Figure 6. Activin-induced animal cap elongation is defective in cybrid embryos.

Animal caps dissected from stage 8 (A) lxl, (B) [l]xl, (C) txt, (D) [t]xt, and (E) [l]xt embryos were cultured either directly in MBS (left), or in MBS supplemented with 5 ng/ml Activin for 1 h, washed, and transferred to MBS overnight (right). (F–G) Induction and elongation response of [l]xt cybrid embryo animal caps are improved if (F) Activin exposure is doubled and improved further if (G) Xbra is also overexpressed. The axis of elongation (length) is highlighted in red and the width, in green. 4–7 representative explants are shown for each experiment; see Table 4 for total numbers. Scale bars in (A, B, E, F–G) and (C, D): 1 mm.