Solving a riddle that has confounded biologists since bacterial spores--inert, sleeping bacteria--were first described more than 150 years ago, researchers at Harvard Medical School (HMS) have discovered a new kind of cellular sensor that allows spores to detect the presence of nutrients in their environment and quickly spring back to life. It turns out that these sensors double as channels through the membrane and remain closed during dormancy but rapidly open when they detect nutrients. Once open, the channels allow electrically charged ions to flow out through the cell membrane, setting in motion the shedding of protective spore layers and the switching on of metabolic processes after years--or even centuries--of dormancy. The team’s findings, published April 28 in Science, could help inform the design of ways to prevent dangerous bacterial spores from lying dormant for months, even years, before waking up again and causing outbreaks. The article is titled “Bacterial Spore Germination Receptors Are Nutrient-Gated Ion Channels.”