FIG. 4.

Effect of nutritional conditions, IME1 overexpression, and the snf1Δ mutation on IME2 transcript levels. RNA was extracted from various cultures, and the amounts of IME2 and control (DED1) transcripts were measured by S1 nuclease protection. (Top) 1-day exposure. (Bottom) 7-day exposure. Lane 1, control reaction in which RNA was omitted; lanes 2 to 8, wild-type cells containing the YEp351 vector in the log phase (lane 2) and 3 or 6 h after transfer to sporulation medium (lanes 3 and 4), to medium lacking carbon and nitrogen (lanes 5 and 6), or to sporulation medium containing 0.4% glucose (lanes 7 and 8); lanes 9 to 12, wild-type cells containing the YEp351-IME1 plasmid 3 or 6 h after transfer to medium lacking both carbon and nitrogen (lanes 9 and 10) or to medium containing 2% glucose (lanes 11 and 12); lanes 13 and 14, snf1Δ mutant cells containing the YEp351 vector 3 or 6 h after transfer to sporulation medium; lanes 15 to 18, snf1Δ mutant cells containing the YEp351-IME1 plasmid 3 or 6 h after transfer to sporulation medium (lanes 15 and 16) or to medium containing 2% glucose (lanes 17 and 18); lane 19, undigested probe at 5% of the concentration used in the protection assays.