Abstract: Experiments were performed to study the incorporation of yolk protein labelled with FITC into housefly follicles in vitro. It was revealed that the rate of yolk protein incorporation depended on the concentration of yolk protein in the culture medium and temperature. The optimal condifion for yolk protein.lncorporation in this Grate's medium was 2 mg yolk protein per ml culture medium at 27℃ for twohours. The capacity of follicles in yolk protein uptake reached summit when housefly ovaries developed to the stage 6-8 about 48 hours after adult emergence.JH III, if added to the culture medium at oncentration of 5.9 to 117.3 ng/μl, could increase the amount of yolk protein incorporated into ovarian follicles. The yolk protein uptake by follicles in vitro was inhibited by ouabain, BSA or NAN₃.

Key words: Musca domestica——yolk protein——juvenile hormone