A yeast DNA microarray for the evaluation of toxicity in environmental water containing burned ash.

Numerous studies on the hazard assessment and epidemiological health responses to burned ash have been reported. However, there is little information on the potential toxicity of unknown chemical complexes in burned ash. For an overall evaluation of the multiple toxicities of burned ash, a DNA microarray was used in this study, as a new attempt to assess these toxicities. Using the global gene expression on yeast DNA chip to reflect the changes in mRNA levels, our study discovered a lot of evidences for the action of cell homeostasis and stress response etc., against the toxic effects on yeast cells. On the genes of 5,117 open reading frames (ORFs), as valid spots in a microarray, 997 were up-regulated, 1,259 were down-regulated and 2,861 remained unchanged. A detailed analysis of the microarray revealed the genes that were dynamically correlated to the function of the subcellular localization, energy/metabolism, various stress responses/cell homeostasis and detoxification. Significantly, the toxicities, caused by reactive oxygen species (ROS), metals and the other xenobiotics, were indicated in burned ash. Also, the possibility of mutagenicity of the burned ash was suggested on the basis of the DNA repair related genes.