Behavioral changes and transcriptomic effects at embryonic and post-embryonic stages reveal the toxic effects of 2,2′,4,4′-tetrabromodiphenyl ether on neurodevelopment in zebrafish (Danio rerio)

https://doi.org/10.1016/j.ecoenv.2022.114310Get rights and content
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Highlights

  • BDE-47 affected hatching, survival, and heart rates of embryo-larvae.

  • BDE-47 exposure increased spontaneous coiling activity and decreased movement in zebrafish larvae.

  • BDE-47 interfered the metabolism of cells and tissues and neurodevelopment.

  • BDE-47 affected the genes for nervous system and axonal development.

  • BDE-47 exposure inhibited Wnt signaling pathway at embryonic stage of zebrafish.

Abstract

Polybrominated biphenyl ethers (PBDEs) are new persistent pollutants that are widely exist in the environment and have many toxic effects. However, their toxicity mechanisms on neurodevelopment are still unclear. In this study, zebrafish embryos were exposed to 2, 2′, 4, 4′-tetrabromodiphenyl ether (BDE-47) (control, 10, 50 and 100 μg/L) at 2 h postfertilization (hpf) – 7 dpf. Locomotion analysis indicated that BDE-47 increased spontaneous coiling activity in zebrafish embryos under high-intensity light stimuli and decreased locomotor in zebrafish larvae. RNA-Seq analysis revealed that most of the up-regulated pathways were related to the metabolism of cells and tissues, while the down-regulated pathways were related to neurodevelopment. Consistent with the locomotion and KEGG results, BDE-47 affected the expression of genes for central nervous system (gfap, mbpa, bdnf & pomcb), early neurogenesis (neurog1 & elavl3), and axonal development (tuba1a, tuba1b, tuba1c, syn2a, gap43 & shha). Furthermore, BDE-47 interfered with gene expression of the Wnt signaling pathway, especially during embryonic stages, suggesting that the mechanisms of BDE-47 toxicity to zebrafish at various stages of neurodevelopment may be different. In summary, early neurodevelopment effects and metabolic disturbances may have contributed to the abnormal neurobehavioral changes induced by BDE-47 in zebrafish embryos/larvae, suggesting the neurodevelopmental toxicity of BDE-47.

Keywords

BDE-47
Neurobehavior
Neurodevelopmental toxicity
Embryos
Larvae

Data Availability

Data will be made available on request.

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