[Colloquium] Brewer’s Yeast Hedges Its Bets – Andrew Murray

Speaker: Andrew Murray, Harvard University

Title: “Brewer’s Yeast Hedges Its Bets”

Abstract:

Microorganisms live in unpredictable and rapidly changing environments. Bet-hedging is one way for a population to deal with this volatility: even though they share the same genome, different cells can use different strategies to grow and survive. In brewer’s yeast, we call the two strategies arrestors and recoverers: arrestors grow faster than recoverers on high glucose concentrations but fail to recover and restart growth when they must metabolize a worse carbon source, like ethanol, whereas recoverers eventually restart their growth and proliferate. The two phenotypes result from the bistability of a dynamical system and can be passed from one cell generation to the next; switches from one strategy to  the  other occur every few cell divisions. I will discuss a model for bistability that is based on competition between processes occurring in different parts of the cell and report on experiments that support the model and argue that it has been widely used during evolution.