Naturehttp://dx.doi.org/10.1038/nature12466 (2013)

The ability to use light to control and modulate gene expression is an important and desired functionality in cell biology research. However, a suitable means for optical modulation of transcription in the mammalian endogenous genome has remained elusive. Now, Silvana Konermann and co-workers in the USA have developed light-inducible transcriptional effectors (LITEs) that can be activated within minutes. LITEs can be delivered via viral vectors and be genetically designed to target specific cell types. The researchers tested LITEs on primary mouse neurons and the brains of living mice in vivo. They say that this technique will help establish the causal roles of genetic and epigenetic regulation in biological processes associated with normal, healthy conditions and in the presence of disease. A train of <1 s pulses of blue (wavelength ∼460 nm) light with an intensity of 5 mW cm−2 was used to activate LITEs.