Fig. 1

Morphological characteristics of (A-F) one-eyed pinhead (oep^tz257) and (G,H) dirty nose (dns^te350) mutant embryos. In each section, wild type (+) is to the left, mutant to the right. (A) Tailbud stage, lateral view: the body axis is shorter; no pillow (indicated by an arrowhead) is formed at the anterior end of the hypoblast. (B,C) 8-somite stage: (B) lateral view, the head is reduced while the tailbud seems enlarged in oep mutants. (C) dorsal view of head region. (D) 24 hours, dorsal view of head region: the anterior part of the forebrain is missing while the eye vesicles are fused in oep mutants. (E) 24 hours, lateral view: the notochord is slightly undulated, the somites are slightly expanded along the a/p axis, the yolk tube is shorter and thicker, and the tail is curled down in oep mutants. (F) 24 hours, lateral view at level of yolk tube: no floorplate (arrow) can be detected in oep mutants. (G,H) dns, 24 hours, ventral view of head region: (G) brownish cells can be observed underneath the eyes (arrowhead); (H) acridine orange staining reveals apoptotic cells in the same region (arrowhead).