Figure 3. The 20S pre-rRNA accumulates in the cytoplasm of rpl3[W255C] cells.

A. Wild-type and rpl3[W255C] cells expressing either L25-eGFP or S2-eGFP were exponentially grown in SD-Ura at 23°C. The GFP signal was analysed by fluorescence microscopy. B. Wild-type and rpl3[W255C] cells were grown in YPD at 23°C. Cells were fixed with formaldehyde, spheroblasted, and subjected to FISH using a Cy3-labelled probe complementary to the D/A₂ segment of ITS1 (Table S3). DAPI staining visualises the nucleoplasm. C. Levels of dimethylated 20S pre-rRNA in the wild-type strain and the rpl3[W255C] and rpl3[Q371H] mutants. RNA was extracted from cells of these strains following exponential growth in YPD at 23°C and analysed by primer extension with probe c (Figure S1 and Table S3). The position of the primer extension stops due to the presence of the modifications is indicated.