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Title: Transcription orofiling of Saccharomyces cerevisiae upon exposure to aaxitoxin      
availability:
available
aggregation:
instance of dataset
privacy:
not applicable
refinement:
curated
dateReleased:
05-01-2014
ID:
E-GEOD-16652
description:
Saxitoxin is a potent neurotoxin produced by several species of dinoflagellates and cyanobacteria. The molecular target of saxitoxin in higher eukaryotes is the voltage-gated sodium channel; however, its target in lower eukaryotic organisms remains unknown. The goal of this study was to obtain the transcriptional fingerprint of the model lower eukaryote Saccharomyces cerevisiae upon exposure to saxitoxin to identify potential genes suitable for biomarker development. Microarray analyses identified multiple genes associated with copper and iron homeostasis and sulfur metabolism as significantly differentially expressed upon exposure to saxitoxin; these results were verified with quantitative reverse-transcriptase PCR (qRT-PCR). Additionally, the qRT-PCR assays were used to generate expression profiles in a subset of the differentially regulated genes across multiple exposure times and concentrations, the results of which demonstrated that overall, genes tended to respond in a consistent manner to the toxin. In general, the genes encoding the metallothioneins CUP1 and CRS5 were induced following exposure to saxitoxin, while those encoding the ferric/cupric reductase FRE1 and the copper uptake transporter CTR1 were repressed. The gene encoding the multicopper ferroxidase FET3, part of the high-affinity iron uptake system, was also induced in all treatments, along with the STR3 gene, which codes for the cystathionine beta-lyase found in the methionine biosynthetic pathway. Experiment Overall Design: Cultures of S. cerevisiae S288C were grown to OD600=1.0 in YPD (1% yeast extract, 2% peptone, 2% dextrose). Four hundred microliters from individual 10 mL overnight cultures were transferred to sterile tubes and saxitoxin added to a final concentration of 16 µM. Sample were mixed gently and incubated at 30° C for 45 min. Controls consisted of deionized water. Three biological replicates were performed under these conditions for microarray analysis. Cells were harvested via sequential centrifugation and placed immediately in liquid nitrogen.Total RNA was extracted from frozen cell pellets using a protocol that combined the hot acid phenol method with the RNEasy kit. Total RNA was processed by the Affymetrix Core Facility at the University of Tennessee (Knoxville, TN) following the protocols of the Affymetrix GeneChip Expression Analysis Technical Manual. MAS5.0 was used to provide present/absent calls; genes absent in all six samples were then removed from the data set. Intensity values for all transcripts were obtained from the scanned image files of the chips. The intensity values of the six arrays were background-corrected and normalized with the GC-RMA algorithm.
keywords:
transcription profiling by array
format:
HTML
storedIn:
Array Express
qualifier:
not compressed
accessType:
landing page
authorization:
none
authentication:
none
primary:
true
accessURL: https://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-16652
format:
JSON
storedIn:
OmicsDI
qualifier:
not compressed
accessType:
download
authorization:
none
authentication:
none
primary:
false
accessURL: www.omicsdi.org/ws/dataset/arrayexpress-repository/E-GEOD-16652.json
format:
XML
storedIn:
OmicsDI
qualifier:
not compressed
accessType:
download
authorization:
none
authentication:
none
primary:
false
accessURL: http://www.omicsdi.org/ws/dataset/arrayexpress-repository/E-GEOD-16652.xml
ID:
SCR:014747
name:
Omics Discovery Index
abbreviation:
OmicsDI
homePage: http://www.omicsdi.org/