PCR analysis for site-specific recombination and the presence of the recombinase gene in the selfed (S
) generation. PCR reactions (a) with primers eand for (b) with primers gand hon representative plant DNAs. a, b) Selfed lines (lanes 1, 2) S1-Bxb1.9; (lanes 3, 4) S1-Bxb1.12; (lane 5, 6) S1-Bxb1.28; (lane 7, 8) S1-Bxb1.35 positive for excised target but the Bxb1 transgene is absent. Control lanes are B (blank, no DNA); E (excision, pN6-Bxb1exc DNA); N (no excision, pN6-Bxb1); P (pCOXS3-Bxb1).