DIFFERENTIAL EFFECT OF RNA-SYNTHESIS INHIBITORS ON ECDYSTERONE INDUCED OVARIAN DEVELOPMENT IN MOSQUITOS

Normally, vitellogenesis and subsequent yolk deposition do not proceed in the anautogenous mosquito Aedes aegypti until after a blood meal. Injection of ecdysterone into non-blood-fed females initiated what visually appeared to be qualitatively normal ovarian development. The yolk proteins from the ovaries of both blood-fed or hormone injected unfed females were extracted and compared using polyacrylamide disk gel electrophoresis. The qualitative patterns obtained were essentially identical; ecdysterone in the absence of a blood meal stimulated the synthesis of authentic vitellogenic proteins. Injection of either .alpha.-amanitin or cordycepin along with ecdysterone did not inhibit the amount of the major vitellogenic protein deposited in oocytes, compared to the hormone-alone injected controls. Actinomycin D was inhibitory. Ecdysterone probably does not induce specific mRNA transcription in this system although it may influence the synthesis of other kinds of RNA. Ecdysterone may regulate vitellogenesis in Aedes through a translational control mechanism.