Transgenerational persistence of neurodevelopmental disorder-like phenotypes in Drosophila melanogaster

Neurodevelopmental disorders (NDDs) arise from complex interactions between genetic and environmental factors, and increasing evidence suggests that environmentally induced molecular changes can persist across generations. This study aimed to investigate the transgenerational effects of parental exposure to imidacloprid (IMI) in Drosophila melanogaster, focusing on behavioral phenotypes analogous to NDDs and alterations in proteins related to synaptic organization, epigenetic regulation, and mitochondrial dynamics. Male and female flies (F0) were exposed to IMI 400 ρM for seven days, and behavioral and molecular analyses were conducted in the unexposed F2 and F3 generations. Behavioral assays included negative geotaxis, open field, social interaction, aggression, and grooming tests. The immunoreactivity of SHANK, HDAC3, and MFN2 proteins was evaluated by Western blot. Parental IMI exposure induced hyperactivity and increased repetitive grooming in both F2 and F3 generations, while alterations in social interaction and aggression were restricted to F2. Molecular analyses revealed a significant reduction of SHANK and an increase in HDAC3 in F2, both returning to control levels in F3, suggesting transient transcriptional and epigenetic dysregulation. In contrast, MFN2 remained consistently reduced in both generations, indicating long-lasting mitochondrial impairment. These findings support the existence of an integrated epigenetic-mitochondrial-synaptic axis through which parental IMI exposure reprograms neuronal and metabolic pathways. Overall, Drosophila melanogaster is highlighted as a powerful model for studying non-genetic inheritance mechanisms linking environmental exposures to neurodevelopmental disturbances.