Fig. 3.

The Müllerian duct cell migrates along the A–P axis without lateral migration or apoptosis. Time course of the E14.5 urogenital ridge whose Müllerian duct was divided at 250 μm (arrow) anterior to the tip (red arrowhead). Transverse sections at 500 μm posterior to the initial incision site (dashed line) were studied for 24 h. E14.5 urogenital ridge was incised in the mesonephros (A) and incubated for 8 h (B), 16 h (C), and 24 h (D), followed by whole mount in situ hybridization for Wnt7a. Transverse sections observed at 0 h (E, I and M) at the level of the dashed line in (A), after 8 h (F, J, N and Q) in (B), after 16 h (G, K and O) in (C), and after 24 h (H, L and P), of incubation in (D). (E–H) H and E staining. (I–L) PAX8 staining, green; DAPI staining, blue. (M–P) TUNEL staining, green; DAPI, blue. (Q and R) BudU staining of section made at the dashed line in (B) after incubation with 50 μM of BrdU for 8 h following Müllerian duct division. Migrating tip of the Müllerian duct contains dividing (BrdU) as well as non-dividing (eosin) cells. (R) is a higher magnification of the dashed square in (Q). BrdU, brown; eosin, pink. Arrow, initial incision site; red arrowhead, tip of the isolated posterior Müllerian duct. Autofluorescence in the blood vessel was observed in the mesenchymal area in (I)–(P). Scale bar: 500 μm in (A)–(D), 100 μm, 100 μm in (Q) and 50 μm in (R).