Fig. 3

Opl and mar share a border of gene expression at tailbud stage that is perturbed in cyclops and MZoep mMutant embryos. Dorsal views; anterior to the top; insets in A and B, sagittal sections with dorsal to the top and anterior to the left. (A) Wild-type embryo labeled with mRNA probes for opl (red) and mar (black). The anterior protrusion of the mar expression domain fits into the indentation at the posterior border of the opl expression domain (arrowhead). The inset shows that the protrusion of mar-expressing cells is wedge-shaped beneath the posterior part of the opl domain. (B) cyclops mutant embryo labeled with mRNA probes for opl (red) and mar (black). The indentation in the opl expression domain and the protrusion in the mar domain are absent (arrowhead). Inset, no wedge shaped protrusion is visible; instead, a vertical border forms between the mar and opl expression domains. (C,E) Wild-type embryos labeled with mRNA probes for opl (C) and mar (E). The arrowheads point to the indentation at the posterior border of the opl expression domain (C) and to the anterior protrusion in the mar expression domain (E). (D,F) MZoep mutant embryos labeled with mRNA probes for opl (D) and mar (F). The indentation in the opl expression domain (D) and the protrusion in the mar domain (F) are absent (arrowheads). The dorsal axis is shortened in MZoep mutant embryos. Scale bar, 100 μm (A-F and insets).