High-fat diets are associated with increased obesity and metabolic disease in mice and humans. Here we used analysis of variance (ANOVA) to scrutinize a microarray data set consisting of 10 inbred strains of mice from both sexes fed atherogenic high-fat and control chow diets. An overall F-test was applied to the 40 unique groups of strain-diet-sex to identify 15,288 genes with altered transcription. Bootstrapping k-means clustering separated these changes into four strain-dependent expression patterns, including two sex-related profiles and two diet-related profiles. Sex-induced effects correspond to secretion (males) or fat and energy metabolism (females), whereas diet-induced changes relate to neurological processes (chow) or immune response (high-fat). The full set of pairwise contrasts for differences between strains within sex (90 different statistical tests) uncovered 32,379 total changes. These differences were unevenly distributed across strains and between sexes, indicating that strain-specific responses to high-fat diet differ between sexes. Correlations between expression levels and 8 obesity-related traits identified 5,274 associations between transcript abundance and measured phenotypic endpoints. From this number, 2,678 genes are positively correlated with total cholesterol levels and associate with immune-related categories while 2,596 genes are negatively correlated with cholesterol and connect to cholesterol synthesis.
Practical applications of the bioinformatics toolbox for narrowing quantitative trait loci.
Sex
View SamplesIdentify genes that are differentially regulated as a consequence of restoration of full-length functional APC in a colorectal cancer cell lines. Overall design: Examine mRNA expression level changes between SW480 (APC defective) and SW480+APC (SW480 cells with restored functional APC) cells, whilst accounting for any non-specific expression changes by comparison to SW480+control vector.
Differential RNA-seq analysis comparing APC-defective and APC-restored SW480 colorectal cancer cells.
No sample metadata fields
View SamplesHigh quality genetic material is an essential pre-requisite when analyzing gene expression using microarray technology. Peripheral blood mononuclear cells (PBMC) are frequently used for genomic analyses, but several factors can affect the integrity of nucleic acids prior to their extraction, including the methods of PBMC collection and isolation. In this study, we compared the Ficoll-Paque density gradient centrifugation and BD Vacutainer cell preparation tube (CPT) protocols to determine if either method offered a distinct advantage in preparation of PBMC-derived immune cell subsets for their use in gene expression analysis. We compared gene expression in PBMC and individual immune cell types from Ficoll and CPT isolation protocols using Affymetrix microarrays.
Immune cell subsets and their gene expression profiles from human PBMC isolated by Vacutainer Cell Preparation Tube (CPT™) and standard density gradient.
Specimen part
View SamplesThis study compares the gene expression changes in Sus scrofa in response to two different methods for abdominal surgical incisions ; electrosurgery and harmonic blade.
Ultrasonic incisions produce less inflammatory mediator response during early healing than electrosurgical incisions.
Specimen part, Treatment
View SamplesSalicylic acid (SA) is a critical molecule mediating plant innate immunity with an important role limiting the growth and reproduction of the virulent powdery mildew (PM) Golovinomyces orontii on Arabidopsis thaliana. To investigate this later phase of the PM interaction, and the role played by SA, we performed replicated global expression profiling for wild type and SA biosynthetic mutant ics1 Arabidopsis from 0 to 7 days post infection. We found that ICS1-impacted genes comprise 3.8% of profiled genes with known molecular markers of Arabidopsis defense ranked very highly by the multivariate empirical Bayes statistic (T2 statistic ((Tai and Speed, 2006)). Functional analyses of T2-selected genes identified statistically significant PM-impacted processes including photosynthesis, cell wall modification, and alkaloid metabolism that are ICS1-independent. ICS1-impacted processes include redox, vacuolar transport/secretion, and signaling. Our data also supports a role for ICS1 (SA) in iron and calcium homeostasis and identifies components of SA crosstalk with other phytohormones. Through our analysis, 39 novel PMimpacted transcriptional regulators were identified. Insertion mutants in one of these regulators, PUX2, results in significantly reduced reproduction of the powdery mildew in a cell death independent manner. Though little is known about PUX2, PUX1 acts as a negative regulator of Arabidopsis CDC48 (Rancour et al., 2004; Park et al., 2007), an essential AAA-ATPase chaperone that mediates diverse cellular activities including homotypic fusion of ER and Golgi membranes, ER-associated protein degradation, cell cycle progression, and apoptosis. Future work will elucidate the functional role of the novel regulator PUX2 in PM resistance.
