Figure 1.

Maternal gro requirement for dorsal-mediated ventral repression. Optical sagittal sections of nuclear cycle 13 embryos are shown in A–F, with dorsal side up and anterior to the left. Ventral views of nuclear cycle 13 embryos are shown in G–I, with anterior to the left. mRNA expression patterns are revealed by whole mount in situ hybridization. dpp expression pattern in wild-type (A), gro^E48mat− (B) and gro^BX22mat− blastoderm embryos (C). zen expression pattern in wild-type (D), gro^E48mat− (E), and gro^BX22− (F) blastoderm embryos. twi expression pattern in wild-type (G), gro^E48− (H), and gro^BX22− (I) blastoderm embryos.