Figure 5.
(A) Drawing depicting cDNA resulting from proper homologous recombination of the endogenous Fbn1 allele with the targeting vector for the C1039G mutation. Above is a representation of the genomic segment prior to Cre-mediated recombination to remove the NeoR flanked by loxP sequences. (B) Representative Southern blot demonstrating correct targeting before and after Cre-mediated loxP recombination. Left lane is from a WT, untargeted mouse, with an undigested 21-kb KpnI fragment; middle lane is from a C1039G heterozygous mutant mouse without Cre-recombinase, resulting in an untargeted band (21 kb) and a targeted band (5.4 kb); right lane is from a C1039G heterozygous mutant mouse after Cre-mediated recombination, resulting in an untargeted band (21 kb) and a targeted band (3.2 kb). (C) Northern blot demonstrating that the level of expression of Fbn1 in mice heterozygous or homozygous for the C1039G allele is unchanged in comparison with untargeted (WT) mice. Expression is normalized to expression of the gene encoding β-actin (βACT). The level of Fbn1 expression in heterozygous and homozygous targeted mice, relative to that seen in WT, is indicated.