白天時(shí)間不夠用，晚上睡眠不好？但現(xiàn)實(shí)生活中，確實(shí)有些人每天睡眠時(shí)間很短，卻精神飽滿。為什么有些人每天只需要睡4、5個(gè)小時(shí)？這其實(shí)是由基因決定的。

A genetic mutation that allows people to feel fully rested with fewer than six hours sleep a night has been identified by studying a family who get by on less than average. It is the second such finding in recent months.

科學(xué)家通過對(duì)一個(gè)家庭的研究，發(fā)現(xiàn)了一種可以使人在每晚睡眠不足6小時(shí)的情況下得到充分休息的基因突變。這個(gè)家庭的成員每日睡眠時(shí)長(zhǎng)低于平均水平。這是近幾個(gè)月來第二個(gè)針對(duì)這一問題的同類發(fā)現(xiàn)。

Ying-Hui Fu at the University of California, San Francisco, and her colleagues have been seeking out and studying families in which some people seem to need less sleep than normal. They have been looking for the gene variants that might be responsible, and genetically engineering these variants into mice to confirm their effect.

加州大學(xué)舊金山分校的傅嫈惠和她的同事們一直在尋找和研究那些所需睡眠少于平均水平的家庭。他們一直在尋找可能起作用的基因變異，并通過基因技術(shù)將這些變異的基因植入老鼠體內(nèi)以證實(shí)其作用。

Her team has found several mutations make people need less sleep. In August, Fu’s team reported that a mutation in a gene called ADRB1 allows 12 members of a family to sleep as little as 4.5 hours per night without feeling tired. This gene codes for a receptor protein common in a brain region called the dorsal pons, known to regulate sleep.

她的團(tuán)隊(duì)已經(jīng)發(fā)現(xiàn)了幾種基因突變會(huì)使人們需要更少的睡眠。今年8月，傅嫈惠的研究小組報(bào)告稱，ADRB1基因突變使一個(gè)家庭的12名成員每晚只睡4.5小時(shí)而不會(huì)感到疲勞。這種基因?yàn)橐环N受體蛋白編碼，這種蛋白在大腦中的腦橋背側(cè)區(qū)域很常見，這一區(qū)域負(fù)責(zé)調(diào)節(jié)睡眠。

mutation [mju??te??n]：n. 突變；變化

Now the team has found a mutation in a gene called NPSR1 in another family in which some people report feeling fully rested after much less sleep than average. Of the two members of this family whose sleep habits they studied, one averaged 5.5 hours a night and the other just 4.3 hours.

現(xiàn)在，研究小組在另一個(gè)家庭中發(fā)現(xiàn)了NPSR1基因突變，一些家庭成員報(bào)告說，他們?cè)谒邥r(shí)間遠(yuǎn)遠(yuǎn)少于平均水平的情況下，仍然感到精力充沛。他們研究了其中兩名家庭成員的睡眠習(xí)慣，一人平均每晚睡5.5小時(shí)，另一人僅睡4.3小時(shí)。

NPSR1 codes for a protein receptor in the brain known to be involved in arousal and sleep behaviour. When the team engineered the mutation into mice, they slept less without any obvious effect on health or memory.

NPSR1基因?yàn)榇竽X中一種參與覺醒和睡眠行為的蛋白質(zhì)受體編碼。當(dāng)研究小組把這種突變基因植入老鼠體內(nèi)時(shí)，它們的睡眠時(shí)間減少了，但對(duì)健康和記憶力沒有明顯影響。

Another variation in NPSR1 has previously been linked to people requiring 20 minutes less sleep than average, based on studies of tens of thousands of people.

此前針對(duì)上萬人的研究發(fā)現(xiàn)，NPSR1基因的另一種變異與所需睡眠時(shí)間比平均少20分鐘的人有關(guān)。

On average, people need 8 hours sleep a night. In most people, sleeping less than 6 hours a night results in a marked decline in cognitive abilities within days. Over long periods, sleep deprivation can contribute to many disorders, including obesity, heart disease, high blood pressure, diabetes and depression.

平均而言，人們每晚需要8小時(shí)的睡眠。對(duì)大多數(shù)人來說，每晚睡眠不足6小時(shí)會(huì)導(dǎo)致認(rèn)知能力在幾天內(nèi)顯著下降。長(zhǎng)時(shí)間缺乏睡眠會(huì)導(dǎo)致許多疾病，包括肥胖、心臟病、高血壓、糖尿病和抑郁癥。

sleep deprivation：睡眠不足

As far as Fu’s team has been able to tell, however, people who sleep less because they have one of these gene variants are healthy and don’t appear to suffer any ill effects. However, to be absolutely sure would require long-term studies involving large numbers of people, which isn’t feasible.

然而，就傅嫈惠的研究小組所知，那些因?yàn)閾碛羞@些基因變異而睡眠較少的人是健康的，而且似乎沒有任何不良影響。但要想完全確定，就需要進(jìn)行涉及大量人群的長(zhǎng)期研究，這是不可行的。

“Right now, we cannot say for sure,” says Fu.

傅嫈惠說：“現(xiàn)在，我們還不太肯定?！?/p>

In theory, if these gene variants provided a big advantage, evolution should have made them common – yet they appear to be rare. It might be, say, that sleeping less only became an advantage after the development of lights. But other advantageous gene variants that appeared only recently in human history, such as those allowing adults to digest milk, became widespread very rapidly.

從理論上講，如果這些基因變異提供了一個(gè)巨大的優(yōu)勢(shì)，進(jìn)化應(yīng)該會(huì)使它們變得普遍，但目前看來還很罕見。這可能是因?yàn)?，少睡覺只是在燈光發(fā)明之后才成為一種優(yōu)勢(shì)。但是其他有利的基因變異，比如那些允許成年人消化牛奶的基因變異，在人類歷史上只是最近才出現(xiàn)的，卻迅速傳播開來。

It might be possible to develop drugs that mimic the effects of these mutations. However, as NPSR1 is also involved in processes such as stress, anxiety and fear, there is a risk of nasty side effects.

研究人員能夠開發(fā)模仿這些基因突變的藥物，但由于NPSR1基因也與壓力、焦慮和恐懼等情緒有關(guān)，因此有可能導(dǎo)致嚴(yán)重的副作用。

Expect more reports soon. Fu say her team has already discovered more sleep-shortening mutations.

我們期待不久之后能有更多的報(bào)道。傅嫈惠說，她的團(tuán)隊(duì)已經(jīng)發(fā)現(xiàn)了更多與睡眠時(shí)間短有關(guān)的基因突變。

英文來源：newscientist

翻譯&編輯：yaning