Circadian rhythms are oscillations with a periodicity of 24 hours that are controlled by an endogenous clock and are observed in virtually all aspects of mammalian function from expression of genes to complex physiological processes. The master clock is present in the suprachiasmatic nucleus (SCN) in the anterior part of the hypothalamus and controls peripheral clocks present in other parts of the body . Although much is known about the mechanism of the central clock in the SCN, the regulation of clocks present in peripheral tissues is still unclear. This study is designed to examine fluctuations in gene expression in lungs within the 24 hour circadian cycle in normal animals. The objectives of this study is to identify and analyze circadian oscillation in gene expression in lungs, and to identify the role of circadian regulation in coordinating the functioning of this dynamic organ.
Light-dark oscillations in the lung transcriptome: implications for lung homeostasis, repair, metabolism, disease, and drug action.
Specimen part
View SamplesCircadian rhythms are oscillations with a periodicity of 24 hours that are controlled by an endogenous clock and are observed in virtually all aspects of mammalian function from expression of genes to complex physiological processes. The master clock is present in the suprachiasmatic nucleus (SCN) in the anterior part of the hypothalamus and controls peripheral clocks present in other parts of the body. Although much is known about the mechanism of the central clock in the SCN, the regulation of clocks present in peripheral tissues is still unclear. This study is designed to examine fluctuations in gene expression in abdominal white adipose tissue within the 24 hour circadian cycle in normal animals. The objectives of this study is to identify and analyze circadian oscillation in gene expression in white adipose tissue, and to identify the role of circadian regulation in coordinating the functioning of this dynamic tissue.
Circadian variations in gene expression in rat abdominal adipose tissue and relationship to physiology.
Sex, Specimen part
View SamplesWe present a new wholly defined Affymetrix spike-in dataset consisting of 18 microarrays. Over 5700 RNAs are spiked in at relative concentrations ranging from 1- to 4-fold, and the arrays from each condition are balanced with respect to both total RNA amount and degree of positive- versus negative-fold change. We use this new Platinum Spike dataset to evaluate microarray analysis routes and contrast the results to those achieved using our earlier Golden Spike dataset.
Preferred analysis methods for Affymetrix GeneChips. II. An expanded, balanced, wholly-defined spike-in dataset.
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View SamplesCells use their wide variety of RNPs to integrate the expression of functionally inter-related proteins by forming RNP complexes with cis-elements that are shared among co-regulated RNAs. In this study, we identified the the associated mRNAs that co-precipitated with hnRNP K in developing juvenile frog brain.
hnRNP K post-transcriptionally co-regulates multiple cytoskeletal genes needed for axonogenesis.
Specimen part
View SamplesThe organs of multicellular species are comprised of cell types that must function together to perform specific tasks. One critical organ function is responding to internal or external change but little is known about how responses are tailored to specific cell types or coordinated among them on a global level. Here we use cellular profiling of five Arabidopsis root cell types in response to a limiting resource, nitrogen, to uncover a vast and predominantly cell-specific response that was largely undetectable using traditional methods. These methods reveal a new class of cell-specific nitrogen responses. As a proof-of-principle, we dissected one cell-specific response circuit that mediates nitrogen-induced changes in root branching from pericycle cells. Thus, cellular response profiling links gene modules to discrete functions in specific cell types.
Cell-specific nitrogen responses mediate developmental plasticity.
Specimen part
View SamplesTo identify potential transient interactions between a TF and its targets, we developed an approach that can identify primary targets based either on TF-induced regulation or TF-binding, assayed in the same samples. Our studies focused on the TF bZIP1 (BASIC LEUCINE ZIPPER 1), a central integrator of cellular and metabolic signaling.
Hit-and-run transcriptional control by bZIP1 mediates rapid nutrient signaling in Arabidopsis.
