Figure 5.

Rli1 is involved in pre-rRNA maturation. (A) Schematic of the pre-rRNA showing the positions of the oligonucleotide probes used for hybridization. Total RNA was extracted from strains expressing wild-type or Tet-regulated RLI1 (tet∷rli1) during growth in the absence of doxycycline (0 h samples), and at time points following doxycycline addition. (B) Northern analyses of high molecular weight RNAs separated on a 1.2% agarose/formaldehyde gel. (C) Northern analyses of low molecular weight RNAs separated on an 8% polyacrylamide/urea gel. Pre-rRNAs and rRNAs detected are indicated on the right of the figure. Oligonucleotides used are listed on the left. tRNA^Leu was used as a loading control (oligonucleotide 306). (D) Pulse-chase labeling of high molecular weight RNAs. Wild-type and tet∷rli1 strains were pregrown in minimal medium and treated with doxycycline for 6 h prior to pulse labeling with [5,6-³H]uracil for 2 min. A large excess of unlabeled uracil was added and samples were taken immediately (0 min) and at the time points indicated. RNA was extracted, separated on a 1.2% agarose/formaldehyde gel, transferred to a nylon membrane and visualized by fluorography.