Cooperation, Cheating, and the Games that Yeast Play

March Meeting 2010


James Riordon, APS
Jason Socrates Bardi, AIP
Phillip Schewe, AIP


Meeting Press Releases

A "Periodic Table" of Biosensors
A Nanoscale Bean-Counter for Viruses
AC/DC Power Converter as Wide as a Human Hair
Blood Clot Glue
Heroines of Modern Physics
Highlighted Sessions
Infrared Pictures with a Digital Camera
Magnetic Tuberculosis Detector
Nanotube Toxicity
New Technique for Measuring the Strength of a Cell
Optimization and Biological Physics
Press Conference Schedule
Solar Cells and Cities of The Future
Solid Metal Batteries
The Flow of Particles in a Room
Topological Insulators
Using DNA as Building Blocks
World's Fastest Transistors

WASHINGTON, D.C. — Yeast is a convenient "model" organism that scientists can use to test ideas about evolution because they can easily genetically alter yeast in the laboratory and grow large populations of different strains in a matter of days.

Mathematicians who study "game theory" often analyze worldly subjects as complex as macroeconomics or evolution by using simple abstractions that involve multiple players competing for limited resources. Such analyses sometimes attest to a simple, if unfair, rule—that in games, as in life, the best strategy may be to cheat. But according to MIT physicist Jeff Gore, who studies cooperation and cheating in different strains of yeast, sometimes the good guys (or yeast) do win in the end.

Populations of certain strains of yeast will cooperate with each other metabolically by secreting an enzyme called invertase that breaks down the sugar sucrose (which they cannot digest) into the sugar glucose (which they can). In a homogeneous pool of such yeast, each cell benefits from the collective actions of the whole pool.

At first glance cheaters—yeast that do not secrete anything—would seem to have an advantage in this scenario because they would enjoy the glucose while being spared from having to spend any energy producing the enzyme. However, according to experiments Gore and his colleagues published in Nature last year, that's not always the case. In populations of yeast where the number of cooperators is initially small, it is the cooperators that enjoy the distinct advantage because they are always as close to the food source as possible. The majority of the sugar they break down diffuses away from them, but they still have preferential access to some portion of it.

In Portland, Gore will discuss his experiments testing game theories in yeast as well as the results of new experiments probing the degree to which evolutionary adaptations are reversible.

Related March Meeting Session

Gray arrow   Abstract: B7.00001 : Games microbes play: The game theory behind cooperative sucrose metabolism in yeast

About APS

The American Physical Society is the leading professional organization of physicists, representing more than 48,000 physicists in academia and industry in the United States and internationally. APS has offices in College Park, MD (Headquarters), Ridge, NY, and Washington, D.C. 

About AIP

Headquartered in College Park, MD, the American Institute of Physics is a not-for-profit membership corporation chartered in New York State in 1931 for the purpose of promoting the advancement and diffusion of the knowledge of physics and its application to human welfare.