Contribution of larval nutrition to adult reproduction inDrosophila melanogaster

Abstract

SummaryWithin the complex life cycle of holometabolous insects, nutritional resources acquired during larval feeding are utilized by the pupa and the adult. The broad features of the transfer of larval resources to the pupae and the allocation of larval resources in the adult have been described by studies measuring and tracking macronutrients at different developmental stages. However, the mechanisms of resource transfer from the larva and the factors regulating the allocation of these resources in the adult between growth, reproduction and somatic maintenance are unknown. Drosophila melanogaster Meigen presents a tractable system to test cellular/tissue mechanisms of resource acquisition and allocation, because of the detailed understanding of D. melanogaster development and the experimental tools to manipulate its tissues across developmental stages. In previous work, we demonstrated that the fat body of D. melanogaster larval is important for surviving starvation stress in the young adult and suggested that programmed cell death of the larval fat cells in the adult is important for allocation of resources for female reproduction. Here, we describe the temporal uptake of larval-derived carbon by the ovaries, and demonstrate the importance of larval fat-cell death in the maturation of the ovary and in fecundity. Larvae and adults were fed stable carbon isotopes to follow the acquisition of larval-derived carbon by the adult ovaries. We determined that over half of the nutrients acquired by the ovaries in 2-day old adult females are dependent upon the death of the fat cells. Furthermore, when programmed cell death is inhibited in the larval fat cells, ovarian development was depressed and fecundity reduced.