HEAT-SHOCK TREATMENT REDUCES IN-SITU TEMPERATURE IN YEAST AT SUBLETHAL HIGH-TEMPERATURE

Cells from the yeast Schizosaccharomyces pombe IFO-0342, once heat sho cked and then treated with ultra-centrifugation showed a significant i ncrease in tolerance compared to non heat-shocked control cells as est imated by colony forming unit (CFU). Fluorescence microscopical observ ation of these treated cells when stained with DAPI revealed that in n on heat-shocked cells the chromatin regions were dislocated to one end due to the acceleration force of gravity. However, prior heat-shocked cells or 2.0 M glycerol suspended cells showed normal localization. F rom these results, it has been postulated that the interior part of th e heat-shocked cells becomes viscous, and that in situ the temperature of the cell interior part might be reduced under semi-lethal high tem perature.