Abstract submitted to the Pennsylvania Academy of Science
for inclusion in the April 12-14 1996 meeting held at State College, PA.
A mutational examination of hormonal regulation of vitellogenesis in
Drosophila melanogaster.
Jayanthi Jayawardena*, Jennifer McGonigle and David S. Richard Ph.D. Department
of Biology, Susquehanna University, Selinsgrove, PA 17870.
The sequiterpenoid juvenile hormones (JHs) have long been thought to drive
the regulation of female reproductive development in the fruit fly Drosophila
melanogaster, and the insect steroid hormones (ecdysteroids) have been
considered of secondary importance to the process.
Our recent studies have demonstrated that the levels of JH production in
a mutant stock (apterous56f) are depressed yet
the flies are normally vitellogenic. However, as we show here, a depressed
level of ecysteroid production by ovaries in vitro is always associated
with a block in oocyte development as in the temperature-sensitive mutant
ecdysoneless1 strain at the restrictive temperature
of 29oC. This study quantifies (by radioimmunoassay)
the whole body titers and levels of production of ecdysteroids by isolated
ovaries from homozygous apterous56f females
and from homozygous ecdysoneless1 mutants in
an attempt to more firmly correlate ecdysteroid production with vitellogenesis.