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FIGURE 1.
Expression of ets1 in NC is regulated by Lrig3 and FGF signaling. A, embryos were injected with chordin (Chd), chordin + wnt3a, or chordin + wnt3a + lrig3MO (L3MO). Animal caps were dissected at stage 9 and cultured to stage 17. Expression of the indicated genes in animal caps was assayed by RT-PCR. Ornithine decarboxylase (odc) was used as an internal standard. WE, uninjected whole embryo; AC, uninjected animal caps; RT−, without reverse transcriptase. B–G, spatial expression pattern of ets1 as detected by in situ hybridization. B, C, and D, dorsal view; D′, anterior view; E, F, and G, lateral view. The white arrow in C indicates the weak ets1 signal starting at stage 13. The ventral blood island is indicated by a white arrow in D′. H, temporal expression of Xenopus ets1a at the indicated stages. I–N, embryos treated with the indicated concentrations of SU5402 from stage 12. ets1 and brachyury (bra) expression was examined at stage 16 by whole-mount in situ hybridization. The expression of the indicated genes was affected in the following percentage of embryos: M, 73% (8 of 11); N, 100% (20 of 20); J, 33% (7 of 21); K, 61% (11 of 18). O, embryos were injected with 10 pg of efgf or 300 pg of wnt3a mRNA, respectively. The caps were dissected from embryos at stage 9 and then cultured to stage 15. Expression of the indicated genes in animal caps was assayed by RT-PCR. |
