EFFECT OF ELEVATED TEMPERATURE ON THE SURVIVAL OF DROSOPHILA MELANOGASTER INFECTED WITH A PATHOGENIC WOLBACHIA STRAIN

Abstract

The pathogenic Wolbachia strain wMelPop is detected in the central nervous system, muscles, and retina of Drosophila melanogaster. It reduces the host lifetime twofold. This fact makes it promising for control of insect pests and transmitters of human diseases. Any symbiotic association is exposed to various stress factors: starvation, heat, cold, etc., which affect the symbiont interaction significantly. This study considers the action of cold (16 °C) and heat (29 °C) on the survival and lifetime of D. melanogaster females infected by the Wolbachia strain wMelPop. The ultrastructure of brain cells and the bacterium distribution in them were studied. Longer (starting from three days) exposure of imagoes to elevated temperature reduces their lifetime. On day 7 of exposure to heat, electron-dense bodies appear in brain cells of the flies. They look like degrading bacteria. Their amount increases dramatically by day 13 of incubation at 29 °C. On the grounds of populational and EM analysis, we recognized the critical time of heat action: days 7–13 after the start of exposure. After that, the survival of Drosophila melanogaster decreases abruptly.

Keywords

• drosophila melanogaster
• pathogenic wolbachia strain wmelpop
• electron microscopy
• elevated temperature