THE EFFECT OF NUTRITION ON LONGEVITY AND FERTILITY IN DIVERSE DROSOPHILA: A TOR-MEDIATED PROCESS

Abstract

Nutrition and growth are strongly linked, but not much is known about how nutrition leads to growth. To understand the connection between nutrition through diet, growth and/or proliferation, we need to study the phenotypes resulting from the activation and inhibition of central metabolic pathways. Here I use the model organism Drosophila melanogaster (D. mel.) and three non-model Drosophila species with different dietary needs, Drosophila guttifera (D. gut.), Drosophila deflecta (D. def.), and Drosophila tripunctata (D. tri.), to study the effects of dietary amino acid availability in these diverse flies on fecundity and longevity. In addition, I inhibited the Target of Rapamycin (TOR) pathway to test how inhibition interplays with the nutritional stimuli in these four fruit fly species. The hypothesis was that the inhibition of the TOR pathway would reverse the phenotypes observed under conditions of overfeeding. The results show that egg-lay rates increased with higher amino acid availability but decreased in response to TOR inhibition. The longevity data were more varied: most species experienced an increase in median lifespan in both genders with an increase in yeast, except for D. mel. females. When exposed to the TOR inhibitor rapamycin, most lifespans decreased, except for D. tri. The obtained data will benefit future studies of metabolism and will also help scientists to adopt non-model organisms into their labs to study the true complexity of pathway evolution across different species with diverse nutritional habits and needs.