Stressed cells dance on a bright stage

While studying the stress response of yeast cells, Jacquet et al. (page 497) discovered a new type of oscillatory process that can control gene expression. In addition to creating a computational model that should help to direct future studies of cell stress, the authors identified a sort of biological Heisenberg effect, in which the process of observing certain cells under the microscope could significantly influence their physiology.

In the yeast Saccharomyces cerevisiae, two related transactivators, Msn2 and Msn4, translocate from the cytoplasm to the nucleus in response to a wide variety of stresses. Using high resolution time-lapse video microscopy, Jacquet et al. examined the translocation of an Msn2-GFP hybrid protein in single cells. Under the bright light of the fluorescence microscope, Msn2 migrates to the nucleus, indicating that light generates a stress response in GFP-...