Figure 4.
Cno is essential for mesoderm invagination. Embryos, antigens, and genotypes are indicated. (A–C) Cross sections of wild-type (WT) ventral furrow. Late cellularization (A), initial furrowing (B), and mesoderm internalized (C) are shown. (D–K) Ventral views, anterior up. (D and E) Wild type, mesoderm completely internalized. (F) Wild type during constriction. (G and H) cnoMZ, Twist (Twi)-positive cells not completely internalized. (I) cnoMZ mesoderm initiates constriction. (J and K) Rap1MZ phenocopies cnoMZ, but some exhibit twisted gastrulation. (L) cnoMZ mesodermal cells elongate along apical–basal axis (red arrow) relative to ectodermal neighbors (green arrow). Arrowhead, actin accumulating in balls. PTyr, phosphotyrosine. Bars, 30 µm.