Temporal global expression data reveal known and novel salicylate-impacted processes and regulators mediating powdery mildew growth and reproduction on Arabidopsis.
Age, Specimen part
View SamplesCrosslinking and immunoprecipitation (CLIP) is increasingly used to map transcriptome-wide binding sites of RNA-binding proteins (RBPs). We developed a method for CLIP data analysis and applied it to compare 254 nm CLIP with PAR-CLIP, which involves crosslinking of photoreactive nucleotides with 365 nm UV light. We found small differences in the accuracy of these methods in identifying binding sites of HuR, a protein that binds low-complexity sequences and Argonaute 2, which has a complex binding specificity. We show that crosslink-induced mutations lead to single-nucleotide resolution for both PAR-CLIP and CLIP. Our results confirm the expectation from original CLIP publications that RNA-binding proteins do not protect sufficiently their sites under the denaturing conditions used during the CLIP procedure, and we show that extensive digestion with sequence-specific ribonucleases strongly biases the set of recovered binding sites. We finally show that this bias can be substantially reduced by milder nuclease digestion conditions. Overall design: We performed duplicate experiments for each variant of the CLIP protocol (CLIP, PAR-CLIP), each protein (HuR, Ago2), and enzymatic digestion (complete T1 digestion, mild MNase digestion). In addition, we performed a single PAR-CLIP experiment with mild T1 digestion.
A quantitative analysis of CLIP methods for identifying binding sites of RNA-binding proteins.
No sample metadata fields
View SamplesWe report the application of ultrashort metabolic labeling of RNA for high-throughput profiling of RNA processing in Drosophila S2 cells. Overall design: Examination of 3 different labeling timepoints in Drosophila S2 cells.
The kinetics of pre-mRNA splicing in the <i>Drosophila</i> genome and the influence of gene architecture.
Cell line, Subject
View SamplesWe obtained global measurements of decay and translation rates for mammalian mRNAs with alternative 3'' untranslated regions (3'' UTRs). Overall design: 1 3P-Seq sample from 3T3 cells and 1 3P-Seq sample from mouse ES cells; 2 2P-Seq steady state and 4 2P-Seq with actinomycin D; 6 polysome fraction 2P-Seq
3' UTR-isoform choice has limited influence on the stability and translational efficiency of most mRNAs in mouse fibroblasts.
Specimen part, Treatment, Subject
View SamplesIn the marrow and lymphatic tissues, chronic lymphocytic leukemia (CLL) cells interact with accessory cells that constitute the leukemia microenvironment. In lymphatic tissues, CLL cells are interspersed with CD68+ nurselike cells (NLC) and T cells. However, the mechanism regulating co-localization of CLL cells and these accessory cells are largely unknown. To dissect the molecular cross-talk between CLL and NLC, we profiled the gene expression of CD19-purified CLL cells before and after co-culture with NLC. NLC co-culture induced high-level expression of B cell maturation antigen (BCMA) and two chemoattractants (CCL3, CCL4) by CLL cells. Supernatants from CLL-NLC co-cultures revealed high CCL3/CCL4 protein levels. B cell receptor triggering also induced a robust induction of CCL3 and CCL4 expression by CLL cells, which was almost completely abrogated by a specific Syc inhibitor, R406. High CCL3 and CCL4 plasma levels in CLL patients suggest that activation of this pathway plays a role in vivo. These studies reveal a novel mechanism of cross-talk between CLL cells and their microenvironment, namely the secretion of two T cell chemokines by CLL-NLC interaction and in response to BCR stimulation. Through these chemokines, CLL cells can recruit accessory cells, and thereby actively create a microenvironment that favors their growth and survival.
High-level expression of the T-cell chemokines CCL3 and CCL4 by chronic lymphocytic leukemia B cells in nurselike cell cocultures and after BCR stimulation.
No sample metadata fields
View SamplesKey regulators of septum formation between the left and right ventricle in mammals, including the transcription factors TXB5 and PITX2, feature loss-of-function phenotypes that affect development of the two-chambered zebrafish heart, suggesting
Generating and evaluating a ranked candidate gene list for potential vertebrate heart field regulators.
Specimen part
View Samples