Project description:We explored transcriptional responses of the chytridiomycete Blastocladiella emersonii to some stress environmental conditions. Three distinct cDNA libraries constructed from mRNAs extracted from cells submitted to heat shock and different cadmium concentrations (50 and 100 mM) were sequenced and generated 6,350 high-quality EST sequences. These ESTs were assembled into 2,326 unigenes, being 51% of them not previously described in B. emersonii and consequently represent a worthy contribution of this work. We assigned to approximately 59% of the unigenes an orthologue in other organism, whereas 41% remained without a putative identification. Using the transcriptome data of B. emersonii we constructed a microarray slide containing 3,773 different cDNAs which comprise many biological processes of this fungus and analyzed its expression pattern in response to cadmium and heat shock. Through cDNA microarray assays we observed that 3,3% and 5,1% of the genes present in B. emersonii microarray slide were up-regulated in response to heat shock and cadmium, respectively. The main categories to which belong these genes were protein folding and proteolysis, proteins with antioxidant properties, cellular transport, carbohydrate and amino acid metabolism. Interestingly, in response to cadmium stress, B. emersonii induced six different genes codifying Glutathione S-transferases and six Metacaspases, as well as several proteins from sulfur amino acid metabolism. Keywords: stress response; heavy metal stress response; heat shock response
Project description:Due to its aquatic saprophytic lifestyle, the fungus Blastocladiella emersonii seems to be adapted to low aerated environments and thus can be an interesting model of study of the hypoxic stress response. Iron deprivation, a hypoxia-mimicking stimulus due to HIF-1 stabilization, and geldanamycin, that causes HIF-1 depletion by HSP90 inhibition, are helpful parameters to find an evidence of an oxygen-dependent regulatory mechanism in B. emersonii similar to the metazoan HIF-1 pathway.
