Project description:We are investigating the transcriptional response of yeast to treatment with enediynes or gamma radiation, which generate different extents of double or single strand breaks in DNA. We used microarrays to detail the global programme of gene expression underlying the DNA damage response in yeast Experiment Overall Design: Yeast were grown to mid log phase and treated with enediynes or gamma radiation (in biological triplicate) resulting in similar extents of cell killing. The responses were compared to each other and we have deciphered a gene expression profile that is specific for double and single strand breaks in DNA.
Project description:Ionizing radiations are categorized by linear energy transfer (LET) into low-LET and high-LET. High-LET is considered to have a higher relative biological effectiveness (RBE) than low-LET radiations. However, the details of the effects have not been clearly determined. The aim of this study was to characterize the difference between high-LET and low LET radiations. The global effects of the three types of high-LET radiations (fast neutron, heavy ion (C) and thermal neutron) were compared with the low-LET radiation (gamma ray) using yeast DNA microarrays. Highly induced genes by the three types of high-LET radiations were those genes related to oxidative stress. Oxidative stress was one of the common factors associated with the four types of radiations. Oxidative stress induced by high-LET radiations may be more serious than that induced by gamma rays. Additionally, genes related to protein synthesis and the ubiquitin and proteasome system were detected. This suggests that more protein damages can be induced by high-LET radiation that denatures the proteins in yeast cells. The genes specifically altered by each type of high-LET radiation were also studied. Keywords: stress response
