Zebrafish methanol exposure causes patterning defects and suppressive cell proliferation in retina.

Purpose: Methanol exposure have been shown to produce retinal abnormalities and visual dysfunctions in rodents and other mammals developing . In this study, we characterized how methanol affects the retinal development in an embryonic system, the zebrafish.

Methods: Zebrafish embryos were raised for 24 hours in fish water supplemented with various concentrations of methanol at 6 hours after fertilisation. The effects of methanol on retinal morphology were assessed by histologic and immunohistochemical analyses.

Results: Zebrafish embryos exposed to moderate (3%) and high (4%) levels of methanol during early embryonic development had a small eye phenotype. Embryos exposed to high (4%) level of methanol had morphological abnormalities of the retinal pigment epithelia and the photoreceptors. Methanol exposure also caused inhibition of cell differentiation and proliferation in the retina at the early developmental stage.

Conclusions: Low concentrations of methanol affect photoreceptor function but do not disturb retinal morphology. Higher levels of methanol exposure cause retinal patterning defects and a small eye phenotype.