Cre-mediated insertion by ScIn-1. A. Schematic (not to scale) of the target locus in clone Rht14-19 before (top) and after (bottom) Cre-mediated insertion of pIN-1. DNA is represented as in Fig. 1 with recognition sites for Dra I (D) and PCR primers indicated. B. Ethidium bromide stained agarose gel of electrophoresed PCR products generated with the primers in A, and pTIGHTluc (Clontech) DNA (+), no DNA (-) or cell pellets of 10 hygr, GFP-negative clones (1–10) selected after transfection of Rht14-19 with pIN-1 and pMC-Cre. M= marker DNA. C. Southern blots of genomic DNA isolated from Rht14-19 (+) and the same Rht14-19 derivatives described in B digested with Dra I. The probe was from the d2EGFP cassette. M = marker DNA. D. Luciferase activity in lysates from Rht14-19 (Rh) or the same Rht14-19 derivatives (1–10) described in C, grown in the absence or the presence (for 48 h.) of tet.