Sheppard, D.M., Li, J., Henbest, K.B., Neil, S.R., Maeda, K., Storey, J., Schleicher, E., Biskup, T., Rodriguez, R., Weber, S., Hore, P.J., Timmel, C.R., Mackenzie, S.R. (2017). Millitesla magnetic field effects on the photocycle of an animal cryptochrome.  Sci. Rep. 7(): 42228.

FBrf0234789

Research paper

Drosophila have been used as model organisms to explore both the biophysical mechanisms of animal magnetoreception and the possibility that weak, low-frequency anthropogenic electromagnetic fields may have biological consequences. In both cases, the presumed receptor is cryptochrome, a protein thought to be responsible for magnetic compass sensing in migratory birds and a variety of magnetic behavioural responses in insects. Here, we demonstrate that photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome are indeed influenced by magnetic fields of a few millitesla. The form of the protein containing flavin and tryptophan radicals shows kinetics that differ markedly from those of closely related members of the cryptochrome-photolyase family. These differences and the magnetic sensitivity of Drosophila cryptochrome are interpreted in terms of the radical pair mechanism and a photocycle involving the recently discovered fourth tryptophan electron donor.

PMC5296725 (PMC) (EuropePMC)