Figure 1. Overview of craniofacial structures in the mouse embryo.

Frontal sections (mid-posterior level) of (A) E13.5 and (B) E14.5 wild type mouse heads were labeled with antibody to laminin-111, which stains all basement membranes. The boxed areas illustrate the region of interest that is presented in most of the following figures. Note that at E13.5 the palatal shelves are vertically oriented besides the tongue, while at E14.5 the shelves have elevated above the tongue to form the secondary palate. e, eye; b, forebrain; t, tongue; p, palatal shelf; tb, tooth buds. Bar, 500 μm. Drawings of E13.5 (C) and E14.5 (D) mouse heads indicate the different anteroposterior section planes through the palatal region (a, anterior; m, middle; p, posterior) that are presented in following figures. Note that at E14.5, the elevated secondary palate now separates the oral from the newly formed nasopharyngeal cavity.