Figure 2. Loss of Rts1 causes a reduced rate of polar bud growth.

(A) rts1Δ reduces polar growth induced by expression of SWE1 from the GAL1 promoter. Cells were grown to log phase in YEP media containing 2% glycerol/ethanol and then arrested in G1 with α factor. The synchronized cells were released into galactose-containing media at 30°C to induce SWE1 expression, and images of cells were obtained at 30 minute intervals. The time indicates the number of hours after release of α factor-arrested cells into galactose. (B) rts1Δ reduces the rate of polar growth in cells that over express SWE1. Polar growth was measured and plotted as a function of time for the experiment shown in (A). The extent of polar bud growth was measured as the ratio of the length of the bud to the width of the bud measured at the widest point. The average ratio and standard deviation were plotted for each time point. (C) Western blots showing equal expression of Swe1 protein in wild type and rts1Δ cells from the experiment shown in (A). A Nap1 Western blot was included as a loading control. (D) rts1Δ causes a delay in bud emergence. Wild-type and rts1Δ cells were released from an α factor arrest at 30°C and the percentage of budded cells was determined at 10 minute intervals. Error bars indicate standard deviation for 3 independent experiments.