Fig. 6. A rearranged Vβ_5.1–Jβ_1.6 exon and flanking intron sequences promotes strong down-regulation in response to nonsense codons. (A) Both constructs have TPI exons 2–4 and flanking intron sequences replaced with the VJ exon and flanking intron sequences from a rearranged Vβ_5.1–Jβ_1.6–Cβ₁ gene. J^– lacks a PTC and J⁵⁺ has a frameshift mutation in the VJ exon that creates a PTC in the exon shown. (B) Transfection, northern blot analysis and quantification were performed as in Figure 2. Comparable results were obtained in two independent transfection experiments.