Figure 3.

Generation of an Allelic Series with Varying Crkl mRNA Expression

(A) Schematic of the Crkl mouse alleles and cardiac expression. Exons are indicated by large black boxes. An allelic series of Crkl expression was obtained by specific genetic crosses that allowed all possible combination of two of the three alleles described, i.e., a, b, and c. The normal locus (a), the floxed allele (loxP, triangle) containing the Neomycin cassette (NEO) (b), and the recombined allele (c) are shown.

(B and C) The fold change (FC) from quantitative RT-PCR (qRT-PCR) assays to detect Crkl mRNA dosage in mouse hearts at E10.5 isolated from each genotype is indicated. All mice were maintained in a pure Swiss-Webster genetic background. The fold change (FC ± SD) of Crkl mRNA expression in the allelic series with respect to the wild-type were as follows: Crkl-WT (1 ± 0.049), Crkl-HET (0.465 ± 0.02), and Crkl-KO (0.003 ± 0.0001) hearts and Crkl-WT (1 ± 0.049), Crkl-NEO/+ (0.436 ± 0.059), Crkl-NEO/NEO (0.025 ± 0.006), and Crkl-NEO/− (0.013 ± 0.003) alleles are shown. Statistical significance of the difference in gene expression was estimated by the two-tailed t test, p values ≤ 0.01. All cross comparisons between the above-mentioned genotypes were significantly different except for NEO/+ versus HET and NEO/NEO versus NEO/−.