Southern blot analysis of NN60 transgenic mice. Genomic tail DNA was digested with BamHI. (A) Hybridization with SV40 polyA probe. (B) Hybridization with a NN60-3 probe (corresponding to rat nucleotides 2384–2770). (C) Copy number of wild type and transgenic neu was calculated by comparing volume of wild type band with volume of transgenic band and normalizing the wild type value at 2. Calculations performed using phosphoimager densitometry.