Figure 8.

Plo1 protein levels remain constant as stf1.1 cells progress through the cell cycle. A cell cycle-synchronized population of stf1.1 cells (IH666) was generated by elutrient centrifugation at 25°C in supplemented EMM2. The small G2 cells were harvested at the beginning of the experiment, and samples were then taken every 20 min for Western blot analysis and scoring the septation index (n = 200 for each time point). The top panel shows the septation index, which indicates good cell cycle synchrony in the culture, whereas the bottom panel shows a Western blot of whole-cell extracts. The blot was cut into two, and the upper portion was probed with antibodies to Plo1 and the lower portion with antibodies to a tubulin (TAT1). The tubulin blot acts as a loading control. The position of the peaks seen in the septation index are indicated by arrows beneath the blots. The relative intensity of the TAT1 and Plo1 bands for each time point were determined for three independent Western blots of both this culture and another synchronous stf1.1 culture. Plo1 levels showed no significant variation during the time course of either experiment (a total of four distinct cell cycles).