Fig. 7. Detection of WT and mutant Vangl1 transcripts. RNA from WT Vangl^+/+, Vangl1^gt/+ heterozygote, and Vangl1^gt/gt homozygote embryos was reverse-transcribed and amplified by PCR, followed by hybridization to a Vangl1 cDNA probe (see Materials and Methods). In tissues from Vangl1^gt/+ heterozygotes, similar levels of WT and b-Geo fusion transcript (targeted allele) are detected. In Vangl1^gt/gt homozygotes, only the mutant transcript is detected, except for a very small amount (1-5% of total) of WT Vangl1 transcript noted in the embryo no. 2 (Lower, lane 22).

Fig. 8. Vangl1 and Vangl2 expression in inner ear. Serial transverse sections (A-D) of the E14.5 WT embryos were stained with anti-Vangl1 (B) and anti-Vangl2 (C) rabbit polyclonal antibodies (magnification, ×630). (D) b-Gal staining indicating Vangl1 expression in the E14.5 Vangl1^gt/gt embryo.

Fig. 9. Orientation of the hair cells of the cochlea in embryos of different genotypes. (A) Whole-mount preparations of organs of Corti from E18.5 WT and Vangl1^gt/gt embryos stained with phalloidin-FITC antibody to visualize actin-based stereociliary bundles. (B) The percentage of aberrantly oriented hair in IHC and OHC1-3 cells of embryos of different genotypes (WT, Vangl1^gt/+, Vangl1^gt/gt) was quantitated. The degree of vertex orientation in relation to the pillar cells (perpendicular direction) in Vangl1^gt/+ and Vangl1^gt/gt does not exceed 90°. The asterisks indicate the level of significance (c² analysis). ***, P < 0.0005; **, P ≥ 0.0005 to P < 0.005; and *P < 0.005. The absence of an asterisk indicates lack of significance (P > 0.05).