Cryptochrome-dependent magnetoreception in a heteropteran insect continues even after 24 h in darkness

Sensitivity to magnetic fields is dependent on the intensity and color of light in several animal species. The light-dependent magnetoreception working model points to cryptochrome (Cry) as a protein cooperating with its co-factor flavin, which possibly becomes magnetically susceptible upon excitation by light. The type of Cry involved and what pair of magnetosensitive radicals are responsible is still elusive. Therefore, we developed a conditioning assay for 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 h in darkness. The light-dependent and dark-persisting magnetoreception based on Cry II may inspire new perspectives in magnetoreception and cryptochrome research.

Automated summary

Sensitivity to magnetic fields in certain animal species is influenced by the intensity and color of light, with cryptochrome and its co-factor flavin potentially becoming magnetically susceptible upon excitation by light. Research on the firebug species Pyrrhocoris apterus, which only possesses mammalian cryptochrome II, has shown that Cry II is essential for the magnetoreception response, which continues even after extended periods in darkness. This light-dependent and dark-persisting magnetoreception based on Cry II could lead to new perspectives in magnetoreception and cryptochrome research.