id_958. EFFECT OF LIGHT POLLUTION ON RETINAL AGEING IN THE DROSOPHILA MELANOGASTER MODEL
Monika Mitka1,2, Kinga Skoczek1,2, Milena Damulewicz1
1 Jagiellonian University, Institute of Zoology and Biomedical Research, Department of Cell Biology and Imaging, 9 Gronostajowa St., Kraków, Poland
2 Jagiellonian University, Doctoral School of Exact and Natural Sciences, 11 Łojasiewicza St., Cracow, Poland
INTRODUCTION: Artificial light at night (ALAN), a major component of light pollution, has emerged as a global environmental issue due to its disruptive effects on biological rhythms and physiological functions. Even short-term exposure to blue light emitted by device screens, especially just before bedtime, may dysregulate circadian machinery and affect sleep. The retina is the tissue most directly exposed to light, making it highly vulnerable to continuous artificial illumination. In Drosophila, the retina has an autonomous peripheral clock that participates in the regulation of activity and sleep and can serve as a model to study age- and light-related changes in circadian mechanisms.
AIM(S): Investigating the effects of aging and light pollution on the retinal peripheral clock in Drosophila.
METHOD(S): Wild-type flies were kept under standard light conditions LD 12:12 (12 h of light and 12 h of darkness), L-dim (12 h of light and 12 h of dimmed light), and LBD (12 h of light, 1 h of blue light, and 12 h of darkness). Young (7 days) and old (30 and 60 days) males were collected at specific time points of the day, their retinas were manually dissected, and clock gene expression was analyzed using qPCR. Sleep and locomotor activity assays were performed on young (1 day) and old (30 days) flies kept under LD, L-dim, and LBD conditions. Finally, the walking optomotor response was assessed in young flies (7 days) under LD and LBD, and in old flies (30 days) under LD, LBD, and L-dim conditions.
RESULTS: Retinal ageing and different light conditions (L-dim and LBD) resulted in alterations in the daily pattern of clock gene expression. The rhythmicity of the optomotor walking response was lost in aged flies. Additionally, its accuracy was lower under L-dim conditions in aged flies. L-dim conditions also affected the pattern and quality of sleep in both young and aged flies.
CONCLUSIONS: Aging and light pollution affect the retinal peripheral clock. They also disrupt sleep patterns and quality, and impair visual motion processing.
FINANCIAL SUPPORT: NCN; 2022/47/B/NZ3/00250; Project leader: PhD Milena Damulewicz