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View SamplesDensely ionizing radiation is a major component of the space radiation environment and has potentially greater carcinogenic effect compared to sparsely ionizing radiation that is prevalent in the terrestrial environment. It is unknown to what extent the irradiated microenvironment contributes to the differential carcinogenic potential of densely ionizing radiation. To address this gap, 10-week old BALB/c mice were irradiated with 100 cGy sparsely ionizing g-radiation or 10, 30, or 80 cGy of densely ionizing, 350 MeV/amu Si particles and transplanted 3 days later with syngeneic Trp53 null mammary fragments. Tumor appearance was monitored for 600 days. Tumors arising in Si-particle irradiated mice had a shorter median time to appearance, grew faster and were more likely to metastasize. Most tumors arising in sham-irradiated mice were ER-positive, pseudo-glandular and contained both basal keratin 14 and luminal keratin 8/18 cells (designated K14/18), while most tumors arising in irradiated hosts were K8/18 positive (designated K18) and ER negative. Comparison of K18 vs K14/18 tumor expression profiles showed that genes increased in K18 tumors were associated with ERBB2 and KRAS while decreased genes overlapped with those down regulated in metastasis and by loss of E-cadherin. Consistent with this, K18 tumors grew faster than K14/18 tumors and more mice with K18 tumors developed lung metastases compared to mice with K14/18 tumors. However, K18 tumors arising in Si-particle irradiated mice grew even faster and were more metastatic compared to control mice. A K18 Si-irradiated host profile was enriched in genes involved in mammary stem cells, stroma, and Notch signaling. Thus systemic responses to densely ionizing radiation enriches for a ER-negative, K18-positive tumor, whose biology is more aggressive compared to similar tumors arising in non-irradiated hosts.
Densely ionizing radiation acts via the microenvironment to promote aggressive Trp53-null mammary carcinomas.
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View SamplesRoot branching in response to changes in nitrogen status in the soil, is a dramatic example of the plants remarkable developmental plasticity. In recent work we investigated the genetic architecture of developmental plasticity, combining phenoclustering and genome-wide association studies in 96 Arabidopsis thaliana ecotypes with expression profiling in 7 ecotypes, to characterise natural variation in root architectural plasticity at the phenotypic, genetic, and transcriptional levels. This series contains the microarray expression data for 7 ecotypes that represent a range of root branching strategies.
No associated publication
Age, Specimen part
View SamplesTo determine early changes leading to human cell transformation (cancer) we exposed an immortalized human bronchial epithelial cell line, BEAS-2B, to one of four different metals that may cause cancer via inhalation in humans or rodents: 2.0 micro-Molar soluble sodium arsenite (NaAsO2), 0.50 micro-Molar potassium chromate (K2CrO4), 250 micro-Molar nickel (II) sulfate (NiSO4), 10 micro-Molar sodium meta-vanadate (NaVO3), or were left untreated (control). After a 30-60 day exposure, cells were rinsed of metals and seeded in soft agar. A small number of the cells formed colonies in the soft agar, demonstrating the potential for anchorage independent growth, a characteristic of cancer. These colonies that originated from a single cell were extracted from the agar and grown out in monolayer for 3-4 weeks. The RNA data provided here is taken from these cells. The significance it that the metal exposure was stopped many generations before the analysis, yet each sample demonstrates changes in gene expression based on the original metal exposure.
Gene expression changes in human lung cells exposed to arsenic, chromium, nickel or vanadium indicate the first steps in cancer.
Specimen part
View SamplesWe investigated the morphological roots decisions of Arabidopsis in a NO3- heterogeneous medium. To do so, we used the Split-Root System which is an experimental set up to assess root decisions in nutrient heterogeneous medium. Split-root plants have been subjected to three different treatments. Control KNO3 plants received KNO3 on both sides of the root system (C.NO3) and Control KCl plants received KCl on both sides (C.KCl) as a nitrogen deprivation treatment. 'Split' plants received KNO3 on one side (Sp.NO3) and KCl on the other side (Sp.KCl) of the root system to assess the root decision-making in a heterogeneous environment.
Nitrogen economics of root foraging: transitive closure of the nitrate-cytokinin relay and distinct systemic signaling for N supply vs. demand.
Specimen part, Treatment
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