), however, are consistently marked by histone H3 K9 methylation on their DNA-methylated allele. In the placenta, the paternal silencing along the Kcnq1 domain on distal chromosome 7 also correlates with the presence of H3-K9 methylation, but imprinted repression at these genes is maintained independently of DNA methylation. To explore which histone methyltransferase (HMT) could mediate the allelic H3-K9 methylation on distal chromosome 7, and at ICRs, we generated mouse conceptuses deficient for the SET-domain protein G9a. We find that in the embryo and placenta, the differential DNA methylation at ICRs and imprinted genes is maintained in the absence of G9a. Accordingly, in embryos, imprinted gene expression is unchanged at the domains analysed, in spite of a global loss of H3-K9 di-methylation (H3K9me2). In contrast, the placenta-specific imprinting of genes on distal chromosome 7 is lost in the absence of G9, and this correlates with a loss of H3K9me2 and H3K9me3. These findings provide the first in vivo evidence for the involvement of a SET domain protein in imprinting and highlight the importance of histone lysine methylation rather than DNA methylation in the maintenance of imprinting in the trophoblast lineage.
Publication Title
G9a histone methyltransferase contributes to imprinting in the mouse placenta.
Sample Metadata Fields
Age, Specimen part
View Samples- Rattus norvegicus
- 6 Downloadable Samples
- Affymetrix Rat Genome U34 Array (rgu34a)
Description
Most commonly used models of non-alcoholic steatohepatitis (NASH) are diets based on specific gene knockouts or represent extreme manipulations of diet. We have examined the effects of modest increased caloric intake and high dietary unsaturated fat content on the development of NASH in male rats using a model in which overfeeding is accomplished via intragastric infusion of liquid diets as a part of total enteral nutrition. Male Sprague dawley rats were fed diets 5% corn oil containing diets at 187 Kcal/kg3/4/d or fed 70% corn oil containing diets at 220 Kcal/kg3/4/d for a period of 3 weeks. Hepatic gene expression were assessed at the end of the study. Our results indicate that overfeeding of high unsaturated fat diets leads to pathological, endocrine and metabolic changes characteristic of NASH patients and is associated with increased oxidative stress and TNF-a.
Publication Title
A new model for nonalcoholic steatohepatitis in the rat utilizing total enteral nutrition to overfeed a high-polyunsaturated fat diet.
Sample Metadata Fields
No sample metadata fields
View Samples- Rattus norvegicus
- 12 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Soy foods have been suggested to have both positive health benefits and potentially adverse effects largely as a result of their content of isoflavone phytoestrogens. Since soy protein isolate (SPI) contains isoflavones, in addition to purported health benefits, safety concerns have been raised regarding the use of SPI and soy formulas, because of potential estrogenic actions during the neonatal period, including the potential for reproductive toxicity, infertility, and the possibility of increased risk for development and recurrence of estrogen sensitive cancers such as breast cancer. In the current study, we used a rat model to compare the effects of SPI with those of 17b-estradiol (E2), on global gene expression profiles and morphology in the female rat mammary gland. Rats were either fed AIN-93G diets containing casein (CAS) or SPI beginning on postnatal day (PND) 30.
Publication Title
Mammary gland morphology and gene expression differ in female rats treated with 17β-estradiol or fed soy protein isolate.
Sample Metadata Fields
Sex
View Samples- Rattus norvegicus
- 12 Downloadable Samples
- Affymetrix Rat Genome U34 Array (rgu34a)
Description
The current study was designed to determine if dietary fatty acid concentration and composition affects the development and progression of nonalcoholic fatty liver disease. Male SD rats were overfed diets low (5%) or high (70%) fat diets via total enteral nutrition where the fat source was olive oil (monounsaturated), or corn oil (polyunsaturated). Overfeeding 5% corn oil produced little steatosis relative to feeding 5% olive oil. This was associated with lower fatty acid synthesis and reduced SREBP-c signaling in the 5% corn oil group. Overfeeding 70% fat diets increased steatosis and lead to increased liver necrosis in the 70% corn oil but not olive oil group. Increased injury after feeding polyunsaturated fat diets was linked to peroxidizability of hepatic free fatty acids and triglycerides and appearance of peroxidaized lipid products HETES and HODES previously linked to clinical nonalcoholic steatohepatitis.
Publication Title
Dietary fat source alters hepatic gene expression profile and determines the type of liver pathology in rats overfed via total enteral nutrition.
