FIG 1.

Screening cell cycle progression using Fucci cells. (A) Fucci cells were transfected with pMZS3F-BORF1 or left untreated and then stained for the FLAG tag on BORF1 and imaged for mKO2 (G₁ cells; red), mAG (S/G₂/M cells; green), and FLAG (blue). An overlay of red and green image layers revealed cells in G₁/S, which display a yellow to orange color (bottom). (B) Fucci cells transfected with pMZS3F-BORF1 and stained for the FLAG tag on BORF1 were FACS sorted into FLAG-positive and FLAG-negative cells (left) and then further separated based on the expression of mKO2-Cdt1 and AG-geminin (middle and right). (C) Cell cycle stages determined from FACS analysis (as for panel B) were quantified for FLAG-positive (BORF1) and FLAG-negative cells from three independent experiments.