Cryptochromes (CRY) are blue light photoreceptors that mediate a variety of blue light-induced responses in plants and animals.Cryptochromes typically have an N-terminal PHR (photolyase related) domain that shares sequence similarity with photolyase, a family of flavoproteins that catalyzes the repair of UV light-damaged DNA, and a distinguishing C-terminal domain that is absent in photolyase and has no strong sequence similarity with any known protein domain.