Editor's Summary

14 May 2009

Facultative cheating in yeast

Yeast secrete invertase to break down sucrose into monosaccharides that they can metabolize. Gore et al. show that 99% of the monosaccharides diffuse away to where they can be used by other yeast cells, making this a cooperative behaviour susceptible to cheating by cells that do not secrete invertase. But that remaining 1% is sufficient to give the cooperators an advantage under certain circumstances. They can invade populations of cheaters, and the equilibrium frequencies of cheaters and cooperators that results depends on the concentration of glucose. Using both this experimental work and theoretical modelling, the authors show that this is not a prisoner's dilemma situation, but rather a snowdrift game, in which cheating can be profitable, but is not necessarily the best strategy if others are cheating too.

LetterSnowdrift game dynamics and facultative cheating in yeast

Jeff Gore, Hyun Youk & Alexander van Oudenaarden