FIG. 6.

RNAi depletion experiments indicate that αβ transcripts are degraded by the nuclear exosome. Shown are Northern blots of RNA isolated from control (RT) or Drosophila S2 cells heat shocked at 32°C after treatment with the dsRNAs indicated above the lanes to deplete Su(s) and several RNA degradation proteins. LacZ dsRNA was used to control for the effects of dsRNA treatment. Probes are indicated on the right. The Northern blots in panel A were from different gels but were processed together. Normalization with rp49 indicates that about one-third as much RNA was loaded in lane 14 as lane 11. Thus, the depletion of Rrp6 and Dis3 may have a more pronounced effect than the αβ signal intensity in lane 14 indicates. The samples for which the results are shown in panel B were from a different experiment.