Role of Commensal Microbes in the γ-Ray Irradiation-Induced Physiological Changes in Drosophila melanogaster.

Hwa-Jin Lee,Ji-Hyeon Lee,Ki Moon Seong,Yongjoong Kim,Shin-Hae Lee,Young Woo Jin,Kyung-Jin Min

doi:10.3390/microorganisms9010031

Hwa-Jin Lee, Ji-Hyeon Lee + Show 5 more

Open Access

https://doi.org/10.3390/microorganisms9010031

Copy DOI

Abstract

Ionizing radiation induces biological/physiological changes and affects commensal microbes, but few studies have examined the relationship between the physiological changes induced by irradiation and commensal microbes. This study investigated the role of commensal microbes in the γ-ray irradiation-induced physiological changes in Drosophila melanogaster. The bacterial load was increased in 5 Gy irradiated flies, but irradiation decreased the number of operational taxonomic units. The mean lifespan of conventional flies showed no significant change by irradiation, whereas that of axenic flies was negatively correlated with the radiation dose. γ-Ray irradiation did not change the average number of eggs in both conventional and axenic flies. Locomotion of conventional flies was decreased after 5 Gy radiation exposure, whereas no significant change in locomotion activity was detected in axenic flies after irradiation. γ-Ray irradiation increased the generation of reactive oxygen species in both conventional and axenic flies, but the increase was higher in axenic flies. Similarly, the amounts of mitochondria were increased in irradiated axenic flies but not in conventional flies. These results suggest that axenic flies are more sensitive in their mitochondrial responses to radiation than conventional flies, and increased sensitivity leads to a reduced lifespan and other physiological changes in axenic flies.

Highlights

Ionizing radiation is being used in various fields, such as cancer treatment [1] and sterilization [2]
Our results suggest that commensal microbes have a radioprotective effect on the lifespan, reactive oxygen species (ROS) generation, and mitochondrial changes induced by γ-ray irradiation
It is known that increased abundance of commensal microbes shortens the lifespan [31], irradiation did not cause significant change in the lifespan in conventional flies

Summary

Introduction

Ionizing radiation is being used in various fields, such as cancer treatment [1] and sterilization [2]. Radiotherapy is a highly effective remedy that destroys cancer by subjecting the cancer cells to radiation. This method uses low or high linear energy radiation to kill tumor cells while minimizing the dose of radiation to healthy cells to prevent toxicity [3]. Sterilization by γ-ray irradiation is commonly used in many disciplines, such as drugs [2], healthcare products [4], and food packaging [5]. After the nuclear leak in Chernobyl [6] and Fukushima [7], people have had concerns about the adverse effects of radiation. Excessive doses of radioactive radon were recently detected in a bed mattress in Korea [8]

Methods

Findings

Discussion

Conclusion