Figure 1. Sp8 is required for proper nasal prominence morphogenesis.

(A,B) E14.5 Sp8 mutant embryos (B) display severe failure of midline fusion and a loss of many facial structures compared to WT (A).
(C–F) Wild type (C,E) and Sp8 mutant (D,F) skeletal preparations show loss of many NC derived bones in mutants, including the maxilla, palate, and frontal bone. Paraxial mesoderm-derived parietal and interparietal bones are also absent in Sp8 mutants. Dotted circle in panel F indicates a hole in the skull where the brain is exposed in the Sp8 mutant.
(G–R) Facial prominences were digitally pseudo-colored red (maxillary prominence), blue (lateral nasal prominence), green (medial nasal prominence), and purple (frontonasal region) in E10.5, E11.5, and E12.5 WT (G,I,K,M,O,Q) and Sp8 mutants
(H,J,L,N,P,R). Mutant lateral and medial nasal prominences are reduced in size and dysmorphic in shape.
Exoccipital, EO; Frontal, FR; Interparietal, IP; Lateral Nasal Prominence, LNP; Mandible, MD; Maxilla, MX; Medial Nasal Prominence, MNP; Nasal, NS; Neuroepithelium, NE; Parietal, PR; Premaxilla, PMX; Supraoccipital, SO; Tongue, T