Fig. 7.

Sagittal views of expression of Bsk ligand(s) during mouse embryogenesis. Neighboring sagittal sections from E10 (A, B), E13 (C,D), and E15 (E–G) embryos were stained with Bsk-AP (A, C,E) or H&E (B, D,G). Human placental alkaline phosphatase not fused to Bsk was used in parallel sections as a control (F). In E10 and E13 embryos, no specific staining was observed in control sections. In E15 (F) and E18 embryos, endogenous heat-resistant alkaline phosphatase activity was detected only in the intestine. die, Diencephalon;mes, mesencephalon; met, metencephalon;mye, myelencephalon; tel, telencephalon;t, tongue; Hyp, hypothalamus;SC, spinal cord; T, tectum; Scale bars:B, 1 mm; D, G, 2 mm.