VPA enhances formation of enlarged vacuoles.
A, electron micrographs of wild-type cells grown in SM to the mid-log phase and treated with VPA for the indicated times. Upper panel, untreated cells (−VPA); bottom panel, cells treated with 1 mm VPA (+VPA). B, percentage of cells with single enlarged vacuoles in VPA-treated cells was compared with that of untreated cells. A total of 120 cells were analyzed. v, vacuole; n, nucleus.