Meeting Abstract

P1.8  Jan. 4  Larval fat cells have a key role in adult starvation resistance in Drosophila melanogaster. AGUILA, J.R.*; SUSZKO, J.W.; GIBBS, A.G.; HOSHIZAKI, D.K.; University of Nevada, Las Vegas; University of Nevada School of Medicine; University of Nevada, Las Vegas; University of Nevada, Las Vegas aguilaj@unlv.nevada.edu

The life history of holometabolous insects is divided into distinct developmental stages from the embryo to the adult. From an energetic standpoint, however, the life history can also be separated into feeding and non-feeding periods. The larval stage is characterized by extensive feeding which supports the rapid growth of the animal and allows the accumulation of energy stores to fuel metamorphosis, a non-feeding stage. In Drosophila melanogaster, the larval fat body is the primary tissue for energy storage, and is unique in that it is refractive to the destruction of larval tissues characteristic of metamorphosis. We demonstrate that the free-floating fat cells in the newly eclosed adult are derived from the larval fat body and that these cells have an important role in starvation resistance of the young adult. We used cell markers to determine the larval origin of fat cells and genetic manipulations to establish that these cells are destroyed by a caspase cascade that leads to apoptosis or autophagy within the first 48 hours of adult life. To establish that the larval fat cells are of nutritional importance to the adult, we blocked cell death specifically using the GAL4/UAS system. Newly-eclosed adults survived starvation for only 58 hours, whereas starvation resistance increased to 72 hours when larval fat-cell death was blocked. Survival time was highly correlated with the number of remaining larval fat cells. We will discuss the implication of these results for the overall nutritional status of the larva as a key factor in adult survival in environmental stresses such as starvation.