Repair of a transgene and regeneration of callus and plantlets. Left, top: Original transgene containing an operon with a deletion (gray line) in GUS (β-glucuronidase) and NPTII (neomycin phosphotransferase), with GUS in blue and NPTII in red. Left, bottom: Repaired transgene with complete GUS:NPTII sequences and sequence traces from PCR products from regenerated calli. Right: Callus and plantlet stained for GUS activity, in blue. (Reprinted from Baltes et al. [2014], Figure 5.)