Project Summary: Molecular genetic tools using DNA recombinases, such as Cre and Flp, and nucleases, Cas9, have been applied to address various biological questions. The genetic technologies allow us to manipulate gene expression and engineer genome to uncover the molecular mechanism underlying a variety of biological activities such as cellular proliferation and differentiation. However, precise spatiotemporal control is still limited though using the existing tools. In this project, we will develop a new set of optogenetic tools with single cell resolution to address this issue, using a new confocal module. Taking advantage of the confocal module-mediated illumination to live cells, we will validate and optimize our optogenetic tool uses in mammalian primary cells such as hematopoietic stem cells. Also, our proposed novel genetic technologies will be widely applicable to various research fields beyond hematopoiesis to address a variety of biological questions.