Suicidal yeast

Programmed cell death (PCD) in multicellular eukaryotes is a form of altruism, in which one cell activates its own death for the greater benefit of the organism. But it is more difficult to envision a benefit for a single-celled microbe. Now, Fedor Severin and Anthony Hyman (Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany) demonstrate that PCD is indeed a normal physiological process for yeast cells during mating.

Mating in yeast is initiated by a and α mating pheromones. High levels of, or prolonged exposure to, the mating factor is toxic to the cells. The group's results now show that the toxicity is due to the onset of PCD. Exogenous addition of α factor to a cells induced several markers of PCD, including production of reactive oxygen species and initiation of DNA...