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Arabidopsis thaliana
12 Downloadable Samples
Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Transcriptional variation, also called expression level polymorphism (ELP), contributes to intra-specific phenotypic variation in many organisms. Differentially expressed transcripts are typically enriched for stress-related genes, suggesting that differences in response to the environment are a particularly common point of divergence among gentoypes. Analysis of ELPs also has been suggested as a way to assess unintended consequences of transgene introduction; however, it is important that interpretation of transcriptional changes be performed within the context of potential fitness effects. In these studies we sought to examine differential gene expression in response to salinity for two widely used Arabidopsis thaliana ecotypes, Wassilewskija (Ws) and Columbia (Col), and a single gene mutation (glabrous, gl1-1) in the Col background (Col(gl)), in relation to genetic, phenotypic, and fitness differences.
Publication Title
Global gene expression analysis of transgenic, mannitol-producing, and salt-tolerant Arabidopsis thaliana indicates widespread changes in abiotic and biotic stress-related genes.
Sample Metadata Fields
Age, Specimen part
View Samples- Arabidopsis thaliana
- 8 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Mannitol is a putative osmoprotectant contributing to salt tolerance in several species. Arabidopsis plants transformed with the mannose-6-phosphate reductase (M6PR) gene from celery were dramatically more salt tolerant (at 100mM NaCl) as exhibited by reduced salt injury, less inhibition of vegetative growth, and increased seed production relative to the wild type (WT). When treated with 200mM NaCl, transformants produced no seeds, but did bolt, and exhibited less chlorosis/necrosis and greater survival and dry weights than the WT. Without salt there were no M6PR effects on growth or phenotype, but expression levels of 2272 genes were altered. Many fewer differences (1039) were observed between M6PR and WT plants in the presence of salt, suggesting that M6PR pre-conditioned the plants to stress. Previous work suggested that mannitol is an osmoprotectant, but mannitol levels are invariably quite low, perhaps inadequate for osmoprotectant effects. In this study, transcriptome analysis reveals that the M6PR transgene activated the downstream abscisic acid (ABA) pathway by up-regulation of ABA receptor genes (PYL4, PYL5, and PYL6) and down-regulation of protein phosphatase 2C genes (ABI1 and ABI2). In the M6PR transgenic lines there were also increases in transcripts related to redox and cell wall-strengthening pathways. These data indicate that mannitol-enhanced stress tolerance is due at least in part to increased expression of a variety of stress-inducible genes.
Publication Title
Global gene expression analysis of transgenic, mannitol-producing, and salt-tolerant Arabidopsis thaliana indicates widespread changes in abiotic and biotic stress-related genes.
Sample Metadata Fields
Age, Specimen part
View Samples- Arabidopsis thaliana
- 24 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Engineered abiotic stress resistance is an important target for increasing agricultural productivity.There are concerns, however, regarding possible ecological impacts of transgenic crops. In contrast to the first wave of transgenic crops, many abiotic stress resistance genes can initiate
Publication Title
Comparison of salt stress resistance genes in transgenic Arabidopsis thaliana indicates that extent of transcriptomic change may not predict secondary phenotypic or fitness effects.
Sample Metadata Fields
Age, Specimen part, Treatment
View Samples- Drosophila melanogaster
- 23 Downloadable Samples
- Affymetrix Drosophila Genome Array (drosgenome1)
Description
A study evaluating the effect of stress resistance selection of Drosophila melanogaster.
Publication Title
Gene expression profile analysis of Drosophila melanogaster selected for resistance to environmental stressors.
Sample Metadata Fields
No sample metadata fields
View Samples- Drosophila melanogaster
- 24 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
We used microarrays to investigate the transcriptome of 6 days old male flies exposed to either 15 or 25 C development at either constant or fluctuating temperatures. Further, we investigated gene expression at benign (20C) and high (35C) temperatures
Publication Title
Thermal fluctuations affect the transcriptome through mechanisms independent of average temperature.
Sample Metadata Fields
Sex
View Samples- Drosophila melanogaster
- 36 Downloadable Samples
- Affymetrix Drosophila Genome Array (drosgenome1)
Description
gene expression was measured in control and heat resistance selected adult female flies before and at 8 time points after heat stress for 1h @ 36 degrees
Publication Title
Full genome gene expression analysis of the heat stress response in Drosophila melanogaster.
Sample Metadata Fields
No sample metadata fields
View Samples- Drosophila melanogaster
- 10 Downloadable Samples
- Affymetrix Drosophila Genome Array (drosgenome1)
Description
gene expression was measured in five independent heat resistance selected replicate lines and five control lines.
