Maternal exposure to nanoplastic induces transgenerational toxicity in the offspring of rotifer Brachionus koreanus.

Nanoplastics have received a great deal of attention as evidence of their potential harmful effects on aquatic biota. In zooplankton, ingestion is known as a major uptake route of nanoplastics due to the low feeding selectivity of filter-feeding organisms. In this study, we propose maternal transfer as an alternative uptake route of nanoplastic in the rotifer Brachionus koreanus. Exposure to nanoplastics in parental rotifers induced maternal transfer in offspring, as revealed by fluorescence in rotifer eggs. We further verified that egg shells are not permeable to nanoplastics, and the observed fluorescence was associated with nanoplastic particles, not leached fluorescent dye, supporting the idea that nanoplastics can be transferred through an intrinsic maternal transfer route. This maternal transfer induced adverse effects on life-cycle parameters, including development and reproduction, in offspring rotifers, and was associated with oxidative stress. The results of this study shed light on the ecological impacts of nanoplastics in marine environments.