Characterization of Drosophila mitochondrial transcripts through high throughput EST data
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster Drosophila pseudoobscura
PROVIDER: GSE16651 | GEO | 2009/12/09
SECONDARY ACCESSION(S): PRJNA116239
REPOSITORIES: GEO
Similar Datasets
Project description:We used high throughput EST sequences to characterize and generate expression profiles for all transcripts encoded in the mitochondrial genome of D. melanogaster and D. pseudoobscura. Mapping of ESTs confirmed previously predicted transcripts and revealed non-canonical transcript structures. Expression of mitochondrial transcripts was not different between the two species, but it was significantly different for males and females. We also detected difference in expression levels among mRNAs from genes located in the same transcriptional unit and among genes interacting in the same protein complexes, NADH dehydrogenase and cytochrome c oxidase complexes, suggesting a complex post-transcriptional regulation to maintain mitochondrial function. Keywords: Transcriptome Analysis Four samples analysed: D. melanogaster males, D. melanogaster females, D. pseuoobscura males, D. pseudoobscura females The number of reads that mapped to each transcript is proportional to the transcript abundance, so it can be used as a measure of the absolute level of expression of that transcript. The gene expression measure as the absolute EST counts and the expression relative to the library size for each mitochondrial gene in each library is displayed in the supplementary file linked below.
2009-12-09 | E-GEOD-16651 | biostudies-arrayexpress
Project description:Characterization of Drosophila mitochondrial transcripts through high throughput EST data
| PRJNA116239 | ENA
Project description:When the yeast Saccharomyces cerevisiae is subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from being purely respiratory to mixed respiratory and fermentative. This shift is characterized by ethanol production, a phenomenon known as the Crabtree effect due to its analogy with lactate overflow in cancer cells. It is well known that at high glycolytic fluxes there is glucose repression of respiratory pathways resulting in a decrease in the respiratory capacity. Despite many years of detailed studies on this subject, it is not known whether the onset of the Crabtree effect (or overflow metabolism) is due to a limited respiratory capacity or caused by glucose-mediated repression of respiration. We addressed this issue by increasing respiration in S. cerevisiae by introducing a heterologous alternative oxidase, and observed reduced aerobic ethanol formation. In contrast, increasing non-respiratory NADH oxidation by overexpression of a water-forming NADH oxidase reduced aerobic glycerol formation. The metabolic response to elevated alternative oxidase occurred predominantly in the mitochondria, while NADH oxidase affected genes that catalyze cytosolic reactions. Moreover, NADH oxidase restored the deficiency of cytosolic NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, while alternative oxidase is directed to the mitochondria. The onset of aerobic ethanol formation is demonstrated to be a consequence of an imbalance in mitochondrial redox balancing. In addition to answering fundamental physiological questions, our findings are relevant for all biomass derived applications of S. cerevisiae. Experiment Overall Design: Heterologous gene expression in chemostats using Affymetrix Yeast Genome 2.0 arrays. Total RNA extraction and sample preparation, hybridization was done according to the manufacturer's protocol.
2008-06-14 | E-GEOD-6277 | biostudies-arrayexpress
Project description:When the yeast Saccharomyces cerevisiae is subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from being purely respiratory to mixed respiratory and fermentative. This shift is characterized by ethanol production, a phenomenon known as the Crabtree effect due to its analogy with lactate overflow in cancer cells. It is well known that at high glycolytic fluxes there is glucose repression of respiratory pathways resulting in a decrease in the respiratory capacity. Despite many years of detailed studies on this subject, it is not known whether the onset of the Crabtree effect (or overflow metabolism) is due to a limited respiratory capacity or caused by glucose-mediated repression of respiration. We addressed this issue by increasing respiration in S. cerevisiae by introducing a heterologous alternative oxidase, and observed reduced aerobic ethanol formation. In contrast, increasing non-respiratory NADH oxidation by overexpression of a water-forming NADH oxidase reduced aerobic glycerol formation. The metabolic response to elevated alternative oxidase occurred predominantly in the mitochondria, while NADH oxidase affected genes that catalyze cytosolic reactions. Moreover, NADH oxidase restored the deficiency of cytosolic NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, while alternative oxidase is directed to the mitochondria. The onset of aerobic ethanol formation is demonstrated to be a consequence of an imbalance in mitochondrial redox balancing. In addition to answering fundamental physiological questions, our findings are relevant for all biomass derived applications of S. cerevisiae. Keywords: Genetic Modification
