Comparative analysis of ventralization phenotypes. Homozygous mutant embryos for chordin (din/din, panel A), ogon (ogo/ogo, panel B) as well as chd morphants in ogon mutant background (C) display ventralization phenotypes similar to those obtained after injection of low amount of bmp2b RNA (1 pg, panel D). Injection of 5 pg bmp2b RNA (E) results in stronger ventralization with complete loss of head while injection of 20 pg RNA (F) completely abolishes the D/V patterning and embryos appear radialized. At the onset of gastrulation, ogo transcripts (G) are observed in the ventral part of the embryo while chd (H) is expressed in a broad dorsal domain, which includes the nog1 expression territory (I). Embryos are in lateral view, anterior to the left (A–F) or anterior to the top (G–I).
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