IdentiM-oM-,M-^Acation of genes responsible for biosynthesis of kojic acid in Aspergillus oryzae
Ontology highlight
ABSTRACT:
ORGANISM(S): Aspergillus oryzae
SUBMITTER: Maiko Umemura
PROVIDER: E-GEOD-43280 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Gene expression analysis of A. parasiticus grown under conditions conducive and nonconductive for aflatoxin production was evaluated using glass slide microarrays containing the 753 ESTs. A complex regulatory network governs the biosynthesis of aflatoxin. While several genes involved in aflatoxin production are known, their action alone cannot account for its regulation. Arrays of clones from an Aspergillus flavus cDNA library and glass slide microarrays of ESTs were screened to identify additional genes. An initial screen of the cDNA clone arrays lead to the identification of 753 unique ESTs. Many showed sequence similarity to known metabolic and regulatory genes; however, no function could be ascribed to over 50% of the ESTs. Gene expression analysis of Aspergillus parasiticus grown under conditions conducive and non-conductive for aflatoxin production was evaluated using glass slide microarrays containing the 753 ESTs. Twenty-four genes were more highly expressed during aflatoxin biosynthesis and 18 genes were more highly expressed prior to aflatoxin biosynthesis. No predicted function could be ascribed to 18 of the 24 genes whose elevated expression was associated with aflatoxin biosynthesis. Keywords = Aspergillus Keywords = aflatoxin Keywords: time-course
2003-01-15 | E-GEOD-204 | biostudies-arrayexpress
Project description:We identified a 14-3-3 homolog (maf1) in an EST library made under conditions conducive to aflatoxin biosynthesis. Disruption of this gene in A. flavus by site directed mutagenesis abolished aflatoxin production. The maf1 mutant was morphologically similar to wild type but had reduced conidiation and growth on some media. DNA expression analysis of the wild type and maf1 mutant revealed that the mutation affected the expression profile of a set of genes associated with aflatoxin production. Keywords = Aspergillus Keywords = aflatoxin Keywords = 14-3-3
2010-05-27 | E-GEOD-861 | biostudies-arrayexpress
Project description:A major virulence factor in S. enterica is the pathogenicity island Spi2. The goal of the experiment was to determine the impact of the NRAMP-1 (natural resistance-associated macrophage protein-1) on expression of Spi2 in S. enterica wild type (WT) and triple mutant strain (TMS) with deletions in SPI-1 TTSS, SPI-2 TTSS, flagella. The stain 14028 was used for the experiment. Cells were grown in a NRAMP-1 wildtype (plus) or deleted (minus) macrophage background. Total RNA was extracted and processed by qRT-PCR. Two strains ( WT and TMS) grown under 2 conditions (NRAMP-1 wildtype (plus) or NRAMP-1 deleted (minus)) - total 4 samples were analyzed in the study. All PCRs were done in duplicates, located on the same PCR plate. For each duplicate the mean value was calculated and used as a data point for further normalization. We averaged the Cp values for all the data points in a sample and then subtracted this sample average Cp from all the data points of the sample. Only 192 primer pairs from 288 on the platform GPL11111 were used.
2011-06-13 | E-GEOD-26806 | biostudies-arrayexpress
Project description:CTCF sites are abundant in the genomes of diverse species but their function is enigmatic. We used chromosome conformation capture to determine long-range interactions among CTCF/cohesin sites over 2 Mb on human chromosome 11 encompassing the β-globin locus and flanking olfactory receptor genes. Although CTCF occupies these sites in both erythroid K562 cells and fibroblast 293T cells, the long-range interaction frequencies among the sites are highly cell type specific, revealing a more densely clustered organization in the absence of globin gene activity. Both CTCF and cohesins are required for the cell-type-specific chromatin conformation. Furthermore, loss of the organizational loops in K562 cells through reduction of CTCF with shRNA results in acquisition of repressive histone marks in the globin locus and reduces globin gene expression, whereas silent flanking olfactory receptor genes are unaffected. These results support a genome-wide role for CTCF/cohesin sites through loop formation that both influences transcription and contributes to cell-type-specific chromatin organization and function. Comparison of CTCF binding in K562 and 293T cells using ChIP-chip. 3 replicates each cell type, ChIP and input DNA for each replicate.
