Fig. 6. Gdnf expression is reduced in the Itga8-null embryonic kidney at E11.5 but is normal at E10.5 and E13.5. (A-L) Transverse sections through Itga8^+/- and Itga8^-/- embryos, showing gene expression as detected by in situ hybridization. (A,B) Note the apparent absence at E11.5 of Gdnf RNA in the MM of the Itga8^-/- mutant (demarcated by dotted circles), whereas the level of Gdnf expression appears comparable in the adjacent limb buds (arrows) in Itga8^+/- and Itga8^-/- embryos. (C,D) Pax2 is expressed in both the MM and the UB (arrowhead). Note the lack of UB invasion in the Itga8^-/- MM (asterisk). (E-L) Expression at E10.5 (E-H) and at E13.5 (I-L) of the genes indicated. Note that expression of Gdnf, Pax2 and Six2 is similar in Itga8^+/- and Itga8^-/- MM at these stages. Open arrowheads point to UB branches in the MM at E13.5. Scale bars: 100 µm. Abbreviations as in previous figures.