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ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe
SUBMITTER: Jeffrey Pleiss
PROVIDER: E-GEOD-74354 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Eukaryotic gene expression requires that RNA Polymerase II (RNAP II) gain access to DNA in the context of chromatin. The C-terminal domain (CTD) of RNAP II recruits chromatin modifying enzymes to promoters, allowing for transcription initiation or repression. Specific CTD phosphorylation marks facilitate recruitment of chromatin modifiers, transcriptional regulators, and RNA processing factors during the transcription cycle. However, the readable code for recruiting such factors is still not fully defined and how CTD modifications affect related families of genes or regional gene expression is not well understood. Here we examine the effects of manipulating the Y1S2P3T4S5P6S7 heptapeptide repeat of the CTD of RNAP II in Schizosaccharomyces pombe by substituting non-phosphorylatable alanines for Ser2 and/or Ser7 and the phosphomimetic glutamic acid for Ser7. Global gene expression analyses were conducted using splicing-sensitive microarrays and validated via RT-qPCR. The CTD mutations did not affect pre-mRNA splicing or snRNA levels. Rather, the data revealed upregulation of subtelomeric genes and alteration of the repressive histone H3 lysine 9 methylation (HeK9me) landscape. The data further indicate that H3K9me and expression status are not fully correlated, suggestive of CTD-dependent subtelomeric repression mechansims that act independently of H3K9me levels. Splicing sensitive S. pombe microarrays (Agilent-027365) were used to compare the splicing and expression profile of four mutant strains relative to WT control with 3-5 biological replicates and dye flipped samples
2016-08-10 | E-GEOD-83426 | biostudies-arrayexpress
Project description:Two-week old bread wheat seedlings hydroponically grown Hoagland solution were transferred to potassium (K+)-free conditions for 8 d, their root and leaf proteome profiles were assessed using iTRAQ proteome method, and NCBInr database combined with the recently published bread wheat genome information were used to analyze the identified protein species. Over 4,000 unique proteins were identified, 818 K+-responsive protein species showed significant abundance regulation. The most majority of the identified K+-responsive protein species had exact gene loci, and showed no global but tissue- and chromosome- dependent genome distributions. The identified protein species were associated with diverse functions and exhibited organ-specific differences. Most of identified protein species associated with hormone synthesis were the enzymes involved in the synthesis of jasmonic acid (JA). Allene oxide synthase (AOS), a key JA synthesis-related enzyme, was significantly induced in both root and leaf organs of K+-deficient wheat seedlings, and its overexpression in rice enhanced the tolerance to low K+ or K+ deficiency, increased contents of K+ and JA and transcription levels of some K+-responsive genes. However, rice AOS T-DNA inserted mutant (osaos) exhibited more sensitivity to K+ deficiency. K+ deficiency significantly increased abundance of a high affinity K+ transporter (TaAHAK1), TaAHAK1 transgenic rice seedlings markedly alleviated sensitivity to K+ deficiency, and K+ deficiency also upregulated expression of homologous OsHAK1 gene in TaAOS transgenic rice plants. These results suggested an essential role of JA in K+ deficiency and gave molecular insight into the responses of plant to K+ deficiency.
2017-10-09 | PXD003570 | Pride
Project description:Chemostat experiments: Predator-prey dynamics were followed in four replicate chemostats (continuous-flow aquatic culture vessels) supplied with nitrogen-limited sterile medium that was otherwise sufficient in all nutrient constituents (Yoshida et al. 2003; Becks et al. 2010). Three chemostats contained 380 mL of medium, while the fourth, used for our algal gene expression study, contained 3000 mL so as to provide sufficient material for genetic analysis. Brachionus calyciflorus was isolated originally from Milwaukee harbor, Wisconsin, and provided by M. Boraas. Chlamydomonas reinhardtii was obtained from the University of Texas algal culture collection (UTEX 89). Both species reproduced asexually in our chemostat system. Though B. calyciflorus is naturally cyclically parthenogenetic, the rotifers in our stock culture have evolved not to produce males because the bubbling in our chemostats prevents mating; we used only one mating type of Chlamydomonas. Absence of sexual reproduction does not preclude the processes of microevolution (Bell 2009) that we study, and it is commonly accepted that asexual species can evolve (Lenski et al. 1991; Barrett et al. 2005). We used a Chlamydomonas lineage, founded from our original Chlamydomonas stock and then exposed continuously to Brachionus predation for six months in chemostat culture prior to this study during which Chlamydomonas evolved to form clumps (the 'grazed Chlamydomonas' lineage in Becks et al. 2010). We tracked changes in Chlamydomonas gene expression throughout two complete cycles of algal and rotifer abundance and concurrent cycles in algal defense. Algal samples were taken from one chemostat at intervals of approximately every ten days (8 dates total), chosen to capture critical transitions in cell clumping. A sample taken at the start of the experiment from the culture that was used to inoculate the chemostat was the standard against which algae from later samples were compared (i.e., the M-^Sgrazed ChlamydomonasM-^T). To obtain sufficient material for microarray analysis, ca. 1 - 1.5 L algal samples were collected and filtered through a 10-um mesh to exclude rotifers and rotifer eggs. The algal samples of ca. 100 ml of chemostat medium were concentrated by centrifugation and frozen. Samples were shock frozen in liquid nitrogen and transferred to -80C.
