Fig. 3

Cre-driver strain impact on recombination and mosaicism at different inter-loxP distances. a Schematic representation of a 0.8-kb floxed allele and a post-cre recombined allele. b Male homozygous floxed mice were bred with female Ella-cre, CMV-cre, or Sox2-cre mice. Note that Ella-cre and CMV-cre are homozygous, and Sox2-cre is hemizygous for the Cre allele. The F1 offspring were then genotyped using PCR from tail DNA to identify floxed and recombined alleles. Offspring with complete recombination were categorized as recombined, those with no recombination as still floxed, and those with both recombined and floxed alleles as mosaic. ‘n’ denotes the number of offspring genotyped. c Schematic representation of an 8-kb floxed allele and a post-cre recombined allele. Note that there is a 10-fold difference in the inter-loxP distance compared to the floxed allele analyzed in (a). d Homozygous floxed male mice were mated with either female Ella-cre, CMV-cre, or Sox2-cre mice, and the F1 offspring were genotyped to screen for floxed and recombined alleles. e The lengths of all protein-coding genes in mice are arranged in ascending order. Gene lengths varied widely from 0.066 kb to 2270 kb. The median length of protein-coding genes in mice is 15.8 kb. f Homozygous floxed male mice with a 10 kb inter-loxP distance were mated with Sox2-cre mice, and the F1 offspring were genotyped to screen for floxed and recombined alleles. Only 22% of the offspring showed complete recombination, while 41% were mosaic, and the remaining 37% showed no recombination. g Homozygous floxed male mice with a 12 kb inter-loxP distance were mated with Sox2-cre mice, and the F1 offspring were genotyped. None of the offspring showed complete recombination; however, 14% of the offspring were mosaic. h Homozygous floxed male mice with a 15 kb inter-loxP distance were mated with Sox2-cre mice, and the F1 offspring were genotyped using PCR from tail DNA to screen for floxed and recombined alleles. All the offspring had intact floxed alleles and showed no signs of recombination or mosaicism.