Fig 2: Effect of QTL genotype on placental PAPPA2 protein expression at day 12.5 post-coitum. Western blot of 8 representative samples of C57BL/6 (C) and DBA/2 (D) genotype placentae. The nitrocellulose membrane was scanned for fluorescence at 700 and 800 nm simultaneously. Fluorescence at 700 nm is shown in red and corresponds to actin (approximately 40 kDa) whereas fluorescence at 800 nm is shown in green and corresponds to PAPPA2 (approximately 250 kDa).

Fig 3: Schematic diagram of the targeting vector used in the generation of PAPP-A2 conditional deletion mice.Shown are the locations of the targeted exon, homology arms, loxP and FRT sites, ampicillin resistance gene (AmpR), phosphoglycerate kinase promoter (PGK), neomycin resistance gene (Neo), bovine growth hormone poly A termination signal (pA), and genotyping primers. The sizes of the primers have been exaggerated for clarity.

Fig 4: Quantitative complementation test.Body mass and tail length at 3, 6 and 10 weeks of age are shown for mice homozygous for wild-type Pappa2 (+/+) or heterozygous for the Pappa2 disruption (+/-) and homozygous for the C57BL6 QTL allele (squares) or heterozygous for the DBA2 and C57BL6 QTL alleles (triangles). In all cases, the difference between QTL alleles is greater for +/- mice than for +/+ mice, consistent with what is predicted if Pappa2 is the gene responsible for the QTL. The total sample size for the quantitative complementation test was 243 (133 females and 110 males), although is slightly lower for some traits due to missed measurements.

Fig 5: Effect of QTL genotype on relative expression levels of placental PAPPA2 mRNA at day 12.5 post-coitum. Quantitative RT-PCR was used to measure levels of PAPPA2 mRNA in mice homozygous for the C57BL/6 (N = 9) or DBA/2 (N = 17) QTL genotype, and a significant difference between genotypes was observed (F(1,24) = 39.8, P < 0.0001). Expression levels are relative to those of the reference sample and are standardized to ß-actin.