Acute exposure to DE‐71 causes alterations in visual behavior in zebrafish larvae

Abstract

Polybrominated diphenyl ethers (PBDEs) cause neurobehavioral toxicity, but their effects on visual behavior remain unknown. In the present study, the impact of PBDEs on visual behavior was examined using optokinetic responses and phototaxis in zebrafish larvae. Zebrafish embryos were exposed to pentabrominated diphenyl ethers mixture (DE-71) at concentrations of 0, 0.32, 3.58, and 31.0 mg/L until 15 d postfertilization. The authors then assessed photoreceptor opsin expression, retinal histology, and visual behavior of the larvae. The results showed that the transcriptions of the opsin genes, zfrho and zfgr1, were significantly upregulated. Western blotting further demonstrated a significant increase in rhodopsin protein expression after exposure of the larvae to DE-71. Histological examination revealed the following morphological alterations in the retina: increased area of inner nuclear layer, decreased area of inner plexiform layer, and decreased density of ganglion cells. Tests of optokinetic and phototactic behavior showed hyperactive responses on exposure to DE-71, including increased saccadic eye movements and phototactic response. The present study is the first to demonstrate that the acute exposure of zebrafish larvae to DE-71 causes biochemical and structural changes in the eye that lead to behavioral alterations. Analysis of these visual behavioral paradigms may be useful in predicting the adverse effects of toxicants on visual function in fish. Environ Toxicol Chem 2013;32:1370-1375. # 2013 SETAC

The PBDE metabolite 6-OH-BDE 47 affects melanin pigmentation and THRβ MRNA expression in the eye of zebrafish embryos

“…37 Alterations in layers of the zebrafish retina were also observed following exposure to DE-71, a commercial PBDE mixture. 38 Therefore, this data plus our findings appear to be a link between THR expression/activity and retinal development in various vertebrate species, including zebrafish.…”

“…12 Others used transient transfection assays, 37,38 and showed that several PBDE congeners (BDE-100, BDE-153, BDE-154, BDE-209, and DE-71) but not BDE-99, BDE-47, or 6-OH-BDE 47 suppressed THR-mediated transcription in CV-1 monkey fibroblast-derived cells. Furthermore, this group suggested that PBDE congeners might disrupt normal brain development.…”

The neurotoxicity of DE‐71: effects on neural development and impairment of serotonergic signaling in zebrafish larvae

“…For PBDE analysis,~100 larvae (5 dpf; n = 3 replicates) from each group were washed five times and randomly sampled for extraction according to a previous study (Chen et al, 2013b). The samples were weighed and freeze-dried, then 5 ng 13 C 12 -labeled BDE-139 was added as recovery spike.…”

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

“…4D), which would affect the transparency of the lens and cornea in the development and function of the eyes (Jester, 2008). A previous acute study on the combined effects of BDE-209 and Pb also reported a synergistic effect on the expressions of crystalline genes in zebrafish larvae (Chen et al, 2016a), thus identifying the eye as a target tissue for ewaste contaminants (Chen et al, 2013;Xu et al, 2015). In the present study, altered abundances of muscular proteins were observed in the proteomic profiles of the larval offspring, which might disassemble the myofibril structure and muscle development, eventually leading to lethargic swimming performance by zebrafish larvae (Chen et al, 2012d;Wang et al, 2014;Zhu et al, 2016).…”