CHAPTER 9: Light Control of Transcription in Cells

Recent studies revealed that the activity of many genes is oscillatory with a periodicity of approximately 2–3 h in various biological events; however, it is difficult to have precise spatiotemporal control of such dynamic gene activity using conventional methods. Optogentic tools that permit the precise control of gene expression have been developed recently. Among them, the LightOn-hGAVPO system, which uses a blue light-sensitive VIVID protein, can induce oscillatory expression with 2–3 h periodicity. With this method, it was shown that oscillatory versus sustained gene expression leads to different outcomes in many biological events, including neurogenesis and somitogenesis. This chapter discusses recent findings on the significance of oscillatory gene expression, as revealed by the LightOn-hGAVPO system.