Identification of the founder mouse of the transgenic β+IVSI-6 line. (a–c) Electrophoretic analyses of PCR products obtained by the amplification of murine genomic DNAs with primers MuActF-MuActR (a), TransF-TransR (b), and HuBetaF-HuBetaR (c), recognizing the murine β-actin gene, the transgene sequence, and the human β-globin gene, respectively. NF, negative founders; (−), negative control (water added to the amplification mixture); M, molecular weight ladder, pUC Mix Marker 8 (Fermentas). Arrows indicate the expected position of the specific amplification products; the lanes carrying the specific PCR products, relative to the founder mouse TG1, are also indicated. (d) Portion of electropherogram obtained by sequencing the HuBetaF-HuBetaR PCR product, obtained by the founder mouse TG1. The arrow indicates the peak corresponding to the β+IVSI-6 thalassemic point mutation (underlined nucleotide).