Hsp26 is not required for growth at high temperatures, nor for thermotolerance, spore development, or germination

Hsp26 is one of the major heat shock proteins of eukaryotic cells. It is also strongly induced at particular times during development at normal temperatures. We have isolated the unique gene for this protein from the yeast Saccharomyces cerevisiae, and we have used it to create disruption and deletion mutations. Surprisingly, the mutations have no detectable effect on the following characteristics: growth rates at various temperatures, in fermentative or in respiratory metabolism, in rich or in minimal media; the acquisition of thermotolerance in log phase or in stationary phase cells; resistance to ethanol; spore development; thermoresistance during sporulation; spore germination; thermoresistance of mature or germinating spores; or survival after long-term storage in stationary phase or as spores.