Recovery from 40 or 180 MPa 4C

Piezophysiology of genome wide gene expression levels in the yeast Saccharomyces cerevisiae: Hydrostatic pressure is one of the physical factors affecting cellular physiology. Hydrostatic pressure of a few hundred MPa decreases the viability of yeast cells, and pressure of a few tens MPa decreases the growth rate. To understand the effect of hydrostatic pressure, we employed yeast DNA microarrays and analyzed genome-wide gene-expression levels after the pressure treatment with 180 MPa (immediate) at 4 degrees C and recovery incubation for 1 h and 40 MPa (16 h) at 4 degrees C and recovery incubation for 1 h. The transcription of genes involved in energy metabolism, cell defense, and protein metabolism was significantly induced by the pressure treatment. Genome-wide expression profiles suggested that high pressure caused damage to cellular organelles, since the induced gene products were localized in the membrane structure and/or cellular organelles. Hierarchical clustering analysis suggested that the damage caused by the pressure was similar to that caused by detergents, oils, and freezing/thawing. We also estimated the contribution of induced genes to barotolerance using some strains that have the deletion in the corresponding genes. Keywords: stress response In the experiment that used 40 MPa, triplicate hybridization from independent biological samples were done, respectively. In the experiment that used 180 MPa, hybridization result was obtained from 5 independent biological samples, respectively. 5th data in 180 MPa have high and low power scanned data, on the other hand, others have single scanned data, respectively.