Figure 8.

Chromosome passenger proteins are not maintained on anaphase spindles in mob1-77, cdc15-2, or cdc14-1 cells at 37°C. (A) The patterns of Ipl1-GFP, Bir1-GFP, and Sli15p-GFP were analyzed in late anaphase-arrested mob1-77 cells. Asynchronously growing cells (FLY1884, FLY1842, FLY1846) were shifted to 37°C for 2–3 h and analyzed by DIC and fluorescence microscopy. Ipl1-GFP, Bir1-GFP, and Sli15p-GFP were not maintained on anaphase spindles in late anaphase-arrested mob1-77 cells. Wild-type cells (wt) are shown for comparison. The mob1-77 cells rapidly recruited all three chromosomal passenger proteins to anaphase spindles when returned to permissive temperature (22°). (B) Sli15p-GFP and Ipl1p-GFP were not present on anaphase spindles in arrested cdc15-2 cells (FLY1849 and FLY2004). When returned to permissive temperature (22°), the cells rapidly recruited Sli15p and Ipl1p to the spindles before mitotic exit. (C) Ipl1p-GFP failed to localize to anaphase spindles in cdc14-1 cells (FLY2069), as previously described (Pereira and Schiebel, 2003). When returned to permissive temperature (22°C), the cells rapidly recruited Ipl1p to the spindles before mitotic exit. We obtained similar data for Sli15p localization (unpublished data). (D) The percentage of arrested cdc15-2, mob1-77, and cdc14-1 cells with Ipl1p-GFP on the kinetochore region was plotted (n = 200 for each strain).