2011.12英语六级阅读：眼睛磁场感应力

文章作者 100test 发表时间 2011:07:21 20:26:52
来源 100Test.Com百考试题网

　　2011.12英语六级考试阅读:眼睛磁场感应力
　　Birds and sea turtles can migrate thousands of miles， by reading the Earth’s magnetic cues. But we too might have magnetic sensing abilities—in our eyes. So says a study in the journal Nature Communications. ［Lauren Foley， Robert Gegear and Steven Reppert， “Human Cryptochrome Exhibits Light-Dependent Magnetosensitivity”］
　　Previous studies suggest long-distance migrators—and even fruit flies—pick up magnetic fields with the help of a light-sensitive protein called “cryptochrome.” We produce cryptochrome too—without it， our circadian clocks would break. Human cryptochrome doesn‘t require light to function， though—and it doesn’t seem to give us a phenomenal sensitivity to magnetic fields. But can it do more than keep the circadian clock ticking？来源：百考试题百考试题成就你的梦想
　　To find out， researchers took out fruit flies‘ usual cryptochrome gene and inserted the human version. And the transgenic flies had no problem navigating a magnetic maze when exposed to light—indicating the human protein can still serve as a light-sensitive magnetic sensor.
　　We happen to have a lot of cryptochrome in our retinas—ideally situated to receive light. Which suggests we might be able to see magnetic fields in some way. On the other hand， evolution might have just given cryptochrome a new job in new organisms. So don’t throw away your GPS.