(A) Primary fibroblasts prepared from the tail tip of the floxed STOP tdTomato reporter transgenic rats; the expressions of AcGFP-NCre by lipofection (i), tdTomato fluorescence (ii), and merged images (iii) are shown. (Bi–ii) Primary fibroblasts cultured from Tg-positive rats treated with vehicle alone. (C) Comparison of the ratio of tdTomato/AcGFP double-positive cells in each group (Tg, n = 5; wild-type, n = 6). Ten fields of interest were unintentionally chosen from each well, and double-blinded counting was applied to detect the fluorescent double-positive cells. In total 219 double positive cells were detected in group (A). *, p < 0.01, one-way ANOVA with Scheffe’s multiple comparison test. (D) PCR assay of the genomic DNA each extracted from the tail and the brain of a wild-type control rat (left 2 lanes), a tdTomato reporter rat (middle 2 lanes) or a FLAME (right 2 lanes). The allele of BAC with STOP sequence was detectable as 497 bp band whereas that without STOP as 217 bp band.