Fig. 2. Cx43 expression is maintained in GDF9 null mutant follicles. Gdf9+/Gdf9 (A,B) and Gdf9/Gdf9 (C,D) ovary sections were immunostained for Cx43. Punctate immunoreactivity characteristic of gap junctions is evident between the granulosa cells of both control (B) and null mutant (D) follicles. Bar, 50 µm.