Fig. 3. The vitelline membrane of Cad99C mutant eggshells is unevenly deposited and displays holes. (A,B) Ultrathin sections of stage-13 egg chambers of (A) heterozygous Cad99C^57A/+ or (B) homozygous mutant Cad99C^57A/57A flies stained for the vitelline membrane protein sV17. Control egg chambers display a continuous line of sV17 staining, whereas mutant egg chambers display sites where the sV17 staining is not detected (asterisk). (C,D) Electron micrographs of sections through stage-11 egg chambers of (C) heterozygous Cad99C^57A/+ or (D) homozygous mutant Cad99C^57A/57A flies. The vitelline membrane (Vm) is unevenly deposited in the mutant egg chambers and is not detected at some sites (asterisks). Oo, oocyte; Fc, follicle cells. Bars, 2 µm (C,D).