Sample Metadata Fields
Sex
View Samples- Rattus norvegicus
- 24 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
In order to properly understand whether xenoestrogens act as estrogens, it is essential to possess a solid portrait of the physiological effects of exogenous estradiol. Because the estrogen-dependent gene expression is one of the primary biomarkers of estrogenic action, we have assessed effects of three doses of exogenous estradiol (0.1, 1.0 and 10 g/kg of body weight/day) on the mammary gland morphology and gene expression profiles by microarray analysis of prepubertal male and female rats of both sexes compared to untreated controls. Estradiol was administered subcutaneously with minipumps from weaning at PND21 to the end of the experiment at PND33. The data suggest that the male mammary is a sensitive tissue for estrogenicity assessment.
Publication Title
Mammary gland morphology and gene expression signature of weanling male and female rats following exposure to exogenous estradiol.
Sample Metadata Fields
Sex
View Samples- Mus musculus
- 11 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Type 1 Diabetes (T1D) in humans and the non-obese diabetic (NOD) mouse model results from autoreactive T cell destruction of pancreatic beta cells. A pathogenic role for B lymphocytes (B cells) in T1D first became evident when NOD mice made deficient in this population through introduction of an inactivated Ig heavy chain gene (NOD.Ignull) or chronic treatment with anti-IgM antibodies were strongly protected from disease. We produced an NOD background strain developing a greatly decreased T1D incidence due to a NOR-derived 44.31Mb congenic region from rs3674285 to D4Mit127 on distal Chr. 4 (termed NOD.NOR-Chr4 (NR4)) containing disease resistance alleles decreasing the pathogenic activity of autoreactive B cells. Microarrays were conducted on B cells purified from spleens of NOD and NR4 mice to highlight differentially expressed genes within the distal Chr. 4 locus. B cells were either cultured in media alone (unstimulated) or with BCR cross-linking anti-IgM-F(ab)2 fragments (stimulated) for 2h before RNA was extracted for transcript analysis.
Publication Title
Subcongenic analyses reveal complex interactions between distal chromosome 4 genes controlling diabetogenic B cells and CD4 T cells in nonobese diabetic mice.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Drosophila melanogaster
- 24 Downloadable Samples
Illumina HiSeq 2500
Description
In order to study the transcriptional response of the fly brain to sugar and complete starvation, we first confirmed that 24 hours of sugar and complete starvation in flies is sufficient to elicit a homeostatic response. Subsequently, we used holidic medium to study effects of deficiency of a specfic macronutrient- cabohydrate in the food. To do so , we generated RNA- seq libraries from brains of 5 day old mated adult male flies maintained on different feeding regimes and used the sequencing data to identify diffrentially expressed genes in the brain under different feeding regimes. Overall design: For each condition, we used RNA prepared from 120-130 manually dissected adult fly brains maintained under complete starvation or sugar starvation regime for 24 hours.
Publication Title
Sugar Promotes Feeding in Flies via the Serine Protease Homolog scarface.
Sample Metadata Fields
Sex, Specimen part, Cell line, Subject
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
While the existence of intestinal epithelial stem cells (IESCs) has been well established, their study has been limited due to the inability to isolate them. Previous work has utilized side population (SP) sorting of the murine small intestinal mucosa to isolate a viable fraction of cells enriched for putative IESCs. We have used microarray analyses to characterize the molecular features of this potential stem cell population.
Publication Title
Molecular properties of side population-sorted cells from mouse small intestine.
Sample Metadata Fields
No sample metadata fields
View Samples- Drosophila melanogaster
- 1 Downloadable Sample
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
We applied genome-wide profiling to successive salt-extracted fractions of micrococcal nuclease-treated Drosophila chromatin. Chromatin fractions extracted with 80mM or 150mM NaCl after digestion contain predominantly mononucleosomes and represent calssical 'active' chromatin. Profiles of these low-salt-soluble fractions display phased nucleosomes over transcriptionally active genes that are locally depleted of histone H3.3 and correspond closely to profiles of RNA polymerase II. Nearly quantitative recovery of chromatin is obtained with 600mM NaCl, however, the remaining insoluble chromatin is enriched in actively transcribed regions. Salt-insoluble chromatin likely represents oligonucleosomes that are attached to large protein complexes. Both low-salt extracted and insoluble chromatin are rich in sequences that correspond to epigenetic regulatory elements genome-wide. The presence of active chromatin at both extremes of salt solubility suggests that these salt fractions capture bound and unbound intermediates in active processes, thus providing a simple, powerful strategy for mapping epigenome dynamics.
Publication Title
Genome-wide profiling of salt fractions maps physical properties of chromatin.
Sample Metadata Fields
Specimen part
View Samples- Caenorhabditis elegans
- 15 Downloadable Samples
- Affymetrix C. elegans Gene 1.0 ST Array (elegene10st)
Description
Worldwide, 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.
Publication Title
Transcriptome analysis reveals molecular anthelmintic effects of procyanidins in C. elegans.
Sample Metadata Fields
Specimen part, Treatment
View Samples