Fig. 3. sar1 and pmm1 null strains accumulate cytoplasmic membranes. sar1, containing pREP3X-sar1, and pmm1, containing pREP81X-pmm1, were grown in media either without thiamine, to allow expression (promoter ON; A-D) or with thiamine, to repress expression (promoter OFF; E-H). After 48 hours, live cells were stained with both DiOC₆, to visualize cellular membranes (A,C,E,G), or Hoechst, to visualize DNA (B,D,F,H). Cells in which the promoter was off contain an increase in cellular membranes compared with cells in which the promoter remained on. Bar, 10 µm.