FIGURE 2.

Kpna7 targeting design and sequence analysis. A, original design of the Kpna7 gene targeting. Exons 5 and 6 were designed to be deleted, and finally the truncated transcript should be destroyed because it caused incorrect splicing and wrong encoding. B, existence of a previously unexpected new exon after exon 6 caused in-frame encoding between exon 4 and the new exon 7, which generated one 1215-bp long truncated Kpna7 mRNA. The truncated Kpna7 mRNA encodes a protein that lacks the exon 5- and exon 6-encoded polypeptide fragment but with a new exon 7-encoded polypeptide fragment. C and D, genomic PCR (C) and RT-PCR (D) analysis of the wild type (wt1-3), Kpna7 heterozygous (F1-162, F2-14, and F2-101), and homozygous (F2-42, F2-46, F3-163, and F3-164) mutation mice.