DIVISION OF CELL PROLIFERATION (Fig.1)


                                   NATIONAL INSTITUTE FOR BASIC BIOLOGY

DIVISION OF CELL PROLIFERATION (Fig.1)

The ability of P-factor to arrest the cell cycle of h- cells at the G1 phase. Flow cytometric analysis of the DNA content was done in S. pombe h- cells (sexually-derepressed mutant) exposed to P-factor. (a) Cells grown in the presence of 2 ｵg/ml P-factor; and (b) with no P-factor. The main peaks at 0h in (a) and (b) correspond to 2C (G2-equivalent) DNA content, whereas the main peak at 6h in (a) corresponds to IC (G1-equivalent) DNA content. The G1 arrest is transient and cells gradually resume growth (a, 9-21h). Without P-factor (b), cells show 2C DNA content because rapidly growing S. pombe cells have only short G1 and S phases and they undergo these phases while the daughter cells are not completely separated.