WHITE, M.A.*; CORLEY, L.S.; Washington State University; Washington State University: Regulation of cellular proliferation during polyembryony in Copidosoma floridanum

Striking morphological differentiation among individuals structures the complex societies found in insects such as termites, bees, and ants. Castes have also evolved in other insects such as aphids, thrips and polyembryonic wasps. Copidosoma floridanum is a polyembryonic parasitoid wasp that produces two castes during development from a single egg. Polyembryonic development proceeds by a process of cellular proliferation resulting in a single brood containing approximately 950 reproductive larvae that develop into adult wasps and 50 precocious larvae that function as soldiers. The Hedgehog (HH) signaling cascade is a candidate gene pathway that may be regulating proliferation within the dividing cells. Among metazoan taxa, one function of HH is to regulate cellular proliferation during development. Within Drosophila, for instance, HH has been shown to control the proliferation and differentiation of somatic stem cells within the ovary. To determine whether HH is implicated in polyembryonic proliferation in C. floridanum, we cloned the C. floridanum HH gene. In addition, we are in the process of cloning downstream genes in the HH signal transduction cascade. Ultimately, we are interested in determining the role of the C. floridanum HH signal transduction pathway in polyembryonic proliferation. We predict that in areas of active cellular proliferation, high levels of HH will be found, while in areas with no proliferation, HH expression will be absent.