Exploiting Fungal Photobiology as a Source of Novel Bio-blocks for Optogenetic Systems
In the past years, optogenetics has been recognized as a powerful and versatile technology to control diverse processes, such as gene expression, in multiple biological systems. This implies utilizing light of defined wavelength to excite a photoreceptor module assembled as part of a circuit or switch, triggering a certain cellular response. Because of the characteristics of light, it is possible to achieve tunable responses with great spatiotemporal resolution. In most cases, the different optogenetic devices are based on the utilization of a photoreceptor assembled as a bio-block forming part of a chimeric protein, circuit, or signaling pathway. Several examples involve the utilization of photoreceptors coming from plants or bacteria, whereas in seldom cases they derive from fungi. Among the latter, the light-oxygen-voltage (LOV) domains, such as found in the proteins VVD and WC-1 from the fungus Neurospora crassa, have been successfully implemented as part of optogenetic systems in diverse biological platforms like mice and recently yeast. This chapter covers basic aspects of optogenetics while also highlighting the fact that the fungal kingdom holds great potential as a source of light-sensing modules that could give rise to new optogenetic devices. Thus, although fungal photobiology has been mainly focused on the effect of light in fungal processes, and the photoreceptors involved in the response, it is easy to foresee that such studies can yield important insights to harness natural optogenetic circuits in the organism of origin while also exporting and domesticating them to be used in diverse other organisms.