Vergata Chiara, Codogno Giuditta, De Russi Gaia, Frigato Elena, Lucon-Xiccato Tyrone, Cannicci Stefano, Bertolucci Cristiano, Fratini Sara
Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto Fiorentino, 50019, Italy.
Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto Fiorentino, 50019, Italy; Department of Earth and Marine Sciences, University of Palermo, Via Archirafi 22, 90123, Palermo, Italy.
Environ Pollut. 2025 Jun 16;382:126683. doi: 10.1016/j.envpol.2025.126683.
Urbanization and human activities are increasing global levels of artificial light at night (ALAN). Several studies have shown that ALAN negatively impacts animals, altering their perception, physiology, and behaviour, eventually leading to reduced fitness. ALAN also disrupts biological rhythms, affecting animals' ability to synchronize with natural cycles. There still is a critical lack of knowledge on ALAN's effects on freshwater ecosystems, which are highly threatened biodiversity hotspots. Our study aimed to understand the molecular effect of prolonged ALAN exposure in the zebrafish, a model species in this field. Using high-throughput RNA sequencing, we investigated the transcriptome-wide gene expression responses in whole brains of ALAN-exposed zebrafish. Samples were collected at four different timepoints along the day, two at daytime and two at nighttime, to identify daily changes in gene expression and metabolic pathways. A one month exposure to ALAN varied the expression of several genes and metabolic pathways, both at night, when zebrafish were directly exposed to artificial light, and during the day, at natural light conditions. The highest number of differentially expressed genes were found at the early hours of the day and at night. Overall, circadian clock genes and those related to immunity, stress response, responses to sensory stimuli, energy production, motor activity, and reproductive processes changed in expression levels. These results provide new insights into the mechanisms through which ALAN affects animal biology, suggesting broader impacts than previously recognised. To safeguard aquatic ecosystems and their biodiversity, it is paramount to mitigate light pollution.
城市化和人类活动正在增加全球夜间人工光（ALAN）水平。多项研究表明，ALAN对动物产生负面影响，改变它们的感知、生理和行为，最终导致健康状况下降。ALAN还会扰乱生物节律，影响动物与自然周期同步的能力。关于ALAN对淡水生态系统的影响，目前仍然极度缺乏相关知识，而淡水生态系统是受到高度威胁的生物多样性热点地区。我们的研究旨在了解长期暴露于ALAN对斑马鱼（该领域的一种模式物种）的分子影响。我们使用高通量RNA测序技术，研究了暴露于ALAN的斑马鱼全脑转录组范围内的基因表达反应。在一天中的四个不同时间点采集样本，白天两个时间点，夜间两个时间点，以确定基因表达和代谢途径的每日变化。暴露于ALAN一个月后，无论是在夜间斑马鱼直接暴露于人工光时，还是在白天自然光条件下，几个基因和代谢途径的表达都发生了变化。在一天的早些时候和夜间发现的差异表达基因数量最多。总体而言，昼夜节律时钟基因以及与免疫、应激反应、感觉刺激反应、能量产生、运动活动和生殖过程相关的基因的表达水平发生了变化。这些结果为ALAN影响动物生物学的机制提供了新的见解，表明其影响比之前认识到的更为广泛。为了保护水生生态系统及其生物多样性，减轻光污染至关重要。
