Acetaldehyde mediates the synchronization of sustained glycolytic oscillations in populations of yeast cells

In the presence of cyanide, populations of yeast cells can exhibit sustained oscillations in the concentration of glycolytic metabolites, NADH and ATP. This study attempts to answer the long-standing question of whether and how oscillations of individual cells are synchronized. It shows that mixing two cell populations that oscillate 180 degrees out of phase only transiently abolishes the macroscopic oscillation. After a few minutes, NADH fluorescence of the mixed population resumes oscillations up to the original amplitude. At low cell densities, addition of acetaldehyde causes transient oscillations. At higher cell densities, where the oscillations are autonomous, 70 mu M acetaldehyde causes phase shifts. Extracellular acetaldehyde is shown to oscillate around the 70 mu M level. We conclude that acetaldehyde synchronizes the oscillations of the individual cells.