Hormonal Control of Systems Associated with Egg Development in Phycitid Moths

摘要

Several proteins associated with oocyte development in Plodia interpunctella were isolated and characterized. Conditions were established for the long term culture of fat body and ovaries, which produce these proteins. The concentration of ecdysteroids, the major hormones associated with metamorphosis and the initiation of ovarian development, was measured by radioimmune assay and HPLC. Ecdysteroids reach a major peak at the beginning of adult development when the oocytes begin to mature. The concentration then declines gradually as development continues to eclosion. The decline may be a means for controlling sequential development of adult structures because elevating hormone titre by injection delays development. Protein synthesis in ovaries is substantially reduced and oocytes do not sequester yolk precursors from the hemolymph. The fat body synthesis protein at what appears to be a normal rate but elevated titres slow the utilization of what has been identified tentatively as storage protein. Fat body and ovaries can be maintained in culture for periods equal to the time of metamorphosis.