2011-01-13 | E-GEOD-26507 | biostudies-arrayexpress
Project description:The Ldb1/GATA-1/TAL1/LMO2 complex mediates long range interaction between the β-globin locus control region (LCR) and gene in adult mouse erythroid cells but whether this complex mediates chromatin interactions at other developmental stages or in human cells is unknown. We investigated human NLI (Ldb1 homologue) complex occupancy and chromatin conformation of the β-globin locus in human erythroid cells. In addition to the LCR, we find robust NLI complex occupancy at a site downstream of the Aγ-globin gene, within sequences of BGL3, an intergenic RNA transcript. In cells primarily transcribing β-globin, BGL3 is not transcribed and BGL3 sequences are occupied by NLI core complex members together with co-repressor ETO2 and γ-globin repressor BCL11A. The LCR and β-globin gene establish proximity in these cells. In contrast, when γ-globin transcription is re-activated by cytokines in these cells, ETO2 participation in the NLI complex at BGL3 is diminished, as is BCL11A occupancy, and both BGL3 and γ-globin are transcribed. In these cells, proximity between the BGL3/γ-globin region and the LCR is established. Thus, alternative NLI complexes mediate γ-globin transcription or silencing through long range LCR interactions involving an intergenic site of non-coding RNA transcription and ETO2 is critical to this process. ChIP-chip of GATA-1, NLI, and pol II in cell lines Comparison of GATA-1, NLI, and pol II binding on chromatin. 2 replicates for each protein; ChIP and input DNA for each replicate
2012-01-05 | E-GEOD-30047 | biostudies-arrayexpress
Project description:Using criteria based on known examples, we identified approximately 1.7 million and 2.4 million sequences encoding putative miRNA precursor (stem-loop) structures in the mouse and human genomes, respectively, as well as large numbers of such structures in the genomes of fish, fruitfly and nematode worm. These predictions were then tested using high density custom microarrays containing modified oligonucleotides interrogated with purified small RNAs from different tissues. We found that 19% of 4,006 randomly chosen mouse predictions and 40% of 1,859 randomly chosen human predictions gave positive signals with small RNA isolated from whole 10-12 day embryos and a mixture of brain and testis, respectively, 84% of which hybridized to only one strand of the predicted stem-loop structure, whereas only 2% and 12% of equivalent random mouse and human predictions were positive. There was no difference in the validation rates between sequences exhibiting conservation and those that did not. High validation rates were also observed with predictions from fish, fly and worm genomes. Northern blot analysis of the array-positive mouse predictions confirmed that the vast majority of these sequences were detectable as small RNAs whose sizes ranged from 20-110 nucleotides. Taking into account false negative rates of the prediction and detection of known miRNAs, and assuming that this holds for other small RNAs, we estimate that there are 1 million small RNAs expressed in mouse and 3 million small RNAs in human. Keywords: genomic survey of small RNAs Stemloops were identified in the mouse and human genome using RNALfold with a window size of 110nt. Folding energy and other criteria were used to filter the structures into a set of miRNA-like stems. Stems were chosen randomly and probes designed against the stem regions. Stems were called present if one of the stem probes was more than 4 standard deviations above the signal distribution of mRNA degradation contamination probes designed against GAPDH and beta-actin.
2010-05-18 | E-GEOD-7217 | biostudies-arrayexpress
Project description:A major virulence factor in S. enterica is the pathogenicity island Spi2. The goal of the experiment was to determine the impact of the toll-like receptor 4 (TLR-4) on expression of Spi2 in S. enterica wild type (WT) and triple mutant strain (TMS) with deletions in SPI-1 TTSS, SPI-2 TTSS, flagella. The stain 14028 was used for the experiment. Cells were grown in a TLR-4 wildtype (plus) or deleted (minus) macrophage background. Total RNA was extracted and processed by qRT-PCR. Two strains (WT and TMS) grown under 2 conditions (TLR-4 wildtype (plus) or TLR-4 deleted (minus)) - total 4 samples were analyzed in the study. All PCRs were done in quadruplicates, located on the same PCR plate. For each quadruplicates the median value was calculated and used as a data point for further normalization. A set of controls was selected for all data sets using the following criteria: the data points for the controls should have Cp <40 and be present in all the samples.
