Growth phenotype of RNA repair mutants. (A) RNA repair mutants rescued by prespliced tRNAs expressed from the (10×-tRNA TRP1 2µ) plasmid grow on -TRP and FOA media, but not on -URA media. Plates were photographed after 3 d of growth at 30°C. (B) Growth of RNA repair mutants is temperature-sensitive. Cells were serially diluted, spotted on YPD media, and incubated at the indicated temperatures. Wild-type and complemented trl1Δ (TRL1) and tpt1Δ (TPT1) cells grow at all temperatures, whereas bypassed trlΔ and tpt1Δ cells fail to grow at 37°C. (C) Sensitivity of RNA repair mutants to translational inhibitors. Cells were serially diluted and spotted on YPD media or YPD media supplemented with sublethal doses of the translational inhibitors anisomycin, hygromycin B, and cycloheximide at the concentrations indicated. Wild-type cells are viable under all conditions, whereas RNA repair mutants fail to grow in the presence of inhibitors of translation. (D) Deletion of XRN1 does not suppress the temperature-sensitive phenotype of trl1Δ rescued with prespliced tRNAs. All plates were photographed after 3–4 d of incubation at 30°C or 37°C.