2007-02-01 | GSE6277 | GEO
Project description:From a set of 15 standard, normalized or full-length cDNA libraries, we generated 139 007 3'- or 5'-end sequenced ESTs, representing more than one-third of the c. 385 000 publicly available Populus ESTs. Clustering and assembly of 107 519 3'-end ESTs resulted in 14 451 contigs and 20 560 singletons, altogether representing 35 011 putative unique transcripts, or potentially more than three-quarters of the predicted c. 45 000 genes in the poplar genome. Using this EST resource, we developed a cDNA microarray containing 15 496 unique genes, which was utilized to monitor gene expression in poplar leaves in response to herbivory by forest tent caterpillars (Malacosoma disstria). After 24 h of feeding, 1191 genes were classified as up-regulated, compared to only 537 down-regulated. Functional classification of this induced gene set revealed genes with roles in plant defence (e.g. endochitinases, Kunitz protease inhibitors), octadecanoid and ethylene signalling (e.g. lipoxygenase, allene oxide synthase, 1-aminocyclopropane-1-carboxylate oxidase), transport (e.g. ABC proteins, calreticulin), secondary metabolism [e.g. polyphenol oxidase, isoflavone reductase, (–)-germacrene D synthase] and transcriptional regulation [e.g. leucine-rich repeat transmembrane kinase, several transcription factor classes (zinc finger C3H type, AP2/EREBP, WRKY, bHLH)]. This study provides the first genome-scale approach to characterize insect-induced defences in a woody perennial providing a solid platform for functional investigation of plant–insect interactions in poplar. Ten hybridizations were performed comparing FTC-treated poplar leaves after 24 h of continuous feeding and untreated control leaves harvested at the same time. RNA isolated from each of the five individual FTC-treated trees was compared directly against the five individual untreated control trees using two hybridizations with a dye flip for each tree pair.
2008-04-22 | E-GEOD-9522 | biostudies-arrayexpress
Project description:The NLRP3 inflammasome is linked to sterile and pathogen-dependent inflammation, and its dysregulation underlies many chronic diseases. Mitochondria have been implicated as regulators of NLRP3 inflammasome through multiple mechanisms including generation of mitochondrial ROS. Here we report that mitochondrial electron transport chain (ETC) complexes I, II, III and V inhibitors all prevent NLRP3 inflammasome activation. Ectopic expression of Saccharomyces cerevisiae NADH dehydrogenase (NDI1) or Ciona intestinalis alternative oxidase (AOX), which can respectively complement the functional loss of mitochondrial complex I or III, without generation of ROS, rescued NLRP3 inflammasome activation in the absence of endogenous mitochondrial complex I or complex III function. Metabolomics revealed phosphocreatine (PCr), which can sustain ATP levels, as a common metabolite that is diminished by mitochondrial ETC inhibitors. PCr depletion decreased ATP levels and NLRP3 inflammasome activation. Thus, mitochondrial ETC sustains NLRP3 inflammasome activation through PCr-dependent generation of ATP but a ROS independent mechanism.
2022-03-09 | GSE197606 | GEO
Project description:From a set of 15 standard, normalized or full-length cDNA libraries, we generated 139 007 3'- or 5'-end sequenced ESTs, representing more than one-third of the c. 385 000 publicly available Populus ESTs. Clustering and assembly of 107 519 3'-end ESTs resulted in 14 451 contigs and 20 560 singletons, altogether representing 35 011 putative unique transcripts, or potentially more than three-quarters of the predicted c. 45 000 genes in the poplar genome. Using this EST resource, we developed a cDNA microarray containing 15 496 unique genes, which was utilized to monitor gene expression in poplar leaves in response to herbivory by forest tent caterpillars (Malacosoma disstria). After 24 h of feeding, 1191 genes were classified as up-regulated, compared to only 537 down-regulated. Functional classification of this induced gene set revealed genes with roles in plant defence (e.g. endochitinases, Kunitz protease inhibitors), octadecanoid and ethylene signalling (e.g. lipoxygenase, allene oxide synthase, 1-aminocyclopropane-1-carboxylate oxidase), transport (e.g. ABC proteins, calreticulin), secondary metabolism [e.g. polyphenol oxidase, isoflavone reductase, (–)-germacrene D synthase] and transcriptional regulation [e.g. leucine-rich repeat transmembrane kinase, several transcription factor classes (zinc finger C3H type, AP2/EREBP, WRKY, bHLH)]. This study provides the first genome-scale approach to characterize insect-induced defences in a woody perennial providing a solid platform for functional investigation of plant–insect interactions in poplar. Keywords: stress response
2008-04-22 | GSE9522 | GEO
Project description:Transcriptional profiles of human CD34+ cells cultured in EPO and EST conditions.
