FIG. 4.

(A) Anaerobic derepression of OLE1 transcription is repressed by oleic acid. Cells of the wild-type strain (SH5141) were inoculated into YPDA medium (lanes 1 and 2) or YPDA medium containing 1 mM oleic acid (lanes 3 and 4) and cultivated at 30°C aerobically (lanes 1 and 3) or anaerobically (lanes 2 and 4). Total RNA was prepared from cells in the logarithmic growth phase. The RNA samples (each 10 μg of RNA) were subjected to Northern blot hybridization as described in the legend to Fig. 1A. (B) The O2R element is responsible for repression by UFA. Cells of SH5143 (wild type) harboring one copy of the respective reporter genes integrated at the ura3 locus were cultivated aerobically without oleic acid (dotted bars), anaerobically without oleic acid (solid bars), aerobically with oleic acid (open bars), or anaerobically with oleic acid (hatched bars) and subjected to an rAPase assay as described in the legend to Fig. 2.