Transgenic Drosophila melanogaster Carrying RNAi Against gce Gene Proved the Involvement of gce in Juvenile Hormone Action

Abstract

Juvenile hormone (JH) is important for multiple aspects of insect development and physiology. Although roles of JH have received considerable studies, JH signaling pathway at the molecular level is still not well understood. Methoprene-tolerant (Met) in Drosophila melanogaster fulfills many of the requirements as a hormone receptor gene. A paralogous gene, germ-cell expressed (gce), possesses homology to Met and is a candidate as a Met partner in mediating JH action. To probe roles of this gene in JH action, we carried out in vivo gce underexpression studies using RNAi technique. Precocious expression of broad (br) gene was found to occur when gce was knocked down in the young larvae. We also demonstrated that RNA interference-driven knockdown of gce expression in transgenic flies results in appearance of resistance to pyriproxyfen (IGRs). These results show that gce is a vital gene and appears to promote JH action in larval stages.