Genetic Influences of the Microbiota on the Life Span of Drosophila melanogaster
Melinda K. Matthews, Hailey Wilcox, Rachel C. Hughes, Madeline Veloz, Austin Hammer, Bethany Banks, Amber Walters, Kyle Schneider, Corinne E. Sexton, John M. Chaston
Abstract
Associated microorganisms (“microbiota”) are intimately connected to the behavior and physiology of their animal hosts, and defining the mechanisms of these interactions is an urgent imperative. This study focuses on how microorganisms influence the life span of a model host, the fruit fly Drosophila melanogaster . First, we performed a screen that suggested a strong influence of bacterial methionine metabolism on host life span. Follow-up analyses of gene expression and metabolite abundance identified stronger roles for vitamin B 6 and glucose than methionine metabolism among the tested mutants, possibly suggesting a more limited role for bacterial methionine metabolism genes in host life span effects. In a parallel set of experiments, we created a distinct bacterial strain that expressed life span-extending methionine metabolism genes and showed that this strain can extend fly life span. Therefore, this work identifies specific bacterial genes that influence host life span, including in ways that are consistent with the expectations of methionine restriction.