Figure 6.

Section in situ hybridizations further define the altered Integrin α8 expression in Hoxa 11/Hoxd 11 mutant kidneys. Serial transverse sections through E13.5 Hoxa 11/Hoxd 11 double-mutant embryos were hybridized with antisense riboprobes to Integrin α8 (A and C, and G and I) or Foxd1 (a marker of stromal cells) (D and F). A, D, and G, darkfield images; B, E, and H, 4′,6-diamidino-2-phenylindole fluorescent-stained images; C, F, and I, merged darkfield and fluorescent images. B shows the dorsoventral orientation of the embryo and the structures present. Arrow, ureteric bud; arrowhead, mesonephric duct; g, gonad. The arrows in A and G indicate the ventral renal mesenchyme, where Integrin α8 expression is severely reduced compared with dorsal expression. For this double mutant the kidney shown on the right-hand side was extremely malformed, with an absence of detectable ureteric bud branching.