Recent discoveries of photoreceptors in many organisms got us excited about the possibility of using light-responsive genetic tools in synthetic biology. Indeed, such tools could in principle induce phenotypic changes in a more localized, preciser and faster fashion than currently available chemical-based methods. To evaluate the biotechnological potential of such tools, we specifically aimed to induce a change in gene expression, more specifically to directly turn a gene on or off, in a living organism, in response to a light stimulus.
For this purpose, we used a light-sensitive DNA binding protein "LovTAP" (for Light, Oxygen, Voltage Tryptophan-Activated Protein) to convert a light input into a chosen output, here fluorescence generated by the RFP reporter gene.
The results clearly show that this light-induced gene switch tool works in vivo, demonstrating the feasibility of implementing such powerful technology for a diverse range of bio(techno)logical applications.