Chronic environmental temperature affects protein expression in the eye of adult zebrafish (Danio rerio)

Vision in vertebrates is mediated by the eye, a complex organ with developmental and functional similarities to the central nervous system. Eye proteomics has emerged as a powerful tool for investigating ocular function and disease mechanisms, including neurodegeneration and ocular toxicity. The zebrafish (Danio rerio) is a well-established model in biomedical research, including ophthalmology, due to its highly developed visual system, rapid eye maturation, and genetic homology with humans. Building on previous findings that thermal stress can affect neural tissues, this study investigates whether prolonged exposure to non-optimal temperatures also impacts the zebrafish eye proteome. Adult zebrafish were maintained for 21 days at elevated (34 °C), control (26 °C), or low (18 °C) temperatures, and eye proteomes were analysed by tandem mass spectrometry. Our results reveal that both low and high temperatures induce distinct alterations in the expression of proteins involved in critical eye processes. Notably, high-temperature exposure modulates pathways such as sirtuin signalling while downregulating proteins involved in oxidative phosphorylation, electron transport, and ATP synthesis, alongside decreased expression of proteins central to visual phototransduction. These data indicate that environmental temperature can directly impact eye protein homeostasis, supporting a potential role for the thermal stress in ocular dysfunction.