Figure 1.

Characteristics and generation of cell cycle G2/M phase fluorescent sensor. (a), The expression pattern and localization of cyclin B1 were showed by graph in the different phases of cell cycle. (b), Schematic of the cyclin B1 fused EGFP as a fluorescent probe illuminated various phases of cell cycle. (c), The structure of human cyclin B1 promoter drove cyclin B1 fused EGFP construct, destruction and subcellular localization of sensor are controlled by destruction box (D-box), cytoplasmic retention sequences (CRS) localized in the N-terminal portion of cyclin B1. (d), HEK293, c2c12 and HeLa cells were transfected with plasmid, the different localizations and intensity of EGFP signal showing the cells in different phases of cell cycle. G1/S phases EGFP signal is very low and localized in cytoplasm. The EGFP signal is increased and localized in cytoplasm in G2 phase. The EGFP signal is high and localized from cytoplasm to nucleus in prophase phase. Nuclear envelope is broken down in metaphase and the EGFP signal is very high and full of whole cell. (e), The quantification of EGFP density of HEK293, c2c12 and HeLa cells in the various cell cycle phases has been performed, the EGFP is significantly increased in the G2, prophase and metaphase compare to the G1 and S phases. (f), The expression levels of cyclin B1 and EGFP in transfected HEK293, c2c12 and HeLa cells and control non-transfected cells were detected by western-blot.