The mammalian gut harbors a vast association of microorganisms that are critical for optimizing host fitness and health. The interaction of bacteria with their hosts is complex, and ranges from pathogenic to beneficial. Beneficial properties of the intestinal flora include the extraction of nutrients from the host diet, priming ofthe host immune system, and development ofthe gut. The fruit fly, Drosophila melanogaster, is a powerful system for identifying and studying the effects of genes on behavior, aging, and disease. The effects of bacterial colonization ofthe Drosophila gut parallel many ofthe observations made in higher organisms, and the presence of bacteria can extend Drosophila lifespan. Preliminary results have identified a Drosophila mutant that is long-lived only in the presence of bacteria and exhibits distinct gut bacterial colonization. This mutant will be characterized and tools will be developed to study microorganisms harbored in the fly host.
In Aim 1, the bacterial species necessary for conferring beneficial effects to fly longevity will be identified. The composition ofthe gut microbiota will be determined as a function of fly age and in response to different nutrient conditions, including under dietary restriction, a manipulation that extends lifespan for a broad range of organisms. Drosophila modulates its gut microbiota using a network of tools including antimicrobial peptides, reactive oxygen species, and acidic lysozymes. These systems will be studied and compared in mutant flies to identify the mechanisms and genes by which hosts affect gut bacterial colonization (Aim 2). To fully characterize host-microbe interactions, a genetic screen will be performed to identify bacterial genes that are critical for colonization of the fly host (Aim 3).

Public Health Relevance

Our research will provide new insights into the interaction of host animals with their gut microbiota. Optimizing host-microbe interactions will promote longevity and improve the quality of human life?features already suggested by the use of probiotics. Additionally, our research may lead to new drug targets for preventing the use of insects as disease vectors by microorganisms.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Transition Award (R00)
Project #
5R00AG030493-05
Application #
8233401
Study Section
Special Emphasis Panel (NSS)
Program Officer
Finkelstein, David B
Project Start
2010-02-01
Project End
2014-01-31
Budget Start
2012-02-15
Budget End
2014-01-31
Support Year
5
Fiscal Year
2012
Total Cost
$239,339
Indirect Cost
$104,610
Name
Scripps Research Institute
Department
Type
DUNS #
781613492
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Lin, Yen-Hung; Chen, Yi-Chun; Kao, Tzu-Yu et al. (2014) Diacylglycerol lipase regulates lifespan and oxidative stress response by inversely modulating TOR signaling in Drosophila and C. elegans. Aging Cell 13:755-64
Deshpande, Sonali A; Carvalho, Gil B; Amador, Ariadna et al. (2014) Quantifying Drosophila food intake: comparative analysis of current methodology. Nat Methods 11:535-40
Bruce, Kimberley D; Hoxha, Sany; Carvalho, Gil B et al. (2013) High carbohydrate-low protein consumption maximizes Drosophila lifespan. Exp Gerontol 48:1129-35