The SWR1 complex replaces the canonical histone H2A with the variant H2A.Z (Htz1 in yeast) at specific chromatin regions. This dynamic alteration in nucleosome structure provides a molecular mechanism to regulate transcription. Here we analysed the transcription profiles of single and double mutants and wild-type cells by whole-genome microarray analysis. Our results indicate that genome-wide transcriptional misregulation in htz1 can be partially or totally suppressed if SWR1 is not formed (swr1), if it forms but cannot bind to chromatin (swc2), or if it binds to chromatin but has no histone replacement activity (swc5). These results suggest that in htz1 the nucleosome remodelling activity of SWR1 affects chromatin integrity because of an attempt to replace H2A with Htz1 in the absence of the latter.
The SWR1 histone replacement complex causes genetic instability and genome-wide transcription misregulation in the absence of H2A.Z.
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View SamplesThe fermentable carbohydrate composition of wort and the manner in which it is utilised by yeast during brewery fermentation has a direct influence on fermentation efficiency and quality of the finished product. In this study the response of a brewing yeast strain to changes in wort fermentable carbohydrate concentration and composition during full-scale (3275 hL) brewery fermentation was investigated by measuring transcriptome changes with the aid of oligonucleotide based DNA arrays. Up to 90% of the detectable genes showed a significant (P 0.05) differential expression pattern during fermentation and the majority of these genes showed either transient or prolonged peaks in expression following the exhaustion of the monosaccharides glucose and fructose from the wort. Those which did not display this apparent carbon catabolite derepression response were mainly those genes involved in cytokinesis and cell budding, which had higher expression values during active growth of cells. Transcriptional activity of many genes was consistent with their known responses to glucose de/repression under laboratory conditions, despite the presence of di- and trisaccharide sugars in the wort.
AtEnsEMBL.
No sample metadata fields
View SamplesSV7tert AML cells were obtained from ATCC and cultured in Dulbecco's modified essential medium (DMEM), glutamine (4mmol) and 10% foetal bovine serum (FBS). Two million SV7tertAML cells were subcutaneously injected into nude mice either with or without subcutaneous oestrogen pellets (n=4 per group); oestrogen was added using 0.36mg 60 day release oestrogen pellets implanted sub-cutaneously. Mice were housed in pathoflex isolators at 26C, on 12 hour light / dark cycles. Irradiated RB2 diet and autoclaved water provided ad libertum.
Analysis of the oestrogen response in an angiomyolipoma derived xenograft model.
Specimen part
View SamplesMetal tolerance is often a result of metal storage or distribution. Thus, with the goal of advancing the molecular understanding of such metal homeostatic mechanisms, natural variation of metal tolerance in Arabidopsis thaliana was investigated. Substantial variation exists in tolerance of excess copper (Cu), zinc (Zn) and cadmium (Cd). Two accessions, Col-0 and Bur-0, and a recombinant inbred line (RIL) population derived from these parents were chosen for further analysis of Cd and Zn tolerance variation, which is evident at different plant ages in various experimental systems and appears to be genetically linked. Three QTLs, explaining in total nearly 50 % of the variation in Cd tolerance, were mapped. The one obvious candidate gene in the mapped intervals, HMA3, is unlikely to contribute to the variation. In order to identify additional candidate genes the Cd responses of Col-0 and Bur-0 were compared at the transcriptome level. The sustained common Cd response of the two accessions was dominated by processes implicated in plant pathogen defense. Accession-specific differences suggested a more efficient activation of acclimative responses as underlying the higher Cd tolerance of Bur-0. The second hypothesis derived from the physiological characterization of the accessions is a reduced Cd accumulation in Bur-0.
Natural variation in Arabidopsis thaliana Cd responses and the detection of quantitative trait loci affecting Cd tolerance.
Specimen part, Treatment
View SamplesMacrophages are a heterogeneous cell type implicated in injury, repair, and fibrosis after AKI, but the macrophage population associated with each phase is unclear.results of this study in a renal ischemia-reperfusion injury model allow phenotype and function to be assigned to CD11b+/Ly6C+ monocyte/macrophage populations in the pathophysiology of disease after AKI.
Differential Ly6C Expression after Renal Ischemia-Reperfusion Identifies Unique Macrophage Populations.
