BMP4 transcript patterns in normal and VAD embryos.

Compared to normal embryos (A, B), the pattern in VAD embryos (C, D) is relatively unchanged in stage 7 (A, C) or stage 8+ (B, D) embryos. However, BMP4 expression is not maintained normally in the VAD embryo, which by stage 14 (E, normal; F, VAD) lacks BMP4 RNA in the caudal embryonic domain (arrows). All views are anterior to the top. In panels A to D, the views are dorsal, whereas in panels E to F, it is ventral. H indicates head; HT, heart. Original magnification × 32.