Fig. 4.

Analysis of vacuole fusion in cdc8^E104A using the lipophilic dye, FM4-64. Cells were incubated for 45 min. in FM4-64, washed and transferred to medium as described in Materials and Methods. The images are of live cells after 60 min. (A) cdc8^wt (SH30), cdc8^E104A (SH41), cdc8^R121A (SH39). (B) The size distribution of vacuoles in cdc8^wt and cdc8^E104A cells based on two independent experiments, each n>140. Mean±s.d.: cdc8^wt, 1.4±0.4 µm; cdc8^E104A, 1.1±0.3 µm (P=4.71×10⁻³¹). (C) The size distribution of vacuoles in cdc8^wt and cdc8^R121A cells in two independent experiments, each n>138. Mean±s.d.: cdc8^wt, 1.3±0.3 µm; cdc8^R121A, 1.1±0.2 µm (P=5.52×10⁻⁴²). In both mutants the vesicles are smaller than in wildtype but greater in number. The vacuole size distributions in cdc8^D16A.K30A, cdc8^D131A, and cdc8^E138A are indistinguishable from cdc8^wt.