260A Poster - 02. Immunity and the microbiome
Thursday April 07, 2:00 PM - 4:00 PM

The relationship between natural diet, microbiome, and life history in Drosophila melanogaster


Authors:
Brittany Burnside; Sarah Gottfredson

Affiliation: Brigham Young University

Keywords:
m. microbiome; i. lifespan

My project focuses on the relationship between natural diets, the microbiome, and Drosophila melanogaster life history traits. I am studying the intersection between these traits in order to better understand how dietary impacts on host microbiota alters D. melanogaster life history.
As a starting point, I have measured the development rate and starvation resistance of a D. melanogaster CantonS stock with an unmanipulated microbiota (‘conventional’) when reared on 22 different, autoclaved diets (12 vegetables and 8 fruits). Eclosion time for each fly vial was measured every 6 hours until eclosion of all eggs was complete. Then, 5–10 day-old female flies were transferred in groups of 10 into vials containing 1% agarose, and their survival was measured every 4 hours until all flies in a vial were dead. There was significant variation in the starvation resistance and development rates of flies reared on the different diets. A tradeoff between these two traits was observed in flies reared on most of the diets, except for carrots, spaghetti squash, and limes.
At the time of transfer, I also stored some flies for microbiome analysis, to determine the conventional microbiota composition of flies reared on each diet. Currently, I am working to sequence the microbiomes of these flies to guide my creation of a gnotobiotic bacterial mixture to use in follow-up experiments that will compare the development rate and starvation resistance of axenic (‘bacteria-free’) and gnotobiotic flies on these same diets. These follow-up experiments will allow me to test how the diet affects the life history of the flies, both dependent upon and independent of the fly microbiota. Diet-dependent life history variation in axenic flies will reveal which diets sustain fly development and maturity independent of the microbiota. Life history values and microbiota composition in gnotobiotic flies will reveal interactions between the diet and the microbiota, including which combinations maximize particular life history traits.
Together, these findings help establish how and why natural variation in the diets and microbiota composition of D. melanogaster can contribute to life history variation in locally adapted fly populations. More broadly, understanding these factors will help establish an explanatory framework for how host-microbe interactions influence animal evolution.