Figure 1.

Whole-mount in situ hybridization with a probe to chicken BMP5. (A) Staining of E4.5 embryos (implanted with a bead soaked in buffer alone) shows the normal expression pattern of BMP5 along the dorsal aspect of the brain, including the diencephalon (upper arrow) and the telencephalon (lower arrow). The expression was through the entire wall of the neural tube (data not shown). No expression was seen in the ventral forebrain (data not shown). Expression persists in embryos exposed to rBMP4 protein (B and C) and may actually be slightly increased (arrowhead points to implanted bead in C; see Materials and Methods), with staining extending laterally in the telencephalon (B). T, telencephalon; D, diencephalon; M, mesencephalon (tectum).