2011-06-13 | E-GEOD-26804 | biostudies-arrayexpress
Project description:Reactive oxygen species (ROS) play a prominent role in signal transduction and cellular homeostasis in plants. However, imbalances between generation and elimination of ROS can give rise to oxidative stress in growing cells. Because ROS are important to cell growth, ROS modulation could be responsive to natural or human-mediated selection pressure in plants. To study the evolution of oxidative stress related genes in a single plant cell, we conducted comparative expression profiling analyses of the elongated seed trichomes (‘‘fibers’’) of cotton (Gossypium), using a phylogenetic approach. We measured expression changes during diploid progenitor species divergence, allopolyploid formation and parallel domestication of diploid and allopolyploid species, using a microarray platform that interrogates 42,429 unigenes. The distribution of differentially expressed genes in progenitor diploid species revealed significant up-regulation of ROS scavenging and potential signaling processes in domesticated G. arboreum. Similarly, in two independently domesticated allopolyploid species (G. barbadense and G. hirsutum) antioxidant genes were substantially up-regulated in comparison to antecedent wild forms. In contrast, analyses of three wild allopolyploid species indicate that genomic merger and ancient allopolyploid formation had no significant influences on regulation of ROS related genes. Remarkably, many of the ROS-related processes diagnosed as possible targets of selection were shared among diploid and allopolyploid cultigens, but involved different sets of antioxidant genes. Our data suggests that parallel human selection for enhanced fiber growth in several geographically widely dispersed species of domesticated cotton resulted in similar and overlapping metabolic transformations of the manner in which cellular redox levels have become modulated. We measured expression changes during diploid progenitor species divergence, allopolyploid formation and parallel domestication of diploid and allopolyploid species, using a microarray platform that interrogates 42,429 unigenes. The distribution of differentially expressed genes was studied for domesticated G. arboreum and two independently domesticated allopolyploid species (G. barbadense and G. hirsutum). These were compared to three wild allopolyploid species. Three biological replicates were performed.
2009-07-24 | E-GEOD-17084 | biostudies-arrayexpress
Project description:Gossypium barbadense is widely cultivated because of its extra-long staple cotton with superior luster, silkiness and high yield. These economically important traits were selected during initial domestication of an agronomically inferior wild ancestor, followed by millennia of human- mediated selection. To reveal the effects of this history on the cotton fiber transcriptome, we conducted comparative expression profiling on mechanically isolated fiber cells at three different stages encompassing early, mid, and late fiber elongation in wild (K101) and domesticated (Pima S-7) accessions, using a microarray platform that interrogates 42,429 unigenes. The distribution of differentially expressed genes across developmental stages was different in the two accessions, with a shift toward greater change earlier in cultivated than in wild G. barbadense. Approximately 4200 genes were differentially expressed between wild and domesticated accessions at one or more of the stages studied. Domestication appears to have led to enhanced modulation of cellular redox levels and the avoidance or delay of stress-like processes. Prolonged fiber growth in cultivated relative to wild G. barbadense is associated with upregulation of signal transduction and hormone signaling genes and down-regulation of cell wall maturation genes. Clues are provided into the processes and genes that may unwittingly have been selected by humans during domestication and development of modern elite lines. Several of the transcriptomic differences between wild and domesticated G. barbadense described here appear to have parallels in a second domesticated cotton species, Gossypium hirsutum, suggesting that replicated domestication of two different species has resulted in overlapping, parallel, metabolic transformations. Two accessions of G. barbadense were studied, the elite cultivar, Pima S-7, and a wild accession from Bolivia, K101. Seeds of both accessions were sown in sterilized potting mix in the Pohl Conservatory at Iowa State University, Ames, IA, and three biological replicates were grown for 3-5 months. Flowers were tagged at anthesis and harvested at three time points, 2, 10, and 20 days postanthesis. For each of three biological replicates, ovules were excised, frozen in liquid nitrogen, and stored at -80C.
2008-11-13 | E-GEOD-13022 | biostudies-arrayexpress
Project description:Global gene expression analysis of induced pluripotent stem cell lines and their corresponding source cells Total RNA was harvested from H9 hESC (P51), non-integrated episomal CB-iPSC clones 6.2, 6.11, 6.13, (P14), 19.11, (P11), nonviral KER-iPSC clones KA.1, KA.3 (P13) nonviral FFB-iPSC: F.1, F.6 (P14) and viral fibroblast iPSC clones IMR1 (P66), IMR4 (P64). A single sample of each condition was used for this analysis.
2012-08-23 | E-GEOD-35028 | biostudies-arrayexpress