Fig. 5

PCR and direct DNA sequencing results. a Electrophoresis of PCR products for exon 3, exon 7, and exon 8 of the β-catenin gene in tumor and non-tumor tissues. Leftmost is a 100-bp DNA ladder (Takara Bio Inc., Shiga, Japan). The PCR products of exon 3 of the β-catenin gene amplified from tumor DNA show two different bands, while that from non-tumor DNA shows a single band. The same band length is detected in exon 7 and exon 8. b DNA sequencing of exons 3 shows a large deletion, including introns between exon 2 and exon 3 to exon 4. The deletion site is marked by the solid black vertical line. PCR, polymerase chain reaction; DNA, deoxyribonucleic acid