Mechanism of Bisphenol S Exposure on Color Sensitivity of Zebrafish Larvae

Color vision, initiated from cone cells, is vitally essential for identifying environmental information in vertebrate. Although the retinotoxicity of bisphenol S (BPS) has been reported, data on the influence of BPS treatment on cone cells are scarce. In the present study, transgenic zebrafish (Danio rerio) labeling red and ultraviolet (UV) cones were exposed to BPS (0, 1, 10, and 100 μg/L) during the early stages of retinal development, to elucidate the mechanism underlying its retinal cone toxicity of BPS. The results showed that 10 and 100 μg/L BPS induced oxidative DNA damage, structural damage (decreased number of ribbon synapses), mosaic patterning disorder, and altered expression of genes involved in the phototransduction pathway in red and UV cones. Furthermore, BPS exposure also caused abnormal development of key neurons (retinal ganglion cells, optic nerve, and hypothalamus), responsible for transmitting the light-electrical signal to brain, and thereby resulted in inhibition of light-electrical signal transduction, finally diminishing the spectral sensitivity of zebrafish larvae to long- and short-type light signal at 5 day post fertilization. This study highlights the cone-toxicity of environmental relevant concentrations of BPS, and clarifies the mechanism of color vision impairment induced by BPS at the cellular level, updating the understanding of visual behavior driven by environmental factors.