FIGURE 3.
(A) Pre-RNA processing defects in r-protein extension mutants. The 27SA2, 27SA3, 27SBS, 27SBL pre-rRNAs were detected by primer extension and used as representatives of different steps of pre-rRNA processing. (B) The steady-state levels of pre-rRNAs (27S, 7S) and mature rRNAs (25S, 18S, and 5.8S) were tested by Northern blots. U3 snoRNA was used as the loading control.