FIG. 7.

Inserting a hairpin structure into exon 6, between 189Ter and intron 6, does not block the nonsense-mediated decay of TPI mRNA. NIH 3T3 cell transfections and the purification and analysis of total-cell RNA were as described in the legend to Fig. 1. The hairpin (hp) (A) was inserted as a Klenow-filled BamHI-HindIII fragment into codon 209, as indicated (B). Values shown are an average of the values obtained from two independently performed experiments, which did not differ by more than 5%.