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E-MEXP-585
Saccharomyces cerevisiae
29 Downloadable Samples
Affymetrix Yeast Genome S98 Array (ygs98)
Description
The mitochondrial respiratory chain is composed of lipoprotein complexes imbedded in the inner mitochondrial membrane. This chain of enzymes transfers electrons from NADH and FADH2, provided from divers metabolic pathways, to oxygen. It couples the transfer of electrons to the translocation of protons across the membrane. Several clinical syndromes have been associated with respiratory dysfunction caused by mitochondrial or nuclear mutations. A number of mutations in the mitochondrial genes encoding for cytochrome b (CYTB) and cytochrome oxidase (COX 1, 2 and 3) have been linked with diseases. We are using yeast mutants to characterize the deleterious effect of mutations reported in patients on the assembly and catalytic properties of the affected enzymes, and to study the impact of mutations in nuclear genes, such as OXA1, encoding for factors required for the assembly of the respiratory complexes. In this work, we monitored the effects of the mutations causing respiratory defect on the whole genome expression. We compared the change in gene expression in rho0 cells (with a complete deletion of the mitochondrial genome, and by consequence without respiratory chain), in cells with either a single defective enzyme or several, and in cells after prolonged treatment with the bc1 inhibitors myxothiazol or antimycin. The impact of the mutations on the respiratory function ranged from mild to severe. The expression of approx. 350 genes was changed in at least one mutant. Cluster analysis was performed using the Cluster program (Eisen, 1998, PNAS 95:14863). Four groups of genes were studied in more details: Group A, the most repressed genes; Group B, the most over-expressed genes; Group C, genes more repressed in rho0 and Doxa1 cells; and Group D, genes more over-expressed in Doxa1.
Publication Title
Multiple defects in the respiratory chain lead to the repression of genes encoding components of the respiratory chain and TCA cycle enzymes.
Sample Metadata Fields
Compound
View Samples- Saccharomyces cerevisiae
- 18 Downloadable Samples
- Affymetrix Yeast Genome S98 Array (ygs98)
Description
Nitric oxide and NO-derived species (RNS) are defense molecules with broad antimicrobial activity. Micro-organisms have developed strategies to sense RNS and counteract their damaging effects. We used Saccharomyces cerevisiae, harbouring a deletion of YHB1 that encodes the main NO scavenger enzyme, to study consequences of RNS exposure on whole genome transcriptional response. The expression of >700 genes was altered on RNS treatment. No major role for ROS-scavenging enzymes was found, and the respiratory chain, the main site of ROS production, had only minor involvement in the RNS-induced stress. The changes were generally transient and also found after treatment with the respiratory inhibitor myxothiazol. 117 genes however showed a persistent response which was not observed after myxothiazol treatment. Of these, genes of the glutathione and DNA repair systems, iron homeostasis and transport were found up-regulated. Severe repression of genes of respiratory chain enzymes was observed. Many of these genes are known to be regulated by the transcription factor Hap1p suggesting that RNS might interfere with Hap1p activity. We showed also that Msn2/4p and Yap1p, key regulators of the response to, respectively, general stress and oxidative stress, played a role in mediating the RNS-induced response.
Publication Title
Transcriptional response to nitrosative stress in Saccharomyces cerevisiae.
Sample Metadata Fields
Compound, Time
View Samples- Mus musculus
- 11 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Primary murine fetal liver cells were freshly isolated from day e14.5 livers and then sorted for successive differentiation stages by Ter119 and CD71 surface expression (ranging from double-negative CFU-Es to Ter-119 positive enucleated erythrocytes) [Zhang, et al. Blood. 2003 Dec 1; 102(12):3938-46]. RNA isolated from each freshly isolated, stage-sorted population was reverse-transcribed, labelled, and then hybridized onto 3' oligo Affymetrix arrays. Important erythroid specific genes as well as the proteins that regulate them were elucidated through this profiling based on coexpression and differential expression patterns as well as by extracting specific GO categories of genes (such as DNA-binding proteins).
