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 presents a tractable system in which to test cellular and 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 larvae is important for survival of 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 was reduced.

Terminal investment strategies following infection are dependent on diet

“…Stocks were kept at 25°C under a 12:12 light:dark regime at densities of 10–20 adult flies per vial, which were allowed to lay for 24 hr before being removed. Flies laid for the experimental generations were density controlled by adding 15 female and 2 male flies to each vial for 24 hr on a standard Lewis diet without additional yeast, as larval diet is known to later influence oogenesis in adult flies (Aguila, Hoshizaki, & Gibbs, ), whereas we were interested in the role of current protein content of diet in mediating life‐history responses to infection. The resulting adult offspring were lightly sedated with CO 2 and divided into two density‐controlled vials for each line by placing 15 females and two males on standard Lewis diet for 24 hr to ensure mating had occurred prior to the experiment.…”

Drosophilaas a model to study obesity and metabolic disease

“…The larval and the adult fat body are composed of two different cell lineages. The larval fat body represents a contiguous organ of a fairly constant number of postmitotic, large endoreplicative cells, which undergo histolysis shortly after the adult fly ecloses (Aguila et al, 2013(Aguila et al, , 2007. In contrast, the adult fat body is believed to be composed of diploid cells derived from cell clusters in the larval body wall and from adepithelial cells of the imaginal discs (Hoshizaki et al, 1995).…”

Drosophila melanogaster larvae make nutritional choices that minimize developmental time

“…Larval nutrition can also directly contribute to the energy stores available for flight and reproduction. In D. melanogaster, the degeneration of the larval fat body during metamorphosis contributes over half of the energy sequestered into the ovary in the first 2 days of adult life, thereby playing an important role in regulating egg production rate (Aguila et al, 2013). Thus it appears that the effects of larval diet go beyond constraining the size of adult structures, and contribute significantly to programming adult metabolic functions.…”