Figure 3

Embryonic abnormalities and craniofacial dysmorphology in Gtf2i ^Δex2 mutant mice. A. H&E staining, Ki67 labeling and TUNEL assay. Sections from normal (top) and abnormal (bottom) E7.5 embryos derived from crosses between Gtf2i ^+/Δex2 females and Gtf2i ^Δex2/Δex2 males. Abnormal embryos lacking detectable embryonic layers by H&E staining are likely to correspond to nonviable Gtf2i ^Δex2/Δex2 embryos. Normal embryos displayed high levels of Ki67-positive cells while they are no detectable in abnormal embryos. No differences were observed in the TUNEL staining. B. Morphologic abnormalities in Gtf2i mice at 8 weeks of age. (Left) The histogram shows the relative average distance from the tip of the nose to the proximal occipital suture (n = 10 per genotype). Pair wise comparisons revealed statistically significant differences between genotypes (Tukey test; P = 0.003 and P = 0.048 for Gtf2i ^Δex2/Δex2 and Gtf2i ^+/Δex2 relative to Gtf2i ^+/+, respectively). (Right) representative photograph of the dissected cranial structure per genotype is shown. A shorter snout could be clearly appreciated in the Gtf2i ^Δex2/Δex2 mice. Gtf2i ^+/+, open; Gtf2i ^+/Δex2, grey; and Gtf2i ^Δex2/Δex2, black squares.