Sex, Specimen part
View SamplesXEN cells are derived from the primitive endoderm of mouse blastocysts. In culture and in chimeras they exhibit properties of parietal endoderm. However, BMP signaling promotes XEN cells to form an epithelium and differentiate into visceral endoderm (VE). Of the several different subtypes of VE described, BMP induces a subtype that is most similar to the VE adjacent to the trophoblast-derived extraembryonic ectoderm.
BMP signaling induces visceral endoderm differentiation of XEN cells and parietal endoderm.
Treatment
View SamplesThe cascade of molecular events involved in mammalian sex determination has been shown to involve the SRY gene, but specific downstream events have eluded researchers for decades. The current study identifies one of the first direct downstream targets of the male sex-determining factor SRY as the basic-helix-loop-helix (bHLH) transcription factor TCF21. SRY was found to directly associate with the Tcf21 promoter SRY/SOX9 response element both in vitro and in vivo during male sex determination. TCF21 was found to promote an in vitro sex reversal of embryonic ovarian cells to promote precursor Sertoli cell differentiation. Therefore, SRY acts directly on the Tcf21 promoter to, in part, initiate a cascade of events associated with Sertoli cell differentiation and embryonic testis development.
Basic helix-loop-helix transcription factor TCF21 is a downstream target of the male sex determining gene SRY.
Sex, Specimen part, Treatment
View SamplesEmbryonic day 13 (E13), E14, and E16 rat testes and ovaries were used for microarray analysis, as well as E13 testis organ cultures that undergo testis morphogenesis and develop seminiferous cords in vitro. A list of 109 genes resulted from a selective analysis for genes present in male gonadal development and with a 1.5-fold change in expression between E13 and E16. Characterization of these 109 genes potentially important for testis development revealed that cytoskeletal-associated proteins, extracellular matrix factors, and signaling factors were highly represented. Throughout the developmental period (E13-E16), sex-enriched transcripts were more prevalent in the male with 34 of the 109 genes having testis-enriched expression during sex determination. In ovaries, the total number of transcripts with a 1.5-fold change in expression between E13 and E16 was similar to the testis, but none of those genes were both ovary enriched and regulated during the developmental period. Genes conserved in sex determination were identified by comparing changing transcripts in the rat analysis herein, to transcripts altered in previously published mouse studies of gonadal sex determination. A comparison of changing mouse and rat transcripts identified 43 genes with species conservation in sex determination and testis development. Profiles of gene expression during E13-E16 rat testis and ovary development are presented and candidate genes for involvement in sex determination and testis differentiation are identified. Analysis of cellular pathways did not reveal any specific pathways involving multiple candidate genes. However, the genes and gene network identified influence numerous cellular processes with cellular differentiation, proliferation, focal contact, RNA localization, and development being predominant.
Regulation of the gonadal transcriptome during sex determination and testis morphogenesis: comparative candidate genes.
No sample metadata fields
View SamplesTemporal changes in the embryo transcriptome between the blastocyst stage (Day 7) and initiation of elongation (Day 13) differ between in vivo- and in vitro-derived embryos and are reflective of subsequent developmental fate.
Transcriptome changes at the initiation of elongation in the bovine conceptus.
Specimen part
View SamplesChromosomal instability (CIN) is thought to be a source of mutability in human cancer. However, CIN is highly deleterious for the cell, and the resulting aneuploidy induces metabolic stress and compromises cell fitness. Here we utilized the X-chromosome dosage compensation mechanism and changes in X-chromosome number to demonstrate in Drosophila epithelial cells the causal relationship between CIN, aneuploidy, gene dosage imbalance and tumorigenesis. Whereas the harmful effects of CIN can be buffered by resetting the X-chromosome dosage compensation to compensate for changes in X-chromosome number, interfering with the mechanisms of dosage compensation suffices to induce tumorigenesis. In addition, multiple mechanisms buffer the deleterious effects of CIN including DNA-damage repair, activation of the p38 signalling pathway, and induction of cytokine expression to promote compensatory cell proliferation. These data reveal a key role of gene dosage imbalances to CIN-induced programmed cell death and tumorigenesis and the existence of robust compensatory mechanisms.
Gene Dosage Imbalance Contributes to Chromosomal Instability-Induced Tumorigenesis.
Specimen part
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