2012-03-20 | E-MEXP-3562 | biostudies-arrayexpress
Project description:TNFα-stimulated gene 6 (TSG-6) is an anti-inflammatory protein. In human epidermis, TSG-6 is secreted in extracellular matrix where it interacts with hyaluronan (HA). However, their functions are not well understood. In this study, immortalized N/TERT keratinocytes were edited by CRISPR/Cas9, used to reconstruct in vitro epidermis (RHE) and stimulated or not with interleukins 4 and 13 for 48h to mimic atopic dermatitis (AD). Two TSG-6-/- clones (respectively TSG-6-/- (a) and TSG-6-/- (b)) harboring major deletions in both alleles were selected and compared to TSG-6+/+ cells. Epidermis reconstructed from TSG-6-/- (a) and TSG-6-/- (b) exhibit normal differentiation process and morphology but show an increased HA leakage in the underlying culture medium of both TSG-6-/- RHE compared to TSG-6+/+ tissues, especially in conditions that mimic AD. While IL-4/13 treatment of RHE induces regulation of genes associated with AD, the absence of TSG-6 don’t seem to show any major transcriptomic regulation.
2021-12-30 | E-MTAB-10095 | biostudies-arrayexpress
Project description:Eco1 is an acetyltransferase subunit of the cohesin complex and acts during DNA replication to establish cohesion between sister chromatids. However, cohesin has additional functions in gene expression, DNA damage repair, and higher-order organization of chromosomes. The eco1 mutant W216G disrupts acetyltansferase activity, and causes genome-wide transcriptional defects which can be suppressed by deletion of FOB1, a gene also involved in DNA replication. This experiment investigates gene expression differences between the eco1-W216G mutant, and mutants in FOB1, and RAD61 a gene involved in inhibition of cohesion establishment but mutation of which is able to suppress temperature sensitivity of the eco1-W216G mutant. Wt and mutant strains of yeast were grown to mid log phase in liquid culture in triplicate and harvested for comparison on Affymetrix microarrays. The following strains were compared: 1) eco1-W216G, 2) eco1-W216G fob1Δ, 3) eco1-W216G rad61Δ, 4) fob1Δ, 5) rad61Δ, and 6) WT.
2014-04-03 | E-GEOD-54741 | biostudies-arrayexpress
Project description:The evolutionarily conserved cohesin complex is crucial for holding sister chromatids together from the time of DNA replication until their segregation during the metaphase to anaphase transition. Human diseases associated with with mutations in the cohesin network are termed "cohesinopathies". Scc2 is required for loading cohesin onto DNA prior to DNA replication. Cornelia de Lange syndrome (CdLS), a developmental disorder characterized by growth and intellectual impairment is caused by mutations in Scc2. How mutations in Scc2 gives rise to these developmental defects is currently unknown, as overt defects in chromosome segregation are not observed in CdLS patients. One hypothesis is that, reduced binding of Scc2 causes gene misregulation. To further explore this idea ChIP-seq was performed using an scc2-4 mutant. We observed from the analysis, we observe reduce binding of Scc2 to Pol II transcribed genes (snoRNAs, ribosomal protein genes) and pol II transcribed genes (tRNAs). Studies are currently underway to examine the biological implications of this observation. Examining genome-wide binding of scc2-4 mutant
2015-06-16 | E-GEOD-55357 | biostudies-arrayexpress
Project description:Upon germination, pollen forms a tube that elongates dramatically through female tissues in order to reach and fertilize ovules. While essential for the life cycle of higher plants, the genetic basis underlying most of the process is not well understood. We used Affymetrix Arabidopsis ATH1 Genome Arrays covering more than 80% of the Arabidopsis genome to compare transcriptomes of cell-sorted, hydrated pollen grains with those of flowers, leaves, seedlings and siliques (all samples with duplicates). This comparison revealed that pollen expresses a reduced set of genes with increased proportions of enriched and selectively-expressed transcripts. Relative gene ontology (GO) category representations in pollen and vegetative tissues revealed a functional skew of the pollen transcriptome towards signaling, vesicle transport and cytoskeleton, suggestive of a commitment towards germination and tube growth. Relative gene ontology (GO) category representations in pollen and vegetative tissues reveal a functional skew of the pollen transcriptome towards signaling, vesicle transport and cytoskeleton, suggestive of a commitment towards germination and tube growth. Relative gene ontology (GO) category representations in pollen and vegetative tissues reveal a functional skew of the pollen transcriptome towards signaling, vesicle transport and cytoskeleton, suggestive of a commitment towards germination and tube growth. Gene family and pathway analysis allowed formulation of novel hypotheses for the role of non-classical MADS-box genes, small RNA pathways and cell cycle components in pollen.
