Figure 3.

Deduction of the structure of the new species present in pop2 and ccr4 strains following RNase H-mediated degradation of poly(A) tails in the presence of oligo(dT). RNA samples corresponding to the 2 min time point presented in Figure 2A (wild-type and pop2 mutant) or 2B (ccr4 mutant) were treated with RNase H and oligo(dT) (lanes 3, 5 and 7). Untreated material is shown for comparison (lanes 2, 4 and 6). RNA samples were fractionated by gel electrophoresis and revealed following northern blotting (see Fig. 2 for details). A DNA molecular weight standard was loaded in lanes 1 and 8. Sizes of the corresponding fragments are indicated on the left. The structures of the various RNA species are given on the right.