Researchers found the genes that code for the MagR and Cry proteins in the retinas of pigeons.WIKIMEDIA, TU7UHA variety of different animal species possess remarkable navigational abilities, using the Earth’s magnetic field to migrate thousands of miles every year or find their way home with minimal or no visual cues. But the biological mechanisms that underlie this magnetic sense have long been shrouded in mystery. Researchers in China may have found a tantalizing clue to the navigational phenomenon buried deep in the fruit fly genome. The team, led by biophysicist Can Xie of Peking University, discovered a polymer-like protein, dubbed MagR, and determined that it forms a complex with a photosensitive protein called Cry. The MagR/Cry protein complex, the researchers found, has a permanent magnetic moment, which means that it spontaneously aligns in the direction of external magnetic fields. The results were published today (November 16) in Nature Materials.
“This is the only known protein complex that has a permanent magnetic moment,” said Peter Hore, a physical chemist at the University of Oxford, U.K., who was not involved in the research. “It’s a remarkable discovery.”
Xie and his colleagues called upon long-standing biochemical models that sought to explain animals’ magnetic sense to initiate the search for a physical magnetoreceptor. One of these involves molecules that incorporate oxides of iron in their structure and another involves Cry, which is known to produce radical pairs in some magnetic fields. “However, this only proved that Cry plays a critical role in the magnetoreptive biological pathways, not necessarily that it is the receptor,” Xie wrote in an email to The Scientist. “We believe there [are] such universal magnetosensing ...
