The goal of the experiment was to perform a large scale study of circadian regulation of gene expression in maize. To identify maize genes with expression regulated by the circadian clock, transcript levels in the aerial tissues of young maize seedlings were determined by transcriptional profiling with the Affymetrix GeneChip Maize Genome Array. Maize inbred B73 seedlings were grown inside Conviron growth chamber. B73 seedlings were grown for 7 days under 12 h light:12 h dark (LD) photocycles, 26 C temperature and 70% humidity. At the 8th day, seedlings were transferred to continuous light (LL) and were allowed to entrain completely for 24 h prior to tissue harvest following which tissue was harvested every 4 hours under LL conditions for a period of 48h. Therefore, for the circadian LL time course 12 time points were collected as follows (also defined as factors in the treatment section): ZT0 - 8:00 am/ subjective dawn/ Day1 ZT4 - 12:00 pm/ subjective mid-day/ Day1 ZT8 - 4:00 pm/ subjective late-day/ Day1 ZT12 - 8:00 pm/ subjective dusk/ Day1 ZT16 - 12:00 am/ subjective mid-night/ Day1 ZT20 - 4:00 am/ subjective pre-dawn/ Day1 ZT24- 8:00 am/ subjective dawn/ Day2 ZT28 - 12:00 pm/ subjective mid-day/ Day2 ZT32 - 4:00 pm/ subjective late-day/ Day2 ZT36 - 8:00 pm/ subjective dusk/ Day2 ZT40 - 12:00 am/ subjective mid-night/ Day2 ZT44 - 4:00 am/ subjective pre-dawn/ Day2 Tissue comprised of aerial portion of the seedlings (corresponding to tissue from the prop roots and up) for RNA isolation. Total RNA was isolated from the entire aerial portion of 7 day-old seedlings (corresponding to tissue from the prop roots and up) by Trizol extraction followed by Qiagen RNeasy columns and treatment with RNase-free DNase I (Qiagen; qiagen.com). RNA was isolated from 3 independent biological replicates was pooled. cRNA was generated from pooled total RNA from 3 biological replicates with the GeneChip One-Cycle Target Labeling kit according to the manufacturers recommendations (Affymetrix, affymetrix.com). The University of California, Berkeley Functional Genomics Laboratory hybridized samples to Affymetrix GeneChip Maize Genome Arrays and scanned the washed arrays as suggested by manufacturer. Probe sets called Not Present or Marginal on one or more microarrays were removed from the downstream analysis, as is common practice with circadian studies. Raw hybridization intensities were normalized across all twelve arrays using RMA express in Perfect Match mode. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Frank G. Harmon. The equivalent experiment is ZM28 at PLEXdb.]
Coordination of the maize transcriptome by a conserved circadian clock.
Specimen part, Treatment, Time
View SamplesMost higher organisms, including plants and animals, have developed a time-keeping mechanism that allows them to anticipate daily fluctuations of environmental parameters such as light and temperature. This circadian clock efficiently coordinates plant growth and metabolism with respect to time-of-day by producing self-sustained rhythms of gene expression with an approximately 24-hour period. The importance of these rhythms has in fact been demonstrated in both phytoplankton and higher plants: organisms that have an internal clock period matched to the external environment possess a competitive advantage over those that do not.
The circadian clock regulates auxin signaling and responses in Arabidopsis.
No sample metadata fields
View SamplesBy sequencing 36 cDNA libraries with Illumina technology, we identified genes differentially expressed in soybean plants in response to water deficit and genes that were either up- or down-regulated in different periods of the day. Of 54,175 predicted soybean genes (Glyma v1.1), 35.52% exhibited expression oscillations in a 24 h period. This number increased to 39.23% when plants were submitted to water deficit. Major differences in gene expression were observed in the control plants from late day (ZT16) until predawn (ZT20) periods, indicating that gene expression oscillates during the course of 24 h in normal development. Under water deficit, dissimilarity increased in all time-periods, indicating that the applied stress influenced gene expression. Results suggest that time of day, as well as light and temperature oscillations that occur considerably affect the regulation of water deficit stress response in soybean plants. Overall design: Gene expression analysis of soybean leaves under water deficit in 6 periods of day by sequencing 36 libraries, in triplicate, in Illumina platform.
