Deep learning-driven behavioral analysis reveals adaptive responses in Drosophila offspring after long-term parental microplastic exposure

Microplastics are widely distributed in the environment and pose potential hazards to organisms. However, our understanding of the transgenerational effects of microplastics on terrestrial organisms remains limited. In this study, we focused on the model organism Drosophila melanogaster. We exposed parental flies to polystyrene microplastics (PS-MPs) continuously and collected offspring larvae at different time points (day 2, day 8, day 14). We then employed deep learning techniques to track and analyze the behavior of the offspring larvae to assess the transgenerational effects of PS-MPs on fruit flies. First, we observed a decline in the mobility of offspring larvae as parental flies aged under non-PS-MP exposure conditions. Second, acute exposure of parental flies to PS-MPs did not result in significant transgenerational effects, but after long-term exposure, offspring larvae showed increased crawling speed and decreased crawling angular velocity, indicating enhanced locomotor ability compared to the control group. This suggests that long-term exposure of parental flies to PS-MPs may help offspring adapt to new environments. Our findings not only support the hypothesis of adaptive parental effects, where parents facing environmental pressure challenges may foster offspring better adapted to the environment, but also provide new insights into the transgenerational effects of PS-MPs on terrestrial organisms.