FIGURE 4.

Northern analysis for steady-state level of rRNAs. (A) W303–1A transformed with pRS414 (WT) and KM1411 (GAL1–RRP14) cultured at 30°C in SCGal were shifted to SC and cultured for the indicated times. Total RNA corresponding to 0.5 OD₆₀₀ of cells was used for Northern blot analysis. [A(a)] Northern blot analysis was carried out using ³²P-labeled DNA probes a, b, c, d, and e, which are shown in Figure 3A. [A(b)] Ethidium bromide staining of a denaturing 6% polyacrylamide/8M urea gel is shown. (B) W303–1A (WT) and KM1422 (rrp14Δ) cultured at 30°C in SC medium. Total RNA corresponding to 0.5 OD₆₀₀ of cells was used for Northern blot analysis. [B(a)] Northern blot analysis was carried out using ³²P-labeled DNA probes a, b, c, d, and e, and a probe for U3 snoRNA. [B(b)] Ethidium bromide staining of a denaturing 6% polyacrylamide/8M urea gel is shown. [A(c)] Mature 25S and 18S rRNA levels shown in B(a) were quantified using BAS-2000 and BAS-1800 (Fuji Photo Film Co.), normalized with the U3 level, and the ratio of the radioactivity value of the rrp14Δ strain per that of wild-type strain serves as the percent.