A.I. ARUOMAREN

Ionizing radiation from diagnostic imaging procedures has raised concerns regarding its potential biological effects, even at low doses. This study investigated the impact of diagnostic radiation exposure on mRNA expression of p53 and DIAP1 in Drosophila melanogaster. Healthy laboratory-reared flies (Harwich strain) were divided into five groups (n=100 per group): a control group (Group A), two X-ray–exposed groups (Group B, 0.1 Gy daily for 7 days; Group C, 0.1 Gy daily for 14 days), and two CT-exposed groups (Group D, 0.1 Gy daily for 7 days; Group E, 0.1 Gy daily for 14 days). Radiation exposure was performed under standardized laboratory conditions at the Biomedical Toxicology Chemicals Safety (BIOTOXCS) Research Laboratory, University of Benin. After exposure, flies were preserved in Trizol reagent for RNA extraction, followed by cDNA synthesis and semi-quantitative PCR analysis. Results showed a significant upregulation of p53 and DIAP1 mRNA expression in radiation-exposed groups compared to the control (p<0.05). Expression levels were dose- and duration-dependent, with Groups C and E (14-day exposures) exhibiting the highest increases. Gel electrophoresis and bar chart analyses further confirmed these findings, demonstrating progressive changes consistent with prolonged radiation stress. These results indicate that even low-dose diagnostic radiation can induce molecular alterations in stress- and apoptosis-related genes in Drosophila melanogaster. The study underscores the utility of Drosophila as a model organism for assessing radiation-induced genetic responses and highlights the need for further research into the implications of cumulative diagnostic radiation exposure.

Diagnostic radiation (X-rays, CT scans) generates reactive oxygen species and DNA damage, affecting apoptotic gene expression in Drosophila melanogaster, a model for cellular responses. Effector caspases DrICE and Dcp-1 regulate apoptosis under stress. The aim of this study was to assess the effect of acute (X-ray) and chronic (CT room) radiation over 7 and 14 days on DrICE and Dcp-1 mRNA expression in Drosophila. The flies were divided into 4 groups; X ray exposure (7days), X ray exposure (14days), CT room exposure (7days), CT room exposure (14days). DrICE and Dcp-1 mRNAs expression were determined using Polymerase chain reaction. The data obtained was analyzed using graphpad prism (version 8.02, California, USA). The result showed that DrICE mRNA increased significantly (p<0.001) in all exposure groups (X-ray/CT room, 7/14 days) when compared to the control (66.16± 0.31), but decreased (p<0.01) in CT room at 14 days (75.84± 2.17) when compared to X-ray (14 days) (83.29± 1.14) and CT room (7 days)(86.18±1.84). Dcp-1 mRNA showed no significant change (p>0.05) with X-ray (7/14 days) when compared to the control, but decreased (p<0.01) in CT room at 14 days ( 57.16±2.37) when compared to control (71.29±1.13) and X-ray 7 and 14 days ( 74.51±2.66 and 69.06±1.72) with a milder drop (p<0.05) at 7 days(61.48±1.15). In conclusion, DrICE upregulation shifts to suppression under chronic CT exposure, indicating an adaptive response. Dcp-1 stability under X-ray contrasts with CT suppression, showing dose-rate effects. This suggests radiation modulates apoptosis, with potential for pest control, needing further protein studies.