PgmNr D1139: The Interaction of Wolbachia and Oxidative Stress with Genetic Background in Drosophila Melanogaster.

Authors:
F. Capobianco; S. Nandkumar; J. Parker


Institutes
SUNY Plattsburgh, Plattsburgh, NY.


Keyword: oxidative damage

Abstract:

            It is recognized that the rate of aging varies among individuals according to genetic background. The intracellular bacterium, Wolbachia, is found in most arthropods and nematodes, including D. melanogaster. Here we explore how Wolbachia infection and oxidative stress interact on aging with infected and uninfected D. melanogaster in two different genetic backgrounds. 

            Two wild caught lines, naturally infected with Wolbachia, were cleared of the bacterium. Infected and uninfected flies from the wild caught lines were acutely treated with oxidative stressors (Paraquat, Hydrogen Peroxide) and a nitric oxide stressor (L-Arginine). When treated with paraquat, levels of superoxide anions increase within the cells. Treatment with hydrogen peroxide causes accumulation of itself outside of the cells. L-Arginine increases the amount of nitric oxide within the cells.              

           It was discovered that Wolbachia increases the sensitivity of oxidative stress in a manner dependent on the genetic background and that the effect Wolbachia itself has on lifespan varies according to genetic background. It was also seen that Wolbachia increases the sensitivity to hydrogen peroxide based on genetic variation and length of the fly line’s lifespan. We propose that Wolbachia may be working like Superoxide Dismutase, only in long lived fly lines.

            The system factors that can govern aging (infection and oxidative stress) are not universal, but are specific to the individual’s genetic makeup. This raises the possibility that selection on Wolbachia infection is related to the lack of selection predicted by the mutation accumulation hypothesis for aging.