[en] Opposite to the replicative aging, which refers to the exponential decline in the capacity of a single cell to divide, chronological aging of the yeast Saccharomyces cerevisiae refers to the time period a yeast cell can survive in a non-dividing state. In 2006, Allen and co-workers reported that yeast cells evolve into two cell types during stationary phase: a high density population defined as quiescent cells (Q) and a low density population defined as non-quiescent (NQ) cells. These two populations mainly differ by their viability, measured as the ability to form colonies when platted on Petri dishes, and can be separated by differential centrifugation on density gradient. In this work, we used the quantitative proteomics technique of 2DDIGE (two Dimensional Differential In-Gel Electrophoresis) to compare the evolution of the yeast cellular soluble proteome during chronological aging. We also checked the impact of the carbon source on stationary-phase cell differentiation. As the ratio of Q/NQ cells is decreasing with time, we have selected three distinct periods: 0 day (32h after outset of yeast culture on glucose, 100% of Q cells), 7 days (50% of Q cells) and 14 days (100% of NQ cells) to realize 3 proteomics comparisons (fig 1).
