Cell Cycle studies with the FUCCI system
In this video cells express the transcription factor SMAD2 in the green Channel and the FUCCI cell cycle indicators (see reference below) in the blue and red Channels. In this system, cells have blue nuclear signal (Cdt1-mCerulean3) in G1 and change to red (Geminin-mCherry) in late G1 to stay red for S, G2 and M phases. This allows us to quantify cell cycle progression at single cell level while measuring the activity of the transcription factor SMAD2. In this case, cells are growing under no stimulation, in 1% serum for 40 hours. Note cells transitioning from blue to red and how mitosis occurs in red cells to create 2 cells that will later be expressing the blue marker.
Reference: Visualizing spatiotemporal dynamics of multicellular cell-cycle progression.
Sakaue-Sawano A et al. Cell. 132, 487-498 (2008)