FIG. 6.

Effects of Idax on axis formation in Xenopus embryos. (A) Ventralizing activity of Idax. (a) Dorsal injection of Xglobin (1 ng). (b) Ventral injection of Xglobin. (c) Dorsal injection of Idax (200 pg). (d) Ventral injection of Idax. (B) Inhibition of siamois expression by Idax. siamois expression in embryos was detected with RT-PCR analysis. Shown are dorsal injection with Xglobin (lane 1, 1 ng); dorsal injection with Idax (lane 2, 50 pg; lane 3, 100 pg; lane 4, 200 pg); and ventral injection with Idax (lane 5, 200 pg). The amounts of cDNA were standardized with EF-1α. no RT, experiments without RT-PCR. (C) Ventralizing activity of Idax deletion mutants. Embryos were injected ventrally (V) or dorsally (D) with Idax (full length) or dorsally with Idax-(1-108) or Idax-(109-198). The phenotypes were expressed as DAI. DAI 0, completely ventralized; DAI 5, normal.