FIG. 5.

hpr1Δ and acc1^cs cells are defective in nuclear export of polyadenylated RNA. Nuclear accumulation of polyadenylated RNA in hpr1Δ and acc1^cs cells at the nonpermissive temperature is shown. Cells were grown to early logarithmic phase at 23°C and shifted to 37 and 17°C, respectively, for 4 h, and fixed and processed for in situ hybridization with a digoxigenin-labeled oligo(dT)_25–30 probe. Strong accumulation of nuclear poly(A)⁺ RNA was visible in hpr1Δ and acc1^cs cells shifted to nonpermissive temperatures (arrows in panels D and J) but not in cells grown at permissive temperatures (A and G). DAPI (4′,6-diamidino-2-phenylindole) staining and differential interference contrast (DIC) pictures of the same visual field are shown to the right. Bar, 10 μm.