Figure 3.

(A) Relative quantification of YAC transgene expression compared with endogenous Fbn1 expression. RT-PCR amplicons were generated using total RNA isolated from mouse aorta and oligonucleotides complementary to exons 10 and 11 that recognize identical sequence in mice and humans. The amplicon from FBN1 has a unique TaqI digest site, resulting in a smaller band that binds to a probe generated from 32P-labeled antisense oligonucleotide in exon 11. Ratio of human to mouse mRNA in the exponential portion of amplification is indicated below. Tg(mut3) is the highest expressing strain, while two other strains were intermediate in their FBN1 expression. (B) Developing limb from Tg(mut3) mouse stained for fibrillin-1, demonstrating robust transgenic production of mutant human fibrillin-1 in tissues expressing endogenous mouse fibrillin-1. Left panel: polyclonal Ab that detects both mouse and human fibrillin-1; middle panel: mAb that is specific to human fibrillin-1; right panel: overlay.