'light switch' flips genes on and off
turning a gene on or off is usually a lot more difficult than just flipping a light switch. but a team of swiss scientists has engineered cells that come pretty close: only when they are bathed in blue light do the cells express a gene that has been inserted into them.
the feat is the latest trick in a rapidly growing discipline known as optogenetics, where light is used to control activities within cells. the new technique, described online today in science,