Yeast in Space: An Overview of the Effects of Microgravity on Saccharomyces Cerevisiae

Nova Southeastern University, Davie, Florida, USA

Objective: This study was conducted to examine the effects of the microgravity of space on yeast growth, cell cycle, and gene expression. Background: Earlier studies show that the microgravity of space has profound effects on the growth of yeast and in their gene expression. In addition to the microgravity of space, other methods of simulating microgravity also have effects on yeast. Methods: For this study, the yeast Saccharomyces cerevisiae was grown under microgravity conditions using the true microgravity of space, a rotating wall vessel with shear stress offset for gravity, Ficoll with buoyancy as an offset for gravity, and magnetic levitation as an offset for gravity. The yeast were grown under each condition, then fixed using ethanol for later analysis by flow cytometry, optical density growth measurements, and gene expression studies with PCR. Results: Yeast exhibited differential gene expression, cell cycle patterns, and growth patterns under the various microgravity conditions. Spaceflight studies yielded a decrease in gene expression of SSA4 (35% ) and YILO52C (45%), both important to the yeast stress response. Conclusion: With this study, we found stimulus specific, dose dependent, and synergistic effects of independent physical forces in Saccharomyces cerevisiae. Grants: This study was partially funded by LaSPACE and the Department of Veterans Affairs.