Daytime soybean transcriptome fluctuations during water deficit stress.
Specimen part, Subject
View SamplesET-743 (trabectedin, Yondelis) and PM00104 (Zalypsis) are marine derived compounds that have antitumor activity. ET-743 and PM00104 exposure over sustained periods of treatment will result in the development of drug resistance, but the mechanisms which lead to resistance are not yet understood. Human chondrosarcoma cell lines resistant to ET-743 (CS-1/ER) or PM00104 (CS-1/PR) were established in this study. The CS-1/ER and CS-1/PR exhibited cross resistance to cisplatin and methotrexate but not to doxorubicin. Human Affymetrix Gene Chip arrays were used to examine relative gene expression in these cell lines.
ZNF93 increases resistance to ET-743 (Trabectedin; Yondelis) and PM00104 (Zalypsis) in human cancer cell lines.
Specimen part, Cell line
View SamplesHematopoietic cells arise from spatiotemporally restricted domains in the developing embryo. Although studies of non-mammalian animal and in vitro embryonic stem cell models suggest a close relationship among cardiac, endocardial, and hematopoietic lineages, it remains unknown whether the mammalian heart tube serves as a hemogenic organ akin to the dorsal aorta. Here, we examined the hemogenic activity of the developing endocardium. Mouse heart explants generated myeloid and erythroid colonies in the absence of circulation. Hemogenic activity arose from a subset of endocardial cells in the outflow cushion and atria earlier than in the aorta-gonad-mesonephros region, and was transient and definitive in nature. Interestingly, key cardiac transcription factors, Nkx2-5 and Isl1, were expressed in and required for the hemogenic activity of the endocardium. Together, these data suggest that a subset of endocardial and yolk sac endothelial cells expressing cardiac markers serve as a de novo source for transient definitive hematopoietic progenitors.
Haemogenic endocardium contributes to transient definitive haematopoiesis.
Specimen part
View SamplesPseudomonas aeruginosa (P. aeruginosa) lung infection is a significant cause of mortality in patients with cystic fibrosis (CF). Existing experimental data in our lab showed significantly different levels of virulence of "early" and "late" P. aeruginosa infection isolates in a C. elegans slow killing model. We wished to examine the expression profile of these isolates in order to explore genes that may be responsible for the observed differences. The expression profiles of two pairs of isolates (four isolates in total) were compared to each other using the Affymetrix P. aeruginosa PAO1 genome array, to gain insight into properties mediating virulence in these isolates. Data analysis was carried out using BIOCONDUCTOR software.
Modulation of gene expression by Pseudomonas aeruginosa during chronic infection in the adult cystic fibrosis lung.
No sample metadata fields
View SamplesThe hypocotyl of Arabidopsis seedlings shows rhythmic periods of elongation. The patterns of elongation are controlled by a combination of internal factors, such as the circadian clock, and external factors such as light. In a previous study we had found that two transcription factors, PIF4 and PIF5 are important integrators of clock and light signals for the control of elongation. Here we use microarrays to find genes that are correlated with elongation and that are controlled by PIF4 and/or PIF5.
Genomic analysis of circadian clock-, light-, and growth-correlated genes reveals PHYTOCHROME-INTERACTING FACTOR5 as a modulator of auxin signaling in Arabidopsis.
