IR-LEGO : a tool for gene induction in targeted single cells

Methods for turning on and off gene expression at the experimentalist's discretion would be useful for analyzing various biological processes. They would also serve as valuable tools for manipulating biological processes in living organisms. We have been developing a novel microscopic system utilizing an infraredinfrared laser 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. Compared with the Coumarin dye laser, which had been used for targeted gene induction mediated by the heat shock response, we expect that the IR-laser can heat biological tissues much more efficiently and is less harmful to cells. Combination of IR-LEGO with other techniques for gene manipulation, such as the in vivo recombination and RNA interference, would further widen its scope of application.