Fig. 3

Induction of dorsal organizer markers by cell line implantation into mid-blastula. Ectopic expression of gsc (A–E), flh (F–J) and chd (K–N) is apparent around implanted cells but not in the cells themselves. (A, F, K) Embryos without implanted cells. (B, G) Embryos with implanted cells. (C, H) Whole-mount in situ hybridization for gsc and flh in the embryos shown in panels B and G, respectively. Ectopic gsc was observed in 24 of 28 embryos, ZE6-1; 22 of 31 embryos, ZE24-1; 13 of 32 embryos, ZE72-1; 15 of 33 embryos, ZE120-1. Ectopic flh was observed in 25 of 32 embryos, ZE6-1; 34 of 37 embryos, ZE24-1; 32 of 34 embryos, ZE72-1; 31 of 38 embryos, ZE120-1. (L) Whole-mount in situ hybridization for chdin implanted embryos. Ectopic chd was observed in 5 of 5 embryos, ZE6-1. (D, E) Longitudinal section and high-magnification view of panel C. (I, J) Longitudinal section and high magnification of panel H with dorsal to the right. (M, N) Longitudinal section and high-magnification view of panel L. (A–C, F–H, K, L) Animal pole views. (D, E, I, J, M, N) Lateral views. Dotted lines in panels E, J and N represent the colonized implanted cells. All embryos are early gastrula (6 hpf). Arrowheads indicate the implant cells and arrows indicate the ectopic expression of gsc, flh and chd. Scale bar, 100 μm.