FIG. 3.

Degradation of deadenylated mRNAs is defective in strains with point mutations in XRN1. A Northern blot shows the accumulation of deadenylated mRNA species. Poly(A)⁺ and poly(A)⁻ RNA was prepared from the same strains used in the experiment in Fig. 2. Poly(A)⁺ RNA (0.5 μg) and poly(A)⁻ RNA (15 μg) were separated on a 1.2% denaturing formaldehyde agarose gel and transferred to a membrane. The hybridization probes were actin and MFα1 (31). Bands were quantified on a PhosphorImager, and the results were normalized to the amount of total RNA. Shown are images from the PhosporImager.