Role of visual and non-visual opsins in blue light-induced neurodegeneration in Drosophila melanogaster

Frontiers in Public Health · 2025 · Harm · Low evidence

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HarmLow evidencePaper 2497

Study snapshot

PublicationFrontiers in Public Health · 2025

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Category: Neuroscience Tags: blue light, neurodegeneration, Drosophila melanogaster, opsins, DNA damage, circadian rhythms, artificial light exposure DOI: 10.3389/fpubh.2025.1644780 URL: frontiersin.org Introduction Light plays a key role in regulating circadian rhythms and downstream physiological and behavioural functions. However, excessive exposure to artificial blue light (450-500 nm) can disrupt sleep, metabolism and neural integrity. Visual opsins mediate light-dependent signalling, but organisms also express non-visual opsins whose roles in blue-light-induced neural stress are not well understood. Methods - Drosophila melanogaster knockout lines lacking either visual rhodopsin 1 (Rh11) or non-visual rhodopsin 7 (Rh71), along with wild-type (w1118) controls, were used. - Flies were continuously exposed to 488 nm blue light (1,320 lux; 1,120 μW/cm2) from egg deposition until 20 days old. - DNA damage (γ-H2Av immunostaining) and vacuole formation were quantified in brain regions related to sensory processing and neurotransmission. Results - Rh11 flies exhibited the highest levels of DNA damage and vacuolisation compared to w1118 and Rh71 lines. - Effects were most pronounced in neuropils linked to sensory integration and synaptic activity. Discussion & Conclusion Findings demonstrate that the visual opsin Rh1 plays a predominant role in blue-light-induced DNA damage and neurodegeneration in the Drosophila central nervous system. This suggests visual, rather than non-visual, opsins mediate the neurotoxic effects of artificial light exposure, highlighting a direct link between electromagnetic field exposure from blue light and neural health risk.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal

Effect directionharm

PopulationDrosophila melanogaster (wild-type w1118 and knockout lines lacking visual rhodopsin 1 (Rh1) or non-visual rhodopsin 7 (Rh7))

Sample sizeNot supplied

Exposureother · continuously from egg deposition until 20 days old

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Flies lacking visual rhodopsin 1 (Rh1) showed the highest levels of DNA damage and vacuolisation compared with wild-type (w1118) and Rh7 knockout lines after continuous 488 nm blue-light exposure. Effects were most pronounced in neuropils linked to sensory integration and synaptic activity, and the authors conclude Rh1 plays a predominant role in blue-light-induced DNA damage and neurodegeneration.

Outcomes measured

DNA damage (γ-H2Av immunostaining)
Vacuole formation / vacuolisation (neurodegeneration)
Brain-region-specific neuropil effects (sensory processing/integration, synaptic activity)

Limitations

Sample size not reported in the abstract
Animal/insect model (Drosophila); generalizability to humans not addressed in the abstract
Exposure conditions are continuous and may not reflect typical real-world light exposure patterns
Only specific opsin knockouts (Rh1, Rh7) and one wavelength/intensity condition described in the abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "other",
    "source": "artificial light exposure",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "continuously from egg deposition until 20 days old"
  },
  "population": "Drosophila melanogaster (wild-type w1118 and knockout lines lacking visual rhodopsin 1 (Rh1) or non-visual rhodopsin 7 (Rh7))",
  "sample_size": null,
  "outcomes": [
    "DNA damage (γ-H2Av immunostaining)",
    "Vacuole formation / vacuolisation (neurodegeneration)",
    "Brain-region-specific neuropil effects (sensory processing/integration, synaptic activity)"
  ],
  "main_findings": "Flies lacking visual rhodopsin 1 (Rh1) showed the highest levels of DNA damage and vacuolisation compared with wild-type (w1118) and Rh7 knockout lines after continuous 488 nm blue-light exposure. Effects were most pronounced in neuropils linked to sensory integration and synaptic activity, and the authors conclude Rh1 plays a predominant role in blue-light-induced DNA damage and neurodegeneration.",
  "effect_direction": "harm",
  "limitations": [
    "Sample size not reported in the abstract",
    "Animal/insect model (Drosophila); generalizability to humans not addressed in the abstract",
    "Exposure conditions are continuous and may not reflect typical real-world light exposure patterns",
    "Only specific opsin knockouts (Rh1, Rh7) and one wavelength/intensity condition described in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "blue light",
    "488 nm",
    "450-500 nm",
    "Drosophila melanogaster",
    "opsins",
    "rhodopsin 1 (Rh1)",
    "rhodopsin 7 (Rh7)",
    "DNA damage",
    "γ-H2Av",
    "neurodegeneration",
    "vacuolisation",
    "circadian rhythms",
    "artificial light exposure"
  ],
  "suggested_hubs": [
    {
      "slug": "blue-light",
      "weight": 0.95,
      "reason": "Study tests continuous 488 nm blue light exposure and neurodegeneration/DNA damage outcomes."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.3389/fpubh.2025.1644780
PubMed: Not supplied

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