Fig. 3. Inhibition of endogenous TSG expression in early Xenopus embryos results in head and tail defects. (A) Control stage matched tadpole. (B) When 5 ng TSG-MO was injected into the marginal zone of each blastomere at the four-cell stage, the resulting tadpoles showed reduced head structures including defective eye formation together with mild tail defects and body curvature. (D,E) When the two dorsal (the region with low BMP signaling) or the two ventral (the region with high BMP signaling) blastomeres were injected with 10 ng TSG-MO per cell at the four-cell stage, the resulting embryos displayed head malformations and a bent body axis (dorsal injection, D) or reduction and ventralward bending of the tails (ventral injection, E) in the tadpoles. The control embryos for this experiment are shown in panel C. In all panels anterior is to the right and dorsal is up.