Histological analysis of the <i>Fstl1^-/-</i> urinary system.

<p>(A-C) Kidneys and ureters from WT and <i>Fstl1^-/-</i> embryos at stages of E15.0 (A), E16.0 (B) and E17.5 (C). Arrows indicate mutant ureters, and arrowheads indicate wild-type ureters. (D) Dye injection experiments detected no complete physical obstruction of the <i>Fstl1</i>^-/- ureter at E18.5. (E-J) H&E staining on transverse sections of WT (E, G, I) and <i>Fstl1</i>^-/- (F, H, J) ureters at E15.0 (E, F), E16.0 (G, H) and E16.5 (I, J). (E, F) No obvious change was detected at E15.0 in <i>Fstl1</i>^-/- ureter. (G, H) <i>Fstl1</i>^-/- ureter became dilated from E16.0. (I, J) There are prominent changes in the histological structure of the <i>Fstl1</i>^-/- ureter compared to the WT ureter at E16.5. Scale bar: (E-J) 40 µm. k, kidney; p, pelvis; u, ureter; bl, bladder; um: ureteral mesenchyme; ue: ureteric epithelium.