Fig. 6

Fig. 6 Zoep genetically interacts with ace/fgf8. All embryos are shown in lateral view, anterior to the left. (A, E, I, and M) wild-type; (B, F, and J) ace mutants; (C, G, and K) Zoep mutants; (D, H, L, and N) Zoep;ace double mutants. (A–D) Live embryos at 48 h. (A) Wild-type embryo. (B) ace mutant embryos lack the cerebellum and have an enlarged tectum (arrow). (C) Zoep mutant embryos are obviously cyclopic (arrow). Both ace and Zoep single mutants have well developed posterior mesoderm and neuroectoderm. (D) Zoep;ace double mutant embryo; the phenotype was additive in anterior neuroectoderm. Posterior development in Zoep;ace embryos was extremely poor, and mesodermal derivatives (somites and notochord) were difficult to distinguish morphologically. (E–H) MyoD expression (24 h). (E) Wild type, (F) ace, and (G) Zoep mutant embryos show strong myoD expression throughout the somites. (H) Severely affected Zoep;ace embryo; myoD is expressed only in a few cells in the anterior trunk (arrow) and not more posterior to this. (I–L) Pax2.1 expression (24 h). (I) In wild-type embryos, pax2.1 is expressed in the retina, midhindbrain border, otic vesicle, dorsal spinal cord, and pronephric mesoderm. (J) In ace mutant embryos, pax2.1 expression is absent from the midhindbrain border and is reduced in the retina and otic vesicle. (K) In Zoep mutant embryos with a strong phenotype, pax2.1 expression is absent from the retina, and is reduced in the otic vesicle. (L) Severely affected Zoep;ace mutant embryo; pax2.1-expressing cells are only detected in the anterior spinal cord (arrow). (M and N) Midsomitogenesis live embryos, anterior to left. Note the large numbers of opaque dead or dying cells in posterior tissues of the Zoep;ace embryo (N), which are not apparent in the wild-type embryos (M).