Human cryptochrome exhibits light-dependent magnetosensitivity

Humans are not believed to have a magnetic sense, even though many animals use the Earth's magnetic field for orientation and navigation. One model of magnetosensing in animals proposes that geomagnetic fields are perceived by light-sensitive chemical reactions involving the flavoprotein cryptochrome (CRY). Here we show using a transgenic approach that human CRY2, which is heavily expressed in the retina, can function as a magnetosensor in the magnetoreception system of Drosophila and that it does so in a light-dependent manner. The results show that human CRY2 has the molecular capability to function as a light-sensitive magnetosensor and reopen an area of sensory biology that is ready for further exploration in humans. In animals, cryptochrome proteins are thought to be the detectors of the Earth's magnetic field, but humans have not been shown to posess mangetosensing capabilities. Foleyet al. demonstrate that the human cryptochrome protein, CRY2, when expressed in Drosophila melanogastercan mediate magnetoreception in a light-dependent manner.