Cryptochrome-dependent magnetoreception in heteropteran insect continues even after 24 hours in darkness
Sensitivity to magnetic fields is dependent on the intensity and color of light in several animal species. The of light-dependent magnetoreception working model points to Cryptochrome (Cry) as a protein able to cooperate with its cofactor flavin, which possibly becomes a magnetically susceptible pair upon excitation by light. What type of Cry is involved as well as what pair of magnetosensitive radicals are responsible is still elusive. Therefore, we developed a conditioning assay for the firebug (the firebug) Pyrrhocoris apterus, an insect species that possesses only the mammalian Cryptochrome (Cry II). Here, using the engineered Cry II null mutant, we show that: i) vertebrate-like Cry II is an essential component of the magnetoreception response, and ii) magnetic conditioning continues even after 25 hours in darkness. The light-dependent and dark-persisting magnetoreception based on Cry II may inspire new perspectives in magnetoreception and Cryptochrome research.