Essential elements of radical pair magnetosensitivity in Drosophila

Abstract

Essential elements of radical pair magnetosensitivity in Drosophila Bradlaugh AA, Fedele G, Munro AL, Hansen CN, Hares JM, Patel S, Kyriacou CP, Jones AR, Rosato E, Baines RA. Essential elements of radical pair magnetosensitivity in Drosophila. Nature. 2023 Feb 22. doi: 10.1038/s41586- 023-05735-z. Abstract Many animals use Earth's magnetic field (also known as the geomagnetic field) for navigation1. The favoured mechanism for magnetosensitivity involves a blue-light-activated electron-transfer reaction between flavin adenine dinucleotide (FAD) and a chain of tryptophan residues within the photoreceptor protein CRYPTOCHROME (CRY). The spin-state of the resultant radical pair, and therefore the concentration of CRY in its active state, is influenced by the geomagnetic field2. However, the canonical CRY-centric radical-pair mechanism does not explain many physiological and behavioural observations2-8. Here, using electrophysiology and behavioural analyses, we assay magnetic-field responses at the single-neuron and organismal levels. We show that the 52 C-terminal amino acid residues of Drosophila melanogaster CRY, lacking the canonical FAD-binding domain and tryptophan chain, are sufficient to facilitate magnetoreception. We also show that increasing intracellular FAD potentiates both blue-light-induced and magnetic-field-dependent effects on the activity mediated by the C terminus. High levels of FAD alone are sufficient to cause blue-light neuronal sensitivity and, notably, the potentiation of this response in the co-presence of a magnetic field. These results reveal the essential components of a primary magnetoreceptor in flies, providing strong evidence that non-canonical (that is, non-CRY-dependent) radical pairs can elicit magnetic-field responses in cells. Open access paper: nature.com

AI evidence extraction

Main findings

Using electrophysiology and behavioural analyses, the authors report magnetic-field responses at single-neuron and organismal levels in Drosophila. They report that the 52 C-terminal amino acids of Drosophila CRY (lacking the canonical FAD-binding domain and tryptophan chain) are sufficient to facilitate magnetoreception, and that increasing intracellular FAD potentiates blue-light-induced and magnetic-field-dependent effects; high FAD alone is reported to be sufficient to cause blue-light neuronal sensitivity and potentiation in the co-presence of a magnetic field.

Outcomes measured

• Single-neuron electrophysiological magnetic-field responses
• Organismal/behavioural magnetic-field responses
• Blue-light-induced neuronal sensitivity
• Magnetic-field-dependent modulation/potentiation of neuronal activity
• Role of CRYPTOCHROME (CRY) C-terminal residues and intracellular FAD in magnetoreception

Limitations

• No magnetic-field exposure parameters (strength, waveform, frequency) are provided in the abstract
• Sample size and detailed methods are not provided in the abstract
• Outcomes are mechanistic/physiological and behavioural in flies; human health relevance is not addressed in the abstract

{
    "study_type": "animal",
    "exposure": {
        "band": null,
        "source": "geomagnetic field",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Drosophila melanogaster (flies)",
    "sample_size": null,
    "outcomes": [
        "Single-neuron electrophysiological magnetic-field responses",
        "Organismal/behavioural magnetic-field responses",
        "Blue-light-induced neuronal sensitivity",
        "Magnetic-field-dependent modulation/potentiation of neuronal activity",
        "Role of CRYPTOCHROME (CRY) C-terminal residues and intracellular FAD in magnetoreception"
    ],
    "main_findings": "Using electrophysiology and behavioural analyses, the authors report magnetic-field responses at single-neuron and organismal levels in Drosophila. They report that the 52 C-terminal amino acids of Drosophila CRY (lacking the canonical FAD-binding domain and tryptophan chain) are sufficient to facilitate magnetoreception, and that increasing intracellular FAD potentiates blue-light-induced and magnetic-field-dependent effects; high FAD alone is reported to be sufficient to cause blue-light neuronal sensitivity and potentiation in the co-presence of a magnetic field.",
    "effect_direction": "unclear",
    "limitations": [
        "No magnetic-field exposure parameters (strength, waveform, frequency) are provided in the abstract",
        "Sample size and detailed methods are not provided in the abstract",
        "Outcomes are mechanistic/physiological and behavioural in flies; human health relevance is not addressed in the abstract"
    ],
    "evidence_strength": "insufficient",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "magnetosensitivity",
        "geomagnetic field",
        "radical pair mechanism",
        "cryptochrome",
        "CRY",
        "FAD",
        "blue light",
        "Drosophila melanogaster",
        "electrophysiology",
        "behaviour"
    ],
    "suggested_hubs": []
}

Comments

Log in to comment.

No comments yet.