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E-GEOD-27022 - Microarray studies of darkness stress and bleaching in the Caribbean coral Acropora palmata

Status
Released on 22 March 2011, last updated on 2 May 2014
Organism
Acropora palmata
Samples (32)
Array (1)
Protocols (7)
Description
Coral bleaching occurs in response to numerous abiotic stressors, the ecologically most relevant of which is hyperthermic stress due to increasing seawater temperatures. Bleaching events can span large geographic areas and are currently a potent threat to coral reefs worldwide. Much effort has been focused on understanding the molecular and cellular events underlying bleaching, and these studies have mainly utilized heat and light stress regimes. In an effort to determine whether different stressors share common bleaching mechanisms, we used cDNA microarrays for the corals Acropora palmata and Montastraea faveolata (containing > 10,000 features) to measure differential gene expression during darkness stress. This is the first coral microarray experiment aimed at darkness stress, and the first for these species to interrogate gene expression at such a large scale. Our results reveal a striking transcriptomic response to darkness in A. palmata involving chaperone and antioxidant up-regulation, growth arrest, and metabolic modifications. As these responses were also measured during thermal stress, our results suggest that different stressors may share common bleaching mechanisms. Furthermore, our results point to ER stress as a critical cellular event involved in darkness-specific (and possibly more general) molecular bleaching mechanisms. On the other hand, we identified a meager transcriptomic response to darkness in M. faveolata, where gene expression differences between host colonies and/or sampling locations were greater than differences between control and stressed fragments. To this end, we discuss the importance of factors related to host genotype, Symbiodinium genotype, and the abiotic environment that influence host gene expression and thereby can hinder an investigator’s ability to measure gene expression during a condition of interest. We employed a reference design where all control and dark-stressed samples were compared to a pooled reference aRNA sample composed of aRNA from all fragments. Since all RNA samples were compared to the reference sample, direct comparisons of gene expression across all time points and conditions can be performed.
Experiment type
transcription profiling by array 
Contacts
Michael DeSalvo <mdesalvo@ucmerced.edu>, Andres Estrada, Michael K DeSalvo, Monica Medina, Shinichi Sunagawa
MIAME
PlatformsProtocolsVariablesProcessedRaw
Files
Investigation descriptionE-GEOD-27022.idf.txt
Sample and data relationshipE-GEOD-27022.sdrf.txt
Raw data (1)E-GEOD-27022.raw.1.zip
Processed data (1)E-GEOD-27022.processed.1.zip
Array designA-GEOD-13113.adf.txt
Links