Ionizing radiation disrupts behavior rhythms and clock-related pathways in Drosophila melanogaster

Growing evidence shows that ionizing radiation (IR) can affect the circadian rhythm of organisms, which serve as a key regulator of behavior. In this study, changes of behavior under different types and doses of ionizing radiation in Drosophila melanogaster were investigated. The Drosophila Activity Monitoring System (DAMS) was used to monitor the activity and sleep rhythm of Drosophila for 3 days. The results showed a significant increase occurred in activity after irradiation under normal light condition. This increase occurred predominantly during the light phase and was most pronounced within the first 36 h post-irradiation. Irradiated flies exhibited a marked reduction in sleep duration. This sleep reduction primarily occurred during the dark phase, with the most substantial alterations concentrated within the 0-48 h after irradiation. Furthermore, both activity and sleep rhythm exhibited dose-dependent alterations under normal light conditions. Constant light or dark conditions disrupt activity and sleep rhythms, and critically exacerbate the effect of irradiation. The results of transcriptome sequencing analysis revealed that irradiation induced changes in genes associated with metabolic pathways and circadian rhythm. Collectively, these results demonstrate that ionizing radiation affects circadian behavioral rhythms in Drosophila in a manner dependent on both radiation dose and type, and circadian genes play a critical regulatory role in these observed changes.