Manipulating behaviors of targeted single cells in vivo by using IR-LEGO

Methods for turning on/off gene expression at any desired time and place in vivo would be useful for analyzing various biological processes. We have developed a novel microscopic system utilizing an infrared laser, IR-LEGO (infrared-laser evoked gene operator), which is designed to deposit heat locally in living organisms. We have shown that IR-LEGO enables us to induce the heat shock response efficiently in targeted single cells of C. elegans worms, thereby driving expression of a transgene under the control of a heat shock promoter. By using IR-LEGO we attempted to rescue several mutant phenotypes of worms at the single-cell level. Diverse cell behaviors including differentiation and migration of target cells can be manipulated by gene induction mediated by IR-LEGO. Our results showed that IR-LEGO can be used to manipulate cell-autonomous as well as cell-nonautonomous behaviors, further confirming that irradiation using IR-LEGO has no harmful effects on the targets. Thus, IR-LEGO serves as valuable tools for manipulating biological processes in living organisms.