Mesoderm invagination in cno^MZ. (A–C) Embryos, ventral views, anterior left, and genotypes are indicated. Moe-GFP reveals F-actin. Brackets, ventral furrow; arrows, mesoderm cells round up to divide and emerge from furrow. Still images from Videos 1 (A), 2 (B), and 3 (C) are shown. (D–F) Graphs show cell cross-sectional areas as ventral furrow invaginates. t = 0, defined as 100%. Wild-type (WT) cells constrict to essentially zero before invaginating, whereas mutant cells disappear in furrow before fully constricting. Bar, 30 µm.