JUVENILE HORMONE AND THE ADULT DEVELOPMENT OF<i>DROSOPHILA</i>

Abstract

Topical application of Cecropia juvenile hormone (JH) blocked metamorphosis of the abdominal integument of pupating Drosophila larvae. JH treated adult flies retained more or less extensive areas of cuticle which could not be distinguished from pupal cuticle in whole mounts. Implantation into mature larvae of fragments of first instar larvae containing brains and ring glands provoked localized retention of patches of incompletely metamorphosed cuticle. An assay procedure for compounds with juvenile hormone activity was developed by defining the critical developmental stage and dose-response relationships. Twenty-two substances suspected of having juvenile hormone activity were assayed for their effect on Drosophila. These findings support the choice of Drosophila for resolving the genetic basis of juvenile hormone action.