Defects of UV orifice and distal ureter in <i>Fstl1^-/-</i> embryo.

<p>(A-F) <i>Fstl1</i>^+/- mice were crossed to <i>Ptch-lacZ</i>^+/- mice. <i>Fstl1</i>^+/-_;<i>Ptch-lacZ</i>^+/- and <i>Fstl1</i>^-/-_;<i>Ptch-lacZ</i>^+/- ureters were stained for β-galactosidase (blue) at E15.5 (A) and E16.5 (D). The <i>Fstl1^-/-</i> and wild-type ureters were paraffin sectioned and stained with hematoxylin-eosin at E15.5 (distal segment) (B, C), E16.5 (distal segment) (E, F). Note that the <i>Fstl1</i>^-/- ureter (A, D, C, F) is narrower than wild-type ureter (A, D, B, E) at both E15.5 and E16.5. The arrows indicated that lacZ staining was reduced in distal part of ureters in <i>Fstl1</i>^-/- embryos compared to wild-type embryos. (G, H) Histological analysis of the ureterovesicle orifice at E15.5. Note that the distance between the left and right orifices (asterisk) is shorter in the <i>Fstl1</i>^-/- embryo (H), compared with the wild-type embryo (G) at E15.5. (I, J) At E11.0, <i>Pax2</i> and <i>Pax3</i> whole mount <i>in situ</i> hybridizations were performed for wild-type (<i>n</i> = 4) (I), <i>Fstl1^-/-</i> (<i>n</i> = 4) (J). The somites, which were labeled by the <i>Pax3 in situ</i> probe, in the caudal region of the embryo were numbered. The initial site of ureteric bud, which was labeled by <i>Pax2</i> and indicated by a triangle, in both the wild-type (I) and <i>Fstl1^-/-</i> (J) embryos aligned with the 28^th somite level. Scale bar: (B-F) 40µm, (G, H) 100µm.