Fig. 1

eomes-eng inhibits epiboly. A-O: All views lateral. J-O: anterior toward the left. Construct injected, if any, is indicated in the bottom left corner. A-C: Embryos at 30% epiboly (4.7 hours postfertilization [hpf]), (D-I) embryos at 60% epiboly (6.5 hpf). A: Uninjected control. B: Embryo injected with gfp and eomes-eng RNA. Arrowheads indicate the region of the blastoderm that has failed to thin, and the arrow indicates the normal region of the blastoderm. C: Same embryo as in B showing green fluorescent protein (GFP) fluorescence. The region indicated by the arrowheads in B is where most of the GFP expression is located. D: Control embryo injected with gfp and eng RNA. E: Higher power view of embryo in D. F: Same embryo as in E, showing that GFP fluorescence is distributed throughout the blastoderm. GFP-positive cells are intermingled with unlabeled cells. G: Embryo injected with gfp and eomes-eng RNA. H: Higher power view of embryo in G. Arrowheads indicate region of the blastoderm that has failed to thin, and the arrow indicates the normal region of the blastoderm. I: Same embryo as in H, showing GFP fluorescence. The region indicated by the arrowheads in H is where most of the GFP expression is located. J-O: Embryos at 1 day postfertilization. J: Control embryo injected with gfp and eng RNA. K: Higher magnification of J, showing the head region. L: Same embryo as in K, showing evenly distributed GFP fluorescence. M: Embryo injected with gfp and eomes-eng RNA. N: Higher magnification of M, showing abnormal head region. O: Same embryo as in N showing GFP fluorescence concentrated in the anterior portion of the head.