Fig 5.

(A) Spot assay. Threefold serial dilutions of each strain were spotted onto YEPD medium alone (upper panels) or YEPD medium containing 1 M sorbitol (bottom). The plates were incubated under the indicated conditions for 3 to 4 days, and photographs were taken. The mutations are given on the right. (B) FM4-64 internalization assay for endocytosis. Representative fluorescent images of each strain stained with the membrane marker FM4-64 are shown. Cells were grown under the conditions indicated on the left. “37°C sorb” means that cells were grown in YEPD medium containing 1 M sorbitol at 37°C; “1% O₂ sorb” means that cells were grown in YEPD medium containing 1 M sorbitol under 1% O₂ and 5% CO₂ at 37°C. Bar, 5 μm. (C) Endosomal staining of deletants with FM4-64. (D) Spot assay. Threefold serial dilutions of each strain were spotted onto YEPD medium and were incubated at 30°C (left) or under 1% O₂ and 5% CO₂ at 37°C (right). No growth defect is seen for any of the three mutants.