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Xenopus laevis
12 Downloadable Samples
Affymetrix Xenopus laevis Genome Array (xenopuslaevis)
Description
Tissues from the eye primordia, lateral endoderm, and posterior
Publication Title
Generation of functional eyes from pluripotent cells.
Sample Metadata Fields
No sample metadata fields
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GSE9173- Xenopus laevis
- 8 Downloadable Samples
- Affymetrix Xenopus laevis Genome Array (xenopuslaevis)
Description
Xenopus laevis embryos were injected with mRNA for EFTFs at 2-cell stage. Animal caps collected at stage 9, cultured to the equivalent of stage 15 and RNA extracted. Four biological replicates of the EFTF-injected and GFP-injected (control) caps were used to profile transcript expression patterns using Affymetrix Xenopus Laevis GeneChip microarrays.
Publication Title
Generation of functional eyes from pluripotent cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 6 Downloadable Samples
- Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
Reactive oxygen species, generated in vivo or exogenously encountered, constantly challenge living organisms. Oxidation of polyunsaturated fatty acids (PUFA), which are susceptible to oxidant attack, can lead to initiation of lipid peroxidation and in turn rapid production of toxic lipid hydroperoxides. Eukaryotic microorganisms such as Saccharomyces cerevisiae can survive harsh industrial conditions that contain high levels of the PUFA linoleic acid and its oxidised derivative, linoleic acid hydroperoxide (LoaOOH). The precise signalling and response mechanisms induced by yeast to overcome lipid hydroperoxide stress are ill understood.
Publication Title
Transcriptomic insights into the molecular response of Saccharomyces cerevisiae to linoleic acid hydroperoxide.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 27 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
For more than a decade, microarrays have been a powerful and widely used tool to explore the transcriptome of biological systems. However, the amount of biological material from cell sorting or laser capture microdissection is much too small to perform microarray studies. To address this issue, RNA amplification methods have been developed to generate sufficient targets from picogram amounts of total RNA to perform microarray hybridisation. In this study, four commercial protocols for amplification of picograms amounts of input RNA for microarray expression profiling were evaluated and compared. The quantitative and qualitative performances of the methods were assessed. Microarrays were hybridised with the amplified targets and the amplification protocols were compared with respect to the quality of expression profiles, reproducibility within a concentration range of input RNA, and sensitivity.
Publication Title
Evaluation of methods for amplification of picogram amounts of total RNA for whole genome expression profiling.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Genome U95 Version 2 Array (hgu95av2)
Description
Considerable variation in gene expression data from different DNA microarray platforms has been demonstrated. However, no characterization of the source of variation arising from labeling protocols has been performed. To analyze the variation associated with T7-based RNA amplification/labeling methods, aliquots of the Stratagene Human Universal Reference RNA were labeled using 3 eukaryotic target preparation methods and hybridized to a single array type (Affymetrix U95Av2). Variability was measured in yield and size distribution of labeled products, as well as in the gene expression results. All methods showed a shift in cRNA size distribution, when compared to un-amplified mRNA, with a significant increase in short transcripts for methods with long IVT reactions. Intra-method reproducibility showed correlation coefficients >0.99, while inter-method comparisons showed coefficients ranging from 0.94 to 0.98 and a nearly two-fold increase in coefficient of variation. Fold amplification for each method was positively correlated with the number of present genes. Two factors that introduced significant bias in gene expression data were observed: a) number of labeled nucleotides that introduces sequence dependent bias, and b) the length of the IVT reaction that introduces a transcript size dependent bias. This study provides evidence of amplification method dependent biases in gene expression data.
