Effects of ZnFe₂O₄ Nanoparticles on Development and Rhythmic Behavior of Drosophila melanogaster

Objectives: This study planned to determine the biological effects associated with ZnFe₂O₄-NPs exposure using Drosophila melanogaster as an in vivo model. Methods: ZnFe₂O₄-NPs were hydrothermally synthesized, and the development of offspring flies were evaluated via dietary exposure to different doses of ZnFe₂O₄-NPs (0, 200, 400, 600 μg/mL). Rhythmic behaviors of parent male flies were monitored. Results: Internalization of ZnFe₂O₄-NPs through the intestinal barrier occurred. Oral intake of ZnFe₂O₄-NPs decreased the eclosed adult numbers and perturbed the insect developmental process. In male flies, significant upregulation of HSPs and Turandot family genes was detected, accompanied by ROS reduction and suppressed antioxidant defense responses, and exposure of ZnFe₂O₄-NPs disrupted sleep patterns of males, including a reduction in sleep duration and aggravation of sleep fragmentation. Suppressed activity levels were also found after ZnFe₂O₄-NPs exposure. Significant increased expressions of circadian genes (Clk and Cyc) were detected, alongside elevation of neurotransmitter levels and related gene expressions. Conclusions: Overall, ZnFe₂O₄-NPs can perturb development process via inducing heat shock and detoxification response, and disrupted rhythmic behaviors may be attributed to elevation of neurotransmitter levels and upregulated gene expressions of circadian genes. Our findings may offer valuable insights for evaluating ecological risks of metal-based nanoparticles and suggest potential applications in developing novel pest management strategies by utilizing insect behavioral and physiological responses to nanomaterials.