Expression patterns of cryptochrome genes in avian retina suggest involvement of Cry4 in light-dependent magnetoreception
The light-dependent magnetic compass of birds provides orientation information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina, and be mediated by a light-induced, biochemical radical-pair mechanism involving cryptochromes as putative receptor molecules. At the same time, cryptochromes are known for their role in the negative feedback loop in