Prions play key role in yeast survival and evolution
Misfolded proteins called prions are best known for causing neurodegenerative disorders such as Creutzfeldt-Jakob disease and mad cow disease. However, a new study by scientists at MIT’s Whitehead Institute finds that they can also play a much more beneficial role.The research team, led by Susan Lindquist, has shown that in yeast, prions awaken dormant stretches of genes that can help the yeast survive environmental stresses. Furthermore, those new traits can be passed on to offspring, contributing to evolution in an unexpected way.Lindquist, a professor of biology at MIT, first proposed this evolutionary mechanism more than a decade ago, but many scientists resisted the idea because no one could find evidence that prions existed in “wild” strains of yeast, as opposed to the laboratory strains used for genetic studies. In a new paper published in the Feb. 15 online edition of Nature, the researchers tested nearly 700 wild yeast strains and...