https://espresso.economist.com/cd50a6640d6284992905dc447fd7701d
Feb 2nd 2019

Falling asleep in your genes: biology

• fall asleep 入睡
• gene 基因
• biology 生物学

Humans spend around a third of their lives asleep.

• around 大约
• spend ... doing sth. 花费的

But the molecular and genetic mechanisms that control sleepiness are mysteries.

• molecular 分子的
• mystery 神秘（的事/东西）

Now researchers have shown that a gene called nemuri could be one of the main drivers.

In a study on fruit flies, neuroscientists at the University of Pennsylvania found that when they suppressed the activity of this gene, the flies woke up easily and had difficulty sleeping.

• fruit flies 果蝇

Conversely, when they ramped up nemuri’s activity, the flies effortlessly entered the land of nod. Intriguingly nemuri, which encodes a small protein secreted by brain cells, was also shown to help the flies fight off bacterial infections.

• ramp up 上升；增加；提高
• Intriguingly 有迷惑力地
• protein 蛋白质
• brain cell 脑细胞
• fight off 击退；排斥；竭力摆脱
• fight off a cold 治好感冒
• bacterial infection 细菌感染；细菌传染

It seems as though sleep is a crucial part of the body’s immune response to infection or illness.

• as though 好像
• crucial 至关重要的；关键性的
• immune response 免疫反应；免疫响应；免疫功能

Anyone sceptical of the recuperative powers of a good night’s rest now has evidence their doctors and mothers were right—sleep really does help.

• sceptical 怀疑的
• recuperative 有助于恢复的
• evidence 证据；证明；物证；根据

The results were published this week in Science.