Extrinsic effect on immunity in D. melanogaster

Abstract

The study of insect immunity is a rapidly expanding field in biology. Much work has been focused on the pathways and molecules that make up the insect immune system, and this has led to an extensive understanding of innate immunity. However, only recently have researchers begun to examine how the external environment affects the immune system of insects. In addition, other extrinsic factors, such as food limitation and resource allocation can have affects on the outcome of host-parasite interactions. In this dissertation, I examine several extrinsic influences on immunity in the fruit fly, Drosophila melanogaster. By combining the genetic tools we have available in this species with experiments that alter environmental variables, we are able to obtain a greater understanding of the innate immune system. Specifically, I examine how temperature, maternal effects, and very early age can influence immune system function and parasite resistance. The results presented here should shed light on what we might consider a new field of ‘environmental immunology.’ By combining demographic experiments with genetic tools we are better able to understand the interactions of species and perhaps develop new ways of controlling insect pests and vectors for disease.