Publication Title
Homeodomain-interacting protein kinase 2 plays an important role in normal terminal erythroid differentiation.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 115 Downloadable Samples
- Affymetrix HT Human Genome U133A Array (hthgu133a)
Description
Patient-derived xenograft models are considered to represent the heterogeneity of human cancers and might be more relevant preclinical models to evaluate effective therapeutic agents. Our consortium joins efforts to extensively develop and characterize a new collection of patient-derived colorectal cancer models. From 86 unsupervised surgical colon sample collection, 54 tumors were successfully xenografted in immunodeficient mice and rats, representing 35 primary tumors, 5 peritoneal carcinosis and 14 metastases. Our histological and molecular characterization of patient tumors, first passage on mice and later passages includes the sequence of key genes involved in CRC (ie APC, KRAS, TP53), CGH array and transcriptomic analysis. This comprehensive characterization demonstrates that our collection recapitulates the clinical situation regarding the histopathological and molecular diversity of colorectal cancers. Moreover, patient tumors and corresponding models are clustering together which gives the opportunity to look for relevant signatures and comparison studies between clinical and preclinical data. Hence, we performed pharmacological monotherapy studies with standard of care for colon cancer (5-FU, oxaliplatin, irinotecan, cetuximab). Through this extensive in vivo analysis, we have compared the molecular profile with the drug sensitivity of each tumor models, and run an equivalent of a cetuximab phase II clinical trial in a preclinical setting. Our results confirm the key role of KRAS mutation in the cetuximab resistance and demonstrate that such collection could bring benefit to evaluate novel targeted therapeutic strategies and potentially help the stratification strategy for cancer patients according to molecular marker. This set correspond to 82 CGH profiles, with 7 samples from patient tumor and 75 samples from mouse xenograft at different passages P0 to P9. All hybridizations are performed with Human CGH 244K Agilent arrays (amadid 014693) in dual color with Human DNA Promega (sex matched) as reference. ID for biosources without an -Px suffix correspond to tumor patients. ID with a suffix correspond to xenograft with 0 for the first passage.
Publication Title
Characterization of a large panel of patient-derived tumor xenografts representing the clinical heterogeneity of human colorectal cancer.
Sample Metadata Fields
Specimen part, Disease, Disease stage, Time
View Samples- Arabidopsis thaliana
- 63 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Living organisms have to cope with multiple and combined fluctuations in their environment. According to their sessile mode of life, plants are even more subjected to such fluctuations impacting their physiology and development. In particular, nutrient availability is known to tune plant development through modulating hormonal signaling, and conversely, hormonal signals are key to control nutrient related signaling pathways (Krouk et al., 2011a). However, very few is known about molecular mechanisms leading to plant adaptation to such combined signals. Here we deployed an unprecedented combinatorial treatment matrix to reveal plant adaptation in response to nitrate (NO3-), ammonium (NH4+), auxin (IAA), cytokinins (CK) and abscisic acid (ABA) and their exhaustive binary combinations.
Publication Title
Combinatorial interaction network of transcriptomic and phenotypic responses to nitrogen and hormones in the Arabidopsis thaliana root.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus
- 36 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
C57Bl6J mice were injected CCL4 for 8 weeks to induce liver injury and livers were used to prepare RNA.
Publication Title
Interspecies NASH disease activity whole-genome profiling identifies a fibrogenic role of PPARα-regulated dermatopontin.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Arabidopsis thaliana
- 26 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
This work uses a time series in order to decipher gene relationships and consequently to build core regulatory networks involved in Arabidopsis root adaptation to NO3- provision. The experimental approach has been to monitor genome response to NO3- at 3, 6, 9, 12, 15 and 20 min, using ATH1 chips. This high-resolution time course analysis demonstrated that the previously known primary nitrate response is actually preceded by very fast (within 3 min) gene expression modulation, involving genes/functions needed to prepare plants to use/reduce NO3-. State-space modeling (a machine learning approach) has been used to successfully predict gene behavior in unlearnt conditions.
Publication Title
Predictive network modeling of the high-resolution dynamic plant transcriptome in response to nitrate.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 7 Downloadable Samples
- Affymetrix Human Gene 2.0 ST Array (hugene20st)
Description
We used Affymetrix microarrays to detail the global programme of gene expression regulated by CBP and/or p300 during human primary myoblast differentiation.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part, Subject, Time
View Samples- Mus musculus
- 20 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
In this study, we sought to identify the mRNAs associated to FMRP protein in mouse cortical neuron using a cross linking immunoprecipitation and microarray (CLIP-microarray).
Publication Title
Fragile X Mental Retardation Protein (FMRP) controls diacylglycerol kinase activity in neurons.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 18 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
NRT1.1 is a nitrate transceptor involved in many nitrate responses including the regulation of gene expression through (i) the Primary Nitrate Response (PNR) and (ii) the regulation the NRT2.1 gene under continuous high NH4NO3 conditions. Phosphorylation of NRT1.1s T101 residue is involved in the modulation of the PNR whereas nitrate transport by NRT1.1 is not. Here we used various NRT1.1 point mutants to study the impact of NRT1.1 on the whole transcriptome under high NH4NO3 supply. Col is the WT control, chl1-5 and chl1-12 are KO mutants, chl1-9 is defective in nitrate transport but not in PNR induction, T101D and T101A mimick the phosphorylated and not phosphorylated forms of NRT1.1 respectively.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part
View Samples