Publication Title
In vitro transcription amplification and labeling methods contribute to the variability of gene expression profiling with DNA microarrays.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 11 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
4 chorionic villus sampling specimens in pregnancies destined for preeclampsia and 8 matched controls were analyzed
Publication Title
Altered global gene expression in first trimester placentas of women destined to develop preeclampsia.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
The goal of this experiment is to define how lack of Ikaros impacts gene expression in mature CD4 T cells, both in the resting and activated state. To do this, a conditional knockout mouse model was generated using Cre/lox technology. The floxed allele was designed such that the last translated exon and 3' UTR of the Ikaros gene (Ikzf1) are deleted in mature T cells (mediated by distal Lck-driven Cre). CD4 T cells from mice with floxed alleles that did not express Cre (Cre-) and those that did express Cre (Cre+) were analyzed.
Publication Title
Lack of Ikaros Deregulates Inflammatory Gene Programs in T Cells.
Sample Metadata Fields
Specimen part
View Samples- Drosophila melanogaster
- 8 Downloadable Samples
Illumina Genome Analyzer II
Description
Long-term memory formation in Drosophila melanogaster is an important neuronal function shaping the insect's behavioral repertoire by allowing an individual to modify behaviors on the basis of previous experiences. In conditioned courtship or courtship suppression, male flies that have been repeatedly rejected by mated females during courtship advances are less likely than na ve males to subsequently court another mated female. This long-term courtship suppression can last for several days after the initial rejection period. Although genes with known functions in many associative learning paradigms, including those that function in cyclic AMP signaling and RNA translocation, have been identified as playing critical roles in long-term conditioned courtship, it is clear that additional mechanisms also contribute. We have used RNA sequencing to identify differentially expressed genes and transcript isoforms between na ve males and males subjected to courtship-conditioning regimens that are sufficient for inducing long-term courtship suppression. Transcriptome analyses 24 hours after the training regimens revealed differentially expressed genes and transcript isoforms with predicted and known functions in nervous system development, chromatin biology, translation, cytoskeletal dynamics, and transcriptional regulation. A much larger number of differentially expressed transcript isoforms were identified, including genes previously implicated in associative memory and neuronal development, including fruitless, that may play functional roles in learning during courtship conditioning. Our results shed light on the complexity of the genetics that underlies this behavioral plasticity and reveal several new potential areas of inquiry for future studies.
Publication Title
Identification of gene expression changes associated with long-term memory of courtship rejection in Drosophila males.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 29 Downloadable Samples
- Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Expression of three topologically distinct membrane proteins elicits unique stress response pathways in the yeast Saccharomyces cerevisiae.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 11 Downloadable Samples
- Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
Misfolded membrane proteins are retained in the endoplasmic reticulum (ER) and are subject to the ER associated degradation pathway, which clears the secretory pathway of potentially toxic species. While the transcriptional response to environmental stressors has been extensively studied, limited data exist describing the cellular response to misfolded membrane proteins. To this end, we expressed and then compared the transcriptional profiles elicited by the synthesis of three ER retained, misfolded ion channels: The subunit of the epithelial sodium channel, ENaC, the cystic fibrosis transmembrane conductance regulator, CFTR, and an inwardly rectifying potassium channel, Kir2.1, which vary in their mass, membrane topologies, and quaternary structures. To examine transcriptional profiles in a null background, the proteins were expressed in yeast, which was previously used to examine the degradation requirements for each substrate. Surprisingly, the proteins failed to induce a canonical unfolded protein response or heat shock response, although messages encoding several cytosolic and ER lumenal protein folding factors rose when ENaC or CFTR were expressed. In contrast, the levels of these genes were unaltered by Kir2.1 expression; instead, the yeast iron regulon was activated. Nevertheless, a significant number of genes that respond to various environmental stressors were upregulated by all three substrates, and when compared to previous microarray data we deduced the existence of a group of genes that reflect a novel misfolded membrane protein response. These data indicate that aberrant proteins in the ER elicit profound yet unique cellular responses.
Publication Title
Expression of three topologically distinct membrane proteins elicits unique stress response pathways in the yeast Saccharomyces cerevisiae.
Sample Metadata Fields
No sample metadata fields
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