The toxic effects of in situ exposure of a native fish species (Anabas testudineus) to electronic waste pollution

In recent decades, crude recycling of electronic waste (e-waste) has caused serious pollution and threatened wild organisms in certain regions. It is therefore valuable to investigate the pollution-induced toxic effects in situ using native fish species. Unlike the death or decline observed in other species, Anabas testudineus can better adapt to severe e-waste pollution. Using it as a model, the true status of this wild organism was revealed. We collected A. testudineus from two polluted sites (st1 and st2) and conducted transcriptome analyses of the liver, gill, and kidney. Clear whole-transcriptome differences were found between polluted and clean sites and between differentially polluted sites (st1 and st2). Pathway analysis revealed that long-term e-waste pollution would cause significant hypoxia, oxidative stress, and potentially apoptosis. Accordingly, several defensive responses were elicited including 'oxidation-reduction' and the 'unfolded protein response'. Certain biological processes, including 'DNA repair' and 'endoplasmic reticulum stress response', were altered in a tissue- or burden-specific pattern suggesting transcriptome plasticity in response to distinct burdens. This study revealed the toxic impacts of e-waste pollution on wild organisms using a native fish species. Additionally, due to its highly adaptive nature, A. testudineus could be a suitable test species for such severe conditions in the wild or otherwise.