Juvenile hormone synthesis by tissues other than the corpus allatum during vitellogenic development in Drosophila melanogaster.
Dana M. Brannigan*, Stephen J. Fischer and David S. Richard, Department of Biology, Susquehanna University, Selinsgrove, PA 17870-1164.
Vitellogenesis in Drosophila melanogaster is driven by the endocrine system such that 20hydroxyecdysone and the juvenile hormones (JHs) are believed to interact to orchestrate synthesis and uptake by developing oocytes of yolk proteins. As part of an ongoing reexamination of the relative roles of these hormones in this process, we have examined the production of JHs by tissues using an in vitro radiochemical assay. Our recent studies, based on the vitellogenic nature of a JH deficient mutant fly (apterous56f) have challenged the notion that the JHs play the primary role in vitellogenesis and data shows the ecdysteroids to be more important. The possibility that tissues other than the corpus allatum may produce JH is being examined. Initial experiments suggest that no JH is synthesized by wild type (Canton-S) ovaries or other tissues except the corpus allatum. These data together with determinations of the levels of receptors to both hormones in JH-deficient, yet vitellogenic, mutant apterous56f females further supports our model in which ecdysteroids and not JHs drive YP uptake. (Supported in part by NIH GM/OD54905, to DSR).