Fig. 2

Fig. 2 Ectopic zOtx1 expression causes cell aggregation. Embryos were co-injected with GFP RNA and an RNA encoding zOtx1-ΔH (A–C) or zOtx1-wt (E–G) or injected with single RNAs encoding myc-zOtx1-ΔH (D, I) or myc-zOtx1-wt (H, J). The two illustrated co-injected embryos were each examined at 8 hpf (A, E), at 12 hpf(B, F), and again at 24 hpf (C, G). The embryos expressing the Myc-tagged zOtx1 proteins were histochemically stained after fixation at 24 hpf. Higher magnification views of 12-hpf embryos injected with myc-zOtx1-ΔH (I) or myc-zOtx1-wt (J) indicate that the expressed proteins are predominantly localized in nuclei (arrowheads). Nuclei in cells located within the trunk, as in (I), are smaller than nuclei in cells located on yolk or embryo surface, as in (J). Extensive cell aggregation of descendants of injected cells can be seen in those embryos which received zOtx-wt RNAs (arrowheads in E–H) but not in embryos injected with zOtx1-ΔH RNAs. All embryos are shown in lateral view with anterior to the top except in (A), which is an animal pole view. Scale bars, 100 μm (A–H, at same magnification) or 5 μm (I and J, at same magnification).