Knockout of PAH1 and steryl acyltransferases abolishes lipid droplets in cells grown in glucose medium. (A) BODIPY staining of the indicated strains in SD. DGA1 and LRO1 encode DAG acyltransferases, and ARE1 and ARE2 encode steryl acyltransferases. Images incorporate both brightfield and FITC channel (for lipid droplets). Bar, 5 µm. (B) Lipid droplet number in strains shown in A. Droplets in ∼30 cells were counted in z-section series from three independent experiments (∼90 cells total per strain). Mean ± SEM is shown. Knockout of pah1Δ always resulted in significantly lower droplets, although the significance in only the middle pair is shown for clarity; **, P < 0.001. (C) Quantification of TAG and StE from mass spectrometry analysis for the indicated strains grown in SD. Means and ranges from two independent experiments are shown. The values for wild type (WT) and pah1Δ are also shown in Fig. 1 D. (D) BODIPY staining of the indicated strains grown in medium containing oleic acid. Bar, 5 µm. (E) A comparison of droplet number in pah1Δ and pah1Δare1Δare2Δ grown in oleic acid. Error bars represent standard deviation; ***, P < 0.0001; based on two fields (∼50 cells per field) from three independent experiments.