FIGE analysis of clones from libraries generated with insertion of either pTn lox511 -iTol2kan (panels A and B) or pTn loxP -iTol2kan (panel C). Deletion clone DNAs shown in FIGE Panels A and B were obtained from libraries made with different APPb BACs that contained the EGFP enhancer-trap located either 2.5 kb upstream (Panel A), or 4 kb upstream (Panel B) of the transcription start site of the APPb gene. Panel C shows clone DNA from the library generated with fgf24:EGFP using TnloxP-iTol2kan transposon. Only clones containing an intact 75 kb fragment are shown here. All clone DNAs were digested with Not I enzyme prior to FIGE analysis. The blue arrows indicate the BAC clones tested in zebrafish for expression and/or "excision assay" analyses. All clones are numbered according to the lanes in which their DNA appears, and are referred to as such throughout the text. Lanes 1, 26 and 34 are marker lanes containing the 5 kb ladder, and BAC 24 (in lane 24) is the starting APPb BAC used to generate the deletions in panel B. The arrow at the side and bottom of Panel B indicates the position of the BAC vector DNA band, which in this case is ~7 kb. Size of DNA bands in kb is indicated on the side of each panel.