Fig. 2
Targeting events in F0 mice and transmission to F1 offspring. a Targeting events in an F0 using design 1. The genotype of the F0 was directly assessed by ear clip DNA analysis. This revealed the presence of two alleles: allele 1 corresponding to the legitimate HDR event and allele 2 corresponding to the WT allele. The genotype of the F0 animal was confirmed through the transmission of both alleles to the F1 population, several of which were identified as heterozygous for the legitimate repair (see trace). b Targeting events in an F0 using design 2. The genotype of the F0 was directly assessed by ear clip DNA analysis. This revealed the presence of three alleles: allele 1 corresponding to an NHEJ event consisting of a 24 nucleotide deletion; allele 2 corresponding to a combination of the intended repair and additional sequence changes (illegitimate repair) comprising modification of the two targeted nucleotides and a 3′ deletion of 24 nucleotides; and allele 3 corresponding to a legitimate repair. The genotype of the F0 animal was confirmed through transmission of these three alleles to the F1 population (F1 allele 1 and F1 allele 2). However, one additional allele was also identified in the F1 population: ‘F1 allele 4’ comprising WT sequence