Project description:Reactive oxygen species, generated in vivo or exogenously encountered, constantly challenge living organisms. Oxidation of polyunsaturated fatty acids (PUFA), which are susceptible to oxidant attack, can lead to initiation of lipid peroxidation and in turn rapid production of toxic lipid hydroperoxides. Eukaryotic microorganisms such as Saccharomyces cerevisiae can survive harsh industrial conditions that contain high levels of the PUFA linoleic acid and its oxidised derivative, linoleic acid hydroperoxide (LoaOOH). The precise signalling and response mechanisms induced by yeast to overcome lipid hydroperoxide stress are ill understood. We used genome-wide microarrays to investigate the changes in gene expression of S. cerevisiae to LoaOOH-induced oxidative stress. S. cerevisiae (BY4743) were exposed to an arresting concentration of LoaOOH (75 M-BM-5M) for 1 hr to induce oxidative stress. Yeast treated with an equivalent volume of solvent (methanol) were used as a control. Following treatment conditions, total RNA was extracted from LoaOOH-treated or control yeast and hybridised onto Affymetrix microarrays.
Project description:Oxidative stress is a harmful condition in a cell, tissue, or organ, caused by an imbalnace between reactive oxygen species and other oxidants and the capacity of antioxidant defense systems to remove them. The budding yeast S. cerevisiae has been the major eukaryotic model for studies of response to oxidative stress. We used microarrays to study the genome-wide temporal response of the yeast S. cerevisiae to oxidative stress induced by cumene hydroperoxide. Keywords: time course The effects of oxidative stress induced by CHP on the transcriptional profile of S. cerevisiae was studied from a dynamical perspective. Yeast cultures were grown in controlled batch conditions, in 1 L fermentors. Three replicate cultures in mid-exponential phase were exposed to 0.19 mM CHP, while three non-treated cultures were used as controls. Samples were collected at t=0 (immediately before adding CHP) and at 3, 6, 12 and 20 min after adding the oxidant. Samples were processed for RNA extraction and profiled using Affymetrix Yeast Genome S98 arrays.