For migratory¹ birds and sea turtles, the ability to sense the Earth's magnetic field is crucial to navigating² the long-distance voyages these animals undertake during migration³. Humans, however, are widely assumed not to have an innate⁴（先天的） magnetic sense. Research published in Nature Communications this week by faculty⁵ at the University of Massachusetts Medical School shows that a protein expressed in the human retina（视网膜） can sense magnetic fields when implanted into Drosophila, reopening an area of sensory⁷ biology in humans for further exploration. In many migratory animals, the light-sensitive chemical reactions involving the flavoprotein（黄素蛋白） cryptochrome (CRY) are thought to play an important role in the ability to sense the Earth's magnetic field. In the case of Drosophila, previous studies from the Reppert laboratory (http://reppertlab.org/) have shown that the cryptochrome protein found in these flies can function as a light-dependent magnetic sensor⁶.

To test whether the human cryptochrome 2 protein (hCRY2) has a similar magnetic sensory ability, Steven Reppert, MD, the Higgins Family Professor of Neuroscience and chair and professor of neurobiology, graduate student Lauren Foley, and Robert Gegear, PhD, a post doctoral fellow in the Reppert lab now an assistant professor of biology and biotechnology at Worcester Polytechnic⁸ Institute, created a transgenic Drosophila model lacking its native cryptochrome protein but expressing hCRY2 instead. Using a behavioral system Reppert's group previously⁹ developed, they showed that these transgenic flies were able to sense and respond to an electric-coil-generated magnetic field and do so in a light-dependent manner.

These findings demonstrate that hCRY2 has the molecular¹⁰ capability¹¹ to function in a magnetic sensing system and may pave the way for further investigation¹² into human magnetoreception. "Additional research on magneto（磁发电机） sensitivity in humans at the behavioral level, with particular emphasis on the influence of magnetic field on visual function, rather than non-visual navigation, would be informative," wrote Reppert and his colleagues in the study.