INDUCTION OF YOLK PROTEIN SYNTHESIS IN FAT BODY OF AN INSECT, LEUCOPHAEA MADERAE, BY AN ANALOG OF JUVENILE HORMONE

During the time that eggs are developing, the fat body from female Leucophaea maderae synthesizes a protein with characteristics similar to a subunit of the major yolk protein. Synthesis does not occur or is much reduced in fat bodies from males, nymphs, and abdomens amputated from adult females before the onset of egg development. Topical application of an analog of the juvenile hormone initiates the development of eggs in isolated abdomens. Forty hours after hormonal treatment and prior to an obvious change in the eggs, labeled leucine is incorporated into a fraction that can be isolated from the fat body together with added yolk protein. This fraction exhibits the same sedimentation characteristics as the subunit of the yolk protein during density gradient centrifugation. © 1969.