CELL-CYCLE IN THE FISSION YEAST, SCHIZOSACCHAROMYCES-POMBE .3. CYCLE DURATIONS IN SYNCHRONIZED CELLS PRODUCED BY HYDROXYUREA

A growing asynchronous culture of the fission yeast Schizosaccharomyces pombe was induced to divide synchronously by a pulse treatment of 2, 3 or 4 h with 8 or 16 mM hydroxyurea (HU). During the pulse treatment, the rate of DNA synthesis was decreased and the cells became abnormally long. After HU removal, a synchronous burst of DNA synthesis occurred followed by synchronous nuclear division. The times for the first complete cell cycles of the HU synchronized cultures were shorter than the time of the normal cycle. These cycles in the synchronized cultures, shortened by a 2 h and by a 3 or 4 h HU-treatment, returned to normal after two and three divisions, respectively. The cycle periods and the recovery modes were dependent on the intervals of the pulse treatment, and could be described quantitatively with relation to cell size. © 1979, Japan Society for Cell Biology. All rights reserved.