Fig. 2

Fig. 2 The bozozok^m168 allele lacks the ability to induce a functional organizer. All embryos are animal pole facing the viewer at the onset of gastrulation (6 hpf). Dorsal is to the right. Embryos were injected in both blastomeres at the two-cell stage with the indicated synthetic, capped, sense RNA (20 pg per blastomere). (a) gsc expression in uninjected wild-type embryo (*AB). gsc expression is confined to a small region of the dorsal margin in the cells of the forming shield. (b) Radial expression of gsc in the entire margin of embryos following injection of wild-type nieuwkoid/dharma RNA into both blastomeres at the two-cell stage. (c) BOZ.M1 RNA, an engineered allele of nieuwkoid/ dharma containing the boz^m168 lesion (W⁷⁰ to opal), can only weakly induce gsc expression when injected into both blastomeres at the two-cell stage. Arrowhead highlights ectopic weak expression of gsc. (d) Injection of BOZ.M3 RNA, a recombinant allele of nieuwkoid/ dharma that contains coding sequence encoding only the N-terminal 85 amino acids of Nieuwkoid/Dharma, fails to induce ectopic gsc expression when injected as in (b) and (c).