Figure 2.

 Prevention of methylation by the dim-2 mutation increases am^RIP8 transcript levels. (A) Southern analysis of genomic DNA from the strains N150 [am⁺; dim⁺ (lane 1)], N150 treated with 5-azaC (lane 2), N540 [am⁺; dim-2 (lane 3)], N617 [am^RIP8; dim⁺ (lane 4)], N617 treated with 5-azaC (lane 5), and N618 [am^RIP8; dim-2 (lane 6)]. Genomic DNA (750 ng) was digested with the methylation-sensitive restriction enzyme Sau3A1, subjected to Southern blotting, and hybridized to an am probe. Size standards (kb) are indicated at right. The Southern blot was stripped and reprobed with the unmethylated mtr gene to ensure complete digestion of the DNA (data not shown). (B) Northern analysis of total RNA (10 μg) from the strains depicted in the Southern blot. The blot at top was hybridized to a wild-type am probe. The size (kb) of the wild-type am transcript and of the three am^RIP8 transcripts is indicated right of the top panel. The blot in the middle was hybridized to a his-3 probe. (Bottom) The methylene blue staining of the rRNA of the blot from the top.