FIG. 5.

Nop56p is not required for snoRNA accumulation. (A) Growth of the GAL::nop56 (solid circles) and NOP56 (open squares) strains following transfer to glucose medium. Cell density was measured at regular intervals, and the cultures were periodically diluted to maintain exponential growth. The results are presented on an exponential scale with the OD₆₀₀ values corrected for the dilution factor. (B) Northern-blot hybridization of NOP56 mRNA in GAL::nop56 and nop56-2 strains. Total RNA was extracted from GAL::nop56 and nop56-2 strains following growth under permissive conditions on RSG medium or at 23°C (0 h) and following transfer to repressive conditions on glucose medium or at 37°C for the times indicated. Isogenic control strains were used. Total RNA was resolved in a 1.2% agarose gel containing formaldehyde. (C) Steady-state levels of the snoRNAs on depletion and heat inactivation of Nop56p. Total RNA was extracted from GAL::nop56 and nop56-2 strains grown in RSG medium or at 23°C (0 h) and following transfer to glucose medium or to 37°C for the times indicated. Isogenic control strains were used. RNA was resolved in an 8% polyacrylamide gel under denaturing conditions.