Ribosomal RNA production is compromised in the <i>scc2-4</i> mutant.

<p>(A) The RNA synthesis rate was examined using ³H-uridine incorporation in WT and <i>scc2-4</i> mutant strains. Strains were grown in triplicate in SD-ura medium with minimal uracil to an approximate OD₆₀₀ of 0.3. ³H-uridine was added for 5 minutes and incorporation was quantified, averaged, and expressed relative to WT. Standard error bars are indicated for n = 4. The difference between WT and mutant was significant at p<0.0001. (B). WT and <i>scc2-4</i> mutant strains were grown in SD-met at 30°C into mid-log phase. Equal numbers of cells were pulse-labeled with ³H-methylmethionine for 5 min, followed by RNA extraction and electrophoresis of the RNA on a formaldehyde gel. The gel was photographed following ethidium bromide staining (bottom). RNA was transferred to a membrane and detected by autoradiography (top). 25S and 18S rRNA were cut from the membrane, quantified with a scintillation counter, and the average is expressed relative to WT (p<0.05). p-values were calculated using a student two-tailed t-test. Standard error is indicated for n = 4.