FIGURE 8.

The availability of inositol affects the abundance of neutral lipid classes in wild type. Lipids in all strains were labeled to steady state with [1-¹⁴C]acetate (1 μCi/ml) in I⁺C⁻ medium at 30 or 37 °C and in I⁺C⁺ medium at 37 °C as described under “Experimental Procedures” for at least seven generations and grown to mid-logarithmic phase. They were shifted by filtration either in I⁻C⁻ medium at 30 and 37 °C or to I⁻C⁺ medium at 37 °C as described under “Experimental Procedures” maintaining label at constant specific activity and cultured for 180 min. At this time point, inositol was reintroduced into the cultures, and aliquots were collected at 0, 5, 15, and 30 min. Lipids were extracted and analyzed as described under “Experimental Procedures.” Each panel of this figure contains two graphs. The graph on the left indicates the neutral lipid composition of both strains shifted to inositol free media for 180 min. The graph on the right represents the neutral lipid composition of both strains when inositol was added back to cultures deprived of inositol. Panel A, wild type. Panel B, dga1Δlro1Δare1Δare2Δ. The data represent the average of three independent experiments. The magnitude of the error is similar to the data in Fig. 3, but error bars were omitted for clarity of the presentation. The lipids indicated are free fatty acids (open triangles), TAG (gray triangles), free sterols (solid circles), DAG (solid diamonds), and SE (open circles). ODU, optical density units.