No sample metadata fields
View SamplesHigh uniform fluid shear stress (FSS) is atheroprotective and preserves the endothelial phenotype and function through activation of downstream mediators such as MAPK7 (Erk5). Endothelial cells respond to FSS thanks to mechanotransduction. However, how the resulting signaling is integrated and resolved at the epigenetic level, remains elusive. We hypothesized that Polycomb methyltransferase EZH2 is involved in the effects of FSS in human endothelial cells. We showed that FSS decreases the expression of the Polycomb methyltransferase EZH2. Despite simultaneous activation of MAPK7, MAPK7 pathway does not directly influence the transcription of EZH2. Interestingly though, the knock down of EZH2 activates the protective MAPK7 signaling in endothelial cells, even in the absence of FSS. To understand the influence of the FSS-decreased expression of EZH2 on endothelial transcriptome, we performed RNA-seq and differential gene expression analysis. We identified candidate groups of genes dependent on both EZH2 and FSS. Among those, Gene Ontology overrepresentation analysis revealed highly significant enrichment of the cell cycle-related genes, suggesting changes in proliferation. Indeed, the depletion of EZH2 strongly inhibited endothelial proliferation, indicating cell cycle arrest. The concomitant decrease in CCNA expression suggests the transition of endothelial cells into a quiescent phenotype. Further bioinformatical analysis suggested TXNIP as a possible mediator between EZH2 and cell cycle-related gene network. Our data show that EZH2 is a FSS-responsive gene. Decreased EZH2 levels enhance the activation of the atheroprotective MAPK7 signaling. Decrease in EZH2 under FSS mediates the decrease in the expression of the network of cell cycle-related genes, which allows the cells to enter quiescence. EZH2 is therefore important for the protective effects of FSS in endothelium. Overall design: Puromycin-selected HUVEC (Human Umbilical Vein Endothelial Cells, Lonza, Switzerland) cells, expressing either scrambled control (SCR) or anti-EZH2 short-hairpin (shEZH2) constructs (at total 7 days after the first viral transduction), were used in FSS experiments (72h of control static culture or exposure to 20 dynes/cm2 of fluid shear stress, using Ibidi pump system (in µ-Slides I 0.4 Luer, Ibidi, Planegg/Martinsried, Germany)). Each replicate experiment consisted of viral transductions and puromycin selection of a separate HUVEC batch, followed by the FSS experiment. Two FSS experimental sets of the same HUVEC batch were run every time in parallel and lysed at the same end time point, one in RNAse-free conditions with RNA-Easy Mini Plus kit RLT Plus lysis buffer (QIAGEN, Venlo, The Netherlands), and one with RIPA buffer. The RIPA-lysates were analyzed with Western blotting and confirmed the complete (no protein present) knock-down of EZH2. From the RNA-lysates, RNA was isolated using the RNA-Easy Mini Plus kit (QIAGEN, Venlo, The Netherlands). High quality RNA samples (pre-assessed by Nanodrop measurements) were further processed in the Genome Analysis Facility of the University Medical Center Groningen. The RNA quality and integrity were verified using PerkinElmer Labchip GX with a cut-off value of 9 (scale 1 to 10, where 9 is very high quality RNA). RNA library was created in accordance with the TruSeqTM RNA Sample Preparation v2 Guide (Illumina, San Diego, CA, USA), using the PerkinElmer Sciclone liquid handler, resulting in 330bp cDNA fragments. The paired-end sequencing (100bp reads) was performed using the Illumina HiSeqTM 2500. (Quoted from the Materials and Methods of the related manuscript, with adjustments).
The decrease in histone methyltransferase EZH2 in response to fluid shear stress alters endothelial gene expression and promotes quiescence.
No sample metadata fields
View SampleshTERT/cdk4 immortalized myogenic human cell lines represent an important tool for skeletal muscle research, being used as therapeutically-pertinent models of various neuromuscular disorders and in numerous fundamental studies of muscle cell function. However, the cell cycle is linked to other cellular processes such as integrin regulation, the PI3K/Akt pathway, and microtubule stability, raising the question as to whether transgenic modification of the cell cycle results in secondary effects that could undermine the validity of these cell models. Here we subjected healthy and disease lines to intensive transcriptomic analysis, comparing immortalized lines with their parent primary populations in both differentiated and undifferentiated states, and testing their myogenic character by comparison with non-myogenic (CD56-negative) cells. We found that immortalization has no measurable effect on the myogenic cascade or on any other cellular processes, and that it was protective against the systems level effects of senescence that are observed at higher division counts of primary cells.
Skeletal muscle characteristics are preserved in hTERT/cdk4 human myogenic cell lines.
Specimen part, Disease, Disease stage
View SamplesType I IFN-signaling suppresses an excessive IFN-{gamma} response and prevents lung damage and chronic inflammation following Pneumocystis (PC)-infection and clearance in CD4 T cell-competent mice.
Type-I IFN signaling suppresses an excessive IFN-gamma response and thus prevents lung damage and chronic inflammation during Pneumocystis (PC) clearance in CD4 T cell-competent mice.
Specimen part
View Samples