2007-08-22 | GSE7874 | GEO
Project description:‘Pulsechip’, a boutique cDNA microarray, generated from a set of chickpea (Cicer arietinum L.) unigenes, grasspea (Lathyrus sativus L.) ESTs and lentil (Lens culinaris Med.) resistance gene analogs, was employed to generate an expression profile of chickpea accessions tolerant and susceptible to high-salinity stress. Two groups of a tolerant and susceptible accession were challenged with high-salinity stress. The experiments were performed in three biological replications. The experiments were conducted in reference design where respective tissues from unstressed plants served as control. The leaf/shoot and root tissues were collected at 24 and 48 h post-treatment (hpt) and used for hybridization to measure changes in RNA abundance of treatment vs. control. The tissues from five experimental replicate plants per biological replication were pooled together (shoot and root tissues separate for each time point) before RNA extraction. This RNA was used to prepare cDNA targets for expression analysis using microarray. The microarray had six technical replicate spots per EST. The transcript level for each EST/cDNA was firstly calculated as the average intensity of the six technical replicates and then the average intensity of three biological replicates. Data analysis included LOWESS normalization (LOcally WEighted polynomial regreSSion) to adjust for differences in quantity of initial RNA, labeling and detection efficiencies. A dye swap in one biological replicate adjusted dye bias, if any. The Differentially Expressed (DE) ESTs were identified as those with a 95% confidence interval for mean fold change (FC) that extended beyond the two-fold cut-off and also passed the Students t test (P<0.05) and FDR correction. These cut-offs translate into induced ESTs having a log2 ratio > 1 and repressed ESTs a ratio of < -1. The analysis consisted of three fold comparison. Firstly, the ESTs that were differentially expressed between treatment and control plants of each accession were detected. Then the ESTs that were similarly expressed by tolerant and susceptible accessions were then eliminated by comparison. This included a two-way comparison, where tolerant and susceptible genotypes were compared within and between groups. Lastly, ESTs that were consensually differentially expressed between tolerant and susceptible accessions of the two batches were identified. The hypothesis was that if a putative gene was consistently expressed only in tolerant or susceptible genotype for a particular stress, it might be a candidate for tolerance/susceptibility for that stress. Globally, the level of 409 transcripts was affected in response to high-salinity stress in all the genotypes and tissue types studied. Of the transcripts consistently expressed in tolerant genotypes in response to high-salinity stress, the annotation of transcripts at 24 hpt suggest a reduction in energy production in shoots and roots by repression of putative genes including P700 chlorophyll a-apoprotein (DY475501) and NADH-plastoquinone oxidoreductase subunit I (DY475287), cytosolic fructose 1,6-bisphosphatase (DY475548) and splicing factor-like protein (DY396290). The ATHP3 (DY396300) and protein kinase (DY475077) that are potentially involved in signalling cascades responsible for sensing and relaying osmotic stress signals, were consistently repressed in tolerant genotypes in response to high-salinity. Additionally a glycine rich protein (DY396342) that is associated with lignification of cell walls in response to wounding and pathogen attack was repressed in tolerant genotypes. In tolerant genotypes at 48 hpt, two energy and metabolic-related transcripts were consistently repressed in roots, including a carbonic anhydrase (DY475403) and putative thiazole biosynthetic enzyme (DY475242). In shoots, only a pathogenesis-related protein (DY396301) was consistently repressed at 48 hpt, but a similar transcript (DY396281) was induced in roots of tolerant genotypes at the same time. Only four transcripts were DE in susceptible genotypes at 24 hpt, all occurring in root tissue. Two of these were unknown/unclear, but the others included a proline oxidase transcript (DY475225) and a nuclear transport factor 2 (DY396436). At 48 hpi, a putative splicing factor-like protein (DY396290) and polyubiquitin (DY396328) were repressed in roots of susceptible genotypes. Interstingly, a putative xylosidase (DY475408) was induced in susceptible roots at 48 hpi. Finally, several unknown/unclear transcripts were DE in both tolerant and susceptible genotypes. Of interest were two unknowns (DY475293 and DY475521) that were consistently expressed in tolerant genotypes and may be important for high-salinity tolerance. Keywords: Chickpea, High-salinity stress, tolerant, susceptible, cDNA microarray
2007-04-03 | GSE7418 | GEO