Publication Title
Full genome gene expression analysis of the heat stress response in Drosophila melanogaster.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 26 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The purpose of this study was to characterize the histologic development of OA in a mouse model where OA is induced by destabilization of the medial meniscus (DMM model) and to identify genes regulated during different stages of the disease, using RNA isolated from the joint organ and analyzed using microarrays.427 genes from the microarrays passed consistency and significance filters. There was an initial up-regulation at 2 and 4 weeks of genes involved in morphogenesis, differentiation, and development, including growth factor and matrix genes, as well as transcription factors including Atf2, Creb3l1, and Erg. Most genes were off or down-regulated at 8 weeks with the most highly down-regulated genes involved in cell division and the cytoskeleton. Gene expression increased at 16 weeks, in particular extracellular matrix genes including Prelp, Col3a1 and fibromodulin.The results support a phasic development of OA with early matrix remodelling and transcriptional activity followed by a more quiescent period that is not maintained.
Publication Title
Disease progression and phasic changes in gene expression in a mouse model of osteoarthritis.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus
- 18 Downloadable Samples
Illumina Genome Analyzer II
Description
miR-132 and miR-212 are structurally-related microRNAs that have been found to exert powerful modulatory effects within the central nervous system (CNS). Notably, these microRNAs are tandomly processed from the same non-coding transcript, and share a common seed sequence: thus it has been difficult to assess the distinct contribution of each microRNA to gene expression within the CNS. Here, we employed a combination of conditional knockout and transgenic mouse models to examine the contribution of the miR-132/212 gene locus to learning and memory, and then to assess the distinct effects that each microRNA has on hippocampal gene expression. Using a conditional deletion approach, we show that miR-132/212 double knockout mice exhibit significant cognitive deficits in spatial memory, recognition memory, and in tests of novel object recognition. Next, we utilized transgenic miR-132 and miR-212 overexpression mouse lines and the miR-132/212 double knockout line explore the distinct effects of these two miRNAs on the transcriptional profile of the hippocampus. Illumina sequencing revealed that miR-132/212 deletion increased the expression of 1,138 genes; Venn analysis showed that 96 of these genes were also downregulated in mice overexpressing miR-132. Of the 58 genes that were decreased in animals overexpressing miR-212, only four of them were also increased in the knockout line. Functional gene ontology analysis of downregulated genes revealed significant enrichment of genes related to synaptic transmission, neuronal proliferation, and morphogenesis, processes known for their roles in learning, and memory formation. These data, coupled with previous studies, firmly establish a role for the miR-132/212 gene locus as a key regulator of cognitive capacity. Further, although miR-132 and miR-212 share a seed sequence, these data indicate that these miRNAs do not exhibit strongly overlapping mRNA targeting profiles, thus indicating that, these two genes may function in a complex, non-redundant manner to shape the transcriptional profile of the CNS. The dysregulation of miR-132/212 expression could contribute to signaling mechanisms that are involved in an array of cognitive disorders Overall design: Hippocampal mRNA was isolated from CaMKII-Cre::miR-132/212f/f, tTA::miR132, and tTA::miR212 animals, as well as their respective nontransgenic controls. cDNA from six animals was pooled into three independent biological replicates for each. Libraries were prepared according to the Illumina TruSeqTM Sample Preparation Guide and sequenced using an Illumina Genome Analyzer II. Sequences were aligned to the UCSC mm9 reference genome using Bowtie v0.12.7 and custom R scripts. The sequence data have been submitted to the NCBI Short Read Archive with accession number in progress. Relative abundance was measured in Fragments Per Kilobase of exon per Million fragments mapped using Cufflinks v1.2.
Publication Title
Targeted deletion of miR-132/-212 impairs memory and alters the hippocampal transcriptome.
Sample Metadata Fields
Cell line, Subject
View Samples
GSE5675- Homo sapiens
- 40 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Pilocytic astrocytomas (PAs) are the most common glioma in children. While many PAs are slow growing or clinically indolent, others exhibit more aggressive features with tumor recurrence and death. In order to identify genetic signatures that might predict PA clinical behavior, we performed gene expression profiling on 41 primary PAs arising sporadically and in patients with neurofibromatosis type 1 (NF1). While no expression signature was found that could discriminate clinically-aggressive or recurrent tumors from more indolent cases, PAs arising in patients with NF1 did exhibit a unique gene expression pattern. In addition, we identified a gene expression signature that stratified PAs by location (supratentorial versus infratentorial).
Publication Title
Distinct genetic signatures among pilocytic astrocytomas relate to their brain region origin.
Sample Metadata Fields
No sample metadata fields
View Samples