1. Essential elements of radical pair magnetosensitivity in Drosophila.
- Author
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Bradlaugh AA, Fedele G, Munro AL, Hansen CN, Hares JM, Patel S, Kyriacou CP, Jones AR, Rosato E, and Baines RA
- Subjects
- Animals, Flavin-Adenine Dinucleotide metabolism, Tryptophan metabolism, Electrophysiology, Behavior, Animal, Single-Cell Analysis, Neurons cytology, Neurons metabolism, Cryptochromes chemistry, Cryptochromes metabolism, Drosophila melanogaster chemistry, Drosophila melanogaster cytology, Drosophila melanogaster metabolism, Drosophila melanogaster physiology, Magnetic Fields
- Abstract
Many animals use Earth's magnetic field (also known as the geomagnetic field) for navigation
1 . 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., (© 2023. The Author(s).)- Published
- 2023
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