Fungal Optogenetics: imagening biotechnological applications and imaging gene expression

Light is a strong environmental cue. Learning how to harness it as a means to control gene expression opens the doors to new strategies to reprogram cell function. Thus, we have adopted different optogenetics strategies to utilize light as an orthogonal signal to control gene expression in yeast. Saccharomyces cerevisiae is naturally incapable of seeing light and therefore, we have design optogenetic switches to tune gene expression in this organism. Thus, now we can efficiently induce gene expression up to 1300-fold in S. cerevisiae and control biotechnological relevant phenotypes such as flocculation by switching on/off the lights.

We have developed these optogenetic switches utilizing LOV domains obtained from Neurospora crassa. The latter has been one of the main models for the study of photobiology, providing great insights on how microorganisms perceive and respond to light. This ascomycete responds specifically to blue light (but not to other wavelengths) through a transcriptional heterocomplex named White Collar Complex (WCC). One of its components, WC-1, possesses a LOV (Light Oxygen Voltage) domain capable of detecting blue light, which promotes a conformational change that leads to dimerization that results in strong transcriptional activation, in a light-intensity dependent manner.

We have also adopted optogenetic approaches to further delve into Neurospora’s circadian and light-responses. In doing so, we were able to genetically program 2D-images in this organism. Thus, we can project a photograph on top of a Neurospora carrying a luciferase reporter under the control of a light responsive promoter and obtain back a bioluminescent pattern mimicking the original image. Thus, we have established a live canvas in which images are genetically processed and reconstituted with real-time dynamics. Such technology not only allows studying light-responses with great resolution, but is also provides a powerful substrate for artistic projects. MN-FISB, FONDECYT 1171151, HHMI International Research Scholar Research Program