Control of gene expression using a red- and far-red light-responsive bi-stable toggle switch
20.02.2014
Müller K, Zurbriggen MD, Weber W.
Nat Protoc. 2014;9(3):622-32
Light-triggered gene expression systems offer an unprecedented spatiotemporal resolution that cannot be achieved with classical chemically inducible genetic tools. Here we describe a protocol for red light–responsive gene expression in mammalian cells.
This system can be toggled between stable ON and OFF states by short pulses of red and far-red light, respectively. In the protocol, CHO-K1 cells are transfected to allow red light–inducible expression of the secreted alkaline phosphatase (SEAP) reporter, and gene expression is tuned by illumination with light of increasing wavelengths. As a starting point for elaborate red light–responsive gene expression, we outline the reversible activation of gene expression and describe how a spatial pattern can be ‘printed’ on a monolayer of cells by using a photomask. The core protocol requires only 4 d from seeding of the cells to reporter quantification, and other than light-emitting diode (LED) illumination boxes no elaborate equipment is required.
