Fig. 8. Placental development in Cx4331/31 conceptuses. HE-stained paraffin sections of Cx43+/+ (A,C) and Cx4331/31 (B,D) placentas at E17.5. No differences in development and placental architecture were found. All trophoblast cell types [labyrinth (L); spongiotrophoblast (S); glycogen cells (G)] are normal in Cx4331/31 placenta compared with Cx43+/+ controls. Bars, 600 µm (A,B); 150 µm (C,D).