Calcium uptake during the cell cycle of Saccharomyces cerevisiae.

Synchronous culture of the budding yeast Saccharomyces cerevisiae was obtained by sucrose density gradient selection with 90-100% of yeast synchronized by using the cells in the bottom. In these adult cells bud emergence is coincident with an increase in calcium uptake at 100 min of the culture, followed by a return to basal values which are maintained until the end of the first cell cycle of study. The phenothiazine derivatives, trifluoperazine and chlorpromazine inhibit bud emergence and trifluoperazine also increases calcium uptake.