Visualization of Notch Signaling Oscillation in Cells and Tissues
The Notch signaling effectors Hes1 and Hes7 exhibit oscillatory expression with a period of about 2–3 h during embryogenesis. Hes1 oscillation is important for proliferation and differentiation of neural stem cells, whereas Hes7 oscillation regulates periodic formation of somites. Continuous expression of Hes1 and Hes7 inhibits these developmental processes. Thus, expression dynamics are very important for gene functions, but it is difficult to distinguish between oscillatory and persistent expression by conventional methods such as in situ hybridization and immunostaining. Here, we describe time-lapse imaging methods using destabilized luciferase reporters and a highly sensitive cooled charge-coupled device camera, which can monitor dynamic gene expression. Furthermore, the expression of two genes can be examined simultaneously by a dual reporter system using two-color luciferase reporters. Time-lapse imaging analyses reveal how dynamically gene expression changes in many biological events.
Key wordsHes1 Hes7 Oscillatory expression Luciferase Bioluminescence CCD Neural stem cell Presomitic mesoderm Segmentation clock
This work was supported by Core Research for Evolutional Science and Technology and Grant-in-Aid for Scientific Research on Innovative Areas (MEXT 22123002).