Site-Specific Expression of Gelatinolytic Activity during Morphogenesis of the Secondary Palate in the Mouse Embryo
Figure 2
Double labeling for gelatinolytic activity and laminin in the palatal region of the mouse embryo.
Frontal cryosections of E13.5 (A–C), E14.5 (D–F), and E15.5 (G–I) wild type mouse heads were subjected to DQ-gelatin zymography (green panels), followed by immunofluorescence labeling for laminin-111 on the same section (red panels). The images show representative sections from the anterior (A, D, G), the middle (B, E, H), and the posterior (C, F, I) level of the palate. No site with significant gelatinolytic activity, as manifested by increased fluorescence, is detected at E13.5 prior to palatal shelf elevation. At E14.5, gelatinolytic activity is evident in the nasal cartilage and in the main palatal arteries (arrows). In addition, signs of gelatinolysis are visible at the midline epithelial seam (asterisks), whereas prominent gelatinolytic activity is detected around the folds of the elevated palatal shelves, where the nasopharynx will form (arrowheads). A similar pattern of gelatinolysis is observed at E15.5, although activity is increased compared to E14.5. Furthermore, prominent activity was evident for maxillary bone. p, palatal shelf; t, tongue; n, nasal cartilage; m, maxillary bone. Bar, 200 μm.