Cashmore A R, Jarillo J A, Wu Y J, Liu D
Plant Science Institute, Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6018, USA.
Science. 1999 Apr 30;284(5415):760-5. doi: 10.1126/science.284.5415.760.
Cryptochromes are blue, ultraviolet-A photoreceptors. They were first characterized for Arabidopsis and are also found in ferns and algae; they appear to be ubiquitous in the plant kingdom. They are flavoproteins similar in sequence to photolyases, their presumptive evolutionary ancestors. Cryptochromes mediate a variety of light responses, including entrainment of circadian rhythms in Arabidopsis, Drosophila, and mammals. Sequence comparison indicates that the plant and animal cryptochrome families have distinct evolutionary histories, with the plant cryptochromes being of ancient evolutionary origin and the animal cryptochromes having evolved relatively recently. This process of repeated evolution may have coincided with the origin in animals of a modified circadian clock based on the PERIOD, TIMELESS, CLOCK, and CYCLE proteins.
隐花色素是蓝光、紫外光-A光感受器。它们最初是在拟南芥中被鉴定出来的，在蕨类植物和藻类中也有发现；它们似乎在植物界广泛存在。它们是黄素蛋白，其序列与光解酶相似，光解酶被认为是它们推测的进化祖先。隐花色素介导多种光反应，包括拟南芥、果蝇和哺乳动物中昼夜节律的同步。序列比较表明，植物和动物的隐花色素家族有不同的进化历史，植物隐花色素起源于古老的进化时期，而动物隐花色素则是相对较近才进化出来的。这种反复进化的过程可能与基于周期蛋白、无时间蛋白、生物钟蛋白和周期蛋白的改良生物钟在动物中的起源同时发生。
