BDE-99 Disrupts the Photoreceptor Patterning of Zebrafish Larvae via Transcription Factor .

Proper visual function is essential for collecting environmental information and supporting the decision-making in the central nervous system and is therefore tightly associated with wildlife survival and human health. Polybrominated diphenyl ethers (PBDEs) were reported to impair zebrafish vision development, and thyroid hormone (TH) signaling was suspected as the main contributor. In this study, a pentabrominated PBDE, BDE-99, was chosen to further explore the action mechanism of PBDEs on the disruption of zebrafish color vision. The results showed that BDE-99 could impair multiple photoreceptors in the retina and disturb the behavior guided by the color vision of zebrafish larvae at 120 h post-fertilization. Although the resulting alteration in photoreceptor patterning highly resembled the effects of 3,3',5-triiodo-l-thyroine, introducing the antagonist for TH receptors was unable to fully recover the alteration, which suggested the involvement of other potential regulatory factors. By modulating the expression of , a key inducer of middle-wavelength opsins, we demonstrated that , not THs, dominated the photoreceptor patterning in the disruption of BDE-99. Our work promoted the understanding of the regulatory role of in the process of photoreceptor patterning and proposed a novel mechanism for the visual toxicity of PBDEs.