Transcriptomic Insights into Micro- and Nanoplastic Toxicity in Zebrafish: A Narrative Review.

Micro- and nanoplastics (MNPs) are emerging global pollutants that pose a significant threat to living organisms due to their widespread presence, ingestion by aquatic species, and ability to cross biological barriers, including the blood-brain barrier. Zebrafish is a well-established and convenient model for ecotoxicological research because of its small size, optical transparency, fully sequenced genome, high genetic homology to humans, ease of breeding, and short life cycle. Exposure to MNPs affects multiple organ systems in zebrafish, including the brain, eyes, liver, intestine, gills, and reproductive system. These particles can induce oxidative stress, inflammation, and interference with diverse biomolecules, leading to adverse biological effects. An analysis of transcriptomic alterations induced by MNPs exposure can contribute to understanding the mechanisms of these adverse effects. In this narrative review, we classify existing studies on MNPs exposure in zebrafish by affected organ system and summarize the gene expression-based evidence of MNP-induced toxicity with a particular focus on high-throughput approaches such as RNA sequencing and single-cell RNA sequencing.