Classic ‘position effect’ experiments repositioned genes to the telomere to demonstrate that the epigenetic landscape can dramatically alter gene expression. Here we show that systematic gene knockout collections provide an exceptional resource for interrogating position effects, not only at the telomere but at every single genetic locus. Because deleted genes are replaced by the same reporter gene, interrogation of this reporter provides a sensitive probe into many different chromatin environments while controlling for genetic context. Using this approach we find that, whereas replacement of yeast genes with the kanMX marker does not perturb the chromatin landscape, differences due to gene position account for more than 35% of marker gene activity. We observe chromatin influences different from those reported previously, including an antagonistic interaction between histone H3 lysine 36 trimethylation (H3K36me3) and the Rap1 transcriptional activation site in kanMX that is mediated through a Set2-Rpd3-dependent pathway. This interaction explains why some yeast genes have been resistant to deletion and allows successful generation of these deletion strains using a modified transformation procedure. These findings demonstrate that chromatin regulation is not governed by a uniform ‘histone code’, but by specific interactions between chromatin and genetic factors. Overall design: Data included are RNA-Seq data for 4 heterzygous diploid yeast strains and diploid wild-type. Therea re three replicates for each heterzygous strain, and six replicates for wild-type.
Decoupling epigenetic and genetic effects through systematic analysis of gene position.
Subject
View SamplesTransformation of Glycine max with seed-targeted expression vectors via Agrobacterium causes measurable unscripted gene expression changes in the seed transcriptome Overall design: mRNA was sequenced from three transgenic events expressing three different recombinant proteins in soybean seeds. Three plants were chosen from each as group replicates, and three seeds from each plant as individual biological replicates.
Transcript Polymorphism Rates in Soybean Seed Tissue Are Increased in a Single Transformant of <i>Glycine max</i>.
Subject
View SamplesWe initiated a study to investigate the transcriptional profiles associated with cell states of the stomatal lineage. A stem-cell like precursor of stomata, a meristemoid. reiterates asymmetric divisions and renews itself before differentiating into guard cells. The transient and asynchronous nature of the meristemoid has made it difficult to study its molecular characteristics. Through combinatorial use of genetic resources that either arrest or constitutively drive stomatal cell-state progressions due to loss- or gain-of-function mutations in the key transcription factor genes, SPEECHLESS, MUTE, and SCRM, we obtained seedlings highly enriched in pavement cells, meristemoids, or stomata. Here we present transcriptome and genome-wide trends in gene regulation associated with each cell state and identify molecular signatures associated with meristemoids.
Molecular profiling of stomatal meristemoids reveals new component of asymmetric cell division and commonalities among stem cell populations in Arabidopsis.
Age, Specimen part
View SamplesIn this study, using a Patient Derived Xenograft (PDX) system established by transplanting primary tumors from pre-metastatic breast cancer patients we demonstrate that development of distant organ metastases correlates with the presence of Bone Marrow Disseminated Tumor Cells (BM DTCs) in the PDX mice. Comparative gene expression analysis of bone marrow (BM) from tumor bearing PDX mice which developed metastatic disease was carried out with BM from non-tumor bearing controls.
Identifying biomarkers of breast cancer micrometastatic disease in bone marrow using a patient-derived xenograft mouse model.
Specimen part
View SamplesVS94 gene expression at different time-points in SAPI medium in absence and presence of AI-2 was studied.
Temporal regulation of enterohemorrhagic Escherichia coli virulence mediated by autoinducer-2.
No sample metadata fields
View SamplesA Transcriptomics Approach to Study the Biocompatibility and Finding out the Potential Applications of Magnetite (Fe3O4) Nanoparticles
Magnetite (Fe3O4) nanocrystals affect the expression of genes involved in the TGF-beta signalling pathway.
Cell line
View SamplesPURPOSE: Previous mouse studies using corn oil (-6) as the dietary fat source suggest that decreasing dietary fat content can slow prostate cancer (PCa) growth. However, other studies, in which the diet was composed around saturated fat, showed no difference in outcomes between high-fat and low-fat diets. The relative effects of other fats, such as fish oil and olive oil, also remain unexplored. To our knowledge, no trial has yet compared the effect of various fats on prostate cancer progression. Therefore, we sought to systematically study the effect of fish oil, olive oil, corn oil, and saturated fat on prostate cancer progression. METHODS: A total of 96 male SCID mice were injected with LAPC-4 human PCa cells. Two weeks following injection, mice were singly-housed and randomized to either a fish oil, olive oil, corn oil, or saturated fat based diet. Animals were euthanized when tumors reached 1,000 mm3. Serum was collected at sacrifice and assayed for PSA, insulin, IGF-1, IGFBP-3, and PGE-2 levels. Tumors were also assayed for PGE-2, and COX-2 levels, and gene array analysis was performed. RESULTS: Mice weights and tumor volumes were equivalent across groups at randomization. Overall, fish-oil consumption was associated with improved survival, relative to all other dietary groups (Log-rank, all p<0.05). We did not detect any significant difference in serum PSA, insulin, IGF-1, IGFBP-3, and PGE-2 levels. Glucose at the time of sacrifice was statistically different between groups, with the fish-oil fed mice having the highest levels of serum glucose (Kruskal-Wallis, p=0.03).
Fish oil slows prostate cancer xenograft growth relative to other dietary fats and is associated with decreased mitochondrial and insulin pathway gene expression.
Specimen part
View SamplesWe performed a time-course microarray experiment to define the transcriptional response to carboplatin in vitro, and to correlate this with clinical outcome in epithelial ovarian cancer (EOC). RNA was isolated from carboplatin and control-treated 36M2 ovarian cancer cells at several time points, followed by oligonucleotide microarray hybridization. Carboplatin induced changes in gene expression were assessed at the single gene as well as at the pathway level. Clinical validation was performed in publicly available microarray datasets using disease free and overall survival endpoints.
Carboplatin-induced gene expression changes in vitro are prognostic of survival in epithelial ovarian cancer.
No sample metadata fields
View SamplesA cancer stem cell cannot be identified solely based on surface markers as none of the markers used to isolate stem cells in various normal and cancerous tissues is expressed exclusively by stem cells. Our experimental results have also identified additional fractions representing true stem-like cells in oral squamous cell carcinoma (OSCC), refuting the concept that cancer stem cells (CSCs) are a rare population, and we have also developed an in vitro model to explore the stem cell concept in oral epithelial tumorigenesis. This model expounds four distinct fractions within a homogenous cell line SCC172 that is morphologically similar (85% cells expressing CSC markers), yet varying in all functional aspects of cell cycle, dye retention, chemoresistance, tumor-forming potential, self renewal, apoptosis resistance and regulation at molecular levels. Relating to our CSC shift model, we analysed the concept of biological heterogeneity in terms of four fractions SP1, SP2, MP1 and MP2 and associated it with variations among patients in a clinical scenario.
Analysis of MicroRNA-mRNA Interactions in Stem Cell-Enriched Fraction of Oral Squamous Cell Carcinoma.
Specimen part, Cell line
View SamplesmicroRNAs play crucial roles in the early development of an organism. However the regulation of transcription through the action of microRNAs during the initial embyonic development has not been studied.
miR-34 is maternally inherited in Drosophila melanogaster and Danio rerio.
Specimen part
View Samples