Differential gene expression in juvenile polyps of the coral Acropora tenuis exposed to thermal and chemical stresses

We describe a strategy to identify stress-responsive genes in corals by means of high-coverage cDNA expression profiling (HiCEP). In this study, the effects of thermal and chemical (DCMU and TBT-Cl) stresses on Acropora tenuis juvenile polyps were examined, and 19 genes were identified as stress-responsive genes. Of these, seven had sequences significantly similar to sequences of known proteins. We quantified the expression levels of these seven using real-time PCR. In corals, the genes encoding heat shock protein 90, calreticulin, methionine adenosyltransferase, and aquaglyceroporin showed differential stress-related expression patterns. In the endosymbiotic algae associated with the corals, genes coding for DnaJ-like protein and chloroplast light-harvesting protein were identified as stress-responsive genes. The only gene showing increased expression in response to all three stresses (thermal and both chemical stresses) was the coral gene coding for the oxidative stress-responsive protein, suggesting that oxidative stress generally occurs in each stress-exposed polyp.

► The effects of thermal and chemical stresses on coral juveniles were examined. ► We identified 19 genes whose expression changed by stress treatment. ► Some chaperon function proteins were identified from coral and the symbiont. ► Only oxidative stress-responsive protein was generally expressed by each stressor.