High-throughput transcriptome sequencing reveals the combined effects of key e-waste contaminants, decabromodiphenyl ether (BDE-209) and lead, in zebrafish larvae

Transgenerational endocrine disruption and neurotoxicity in zebrafish larvae after parental exposure to binary mixtures of decabromodiphenyl ether (BDE-209) and lead

“…This contrasting changing trend of BDE-197 and the other congeners indicated that transfer of Pb to 5 dpf larvae accelerated the successive and selective removal of bromine atoms at the meta position from BDE-209 and -207 to BDE-197, but blocked the advanced debromination of BDE-197 to lower brominated congeners (e.g., BDE-100 and -47), which caused the increased accumulation of . Although previous studies demonstrated that acute exposure to Pb inhibited the uptake of BDE-209 in zebrafish larvae (Chen et al, 2016a;Zhu et al, 2014Zhu et al, , 2016 and earthworms Zhang et al, 2014), the observed blockage of bromination towards BDE-47 is consistent with current results. Interestingly, in contrast to the eggs, the concentrations of Pb in the larvae were gradually decreased with increasing concentrations of BDE-209 in the coexposure groups (M1, M10 and M100) and a significant difference was observed between the M10 group and the Pb group (Fig.…”

“…1E). In the presence of BDE-209, enhanced bioavailability of Pb in zebrafish larvae was also noted in previous acute scenarios (Chen et al, 2016a;Zhu et al, 2014Zhu et al, , 2016.…”

“…Previous studies have shown that high levels of Pb can inhibit the uptake and debromination kinetics of BDE-209 in earthworms Zhang et al, 2014) and zebrafish larvae (Chen et al, 2016a;Zhu et al, 2014Zhu et al, , 2016. Toxicological actions are also altered under coexposure scenarios via synergistic, inhibitory, or additive interactions.…”

“…A synergistic effect on developmental neurotoxicities was also initiated in zebrafish larvae by the combination of BDE-209 and Pb, as manifested by impaired neuronal growth and locomotor behavior (Zhu et al, 2016). In addition, transcriptomic profiling of acutely exposed zebrafish larvae showed both synergistic and antagonistic interactions between BDE-209 and Pb, with concerted contributions from individual toxicological behaviors (Chen et al, 2016a). Therefore, changes in their mode of action when mixed underlie our insufficient understanding of their combined toxicological effects.…”

“…After freezedrying, the dw of each sample was recorded. The samples were then digested in concentrated nitric acid using a microwave digestion system (Multiwave 3000, Anton Paar, Graz, Austria), according to previous reports (Chen et al, 2016a;Zhu et al, 2014). The extracts were further diluted using ultrapure water and measured on an ICP-MS (Perkin-Elmer, Waltham, MA, USA) for their Pb content, which was expressed as ng/g dw.…”