2005-06-01 | E-MEXP-285 | biostudies-arrayexpress
Project description:During translation elongation, the ribosome ratchets along its mRNA template, incorporating each new amino acid and translocating from one codon to the next. The elongation cycle requires dramatic structural rearrangements of the ribosome. We show here that deep sequencing of ribosome-protected mRNA fragments reveals not only the position of each ribosome but also, unexpectedly, its particular stage of the elongation cycle. Sequencing reveals two distinct populations of ribosome footprints, 28-30 nucleotides and 20-22 nucleotides long, representing translating ribosomes in distinct states, differentially stabilized by specific elongation inhibitors. We find that the balance of small and large footprints varies by codon and is correlated with translation speed. The ability to visualize conformational changes in the ribosome during elongation, at single-codon resolution, provides a new way to study the detailed kinetics of translation and a new probe with which to identify the factors that affect each step in the elongation cycle. Ribosome profiling, or sequencing of ribosome-protected mRNA fragments, in yeast. We assay ribosome footprint sizes and positions in three conditions: untreated yeast (3 replicates) and yeast treated with translation inhibitors cycloheximide (2 replicates) and anisomycin (2 biological replicates, one technical replicate). We also treat yeast with 3-aminotriazole to measure the effect of limited histidine tRNAs on ribosome footprint size and distribution (two treatment durations).
2014-06-10 | E-GEOD-58321 | biostudies-arrayexpress
Project description:Ribosomal proteins are essential to life. While the functions of ribosomal protein-encoding genes (RPGs) are highly conserved, the evolution of their regulatory mechanisms is remarkably dynamic. In Saccharomyces cerevisiae, RPGs are unusual in that they are commonly present as two highly similar gene copies and that they are over-represented among intron-containing genes. To investigate the role of introns in the regulation of RPG expression, we constructed 16 S. cerevisiae strains with precise deletions of RPG introns. We found that several yeast introns function to repress rather than to increase steady-state mRNA levels. Among these, the RPS9A and RPS9B introns were required for cross-regulation of the two paralogous gene copies, which is consistent with the duplication of an autoregulatory circuit. Splicing specific microarrays were used to assess the genome-wide defects in gene expression and pre-mRNA splicing that result from a deletion of a single ribosomal protein gene intron.
2012-03-01 | E-GEOD-35541 | biostudies-arrayexpress
Project description:MSI (Microsatellite Instability) colorectal cancer (CRC) show improved survival, are less prone to metastasis and show poor response to chemotherapy (compared to MSS tumors). The underlying reasons for these characteristics are still not understood and no specific therapeutic approach for MSI colon tumours (15% of CRC overall) has yet been developed.
The MSI process is oncogenic when it affects DNA repeat sequences that have a functional role, e.g. Small Coding Repeats (SCR). MSI also frequently affects Long Non-Coding Repeats (LNCR) in tumour DNA. In contrast to SCR, only a few LNCR are endowed with biological activity. Consequently, this area has received very little attention. Our group recently identified HSP110 mutant chaperone protein in MSI CRC that was generated by somatic deletion of a LNCR. Of interest, HSP110 mutant (due to exon skipping) have anti-oncogenic properties and the survival of MSI CRC patients receiving chemotherapy is positively associated with HSP110 mutations in tumour DNA.
The aim of the current project is to identify additional clinically relevant MSI-associated splicing aberrations due to mutations in LNCR located in splice acceptor sites. The four main steps are as follows:
1. To identify exon/intron sites affected by aberrant splicing events due to MSI in CRC . All RNASeq data will be exploited to identify recurrent splicing aberrations (mostly exon skipping) that occur specifically in MSI colon tumours;
2. To investigate for possible functional links between MSI and any detected aberrant splicing events . All specific aberrant splicing events detected by RNAseq in MSI CRC samples will be first confirmed (quantitative RT-PCR) in order to eliminate false positive cases. For validated exon candidates, the allelic profiles of adjacent intronic LNCR will be analysed (PCR and fluorescence genotyping) in CRC cell lines and primary tumours (MSI and MSS), as well as in matching normal mucosa samples in order to assess their polymorphic status;
3. To identify splicing events and LNCR mutations with clinical relevance in MSI CRC patients . All LNCR with a confirmed role in gene splicing in MSI CRC will be analysed. The clinical relevance of candidate genes will be assessed using multivariate survival regression models for Relapse- Free Survival, with interaction terms (response to chemotherapy);
4. To initiate functional studies on a limited number of clinically relevant, cancer-related genes whose splicing is perturbed in MSI cancer cells, and to develop biological tools to simplify screening in future clinical assays Similar to HSP110, we will focus on 4 or 5 mutant proteins that are promising drug therapeutic targets. Functional assays will be developed to further elucidate their role in the pathophysiology of MSI tumours. We also aim to develop biological tools for these candidate genes, such as the detection of wild-type or mutant proteins by immunohistochemistry.
| 2266966 | ecrin-mdr-crc