Fig. 3. Intercellular coupling is maintained in GDF9 null mutant follicles. Dichlorofluorescein was injected into a single granulosa cell (asterisk) of a Gdf9⁺/Gdf9^– (A) and a Gdf9^–/Gdf9^– follicle (B). The extent of intercellular dye spread did not differ significantly between the two genotypes (C). These images are representative of the ten control and 13 mutant follicles that were tested. Bar, 50 µm.