Effect of high temperature on survival of Drosophila melanogaster infected with pathogenic strain of Wolbachia bacteria

Abstract

The pathogenic Wolbachia strain wMelPop is detected in the central nervous system, muscles, and retina of Drosophila melanogaster. It reduces the host lifespan by a factor of two. This fact makes it promising for the control of insect pests and vectors of human diseases. Any symbiotic association is exposed to various stress factors: starvation, heat, cold and etc., which affect the symbiont interaction significantly. This study considers the influence of low (16°C) and high (29°C) temperature on the survival and lifespan of D. melanogaster females infected with the Wolbachia strain wMelPop. The ultrastructure of brain cells and distribution of the bacteria in this cells were studied. On day 7 of exposure to high temperature, electron-dense bodies occur in brain cells of the flies, resembling degrading bacteria. The amount of these bodies increases dramatically by day 13 of incubation at 29°C. On the basis of population and EM analysis, we identified the critical period (7–13 days) of high temperature influence, which dramatically decreases the survival of D. melanogaster.