Cell death in yeast: growing applications of a dying buddy.

摘要

The discovery of regulated cell death in the budding yeast Saccharomyces cerevisiae and its conservation to the mammalian system has paved the way for a new and fast-growing research area. Cell death in yeast is often accompanied by diagnostic apoptotic markers such as externalization of phosphatidylserine to the outer leaflet of the plasma membrane, DNA degradation, chromatin condensation, and the generation of reactive oxygen species, all of which can be measured both at a qualitative (microscopic) and at a quantitative (e.g. flow cytometric) level. A teleological explanation for this at first sight counterintuitive phenomenon, in which a unicellular organism succumbs to cellular suicide, has been provided by demonstrating its role in several physiological scenarios, for example, meiosis, aging and mating. Here, the death of damaged individual cells provides a selective advantage for the yeast population as a whole, facilitating the spreading of the clone. In other words, single cells sacrifice themselves for the benefit of the group, which may be regarded as an early root of social biology.